Differences of temporomandibular joint symmetry in patients with unilateral complete cleft lip and palate at different developmental stages / 中南大学学报(医学版)

OBJECTIVES@#Currently, the research results regarding the bilateral temporomandibular joint symmetry in patients at different ages with unilateral complete cleft lip and palate (UCLP) are still controversial. In this study, the position of condyle in the articular fossa and morphology of condyle in UCLP patients at different developmental stages was measured and analyzed to explore the asymmetry difference, which can provide a new theoretical basis for the sequential therapy.@*METHODS@#A total of 90 patients with UCLP were divided into a mixed dentition group (31 cases), a young permanent dentition group (31 cases) and an old permanent dentition group (28 cases) according to age and dentition development. Cone beam computed tomography (CBCT) images were imported into Invivo5 software for 3D reconstruction, and the joint space, anteroposterior diameter, medio-lateral diameter, and height of condylar were measured, and its asymmetry index was calculated.@*RESULTS@#The asymmetry index of condylar height and anteroposterior diameter among the 3 groups, from small to large, was the mixed dentition group<the young permanent dentition group<the old permanent dentition group (both P<0.05). There was no significant difference in condylar anteroposterior diameter and asymmetry index between the mixed dentition group and the young permanent dentition group (both P>0.05), all of them were lower than those in the old permanent dentition group (both P<0.05). Compared with the normal side, the height of fracture condyle was smaller among the 3 groups (all P<0.05), and the anterior joint space was smaller (P<0.05) and the posterior joint space was larger (P<0.05) in the mixed dentition group.@*CONCLUSIONS@#In patients with UCLP, the asymmetry of condylar morphology increases with age, but the condylar position tends to normal. These results suggest that early treatment has important clinical significance for the morphologic development of temporomandibular joint in UCLP patients.

Effects of lead exposure and chelation therapy in different developmental stages on mouse short-term and long-term cognitive functions / 环境与职业医学

Background Lead (Pb) exposure impairs cognitive functions of children. Whether Pb exposure in different developmental stages induces long-term cognitive impairment, and whether chelation therapy could mitigate the cognitive impairment is rarely reported. Objective This experiment is designed to investigate effects of Pb exposure and chelation therapy during different developmental stages (breastfeeding, weaning, and early puberty periods) on mouse short-term and long-term cognitive functions. Methods C57BL/6 male mice in breastfeeding period, weaning period, and early puberty period (postnatal day 2, 21, and 41; PND 2, PND 21, and PND 41, n=30, respectively) were randomly divided into control, Pb exposure, and Pb+dimercaptosuccinic acid (DMSA) treatment groups (n=10 in each group). The control groups received standard food and deionized water. The Pb exposure mice received standard food and free drinking water containing Pb acetate (0.1% for dams, and 0.05% for pups). After receiving Pb acetate for 19 d, the Pb+DMSA treatment groups were given 1 mmol·kg−1·d−1 DMSA for 6 d with gastric infusion. Whole blood Pb levels were measured after DMSA treatment on experimental day 25. The effects on short-term cognitive function were tested in the Morris Water Maze task by the analyses of escape latency on PND 75−79, as well as target quadrant time and times of platform-crossing on PND 80. Hippocampal long-term potentiation of field excitatory postsynaptic potential (fEPSP) of mice on PND 365 was induced to demonstrate the effects on long-term cognitive function. Results The blood Pb levels among the Pb, Pb+DMSA, and control groups were statistically different for each developmental stage (Fbreastfeeding period=43.47, Fweaning period=228.6, Fearly period of puberty=274.2, all P<0.001). Compared to the counterpart control groups, blood Pb levels of the pb exposure groups (386.4, 265.0, and 178.1 μg·L−1 in breastfeeding period, weaning period, and early puberty period, respectively) were significantly higher for all stages. After the chelation therapy, the blood Pb significantly decreased for all stages (28.68, 47.29, and 20.93 μg·L−1 in the three periods, respectively, all P<0.001) and the Pb levels of the mice exposed in the breastfeeding period decreased most (by 92.58%, 82.15%, and 88.25% in the three periods, respectively, P<0.01). In the water maze task, the mice exposed to Pb in the breastfeeding period had a gentler decrease in escape latency (from 54.20 s on day 1 to 30.54 s on day 5, by 43.65 % decrease) than the control group (from 32.44 s on day 1 to 15.20 s on day 5, by 53.14 % decrease) (P<0.01) and a significant decrease in target quadrant time (P<0.05). After the chelation therapy, the escape latency of the DMSA-treated mice in the breastfeeding period (from 40.94 s on day 1 to 20.87 s on day 5, by 48.99 % decrease) was steeper than that of the Pb-exposed mice (P<0.05). The differences in the escape latency, target quadrant time, and times of platform-crossing were not significant between the Pb-exposed mice and the control mice in the weaning period and early period of puberty (all P>0.05). After the chelation therapy, such differences were also not significant compared with before therapy. Due to the small sample size, data were merged for different developmental stages in the long-term potentiation test. The amplitudes of fEPSP induced in the control, Pb-exposed, and DMSA treatment groups were significantly different (Fgroups=212.2, Ftime=11.36. P<0.001). The average fEPSP amplitude induced in the last 10 min recorded in the hippocampal slices in the Pb exposure group was significantly lower than that in the control group (P<0.05). After the DMSA treatment, no significant differences were observed in the fEPSP amplitudes between the Pb exposure group and the DMSA treatment group (P>0.05). When observing the fEPSP data by developmental stages, the fEPSP amplitude in the breastfeeding Pb-exposure group was 27.2% lower than that of the breastfeeding control group, while such changes were not obvious in the weaning period or in the early period of puberty. The fEPSP amplitude in breastfeeding DMSA treatment group was 44.3% higher than that of the breastfeeding Pb exposure group, while such changes were not observed in the weaning period or in early period of puberty. Conclusion Pb exposure during different developmental stages, especially in breastfeeding period, could affect short-term and long-term cognitive functions of mice. The harmful effects may be partially reversed by DMSA chelation therapy, especially being treated in breastfeeding period.

