Estudio Histológico en Embriones de Cobayo (Cavia porcellus) y su Utilidad como Modelo para la Comprensión del Desarrollo Embrionario Humano / Histological Study in Guinea Pig Embryos (Cavia porcellus) and its Usefulness as a Model for Understanding Human Embryonic Development

El cobayo es un modelo animal ampliamente utilizado en la investigación biomédica debido a sus similitudes biológicas con los seres humanos. El objetivo de nuestro estudio es proporcionar sustento morfológico para utilizar preparados histológicos de embriones de cobayo como modelo de estudio para comprender los procesos del desarrollo embrionario humano. Nuestros resultados muestran que los embriones de cobayo presentan características morfológicas similares a las observadas en los embriones humanos, lo que sugiere que pueden utilizarse como un modelo efectivo para estudiar el desarrollo embrionario humano. Este hallazgo tiene importantes implicancias para la investigación y la docencia utilizando este modelo animal. Se analizaron preparados histológicos de embriones de cobayo teñidos con hematoxilina eosina, adquiridos por la Universidad Autónoma de Chile. Se tomaron microfotografías de preparados histológicos de cobayo en diferentes estadios del desarrollo y se seleccionaron las mejores imágenes para la descripción de estructuras y establecer estimados de la embriogénesis. Del análisis de los preparados se desprende que órganos como esófago, médula espinal y corazón presentan similitudes anatómicas e histológicas que hacen posible compararlas con el desarrollo embrionario humano y la edad de gestación en etapas tempranas. El uso de preparados de embriones de cobayo y su análisis desde un aspecto histológico resulta ser una estrategia metodológica factible debido a las similitudes en la embriogénesis de los mamíferos y las concordancias morfológicas con el desarrollo de los órganos entre humanos y roedores. Esto permite implementar este modelo animal como una herramienta para comprender el desarrollo embrionario humano.

SUMMARY: The guinea pig is an animal model widely used in biomedical research due to its biological similarities with humans. The objective of our study is to provide morphological support to use histological preparations of guinea pig embryos as a study model to understand the processes of human embryonic development. Our results show that guinea pig embryos present morphological characteristics similar to those observed in human embryos, suggesting that they can be used as an effective model to study human embryonic development. This finding has important implications for research and teaching using this animal model. Histological preparations of guinea pig embryos stained with hematoxylin eosin, acquired by the Autonomous University of Chile, were analyzed. Photomicrographs of histological preparations of guinea pigs at different stages of development were taken and the best images were selected to describe structures and establish estimates of embryogenesis. From the analysis of the preparations it is clear that organs such as the esophagus, spinal cord and heart present anatomical and histological similarities that make it possible to compare them with human embryonic development and gestation age in early stages. The use of guinea pig embryo preparations and their analysis from a histological aspect turns out to be a feasible methodological strategy due to the similarities in mammalian embryogenesis and the morphological concordances with the development of organs between humans and rodents. This allows this animal model to be implemented as a tool to understand human embryonic development.

Synergistic impact of -linolenic acid and -tocopherol on in vitro maturation and culture of buffalo oocytes

Abstract The objective of the current study was to investigate the synergistic impact of -Tocopherol and -Linolenic acid (100 µM) on IVM and IVC of Nili Ravi buffalo oocytes. Oocytes were obtained from the ovaries of slaughtered buffaloes within two hours after slaughter and brought to laboratory. Buffalo cumulus oocyte complexes were placed randomly in the five experimental groups included; GROUP 1: Maturation media (MM) + 100 µM ALA (control), GROUP 2: MM + 100 µM ALA + 50M -Tocopherol, GROUP 3: MM + 100 µM ALA + 100M -Tocopherol, GROUP 4: MM + 100 µM ALA + 200 M -Tocopherol and GROUP 5: MM + 100 µM ALA + 300 M -Tocopherol under an atmosphere of 5% CO2 in air at 38.5 °C for 22-24 h. Cumulus expansion and nuclear maturation status was determined (Experiment 1). In experiment 2, oocytes were matured as in experiment 1. The matured oocytes were then fertilized in Tyrodes Albumin Lactate Pyruvate (TALP) medium for about 20 h and cultured in synthetic oviductal fluid (SOF) medium to determine effect of -Linolenic acid (100 µM) and -Tocopherol in IVM medium on IVC of presumptive zygotes. To study the effect of -Linolenic acid (100 µM) in IVM media and increasing concentration of -tocopherol in the culture media on early embryo development (Experiment 3), the presumptive zygotes were randomly distributed into the five experimental groups with increasing concentration of -tocopherol in culture media. Higher percentage of MII stage oocytes in experiment 1(65.2±2.0), embryos at morula stage in experiment 2 (30.4±1.5) and experiment 3 (22.2±2.0) were obtained. However, overall results for cumulus cell expansion, maturation of oocyte to MII stage and subsequent embryo development among treatments remain statistically similar (P > 0.05). Supplementation of -tocopherol in maturation media having -Linolenic acid and/or in embryo culture media did not further enhance in vitro maturation of oocyte or embryo production.

Resumo O objetivo do presente estudo foi investigar o impacto sinérgico do -tocoferol e do ácido -linolênico (100 µM) na MIV e CIV de oócitos de búfala Nili Ravi. Os oócitos foram obtidos dos ovários de búfalos abatidos duas horas após o abate e levados ao laboratório. Complexos de oócitos cumulus de búfalo foram colocados aleatoriamente nos cinco grupos experimentais incluídos; GRUPO 1: Meio de maturação (MM) + 100 µM ALA (controle), GRUPO 2: MM + 100 µM ALA + 50 µM -tocoferol, GRUPO 3: MM + 100 µM ALA + 100 µM -tocoferol, GRUPO 4: MM + 100 µM ALA + 200 M -tocoferol e GRUPO 5: MM + 100 µM ALA + 300 M -tocoferol sob uma atmosfera de 5% de CO2 em ar a 38,5 °C por 22-24 h. A expansão cumulus e o estado de maturação nuclear foram determinados (Experimento 1). No experimento 2, os oócitos foram maturados como no experimento 1. Os oócitos maturados foram então fertilizados em meio de Tyrode's Albumina Lactato Piruvato (TALP) por cerca de 20 h e cultivados em meio de fluido oviductal sintético (SOF) para determinar o efeito do ácido -linolênico (100 µM) e -tocoferol em meio IVM em IVC de presumíveis zigotos. Para estudar o efeito do ácido -linolênico (100 µM) em meio IVM e aumentar a concentração de -tocoferol no meio de cultura no desenvolvimento inicial do embrião (Experimento 3), os presumíveis zigotos foram distribuídos aleatoriamente nos cinco grupos experimentais com concentração crescente de -tocoferol em meios de cultura. Maior porcentagem de oócitos em estágio MII no experimento 1 (65,2 ± 2,0), embriões em estágio de mórula no experimento 2 (30,4 ± 1,5) e experimento 3 (22,2 ± 2,0) foram obtidos. No entanto, os resultados gerais para a expansão das células do cumulus, maturação do oócito para o estágio MII e desenvolvimento embrionário subsequente entre os tratamentos permanecem estatisticamente semelhantes (P> 0,05). A suplementação de -tocoferol em meios de maturação com ácido -linolênico e / ou em meios de cultura de embriões não aumentou ainda mais a maturação in vitro de oócitos ou a produção de embriões.

