Inmunolocalización de Sonic hedgehog en el desarrollo embrio-fetal de ratones ( Mus musculus ) / Immunolocalization of Sonic hedgehog in embryo-fetal mouse ( Mus musculus ) development

Sonic hedgehog (Shh) es un morfógeno esencial para el desarrollo de diversas estructuras, tales como notocorda, placa del piso del tubo neural, miembros, entre otros. Se buscó determinar la inmunolocalización de Shh en embriones y fetos de ratón. Para ello, se eutanasiaron 10 ratones gestantes (Mus musculus) BALB/c, un grupo de 5 animales a los 12,5 días post-coito (dpc), y otro grupo a los 17,5 dpc. Los embriones y fetos obtenidos fueron fijados en formalina al 10 % tamponada en PBS e incluidos en paraplast. Se realizaron cortes transversales seriados. Se utilizó anticuerpo policlonal Shh (Santa Cruz Biotechnology, H-160, conejo), dilución 1:100. Se identificó y describió la inmunolocalización de las muestras marcadas positivamente. La expresión de Shh en los embriones de 12,5 dpc fue inmunopositiva en notocorda, placa del piso del tubo neural, precartílago de radio y ulna, y prácticamente todos los epitelios: bronquial, intestinal, vejiga y uretra. En la etapa fetal, a los 17,5 dpc la inmunopositividad desaparece en el cartílago a excepción de zonas de osificación, disminuye en la epidermis pero aparece en folículos pilosos. La mucosa intestinal se ha diferenciado en segmentos, mostrando una inmunotinción mayor a nivel de las vellosidades intestinales. Shh actúa en distintos estadios del periodo gestacional, siendo clave en la diferenciación de distintas estructuras. En etapas embrionaria, es vital en la formación del sistema nervioso, organogénesis y formación de miembros, por lo que su expresión se encuentra en estas zonas. Sin embargo, en la etapa fetal la expresión cambia a estructuras de mayor especialización como folículo piloso y vellosidades intestinales.

Sonic hedgehog (Shh) is an essential morphogen for the development of various structures, such as notochord, neural tube floor plate, limbs, among others. We sought to determine the immunolocalization of Shh in embryos and mouse fetuses. To do this, 10 pregnant mice (Mus musculus) BALB /c were euthanized, a group of 5 animals at 12.5 days postcoitus (dpc), and another group at 17.5 dpc. Embryos and fetuses obtained were fixed in 10 % formalin buffered in PBS and embedded in paraplast. Serial cross sections were made. Polyclonal antibody Shh (Santa Cruz Biotechnology, H-160, rabbit), dilution 1:100 was used. The immunolocalization of the positively labeled samples was identified and described. Shh expression in 12.5 dpc embryos was immunopositive in notochord, neural tube floor plate, radius precartilage and ulna, and practically all epithelia: bronchial, intestinal, bladder and urethra. In the fetal stage, at 17.5 dpc the immunopositivity disappears in the cartilage except for areas of ossification, decreases in the epidermis but appears in hair follicles. The intestinal mucosa has differentiated into segments, showing greater immunostaining at the level of the intestinal villi. Shh acts in different stages of the gestational period, being key in the differentiation of different structures. In embryonic stages, it is vital in the formation of the nervous system, organogenesis and formation of limbs, so its expression is found in these areas. However, in the fetal stage the expression changes to more specialized structures such as hair follicles and intestinal villi.

Transitando de embrión a feto: la metamorfosis de los cordados / Transiting from embryo to fetus: the metamorphosis of the chordata

Durante el período del desarrollo conocido como prefetal, el embrión cambia sus características ictiomórficas comunes a todos los vertebrados y adquiere gradualmente las formas propias de la especie que representa. Durante este período se forma la cara, involucionan los arcos faríngeos (branquiales) formándose el cuello, y aparecen los miembros. Se constituye, además, la hernia umbilical fisiológica, que consiste en la presencia de asas intestinales dentro del cordón umbilical. El sistema nervioso origina las vesículas telencefálicas, el diencéfalo, mesencéfalo, metencéfalo, y mielencéfalo. Este periodo corresponde a una etapa de máxima susceptibilidad ante los teratógenos que pueden generar malformaciones en todas las especies animales. El objetivo del presente trabajo es presentar los principales eventos acontecidos durante el periodo prefetal, además de una visión y opinión de los autores, proponiendo una nueva denominación a la etapa: periodo metamórfico.