Identification and sequence analysis of prolactin receptor and its differential expression profile at various developmental stages in striped hamsters

Prolactin (PRL) plays critical roles in regulation of biological functions with the binding of specific prolactin receptor (PRLR). Revealing the expression patterns of PRLR at different developmental stages is beneficial to better understand the role of PRL and its mechanism of action in striped hamsters. In this study, the cDNA sequence of PRLR (2866-base-pairs) was harvested from the pituitary of mature female striped hamsters (Cricetulus barabensis) that contains an 834-base-pair 5′-untranslated region (1-834 bp), a 1848-base-pair open reading frame (835-2682 bp), and a 184-base-pair 3′-untranslated region (2683-2866). The 1848-base-pair open reading frame encodes a mature prolactin-binding protein of 592 amino acids. In the mature PRLR, two prolactin-binding motifs, 12 cysteines, and five potential Asn-linked glycosylation sites were detected. Our results showed that the PRLR mRNA quantity in the hypothalamus, pituitary, ovaries, or testis was developmental-stage-dependent, with the highest level at sub-adult stage and the lowest level at old stage. We also found that PRLR mRNAs were highest in pituitary, medium level in hypothalamus, and lowest in ovaries or testis. PRLR mRNAs were significantly higher in males than in females, except in the hypothalamus and pituitary from 7-week-old striped hamsters. Moreover, the PRLR mRNAs in the hypothalamus, pituitary, and ovaries or testis were positively correlated with the expression levels of GnRH in the hypothalamus. These results indicated that the PRLR has conserved domain in striped hamster, but also possesses specific character. PRLR has multiple biological functions including positively regulating reproduction in the striped hamster.

Effects of light quality on growth and icariin flavonoid content of Epimedium pseudowushanense under different light intensity / 中国中药杂志