A comprehensive review on the documented characteristics of four Reticulitermes termites (Rhinotermitidae, Blattodea) of China / Uma revisão abrangente sobre as características documentadas de quatro cupins Reticulitermes da China

Termites are known as social insects worldwide. Presently in China 473 species, 44 genera and 4 families of termites have been reported. Of them, 111 Reticulitermes species are widely spread in different zones of China. The dispersion flight season of these Chinese Reticulitermes species are usually started from February to June, but in some regions different species are distributed, sharing their boundaries and having overlapping flight seasons. These reasons become important sources of hybridization between two different heterospecific populations of termites. It was confirmed that the fertilized eggs and unfertilized eggs of some Reticulitermes termites have the capacity of cleavage. While the unfertilized eggs of R. aculabialis, R. chinensis and R. labralis cleaved normally and the only R. aculabialis unfertilized eggs develop in embryos. While, the R. flaviceps and R. chinensis were observed with their abnormal embryonic development, and not hatching of eggs parthenogenetically. They were reported more threatening to Chinese resources as they propagate with parthenogenesis, hybridization and sexual reproduction. Eggshell and macrophiles of eggs play important roles in species identification and control. Although, they are severe pests and cause a wide range of damages to wooden structures and products in homes, buildings, building materials, trees, crops, and forests in China's Mainland.

Os cupins são conhecidos como insetos sociais em todo o mundo. Atualmente na China foram relatadas 473 espécies, 44 gêneros e 4 famílias de cupins. Destas, 111 espécies de Reticulitermes estão amplamente distribuídas em diferentes zonas da China. A temporada de voo de dispersão dessas espécies chinesas de Reticulitermes geralmente começa de fevereiro a junho, mas em algumas regiões diferentes espécies são distribuídas, compartilhando seus limites e tendo temporadas de voo sobrepostas. Essas razões tornam-se importantes fontes de hibridização entre duas populações heteroespecíficas de cupins. Foi confirmado que os ovos fertilizados e não fertilizados de alguns cupins Reticulitermes possuem capacidade de clivagem. Já os ovos não fertilizados de R. aculabialis, R. chinensis e R. labralis clivaram normalmente, e os únicos ovos não fertilizados de R. aculabialis se desenvolvem em embriões. R. flaviceps e R. chinensis foram observados com desenvolvimento embrionário anormal, e não eclosão de ovos por partenogênese. Eles foram relatados como mais ameaçadores para os recursos chineses à medida que se propagam com partenogênese, hibridização e reprodução sexual. Casca de ovo e macrófilos de ovos desempenham papéis importantes na identificação e controle de espécies, embora sejam pragas graves e causem uma ampla gama de danos a estruturas e produtos de madeira em residências, edifícios, materiais de construção, árvores, plantações e florestas na China continental.

Telocytes in Human Embryonic Development: A Preliminary Microscopic Anatomy Study / Telocitos en el Desarrollo Embrionario Humano: Un Estudio Preliminar de Anatomía Microscópica

SUMMARY: Telocytes are a cell population described in 2011 with a multitude of functions such as tissue support, regulation of stem cell niches or intercellular signal transmission. However, there are no studies about their embryonic origin, their function in development, or their moment of appearance. The objective of this work is to try to answer these questions through histological and immunofluorescence studies with samples from the embryological collection of the Department of Anatomy of the University of Granada. In the results obtained, as demonstrated by immunofluorescence for CD34, the presence of these cells can be seen in the fourth week of embryonic development in the perinotochordal region. Its presence is evident from the sixth week of development in a multitude of organs such as the heart, skeletal muscle tissue and supporting tissue of various organs such as the kidney, brain or pericardium. Its function seems to be when the embryonic histological images are analyzed in an evolutionary way, to act as a scaffold or scaffold for the subsequent population by mature tissue elements. In conclusion, telocytes appear at a very early stage of embryonic development and would have a fundamental role in it as scaffolding and directors of organ and tissue growth.

Los telocitos son una población celular descrita en 2011 con multitud de funciones como el sostén tisular, la regulación de los nichos de células madre o la transmisión de señales intercelulares. Sin embargo, no existen estudios acerca del origen embrionario de los mismos, su función en el desarrollo ni su momento de aparición. El objetivo de este trabajo es tratar de responder a estos interrogantes mediante estudios histológicos y por inmunofluorescencia con muestras de la colección embriológica del Departamento de Anatomía de la Universidad de Granada. En los resultados se puede observar como se demuestra mediante inmunofluorescencia para CD34, la presencia de estas células en la cuarta semana del desarrollo embrionario en la región perinotocordal. Su presencia se evidencia a partir de la sexta semana del desarrollo en multitud de órganos como corazón, tejidos músculo esqueléticos y tejidos de sostén de diversos órganos como riñón, encéfalo o pericardio. Su función parece ser al ser analizadas las imágenes histológicas embrionarias de forma evolutiva, la de actuar como un andamiaje o scafold para el posterior poblamiento por elementos tisulares maduros. Como conclusión, los telocitos aparecen en un momento muy precoz del desarrollo embrionario y presentarían una función fundamental en el mismo como andamiajes y directores del crecimiento de los órganos y tejidos.

Study of ex-ovo embryonic development of Gallus gallus domesticus / Estudio inicial del desarrollo embrionario ex-ovo de Gallus gallus domesticus

SUMMARY: The domestic chicken is a species of bird that has been extensively studied in regard to its biology and as a model organism for science. The reproduction of the species is by the laying of fertilized eggs, which in a period of 21 days will develop a chick inside. Several methods have been described to develop embryos ex-ovo, allowing the observation and manipulation of the organism. This work has the propose to standardize a method that allows the development of the embryos inside the artificial incubation system, which has a low cost and is easy to make. In this work, 100 chicken eggs were used to study the effects of humidity, mineral supplementation, and the preincubation time of the egg on the incubation ex-ovo of the embryos. Embryo development was documented through the different days. Pulverized eggshell was selected as an optimal source to provide calcium, magnesium, phosphorus, and other minerals to the developing embryo. By providing 900-1200 mg of pulverized eggshell, 40 mL of the 0.001 % solution of benzalkonium chloride, and a preincubation time of approximately 56 h, the embryos were able to develop until 19 days, and even though they did not reach hatching, the incubation conditions that allowed the survival and development of embryos until late stages were achieved. Thus, due to the conditions established for calcium, humidity and preincubation time, in the present work, the chicks reached 19 days of development.