During the period of development known as prefetal, the embryo changes its ictiomorphic characteristics common to all vertebrates and gradually acquires the proper forms of the species it represents. During this period the face is formed, the pharyngeal arches (branchial) involute forming the neck, and the limbs appear. In addition, the physiological umbilical hernia is constituted, which consists of the presence of intestinal loops inside the umbilical cord. The nervous system originates the telencephalic vesicles, the diencephalon, mesencephalon, metencephalon, and myelencephalon. This period corresponds to a stage of maximum susceptibility to teratogens that can generate malformations in all animal species. The objective of this paper is to present the main events that took place during the preferential period, as well as a vision and opinion of the authors, proposing a new name for the stage: metamorphic period.

Aspectos actuales de la organogénesis. Función e involución del timo / Present aspects of organogenesis. Function and thymic involution

El timo es un órgano linfoide central o primario localizado en la parte anterosuperior del tórax. Constituye el principal sitio de diferenciación y maduración de las células T. En esta revisión se detallan aspectos actuales de la embriología, la histología y la función tímica y en la generación de los diferentes subtipos de timocitos y su diferenciación a células T maduras efectoras, la inducción de las células T tímicas reguladoras involucradas en el mantenimiento de la tolerancia a lo propio y la involución que sufre este órgano durante el proceso de inmunosenescencia

Thymus is a primary organ located in the antesuperior area of the torax. It is the principal place of differentiation and maduration of T cells. In this review present aspects of the embriology, histology and thymic function are detailed, as well as its role in the generation of different kinds of thymic cells; its differentiation to mature cells and of regulator T cells has a crucial role in tolerance induction. Moreover, thymic involution during of immunosenescence process is shown

Organogenesis and plant regeneration of Arachis villosa Benth. (Leguminosae) through leaf culture

With the aim of developing an efficient plant regeneration protocol, leaflet explants of three accessions of Arachis villosa Benth. (S2866, S2867 and L97) were cultured on basic Murashige and Skoog medium supplemented with different combinations of plant growth regulators: alpha-naphthalenacetic acid, indole-3-butyric acid, 6-benzylaminopurine, kinetin and thidiazuron. The accession L97 was the only one able to differentiate buds through indirect organogenesis. The most suitable combination for bud regeneration was the basic medium added with 13.62 microM thidiazuron and 4.44 microM 6-benzylaminopurine. These results show the important role of the genotype in morphogenetic responses and the organogenetic effect of thidiazuron in Arachis villosa accession L97. A thidiazuron lacking media (only 0.54 microM alpha-naphthalenacetic acid, 13.95 microM kinetin and 13.32 microM 6-benzylaminopurine were added) promoted the elongation of the regenerated buds. Adventitious rooting was achieved 90 days after the isolated shoots were transferred to a rooting medium containing 0.54 microM alpha-naphthalenacetic acid.

Evaluación de diferentes combinaciones fitohormonales en la regeneración de Solanum tuberosum (Solanaceae) Var. Pastusa Suprema a partir de explantes internodales / Evaluation of different phytohormonal combinations in Solanum tuberosum (Solanaceae) Var. Pastusa Suprema regeneration from intermodal explants

La regeneración de plantas mediante el cultivo de tejidos es un importante componente de la biotecnología que es requerido para procesos tales como la obtención de plantas transgénicas. Se estableció un sistema eficiente de regeneración para la especie Solanum tuberosum L. var. Pastusa Suprema, susceptible de ser transformada genéticamente. Se evaluó el efecto de las fitohormonas zeatina ribósido (ZR), ácido naftalénacetico (ANA) y ácido gibérelico (AG3), utilizadas en combinaciones específicas, sobre la inducción de callo, la regeneración y el número de brotes producidos por explante. La presencia de ANA demostró ser esencial en la respuesta callogénica y regenerativa de los explantes. Se encontró que la adición de 3,0 mg/L de ZR, 0,02 mg/L de ANA y 1,0 mg/L de AG3 sobre un medio básico M-S, es una formulación hormonal adecuada para inducir el proceso de organogénesis indirecta sobre la variedad de papa Pastusa Suprema; produce callogénesis y regeneración en porcentajes superiores al 90%, con un promedio de seis regenerantes por explante.