In this study, the growth index including plant height, compound leaf area, specific leaf area, leaf water content, number of branches, and leaf biomass per plant and the icariin flavonoids such as epimedin A, epimedin B, epimedin C and icariin of Epimedium pseudowushanense were determined on 30 d and 60 d under light intensity(18.2±2.5) μmol·m~(-2)·s~(-1)(L1) and(90.9 ±2.5) μmol·m~(-2)·s~(-1)(L2), and white light as control, red light, blue light and yellow light were used as three light quality treatments, to study the effect of light quality on the growth and flavonoids accumulation of E. pseudowushanense. The E. pseudowushanense was sui-table for growth under L1 light intensity, the blue light treatment significantly reduced the leaf area, but had little effect on the stem height, the red light treatment and the yellow light treatment had no obvious effect on the stem height and leaf area, but the yellow light treatment significantly increased the germination of new branches, and had a sustained promoting effect, and the biomass was significantly higher than the white light treatment at 60 d. The content of icariin flavonoids in red light, blue light and yellow light treatment was higher than that in white light treatment at 30 d and 60 d under L1 light intensity, while yellow light treatment promoted the synthesis of icariin flavonoids to the largest extent, which was 1.8 and 1.9 times of white light treatment(30 d and 60 d).Under L2 light intensity, the effect of strong light on promoting stem germination became the main factor, while the yellow light treatment showed no significant effect on promoting stem germination, and the red light treatment exhibited a significant effect on reducing leaf area. Icariin flavonoids under red light, blue light and yellow light treatment were all lower than that under white light treatment, that is, the effect of white light treatment on the synthesis of icariin flavonoids is better than red light, blue light and yellow light treatment. When the time of strong light treatment was longer, the degradation range of icariin flavonoids in other light treatment appeared, while red light treatment promotes the synthesis of icariin flavonoids. Therefore, the influence of light quality on E. pseudowushanense is quite different under different light intensity, no matter from growth index or flavonoid content index. The results support that the biomass and icariin flavonoid content can be increased by providing appropriate red and yellow light.

A macroscopic classification of the embryonic development of the one-sided livebearer Jenynsia multidentata (Teleostei: Anablepidae)

This study proposes eight stages according to the main discernible changes recorded throughout the embryonic development of Jenynsia multidentata. The development of morphological embryo structures, pigmentation, and changes in tissues connecting mother and embryo were included in the stage characterization. From the fertilized egg (Stage 1), an embryo reaches the intermediary stages when presenting yolk syncytial layer (Stage 2), initial pigmentation of the outer layers of the retina and dorsal region of the head (Stage 3), and the sprouting of the caudal (Stage 4), dorsal and anal fins (Stage 5). During the later stages, the ovarian folds enter the gills, and the body pigmentation becomes more intense (Stage 6), the body becomes elongated (Stage 7), and there is a greater intensity in body pigmentation and increased muscle mass (Stage 8). The dry weight of the batches varied between 0.6 ± 0.3 mg (Stage 3) to 54.6 ± 19.7 mg (Stage 8), but the dry weight of the maternal-embryonic connecting tissues remained almost constant. After controlling the effect of those reproductive tissues, the gain in dry weight of the batches throughout development increased exponentially from Stage 6, reflecting the increase in size and weight of the embryos due to matrotrophy.(AU)

Este estudio propone una clasificación constituida por ocho etapas, establecidas con base en los principales cambios macroscópicos registrados a lo largo del desarrollo embrionario de Jenynsia multidentata. El desarrollo de estructuras embrionarias, los patrones de pigmentación y los cambios en los tejidos de conexión entre la madre y el embrión fueron incluidos en la caracterización de cada etapa. Inicia con el huevo fertilizado (Etapa 1), siguiendo con etapas intermedias del embrión en las cuales es visible la capa sincitial del vitelo (Etapa 2), la pigmentación inicial de las capas externas de la retina y el dorso de la cabeza (Etapa 3), y la aparición de las aletas caudal (Etapa 4), dorsal y anal (Etapa 5). En las etapas posteriores, los pliegues del tejido ovárico se introducen por las branquias y se intensifica la pigmentación corporal (Etapa 6), el cuerpo se extiende (Etapa 7) y hay un marcado aumento en la pigmentación corporal y masa muscular (Etapa 8). El peso seco de los lotes varió entre 0,6 ± 0,3 mg (Etapa 3) y 54,6 ± 19,7 mg (Etapa 8); sin embargo, el peso seco del tejido que conecta a la madre con el embrión se mantuvo prácticamente constante. Después de controlar el efecto del peso seco de estos tejidos, la ganancia de peso seco de los lotes de embriones a lo largo del desarrollo aumentó de forma exponencial a partir de la Etapa 6, evidenciándose en el aumento en tamaño y peso de los embriones debido a la matrotrofia.(AU)