El pollo doméstico es una especie de ave que ha sido ampliamente estudiada en cuanto a su biología y como organismo modelo para la ciencia. La reproducción de la especie es por la puesta de huevos fecundados, que en un período de 21 días desarrollarán un polluelo en su interior. Se han descrito varios métodos para desarrollar embriones ex-ovo, permitiendo la observación y manipulación del organismo. Este trabajo tuvo como objetivo estandarizar un método que permita el desarrollo de los embriones dentro del sistema de incubación artificial, el cual tiene un bajo costo y es fácil de realizar. En este trabajo se utilizaron 100 huevos de gallina para estudiar los efectos de la humedad, la suplementación mineral y el tiempo de preincubación del huevo sobre la incubación ex-ovo de los embriones. El desarrollo embrionario se documentó a través de los diferentes días. Se seleccionó la cáscara de huevo pulverizada como una fuente óptima para proporcionar calcio, magnesio, fósforo y otros minerales al embrión en desarrollo. Al suministrar 900-1200 mg de cáscara de huevo pulverizada, 40 mL de la solución de cloruro de benzalconio al 0.001 % y un tiempo de preincubación de aproximadamente 56 h, los embriones lograron desarrollarse hasta los 19 días, y aunque no llegaron a eclosionar, los embriones lograron desarrollarse hasta los 19 días. Se lograron condiciones de incubación que permitieron la supervivencia y desarrollo de los embriones hasta etapas tardías. Así, debido a las condiciones establecidas de calcio, humedad y tiempo de preincubación, en el presente trabajo los pollitos alcanzaron los 19 días de desarrollo.

Effect of Qigongwan on Quality of Oocytes and Embryonic Development Potential in Patients with PCOS Infertility with Phlegm-dampness Syndrome / 中国实验方剂学杂志

ObjectiveTo observe the regulation of Qigongwan on the expression of proliferation and apoptosis-related factors programmed cell death 4 （PDCD4） and proliferating cell nuclear antigen （PCNA） in ovarian granulosa cells （GCs） in patients with polycystie ovarian syndrome （PCOS） infertility with phlegm-dampness syndrome， and to explore the effect of Qigongwan on the quality of oocytes and embryonic development potential. MethodSixty-six patients with PCOS with phlegm-dampness syndrome who underwent in vitro fertilization and embryo transfer （IVF-ET） were randomly selected and divided into an observation group （Qigongwan + western medicine） and a control group （western medicine）， with 33 patients in each group. Antagonist regimen was used to promote ovulation in the two groups. The observation group was given Qigongwan one cycle before IVF based on the treatment of conventional western medicine， while the control group was not given Chinese medicine. The improvement of phlegm and dampness syndrome， the dosage and the number of days of using gonadotropins （Gn）， the levels of luteinizing hormone （LH）， estradiol （E2）， and progesterone （P） on the day of human chorionic gonadotropin（HCG） injection， the 2PN fertilization rate， and the high-quality embryo rate of patients in the two groups were compared. Real-time polymerase chain reaction （Real-time PCR） and Western blot technology were used to detect the expression of PCNA and PDCD4 in GCs. ResultAs compared with groups before treatment， the score of phlegm-dampness syndrome in both groups was significantly lower （P<0.01）. The score of phlegm and dampness syndrome in the observation group was significantly lower than that of the control group （P<0.01）. As compared with the control group， the levels of LH， E2， and P in the observation group was higher， but only the difference in the level of E2 was statistically significant （P<0.01）. The 2PN fertilization rate ［82.25% （556/676） vs 69.92% （365/522）， χ2=25.172， P<0.01］ and high-quality embryo rate ［44.19% （190/430） vs 34.23% （102/298）， χ2=7.266， P<0.01］ in the observation group were significantly higher than that of the control group （P<0.01）. As compared with the control group， the mRNA and protein expression of PDCD4 in ovarian GCs was down-regulated in the observation group and that of PCNA was up-regulated （P<0.05）. ConclusionBy down-regulating the expression of PDCD4 and up-regulating the expression of PCNA， Qigongwan may interfere with follicle development， adjust hormone levels， improve the symptomatic manifestations of patients with PCOS with phlegm-dampness syndrome， inhibit the apoptosis of GCs， and promote growth， thus improving the quality of oocytes and embryonic development potential.

Mild overexpression of a novel transcription factor Grainy head like-2 (Grhl2) elicits hybrid phenotype in human astrocytoma cells

The Grainy head like-2 (Grhl2) transcription factor plays a major role in embryonic and cancer development. The role of Grhl2 has been intensively studied in various cancers but not for brain cancer. Hence, in this study, we provide a preliminary understanding on the role of Grhl2 that regulate the transition of astrocytoma cells. The human A172 astrocytoma cell line, a mesenchymal cell characterized by mild overexpression of Grhl2 transcription factor, was used in this study. At first, the Grhl2 stably overexpressing A172 clones into three types i.e., Grhl2+ (mild), Grhl2++ (moderate) and Grhl2+++ (high) based on mRNA and protein expression levels of Grhl2 were characterized. Phenotypic characteristics of vector and Grhl2+ cells were observed using phase contrast microscopy. Quantitative PCR (qPCR), Western blot and immunofluorescence were used to detect the level of mesenchymal markers (N-cadherin/vimentin) and also epithelial markers (E-cadherin/ ?- catenin) in vector and Grhl2+ cells. The migration and invasion characteristics of vector and Grhl2+ cells were determined by scratch assay and Boyden chamber assay. Further, the Grhl2+ cells were characterized to determine the effect of temozolomide chemotherapy drug which were widely used in treating brain cancer. As expected, in phase contrast image, we observed the mesenchymal characteristic of A172 cells becomes hybrid phenotype i.e., mixture of mesenchymal (spindle-like fibroblast morphology) and epithelial (cobblestone like appearance) cells upon Grhl2 mild expression (Grhl2+) when compared to vector cells. Further, we found that there was a significant upregulation of E-cadherin at both mRNA and protein levels in Grhl2+ cells when compared to vector cells. There was a significant upregulation of ?-catenin, N-cadherin and vimentin at mRNA levels, but there was no significant upregulation at the protein levels in Grhl2+ cells compared to the vector cells. The migration and invasion were diminished in Grhl2+ cells when compared to the vector control cells. We observed that the Grhl2+ were sensitive to the temozolomide compared to the vector cells. This infers that the Grhl2+ cells were unable to attain complete transition of mesenchymal to epithelial state, and hence we categorized the Grhl2+ cells as hybrid phenotype. The results provide a better understanding of the largely unknown function of Grhl2 in human astrocytoma cells as tumor progression or suppression.