Plant regeneration using tissue culture represents an important biotechnological tool which is necessary in processes such as obtaining transgenic plants. An efficient regeneration system was established for Solanum tuberosum L. var. Pastusa Suprema; this specie is susceptible to being genetically transformed. The effect of zeatin riboside (ZR), gibberellic acid (GA3) and naphthalene acetic acid (NAA) phytohormones used in specific combinations was evaluated regarding callus induction and bud regeneration and number per explant.The presence of NAA was seen to be essential in explants’ callogenic and regenerative response. Adding 3.0 mg/L ZR, 0.02 mg/L NAA and 1.0mg/L GA3 to a basic M-S medium was an appropriate hormonal combination for inducing indirect organogenesis in the Pastusa Suprema potato variety; it produced more than 90% callus genesis and plant regeneration and an average of six regenerants per explant.

Development beyond the gastrula stage and digestive organogenesis in the apple-snail Pomacea canaliculata (Architaenioglossa, Ampullariidae)

Development of Pomacea canaliculata from the gastrula stage until the first day after hatching is described. Trochophore embryos are developed after gastrulation, showing the prototroch as a crown of ciliated orange-brownish cells. However, no true veliger embryos are formed, since the prototroch does not fully develop into a velum. Afterward, the connection between the fore- and midgut is permeated and the midgut becomes full of the pink-reddish albumen, which is stored into a central archenteron's lake, from where it is accumulated into the large cells forming the midgut wall ("giant cells"). Electron microscopy of giant cells in late embryos showed that albumen is engulfed by large endocytic vesicles formed between the irregular microvilli at the top of these cells. By the end of intracapsular development, giant cells become gradually replaced by two new epithelial cell types which are similar to those found in the adult midgut gland: the pre-columnar and the pre-pyramidal cells. Pre-columnar cells have inconspicuous basal nuclei and are crowned by stereocilia, between which small endocytic vesicles are formed. Pre-pyramidal cells have large nuclei with 2-3 nucleoli and show a striking development of the rough endoplasmic reticulum. The genesis of the three cell lineages (giant, pre-columnar and pre-pyramidal cells) is hypothetically attributed to epithelial streaks that occur at both sides of the midgut since early stages of development.

Immunohistochemical identification and quantitative analysis of cytoplasmic Cu/Zn superoxide dismutase in mouse organogenesis

Cytoplasmic Cu/Zn superoxide dismutase (SOD1) is an antioxidant enzyme that converts superoxide to hydrogen peroxide in cells. Its spatial distribution matches that of superoxide production, allowing it to protect cells from oxidative stress. SOD1 deficiencies result in embryonic lethality and a wide range of pathologies in mice, but little is known about normal SOD1 protein expression in developing embryos. In this study, the expression pattern of SOD1 was investigated in post-implantation mouse embryos and extraembryonic tissues, including placenta, using Western blotting and immunohistochemical analyses. SOD1 was detected in embryos and extraembryonic tissues from embryonic day (ED) 8.5 to 18.5. The signal in embryos was observed at the lowest level on ED 9.5-11.5, and the highest level on ED 17.5-18.5, while levels remained constant in the surrounding extraembryonic tissues during all developmental stages examined. Immunohistochemical analysis of SOD1 expression on ED 13.5-18.5 revealed its ubiquitous distribution throughout developing organs. In particular, high levels of SOD1 expression were observed in the ependymal epithelium of the choroid plexus, ganglia, sensory cells of the olfactory and vestibulocochlear epithelia, blood cells and vessels, hepatocytes and hematopoietic cells of the liver, lymph nodes, osteogenic tissues, and skin. Thus, SOD1 is highly expressed at late stages of embryonic development in a cell- and tissue-specific manner, and can function as an important antioxidant enzyme during organogenesis in mouse embryos.

Low birth weight and its implication in renal disease.

It has been demonstrated that intrauterine growth retardation, defined as birth weight below the 10th percentile, gives rise to a reduction in nephron number. Oligonephropathy has been suggested to increase the risk for systemic and glomerular hypertension in adult life as well as enhance risk for expression of renal disease after exposure to potentially injurious renal stimuli. Diseases, such as diabetes, that damage the kidney, may enhance this risk. In addition, it has been hypothesized that the same factors affecting kidneys in utero also impact on pancreatic tissue development, thus predisposing infants of low birth weight to an increased risk for the subsequent development of diabetes and diabetic nephropathy, consistent with the so-called "thrifty phenotype" hypothesis. Impact of low birth weight on nondiabetic renal disease has also been shown in some studies. In the current scenario, chronic kidney disease is increasing all over the world and the major two causes are diabetes and hypertension. Once the issues are shifting from management of end-stage renal disease to prevention of chronic kidney disease, prevention of low birth weight is likely to be an issue for the nephrologists in future.