Analysis on stability of reference genes in different developmental stages of seeds from Carthamus tinctorius / 中草药

Objective: To select the appropriate reference genes for qRT-PCR by analyzing the stability of housekeeping genes as reference genes in different developmental stages of safflower. Methods: Six housekeeping genes such as ACT, EF1α, GAPDH, UBI, TUA, and TUB were selected as candidate reference genes to analyze their expression levels in safflower seeds under different developmental stages by qRT-PCR. The expression stability was evaluated by GeNorm and NormFinder softwares. Results: The expression levels of six reference genes were different, but the best was EF1α and the best combination reference genes were EF1α, TUB, and ACT. Normfinder software was applied to the verification of analysis result by GeNorm software. The Normfinder software results showed that UBI gene was not stable, and other genes were stable. Conclusion: This study provides a detailed reference of housekeeping gene for qRT-PCR in different developmental stages of safflower.

Estimating the development of landrace and improved maize cultivars as a function of air temperature / Estimativa do desenvolvimento de cultivares crioulas e melhoradas de milho em função da temperatura do ar

ABSTRACT: The objective of this study was to determine the maximum development rates for the phases of emergence, vegetative and reproductive, and to test the performance of the Wang and Engel (WE) model for simulating the development of landrace and improved maize cultivars sown on different dates. Model calibration was with data collected from a field experiment with a sowing date on December 13, 2014, and the model was tested with independent data from experiments with five sowing dates (August 20 and November 4, 2013, February 3 and August 15, 2014, and January 7, 2015) in Santa Maria, RS. The experiment was a complete randomized block design with four replicates. The dates of emergence (EM), silking (R1), and physiological maturity (R6) of two landraces ('Cinquentinha' and 'Bico de ouro') and two improved maize cultivars ('BRS Planalto' and 'AS 1573PRO') were recorded. Maximum daily developmental rates varied among cultivars from 0.2400 to 0.3411 d-1 for the emergence phase, from 0.0213 to 0.0234 d-1 for the vegetative phase, and from 0.0254 to 0.0298 d-1 for the reproductive phase. The WE model adequately estimated the developmental stages of landraces and improved maize cultivars with a mean error of 3.7 days. The cardinal temperatures used in the WE model were appropriate to estimate the developmental stages of landraces and improved maize cultivars.

RESUMO: O objetivo neste trabalho foi obter as taxas máximas de desenvolvimento para as fases de emergência, vegetativa e reprodutiva, e testar o desempenho do modelo de Wang e Engel (WE) para estimar o desenvolvimento de cultivares crioulas e melhoradas de milho em diferentes datas de semeadura. A calibração foi realizada com dados de um experimento de campo semeado em 13/12/2014, e a validação com dados independentes de experimentos semeados em 20/08/2013, 04/11/2013, 03/02/2014, 15/08/2014 e 07/01/2015 em Santa Maria, RS. O delineamento foi blocos ao acaso com quatro repetições. Foram registradas as datas de emergência (EM), espigamento (R1) e maturidade fisiológica (R6) de duas cultivares crioulas ('Cinquentinha' e 'Bico de ouro') e duas melhoradas ('BRS Planalto' e 'AS 1573PRO'). As taxas máximas de desenvolvimento diário diferiram entre as cultivares variando de 0,2400 a 0,3411 dia-1 para a fase de emergência, de 0,0213 a 0,0234 dia-1 para a fase vegetativa e de 0,0254 a 0,0298 dia-1 para a fase reprodutiva. O modelo WE estimou adequadamente os estágios de desenvolvimento de cultivares crioulas e melhoradas de milho, com um erro médio de 3,7 dias. As temperaturas cardinais utilizadas no modelo WE são apropriadas para estimar os estágios de desenvolvimento de cultivares crioulas e melhoradas de milho.