Asynchrony between in vivo and in vitro rabbit embryos

Background: Comparative features of embryos developed under in vitro and in vivo conditions are particularly important in designing embryo transfer procedures that fulfil embryo-recipient synchronization requirements. Objective: To determine the degree of asynchrony in rabbit embryo development between cultured and in vivo embryos. Methods: A total of 55 non- lactating multiparous female rabbits were used. Embryos were classified as 16-cells or early morulae at 48 hours post-coitum (hpc). Embryos were cultured during 30 or 32 h and embryo development was compared with in vivo embryos of 72 hpc. In vitro and in vivo embryos at 72 hpc were classified as early or compacted morulae. Bayesian statistics was used. Difference between in vivo and in vitro embryos and the actual probability of the difference between the in vivo and in vitro embryo higher than zero (P) was estimated. Results: The percentage of compacted morulae was higher in in vivo embryos than in in vitro embryos with +6 h of asynchrony (73.5 and 32.8%, P=1.00). But the percentage of compacted morulae was similar with +8 h asynchrony. Conclusions: In vitro embryos delay their development by + 8 hours compared to in vivo embryos.

Antecedentes: El desarrollo comparativo de embriones producidos in vitro e in vivo es particularmente importante para el diseño de procedimientos de transferencia de embriones cuando se requiere sincronización entre el embrión y la hembra receptora. Objetivo: Determinar el grado de asincronía en el desarrollo embrionario entre embriones in vivo y cultivados. Métodos: Un total de 55 conejas multiparas no lactantes fueron utilizadas. Los embriones se clasificaron en 16 células o mórulas tempranas a las 48 horas después del coito (hpc). Los embriones se cultivaron durante 30 ó 32 horas y el desarrollo embrionario se comparó con embriones de 72 hpc obtenidos in vivo. Los embriones in vitro e in vivo a 72 hpc se clasificaron como mórulas tempranas o compactas. Se utilizó estadística bayesiana. Se estimó la diferencia entre embriones in vivo e in vitro y la probabilidad de que la diferencia sea superior a cero (P). Resultados: El porcentaje de mórulas compactas fue mayor en embriones in vivo que en embriones in vitro con +6 horas de asincronía (73,5 y 32,8%, P=1,00), pero el porcentaje de mórulas compactas fue similar con asincronía de +8 horas. Conclusión: Los embriones cultivados retrasan +8 horas su desarrollo en comparación con los embriones in vivo.

Antecedentes: A aquisição do desenvolvimento de embriões produzidos in vitro e in vivo é particularmente importante na concepção de procedimentos de transferência de embriões em que a sincronização entre o embrião e a fêmea receptora é necessária. Objetivo: Determinar o grau de assincronia no desenvolvimento embrionário entre embriões cultivados e in vivo. Métodos: Um total de 55 coelhos multíparos não lactantes foram usados. Os embriões foram classificados em 16 células ou mórulas iniciais 48 horas de gestação (hpc). Os embriões foram cultivados por 30 ou 32 horas e o desenvolvimento embrionário foi comparado com embriões de 72 hpc obtidos in vivo. Embriões in vitro e in vivo a 72 hpc foram classificados como mórulas precoces ou compactadas. Estatísticas bayesianas foram usadas. A diferença entre embriões in vivo e in vitro e a probabilidade de que a diferença seja maior que zero (P) foi estimada. Resultados: A porcentagem de mórulas compactadas foi maior em embriões in vivo do que em embriões in vitro com +6 horas de assincronia (73,5 e 32,8%, P=1,00). Mas a porcentagem de mórulas compactadas foi semelhante com assincronia de +8 horas. Conclusão: Embriões cultivados atrasam seu desenvolvimento em +8 horas em comparação com embriões in vivo.

Derechos del concebido

La fecundación consiste en la fusión de los gametos masculino y femenino en el tercio externo de la trompa uterina para constituir el cigoto, que inicia su división celular, viaja al útero, se implanta como blastocito en el endometrio a los siete días y comienzan los procesos de embriogénesis y morfogénesis. Concepción es la acción o efecto de quedar embarazada una mujer. En el tema de los derechos establecidos al concebido, el inicio de la vida humana plantea amplia discusión entre las definiciones que plantea la ciencia frente a las de grupos de la sociedad civil. No siendo el cigoto una persona humana, de acuerdo con la Corte Interamericana de Derechos Humanos (CIDH) y otros no sería sujeto de los derechos establecidos para la persona, los cuales estarían íntimamente relacionados a los derechos de la mujer embarazada. La concepción ocurriría cuando el embrión se implanta en el útero y no aplicaría el artículo 4 de la CIDH. La doctrina, la legislación y la jurisprudencia peruana establecen amplia tutela jurídica a favor del concebido e instauran el inicio de la vida a partir de la fecundación. La Sentencia de la CIDH para el caso Artavia Murillo contra Costa Rica introduce la figura española del preembrión, al cual no se le otorga tutela jurídica hasta los 14 días, momento en que la ciencia médica establece la implantación del embrión en el endometrio materno. Para consideraciones éticas actuales, el embarazo humano empieza con la implantación del blastocisto en el endometrio y no existe sustento para aceptar el derecho del concebido desde el momento de la fecundación como si fuera una persona. Empero se señala que la vida humana posee una continuidad ininterrumpida desde su concepción hasta su fin natural, la muerte. El cigoto es vida que se inicia con dotación genética propia diferente a la de sus progenitores. El embrión preimplantatorio solo podrá originar un ser humano que se gesta y desarrolla dentro del cuerpo de otra persona, con propia dinámica vital.

Fertilization consists of the fusion of the male and female gametes in the outer third of the uterine tube to form the zygote, which begins its cell division, travels to the uterus, implants as a blastocyst in the endometrium after seven days and begins the processes of embryogenesis and morphogenesis. Conception is the action or effect of a woman becoming pregnant. About the rights established for the conceived, the beginning of human life raises a wide discussion between the definitions proposed by science and those of civil society groups. Not being the zygote a human person, according to the Inter-American Court of Human Rights (IACHR) and others, it would not be subject to the rights established for the person, which would be closely related to the rights of the pregnant woman. Conception would occur when the embryo implants in the uterus and Article 4 of the IACHR would not apply. Peruvian doctrine, legislation and jurisprudence establish broad legal protection in favor of the conceived and indicate the beginning of life from the moment of fertilization. The Judgment of the IACHR in the case of Artavia Murillo v. Costa Rica introduces the Spanish figure of the pre-embryo, which is not granted legal protection until 14 days, when medical science establishes the implantation of the embryo in the maternal endometrium. For current ethical considerations, human pregnancy begins with the implantation of the blastocyst in the endometrium and there is no basis for accepting the right of the conceived from the moment of fertilization as if it were a person. However, it is pointed out that human life has an uninterrupted continuity from conception to its natural end, death. The zygote is life that begins with its own genetic endowment different from that of its progenitors. The preimplantation embryo can only give rise to a human being that is gestated and develops within the body of another person, with its own vital dynamics.

Ambystoma mexicanum, A MODEL ORGANISM IN DEVELOPMENTAL BIOLOGY AND REGENERATION: A COLOMBIAN EXPERIENCE / Ambystoma mexicanum, un organismo modelo en biología del desarrollo y regeneración: experiencia colombiana

ABSTRACT Ambystoma mexicanum is a urodele amphibian endemic to Xochimilco Lake in Mexico, it belongs to the salamander family Ambystomatidae. This species has frequently been used as model organism in developmental biology and regeneration laboratories around the world due to its broad regenerative capacities and adaptability to laboratory conditions. In this review we describe the establishment of the first colony of axolotls in Colombia to study tissue regeneration and our perspectives on the use A. mexicanum as a model organism in Colombia are discussed emphasizing its possible uses in regeneration and developmental biology.

RESUMEN Ambystoma mexicanum es un anfibio urodelo endémico del lago Xochimilco en México, perteneciente a la familia de salamandras Ambystomatidae. Esta especie se ha empleado frecuentemente como organismo modelo en laboratorios de biología del desarrollo y regeneración alrededor del mundo, dadas sus amplias capacidades regenerativas y adaptabilidad en condiciones de laboratorio. En esta revisión, se describe el establecimiento de la primera colonia de ajolotes en Colombia, para adelantar estudios de regeneración de tejidos, y se discuten las perspectivas de A. mexicanum como organismo modelo en el país, enfatizando sus posibles usos en regeneración y biología del desarrollo.

Two-dimensional ultrasound combined with HD-live silhouette technology in embryos/fetuses with normal or abnormal central nervous system during early pregnancy / 中华围产医学杂志

Objective:To study the ultrasonographic characteristics of embryos/fetuses with normal or abnormal central nervous system (CNS) from 7 to 13 +6 weeks of gestation using high resolution two-dimensional ultrasound combined with HD-live silhouette technology and provide a reference for early diagnosis of CNS abnormalities. Methods:Eighty normal embryos/fetuses during 7-13 +6 weeks and 41 fetuses with CNS malformations in early pregnancy during 11-13 +6 weeks were selected to observe the ultrasonographic features of embryos/fetuses with normal or abnormal CNS using transvaginal high resolution two-dimensional ultrasound and HD-live silhouette technology. Descriptive analysis was performed on the results. Results:From seven weeks of gestational age, high resolution two-dimensional ultrasound combined with HD-live silhouette technology can clearly and stereoscopically show the prosencephalon, mesencephalon and rhombencephalon. The rhombencephalon changed the most in the brain development of embryos. At nine weeks of gestation, cleared structures of pons curvature, the fourth ventricle and cisterna magna were observed. The developing cerebellum and the original Blake pouch cyst were seen at 10 weeks of gestation. From 11 to 13 +6 weeks, the most remarkable change was the choroid plexus of the fourth ventricle changed from perpendicular to parallel to the long axis of the neural tube. Of the 41 fetuses with CNS malformation, 16 (39.0%) were exencephaly, 11 (26.8%) were holoprosencephaly, five (12.2%) were encephalocele, four (9.7%) were anencephaly, three (7.3%) were fourth ventricle dilatation, and two (4.9%) were open spina bifida. Conclusions:High resolution two-dimensional ultrasound combined with HD-live silhouette technology can clearly and stereoscopically display the morphological changes in embryonic embryos/fetuses with development of normal CNS at 7-13 +6 weeks, which is helpful to better understand the origin of CNS embryonic abnormalities and provide diagnostic clues for the early detection of CNS abnormalities.

Reproductive biology of the emerald frog Hylorina sylvatica (Anura: Batrachylidae) in northwest Patagonia, Argentina / Biología reproductiva de la rana esmeralda Hylorina sylvatica (Anura: Batrachylidae) en el noroeste de la Patagonia Argentina

Abstract Hylorina sylvatica (Anura: Batrachyidae), or the emerald frog, is a pond-breeding anuran endemic to the austral temperate forests of Chile and Argentina. It is considered a vulnerable species in Argentina, where it has a narrow distribution; records and biological information relating to the frog in this area are scarce. In this study, conducted in 2016, the reproductive parameters of the emerald frog were investigated in detail in a ­semi-temporary wetland of Northwestern Patagonia, Argentina. During the spring, the wetland was visited weekly in search of calling males, adults and individuals in amplexus. When amplexus was observed, eggs and larvae were collected from among the aquatic vegetation using dip-nets. Egg size and larval stage at hatching were registered. Calling males were registered during the second week of October, and the first couples were observed on 26 October. Three pairs of emerald frogs were captured and placed in enclosures within the wetlands in the afternoon. The males were smaller than the females. After 24 h the number of eggs laid in each enclosure was counted, and the males and females were released. The eggs were kept in each enclosure until hatching. Hatching occurred after 10-14 days in the enclosures. This information contributes to our knowledge of the biology of the emerald frog in Patagonia, Argentina, and is the only information currently available on this species in Nahuel Huapi National Park, where the species breeds in various aquatic environments, from semi-temporary wet meadows to large permanent ponds.