Analistas praticando outra coisa? Desafios das crianças e dos bebês à psicanálise / Analysts practicing something else? Challenges of children and infants to psychoanalysis / ¿Analistas practicando otra cosa? Desafíos de los niños y los bebés para el psicoanálisis

A autora destaca os desafios que o contato direto com crianças e bebês traz para a teoria e a técnica psicanalítica. Ressalta a importância do método de observação de bebês criado por Esther Bick para instrumentalizar melhor o analista para lidar com fenômenos transferenciais/contratransferenciais primitivos, para o quais o setting se torna mais importante do que a interpretação. A função do observador e as transformações que ele sofre no decorrer do processo - especificamente na forma de uma escuta refinada dos fenômenos psíquicos primitivos - resultam em um setting aprimorado pela experiência de observação que se adapta a diferentes settings externos. É apresentado material de aplicações do método em ultrassonografias obstétricas, centro obstétrico e UTI neonatal com o objetivo de ilustrar o enriquecimento pessoal do analista, assim como a importante função terapêutica dessas aplicações, muito bem-vindas nessas etapas primitivas do desenvolvimento humano.

The author emphasizes the challenges that direct contact with children and infants brings to psychoanalytic theory and technique. She shows the importance of the infant observation method created by Esther Bick as a tool for the analyst when dealing with primitive transference/countertransference phenomena in which the setting is more important than interpretation. The observer's function and the changes he/she undergoes throughout the process - specifically the development of a refined listening of primitive psychic phenomena - result in a setting enriched by infant observation experience which may be adapted to different external settings. Observational material taken from applications of the method to obstetric ultrasounds, at an obstetric centre and a Neonatal Intensive-Care Unit is presented aiming to illustrate the analyst's personal enrichment, as well as the important therapeutic function of these applications, which are most welcome in early developmental stages.

La autora subraya los desafíos que el contacto directo con niños y bebés trae a la teoría y la técnica psicoanalíticas. Pone de relieve la importancia del método de observación de bebés creado por Esther Bick para instrumentalizar mejor al analista al lidiar fenómenos transferenciales/contratransferenciales primitivos para los que el setting se hace más importante que la interpretación. La función del observador y las transformaciones que él sufre en el trascurso del proceso - específicamente en la forma de una escucha refinada de los fenómenos psíquicos primitivos - resultan en un setting perfeccionado por la experiencia de la observación que se adapta a distintos settings externos. Se presenta material de aplicaciones del método en ultrasonografías obstétricas, centro obstétrico y UCI neonatal con el objetivo de ilustrar el enriquecimiento personal del analista, así como la importante función terapéutica de esas aplicaciones, muy bienvenidas en esas etapas primitivas del desarrollo humano.

Differential expression levels of synaptophysin through developmental stages in hippocampal region of mouse brain / 대한해부학회지

The formation of neural synapses according to the development and growth of neurite were usually studied with various markers. Of these markers, synaptophysin is a kind of synaptic protein located in the synaptic vesicle of neuron or neuroendocrine cell known to be distributed consistently in all neural synapses. The purpose of this study was to investigate differential expression levels and patterns of synaptic marker (synaptophysin) in the mouse hippocampal region according to the developmental stages of embryonic, neonatal, and adulthood respectively. In the embryonic and neonatal groups, synaptophysin immunofluorescence was almost defined to cornu ammonis subfields (CA1 and CA3) of hippocampus and subiculum proper in the hippocampal region. However in dentate gyrus, synaptophysin immunoreactivities were insignificant or absent in all developmental stages. In embryonic and neonatal hippocampus, the intensities of immunofluorescence were significantly different between molecular and oriens layers. Furthermore, those intensities were decreased considerably in both layers of neonatal group compared to embryonic. The results from this study will contribute to characterizing synaptogenic activities in the central nervous system through developmental stages.

Differential expression levels of synaptophysin through developmental stages in hippocampal region of mouse brain / 대한해부학회지

The formation of neural synapses according to the development and growth of neurite were usually studied with various markers. Of these markers, synaptophysin is a kind of synaptic protein located in the synaptic vesicle of neuron or neuroendocrine cell known to be distributed consistently in all neural synapses. The purpose of this study was to investigate differential expression levels and patterns of synaptic marker (synaptophysin) in the mouse hippocampal region according to the developmental stages of embryonic, neonatal, and adulthood respectively. In the embryonic and neonatal groups, synaptophysin immunofluorescence was almost defined to cornu ammonis subfields (CA1 and CA3) of hippocampus and subiculum proper in the hippocampal region. However in dentate gyrus, synaptophysin immunoreactivities were insignificant or absent in all developmental stages. In embryonic and neonatal hippocampus, the intensities of immunofluorescence were significantly different between molecular and oriens layers. Furthermore, those intensities were decreased considerably in both layers of neonatal group compared to embryonic. The results from this study will contribute to characterizing synaptogenic activities in the central nervous system through developmental stages.