Resumen Hylorina sylvatica (Anura: Batrachyidae) o rana esmeralda, es un anuro que se reproduce en estanques, endémico de los bosques templados australes de Chile y Argentina. Actualmente es considerada una especie vulnerable en Argentina. La distribución es estrecha en Argentina con pocos registros de la especie y muy limitada información sobre la biología de esta especie en la región. En este estudio realizado durante 2016, investigué en detalle los parámetros reproductivos de la rana esmeralda en un humedal semitemporal del Noroeste de la Patagonia Argentina. Durante la primavera de 2016, visité el humedal semanalmente en busca de coros, adultos y amplexos. También después de que se observaron amplexos, recolecté huevos y larvas entre la vegetación acuática utilizando un muestreo con redes de mano. Se registró el tamaño del huevo y el estado larvario al eclosionar. Los coros de machos se registraron durante la tercera semana de octubre y los primeros amplexos se observaron el 26 de octubre. Tres parejas de rana esmeralda fueron capturadas y colocadas en clausuras dentro de los humedales durante la tarde. Los machos eran más pequeños que las hembras. Después de 24 h conté el número de huevos puestos en cada recinto y luego se liberaron machos y hembras. Los huevos se mantuvieron en cada clausura hasta que eclosionaron. La eclosión se produjo entre 10-14 días en las clausuras. Esta información contribuye al conocimiento de la biología de la rana esmeralda que habita la Patagonia Argentina y es la única información disponible al momento de esta especie en el Parque Nacional Nahuel Huapi, donde la especie se reproduce en diferentes ambientes acuáticos, desde humedales semitemporales hasta lagos y lagunas permanentes.

Gonadal differentiation during embryonic and fetal development of male New Zealand rabbits (Oryctolagus cuniculus) / Diferenciación gonadal durante el desarrollo embrionario y fetal de conejos machos neozelandeses (Oryctolagus cuniculus)

SUMMARY: The rabbit is considered an ideal animal model for studies that describe abnormalities in the testicles due to the similar morphogenetic mechanisms of sexual development and diseases commonly found in humans. The aim of this study was to determine the male sexual differentiation of the New Zealand rabbit (Oryctolagus cuniculus) through development. The gestational age was estimated and classified as 9, 12, 14, 16, 18, 20, 23 and 28 gestational days. The morphological and sexual determination were performed by histological analysis of the reproductive tract in the embryos and fetuses (9-28 days) as well as by immunohistochemistry- Desert hedgehog-Dhh- (testis-specific protein on Y chromosome- 16, 20, 23 days and adult rabbits). Gonads were observed from the 14th day in an undifferentiated stage and with homogeneous aspect. Sexual differentiation was observed from the 16th day with presence of cells forming gonadal cords and Dhh+ cells in the gonadal parenchyma. From the 18th gestational day testicular cords were observed, which evolved into organized seminiferous tubules. The formation of the efferent ducts and ductus deferens and epididymis was observed on the 20th and 23rd days, respectively. The differentiation of the external genitalia occurred from the 23rd days from the anogenital distance and was identified to identify the penile structures. In summary, the features of the sexual differentiation were determined by observation of the Dhh+ protein in embryos from the 16th day to adulthood, and the morphological particularities observed from the 18th gestational day, determined by differentiation of the external genitalia from the 23rd day.

RESUMEN: El conejo se considera un modelo animal ideal para estudios que describen anomalías a nivel testícular debido a que presenta mecanismos morfogenéticos similares al desa- rrollo sexual y enfermedades que se encuentran comúnmente en los seres humanos. El objetivo de este estudio fue determinar la diferenciación sexual masculina del conejo de Nueva Zelanda (Oryctolagus cuniculus) a través del desarrollo. La edad gestacional se estimó y clasificó en 9, 12, 14, 16, 18, 20, 23 y 28 días gestacionales. La determinación morfológica y sexual se realizó mediante análisis histológico del tracto reproductivo en los embriones y fetos (9 - 28 días) así como mediante inmunohistoquímica -Desert hedgehog-Dhh- (proteína testicular específica en el cromosoma Y- 16, 20, 23 días y conejos adultos). Las gónadas se observaron a partir del día 14 en un estadio indiferenciado y con aspecto homogéneo. Se observó diferenciación sexual a partir del día 16 con presencia de células formadoras de cordones gonadales y células Dhh+ en el parénquima gonadal. A partir del día 18 de gestación se observaron cordones testiculares, que evolucionaron a túbulos seminíferos organizados. La formación de los conductos eferentes, deferentes y del epidídimo se observó a los 20 y 23 días, respectivamente. La diferenciación de los genitales externos ocurrió a partir del día 23 desde la distancia anogenital y se utilizó para identificar las estructuras del pene. En conclusión, las características de la diferenciación sexual se determinaron mediante la observación de la proteína Dhh en embriones desde el día 16 hasta la edad adulta, y las particularidades morfológicas observadas a partir del día 18 de gestación, determinadas por diferenciación de los genitales externos a partir del día 23.

Relación entre la temperatura de incubación y la asimetría del carapacho de neonatos de Lepidochelys olivacea incubados en el Área de Usos Múltiples Hawaii (AUMH), Santa Rosa, Guatemala / Relationship between incubation temperature and carapace asymmetry of neonates of Lepidochelys olivacea incubated in the Area of Multiple Use Hawaii (AUMH), Santa Rosa, Guatemala

Los embriones de tortugas marinas son susceptibles a perturbaciones ambientales, las cuales se traducen en anomalías en su fenotipo. Uno de los principales parámetros para la medición de estas perturbaciones es la asimetría en los carapachos (caparazones), que puede ser obtenida a través del Índice de Inestabilidad de Desarrollo (DIx, por sus siglas en inglés). La temperatura juega un rol importante, influenciando no solo en la futura supervivencia de los neonatos en temperaturas extremas (altas o bajas), sino en atributos específicos, tales como la determinación del sexo, o incluso puede ser la causa del incremento en el número de apéndices dérmicos (escudos) sobre la parte dorsal del carapacho. Este estudio evaluó la relación entre la temperatura de incubación con la asimetría de carapacho de los neonatos de Lepidochelys olivacea incubados en condiciones relocalizadas en el tortugario del Área de Usos Múltiples Hawaii en Santa Rosa, Guatemala. Para lograrlo, se replicaron las condiciones de anidación seleccionadas por las hembras anidadoras en nidos relocalizados, utilizando dispositivos termosensitivos para la toma de la temperatura durante el período de incubación. A través del cálculo del DIx en 210 neonatos, y mediante las pruebas de correlación de Kendall y Jockheere-Terpstra, se obtuvo que en valores de temperaturas extremas tanto altas (Kendall tau = .23, p < .001; JT = 2,891, p < .001), como bajas (Kendall tau u= -.21, p < .001; JT = 5,005, p < .001), así como en altos rangos de variación durante el período de desarrollo embrionario (Kendall tau = .23, p < .001; JT = 6,619, p < .05), los neonatos presentan una mayor asimetría.

Sea turtle embryos are susceptible to environmental disturbances, which result in abnormalities in their phenotype. One of the main parameters for measuring these disturbances is the asymmetry in the carapaces, which can be obtained through the Developmental Instability Index (DIx). Temperature plays an important role, influencing not only the future survival of hatchlings in extreme temperatures (high or low), but also specific attributes, such as sex determination, or it can even be the cause of the increase in the number of dermal appendages (shields) on the dorsal part of the carapace. This aimed to evaluate the relationship between incubation temperature and carapace asymmetry of Lepidochelys olivacea hatchlings incubated in relocated conditions in the Hawaii Multiple Use Area turtle rookery in Santa Rosa, Guatemala. To achieve this, the nesting conditions selected by the nesting females were replicated in relocated nests, using thermosensitive devices to measure the temperature during the incubation period. rough the calculation of DIx in 210 hatchlings, and using Kendall and Jockheere-Terpstra correlation tests, it was obtained that hatchlings present greater asymmetry in values of extreme temperatures, for both, high (Kendall: p<.05, tau = .232 ; JT p<.05, JT=2891) and low (Kendall: p<.05, tau= -.211 ; JT p<.05, JT=5005); as well as in high ranges of variation (Kendall: p<.05, tau= .231 ; JT p<.05, JT=6619), during the embryonic development period

Differences in implant osseointegration in the jaw and femur in animal experiments / 口腔疾病防治

@#The jaw and femur are commonly used sites in basic research for modeling bone defects or inserting implants. An increasing number of studies have identified that the jaw and femur indeed show great differences in embryonic development and growth, histomorphology and bone metabolism. A literature review showed that, compared with the femur, the main osteogenic pathway of the jaw may have better osteogenic ability, and its stem cells have better proliferation and osteogenic differentiation ability. However, the jaw structure is less regular, the osteogenic differentiation ability of its osteoblasts is mineralization slightly weak, and the immune cells of the jaw are more sensitive to cytokines. These may be the reasons why the osseointegration of the jaw implant is different from that of the femur in animal experiments, but its specific mechanism has not been clarified.

Non-coding RNAs and chromatin: key epigenetic factors from spermatogenesis to transgenerational inheritance

Cellular fate and gene expression patterns are modulated by different epigenetic factors including non-coding RNAs (ncRNAs) and chromatin organization. Both factors are dynamic throughout male germ cell differentiation on the seminiferous tubule, despite the transcriptional inactivation in the last stages of spermatogenesis. Sperm maturation during the caput-to-cauda transit on the epididymis involves changes in chromatin organization and the soma-to-germ line transference of ncRNAs that are essential to obtain a functional sperm for fertilization and embryo development. Here, the male environment (diseases, drugs, mental stress) is crucial to modulate these epigenetic factors throughout sperm maturation, affecting the corresponding offspring. Paternal transgenerational inheritance has been directly related to sperm epigenetic changes, most of them associated with variations in the ncRNA content and chromatin marks. Our aim is to give an overview about how epigenetics, focused on ncRNAs and chromatin, is pivotal to understand spermatogenesis and sperm maturation, and how the male environment impacts the sperm epigenome modulating the offspring gene expression pattern.

Técnicas de substituição de DNA mitocondrial para reduzir a transmissão da Síndrome de Leigh / Mitochondrial DNA replacement techniques to reduce Leigh syndrome transmission

A Síndrome de Leigh (SL) é uma doença neuro-metabólica congênita, que faz parte do grupo das encefalopatias fatais, com progressão e morte dentro de 2 anos, em média. A SL é causada por mutações no DNA que causam alterações na geração de ATP celular pelas mitocôndrias. As mitocôndrias contêm seu próprio DNA (mtDNA) e, ao contrário do DNA nuclear, o mtDNA é herdado somente da mãe. Mulheres portadores de mutações causadoras da SL podem vivenciar experiências muito tristes ao tentarem realizar o sonho da maternidade. As técnicas de substituição de mtDNA mutado com mtDNA saudável de doadora, oferecem a essas mulheres a possibilidade de terem uma criança geneticamente relacionada sem a SL. O desenvolvimento e a aplicação clínica de terapias de substituição de mtDNA já são uma realidade, tendo o primeiro bebê gerado a partir da técnica nascido em 2016. Mas será que essas técnicas são seguras? Neste trabalho, revisamos a SL e algumas técnicas de substituição de mtDNA já aplicadas em humanos, que envolvem a transferência de pronúcleos de zigotos ou de fuso acromático de oócitos. Concluímos que, apesar dos resultados promissores, ainda é cedo para assegurar a aplicabilidade clínica de técnicas de substituição de mtDNA em seres humanos. (AU)

Leigh syndrome (SL) is a congenital neurometabolic disease included in the group of fatal encephalopathies, with progression and death within 2 years on average. SL is caused by mutations in the DNA that cause changes in the generation of cellular ATP by mitochondria. Mitochondria contain their own DNA (mtDNA) and, unlike nuclear DNA, mtDNA is inherited only from the mother. Women with SL mutations may experience mournful situations when attempting to fulfill the dream of motherhood. Techniques for replacing mutant mtDNA with healthy donor mtDNA provide these women with the possibility of having a genetically related child without SL. The development and clinical application of mtDNA replacement therapies is a reality, and the first baby generated using the technique was born in 2016. However, are these techniques safe? In this article, we review SL and some mtDNA replacement techniques that have been used in humans, which involve zygote pronuclear transfer or oocyte spindle transfer. We conclude that, despite the promising results, it is too early to ensure that mtDNA replacement techniques are clinically applicable to humans. (AU)

Sirenomelia associated with VACTERL and VACTERL-H syndrome / Sirenomelia asociaciada con síndrome de VACTERL y VACTERL-H

Sirenomelia or mermaid syndrome is an extremely rare congenital lethal malformation with a frequency between 1.5 and 4.2 per 1 000 000 pregnancies.The association of sirenomelia with the VACTERL association is very rare, with twenty cases reported in the literature and only two cases with VACTERL-H. We present two cases of sirenomelia, type I and type II associated with VACTERL-H and VACTERL syndromes and we review the literature. First time pregnancy women aged 15 and 40 years, without harmful habits and diseases, where between 25-27 gestational week (GW) the prenatal study identifies malformative fetus and the pregnancy is interrupted by medical evidence. The fetopathological examination in the first case identified sirenomelia type I associated with myelomeningocele, hydrocephalus, anal imperforation, single umbilical artery, bilateral renal agenesis, ureteral and bladder agenesis, tracheo-esophageal fistule, agenesis of external genitals, monkey fold of the left palm of the hand - VACTERL-H. In the second case, where genetic testing is normal, sirenomelia type II associated with agenesis of external genitalia, anal imperforation, myelomeningocele, dolichocrania, macroglossia, low set ears, left preauricular skin tag, long philtrum, lung hypoplasia, split cadiac apex, single umbilicalis artery, blind end colon, hepatomegaly, accessory spleen, polycystic horseshoe kidney, uterine and vaginal agenesis, presence of two ovaries and duodenal stenosis - VACTERL association. This two cases, lead us to believe that sirenomelia and the VACTERL association are probably different manifestations of a pathogenetic process leading to disorders of blastogenesis at different levels during embryonic development.