Toxoplasma gondii: 1908-2008, homage to Nicolle, Manceaux and Splendore

The discovery of Toxoplasma gondii independently by Nicolle and Manceaux (1908) and Splendore (1908) was to open a "Pandora's Box" that has led research on this parasite into a number of scientific disciplines. In the 100 years since its discovery, the mystery surrounding T. gondii and its inter-relationship with humans has continued to provide a stimulating source of material in many areas of research, resulting in the publication of almost 20,000 papers and a number of books. This flood of diverse information shows no sign of abating, with an average of 10 papers per week appearing in PubMed. Herein, it is impossible to do more than provide a very superficial comment on what has become a massive body of scientific information. T. gondii has many unique features and seems to be the "exception to almost every rule" thus acting as a focus for research in disciplines from epidemiology to immunology to human behaviour to cell biology to human disease. In this review a number of the historical advances will be mentioned and combined with a description of the basic biology of the parasite.

Descrição do gene do receptor de TNF-α Schistosoma mansoni e efeito do TNF-α humano na expressão gênica do parasita / Description of the TNF-α receptor gene in Schistosoma mansoni and the effect of human TNF-α on the parasite's gene expression

O parasita Schistosoma mansoni é um dos principais causadores da esquistossomose, doença que acomete 200 milhões de indivíduos no mundo. O parasita possui um complexo ciclo de vida composto de seis estágios evolutivos em dois hospedeiros. S. mansoni possui um sofisticado sistema de interação com seus hospedeiros de modo a escapar da resposta imune e interagir com moléculas produzidas por eles. Alguns trabalhos na literatura descreveram o efeito do TNF-α humano sobre o processo de ovoposição do parasita adulto. Nosso trabalho teve por objetivo analisar o perfil de expressão gênica do S. mansoni ao longo de seus estágios de desenvolvimento, avaliar o efeito do TNF-α humano sobre o perfil de expressão gênica do parasita em dois estágios de desenvolvimento e descrever o gene homólogo ao receptor de TNF-α humano em S. mansoni. Para isso, duas plataformas de microarrays distintas foram utilizadas: uma composta por 4000 sondas de cDNA dupla fita produzida pelo nosso grupo de pesquisa e a outra, composta por 44000 sondas de oligonucleotídeos desenhadas pelo nosso grupo e produzida pela empresa Agilent Technologies. Com estas plataformas foi detectada a expressão de 5798 genes em vermes adultos, sendo que 156 genes apresentavam a transcrição nas fitas senso e anti-senso; 6 destes tiveram confirmadas a transcrição nas duas fitas por transcrição reversa fita específica seguida de PCR em Tempo Real. Adicionalmente foram identificados 229 genes diferencialmente expressos entre vermes adultos machos e fêmeas. A análise de expressão gênica entre 5 estágios de desenvolvimento do parasita mostrou dois tipos de conjuntos de dados: (i) 1423 genes diferencialmente expressos entre dois estágios subseqüentes de desenvolvimento e (ii) 342 genes com expressão enriquecida em um estágio exclusivamente. 68 destes são transcritos intrônicos que não possuem potencial codificador de proteinas. Um gene ortólogo ao receptor de TNF-α humano (SmTNFR) foi clonado e...