La sirenomelia es una malformación congénita y excepcionalmente rara, con una frecuencia entre 1,5 y 4,2 en un millón de embarazos. La combinación de la sirenomelia con el síndrome de VACTERL es igualmente rara. La literatura especializada informa sobre la existencia de una veintena de casos solamente; en lo que respecta a su asociación con el síndrome de VACTERL-H se conocen solo dos casos. Luego de realizar una revisión de la literatura presentamos dos casos de sirenomelia asociada con los síndromes de VACTERL-H y de VACTERL En el estudio se analizaron los primeros embarazos de dos mujeres, edad de 15 y de 40 años, respectivamente, ambas mujeres completamente sanas y sin hábitos viciosos. Entre la vigésima quinta y la vigésima séptima semana gestacional (SG) del embarazo ambas mujeres, el análisis prenatal comprueba la existencia de malformación del feto debido a lo cual los embarazos fueron interrumpidos por prescripción médica. El análisis fetopatológico del primer caso comprueba la existencia de sirenomelia de tipo I asociada con mielomeningocele, hidrocefalia, atresia anal, arteria umbilical única, agenesia bilateral de los riñones y de los ureteres que transportan la orina desde los riñones hasta la vejiga, fístula traqueoesofágica, agenesia de los órganos genitales externos, línea simiesca en la palma de la mano izquierda - VACTERLH. En el segundo caso, en que el análisis genético ha resultado normal, se observó la presencia de sirenomelia de tipo II asociada con agenesia de los órganos genitales externos, atresia anal, mielomeningocele, dolicocrania, macroglosia, orejas bajas, filtrum alargado, hipoplasia pulmonar, ápice cardíaco escindido, arteria umbilical única, colon terminado en ciego, bazo accesorio, poliquistosis renal, riñón en herradura, agenesia vaginal y de útero, presencia de dos ovarios y estenosis duodenal - VACTERL asociación. Los dos casos investigados permiten llegar a la conclusión de que la sirenomelia y su combinación con el síndrome de VACTERL probablemente sean manifestaciones diferentes de un proceso patogenético que conlleva la alteración de la blastogénesis en distintos niveles durante el proceso del desarrollo embrionario.

Effects of parasitoid and host age on the parasitism of Trichogramma pretiosum on eggs of Anticarsia gemmatalis

Abstract The ages of parasitoid females and their hosts can have substantial effects on parasitism and parasitoid efficacy. This relationship has been investigated over the last few decades and found to vary among species. To our knowledge, it was virtually unknown for Trichogramma pretiosum wasps that parasitize Anticarsia gemmatalis eggs. Therefore, the influence of parasitoid and host age on the parasitism of T. pretiosum on eggs of A. gemmatalis was here evaluated in three independent bioassays. Neither the number of parasitized eggs nor that of emerged parasitoids differed between T. pretiosum females of different age. The number of parasitoids per egg and the sex ratio were higher for 5-day-old females. Regarding host age, the number of parasitized eggs was highest for A. gemmatalis eggs aged 24 h (9.60), followed by eggs aged 48 h (1.00), while no parasitism was observed for eggs aged 72 h. The number of parasitoids per egg and sex ratio were not influenced by host age. Preference was significantly higher for host eggs aged 24 h (79.67%), followed by eggs aged 48 h (16.99%) and 72 h (3.33%). Accordingly to these results, the key challenge for a successful T. pretiosum release to control A. gemmatalis in the field is to synchronize the presence of up to 5-day-old adults with the most susceptible phase of the host eggs (1 day).

Desove y desarrollo intracapsular del caracol marino Hexaplexnigritus (Neogastropoda: Muricidae) en laboratorio

Introducción: El caracol marino Hexaplex nigritus es un murícido fuertemente explotado en el Golfo de California para consumo y artesanías. Cuando se reproducen, los adultos se agregan en forma de arrecifes artificiales facilitando su identificación y extracción, lo cual, ha mermado su población en dicha zona. Objetivo: Investigar el desove y desarrollo intracapsular y larvario de esta especie como herramientas para su producción en cautiverio con fines de repoblamiento. Métodos: Se recolectaron 18 progenitores que fueron mantenidos en un sistema cerrado con parámetros y alimentación controladas durante abril 2017 hasta septiembre 2018. Se registró: crecimiento de progenitores, desove de masas ovígeras, cantidad de cápsulas y número de embriones y larvas dentro de las cápsulas. La temperatura de incubación fue de 28.2 ± 1.5 °C. Las principales estructuras morfológicas de embriones y larvas fueron documentadas conforme su desarrollo. Resultados: El desarrollo embrionario intracapsular y de la larva velígera hasta su asentamiento tuvieron una duración de 14-15 y 31-32 días, respectivamente. Cada hembra de 80-88 mm de longitud produjo alrededor de 4 masas ovígeras, 627 cápsulas y 663 993 larvas velígeras extracapsulares por año. Conclusiones: La fácil adaptación y el potencial reproductivo mostrado por H. nigritus en laboratorio se presentan como estrategias promisorias para su repoblación y conservación.

Introduction: The marine snail Hexaplex nigritus is a heavily exploited muricid in the Gulf of California for consumption and handcrafts. When they reproduce, adults aggregated in the form of artificial reefs facilitating their identification and extraction, situation that has reduced their population in that area. Objective: In order to investigate the spawning and intracapsular and larval development of this species as tools for its production in captivity for repopulation purposes. Methods: Eighteen brooders were collected and kept in a closed system with controlled parameters and feeding from April 2017 to September 2018. Growth of parents, spawning of ovigerous masses, number of capsules, and number of embryos and larvae within the capsules, were registered. The main morphological structures of embryos and larvae were documented according to their development. Results: Intracapsular embryonic development and veliger larva until its establishment lasted 14-15 and 31-32 days, respectively. Each 80-88 mm length female produced around 4 ovigerous masses, 627 capsules and 663 993 extracapsular veliger larvae per year. Conclusions: Easy adaptation and reproductive potential shown by H. nigritus in the laboratory are presented as promising strategies for its repopulation and conservation.