The parasite Schistosoma mansoni is one of major causative agents of schistosomiasis, a disease which affects 200 million people in the world. The parasite has a complex life cycle with six developmental stages in two hosts. S. mansoni has a sofisticated system of interaction with the hosts, permitting it to escape the immune response and to interact with molecules produced by the hosts. The effect of human TNF-α on adult parasite egg-laying has been described in the literature. The present work intended to analyse the gene expression profile of S. mansoni among its developmental stages, to evaluate the effect of human TNF-α on gene expression profile in two different developmental stages and to describe a homologous gene to human TNF-α receptor in S. mansoni. Two microarrays platfoms were used: one comprised by 4000 cDNA probes and printed by our research group and another, comprised by 44000 oligonucleotide probes designed by our group and printed by Agilent Technologies Company. With these platforms, we detected the expression of 5798 genes in adult worms, of which 156 showed transcription in sense and anti-sense strands; 6 of them had their expression levels confirmed by strand specific Real Time PCR. 229 genes were identified as differentially expressed between male and female adult worms. Gene expression analysis among 5 parasite developmental stages identified two data sets: (i) 1423 differentially expressed genes between two subsequent developmental stages and (ii) 342 expressed genes enriched in one exclusive stage. 68 of them are intronic transcripts with no protein-coding potential. An ortologue to human TNF-α receptor (SmTNFR) was cloned and sequenced. SmTNFR transcritpt has 1967bp and encodes a 599-amino acid protein. Other 9 genes encoding conserved elements of the TNF-α signaling pathway were identified among the public S. mansoni ESTs dataset, thus revealing a complete TNF-α signaling pathway in the parasite...

Embryonic development of Girardia tigrina (Girard, 1850) (Platyhelminthes, Tricladida, Paludicola) / Desenvolvimento embrionário de Girardia tigrina (Girard, 1850) (Platyhelminthes, Tricladida, Paludicola)

The embryonic development of freshwater triclads is mainly known from studies of species of Dendrocoelum, Planaria, Polycelis, and, more recently, Schmidtea. The present study characterizes the development of Girardia tigrina (Girard, 1850) by means of optical microcopy using glycol methacrylate semi-thin sections. 94 cocoons were collected in the period from laying to hatching, with intervals of up to twenty-four hours. The sequence of morphological changes occurring in the embryo permitted the identification of nine embryonic stages. At the time of cocoon laying, numerous embryos were dispersed among many yolk cells, with a rigid capsule covering the entire cocoon. In the first stage (approx. up to 6 hours after cocoon laying), yolk cells and embryonic cells showed random distribution. Stage II (between 12 and 24 hours after cocoon laying) is characterized by aggregates of blastomeres, which later aggregate forming an enteroblastula. Approximately 2 days after cocoon laying (stage III), formation of the embryonic epidermis and embryonic digestive system took place, the latter degenerating during the subsequent stage. Stage V (until the fourth day) is characterized by the formation of the definitive epidermis. Between 4 and 6 days after laying, organogenesis of the definitive inner organs starts (stage VI). Approximately 14 days after laying (stage IX), formation of the nervous system is completed. At this stage, the embryo shows similar characteristics to those of newly hatched juveniles. The hatching of Girardia tigrina occurs in the period between twelve to twenty-two days after cocoon laying.

O desenvolvimento embrionário dos tricladidos é conhecido, fundamentalmente, por estudos realizados em espécies de Dendrocoelum, Planaria, Polycelis e, mais recentemente, Schmidtea. O presente estudo descreve o desenvolvimento embrionário de Girardia tigrina (Girard, 1850), a partir de análises realizadas em cortes histológicos seriados e semifinos de glicol-metacrilato, ao microscópio óptico. Noventa e quatro casulos foram coletados no período entre a postura e a eclosão, em intervalos de até vinte e quatro horas. A seqüência das modificações morfológicas no embrião permitiu a identificação de nove estágios embrionários. Na postura dos casulos, envoltos por uma cápsula rígida, observam-se numerosos embriões dispersos entre grande quantidade de células vitelinas. No estágio I (aproximadamente até 6 horas após a postura), as células vitelinas e as embrionárias mostram uma distribuição aleatória. O estágio II (entre 12 e 24 horas após a postura) caracteriza-se pela formação de agrupamentos de blastômeros, os quais posteriormente formam uma enteroblástula. Aproximadamente dois dias após a postura (estágio III), ocorre a formação da epiderme e do sistema digestivo embrionário, sendo que este último degenera no estágio seguinte. O estágio V (até o quarto dia após a postura) caracteriza-se pela formação da epiderme definitiva. Entre o quarto e o sexto dia posteriores à postura, começa a organogênese dos órgãos internos definitivos (estágio VI). Aproximadamente catorze dias após a postura (estágio IX), completa-se a formação do sistema nervoso. Neste estágio, o embrião já apresenta características similares aos espécimes juvenis. A eclosão de Girardia tigrina ocorre entre doze e vinte e dois dias após a postura dos casulos.