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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Mechanisms of inhibition in the avian cochlear nucleus /

Howard, MacKenzie A. January 2008 (has links)
Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 105-114).
32

Efeitos da somatotropina recombinante bovina na taxa de concepção, composição celular do corpo lúteo e morfometria das glândulas endometriais em vacas de corte /

Costa, Natália Paulozzi. January 2014 (has links)
Orientador:Flávia Lombardi Costa / Co-orientador:Cláudia Maria Bertan Membrive / Banca:Caliê Castilho / Banca:Ricardo da Fonseca / Resumo:Fêmeas bovinas leiteiras tratadas com somatotropina recombinante bovina (bST) apresentam maior taxa de concepção. Verificou-se que componentes maternais e embrionários são positivamente afetados pela bST favorecendo a concepção. Entretanto, poucas investigações foram realizadas em fêmeas de corte. Hipotetizou-se que vacas de corte tratadas com bST, no dia da inseminação artificial em tempo fixo (IATF) ou sete dias após a IATF, apresentam maiores taxas de concepção e que a morfometria das glândulas endometriais e a proporção de células esteroidogênicas luteais são alteradas por tal tratamento. No presente estudo objetivou-se avaliar o efeito da aplicação de bST, na dose de 250 ou 500mg, no dia da IATF, na taxa de concepção aos 30 dias de gestação (Experimento 1); verificar os efeitos da aplicação de 500mg de bST, sete dias após a IATF, na taxa de concepção aos 30 dias de gestação (Experimento 2) e averiguar os efeitos da bST na proporção de células esteroidogênicas luteais e na morfometria das glândulas endometriais (Experimento 3). No Experimento 1, vacas Nelore (n=587) receberam um dispositivo intravaginal contendo progesterona (1g; DIB®) associado a uma injeção intramuscular (IM) de benzoato de estradiol (2mg; Gonadiol®). Os dispositivos foram removidos oito dias após, quando as vacas foram tratadas com D-cloprostenol (0,530μg; Ciosin®) e gonadotrofina coriônica equina (300UI; Novormon®) e 24 horas após receberam benzoato de estradiol (1mg; Gonadiol®), via IM. Após 30 horas da última injeção (D0) as fêmeas foram submetidas à IATF e receberam 5ml de solução salina (Grupo Controle; n= 194) ou bST (Boostin) na dose de 250mg (Grupo bST 250; n=197) ou 500mg (Grupo bST 500; n=196), via subcutânea (SC). O diagnóstico de gestação foi realizado 30 dias após a IATF por ultrassonografia. No Experimento 2, vacas Nelore (n=243) receberam o... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract:cows treated with recombinant bovine somatotropin (bST) have higher conception rate. It was found that maternal and embryonic components are positively affected by the design favoring bST. However, few investigations have been done on beef cows. It was hypothesized that beef cows treated with bST, the day timed AI (TAI) or seven days after TAI, have higher conception rates and the morphology of the endometrial glands and the proportion of steroidogenic luteal cells are altered by such treatment. The present study aimed to evaluate the effect of bST at a dose of 250 or 500mg, the day of TAI, the conception rate at 30 days of gestation (Experiment 1); verify the effects of application of 500mg of bST, seven days after TAI, the conception rate at 30 days of gestation (Experiment 2) and investigate the effects of bST in the proportion of steroidogenic luteal cells and morphometry of the endometrial glands (Experiment 3). In Experiment 1, Nelore cows (n=587) received an intravaginal device containing progesterone (1g; DIB®) associated with an intramuscular (IM) injection of estradiol benzoate (2mg; Gonadiol®). The devices were removed after eight days, when cows were treated with D-cloprostenol (0.530 mg; Ciosin®) and equine chorionic gonadotropin (300UI; Novormon®) and after 24 hours received estradiol benzoate (1 mg; Gonadiol®), via IM. After 30 hours of the last injection (D0) females were inseminated and received 5ml of saline (Control Group; n=194) or somatotropin (Boostin®) at a dose of 250mg (Group bST 250; n=197) or 500mg (Group bST 500; n=196), subcutaneously (SC). Pregnancy diagnosis was performed 30 days after TAI by ultrasonography. In Experiment 2, Nelore cows (n=243) received the Experimento1 similar protocol and were inseminated on D0. In D7 received 5ml of saline (Control Group; n=124) or somatotropin (Boostin®) at a dose of 500mg (Group bST 500; n =119) subcutaneously...(Complete abastract click eletrononic acess below) / Mestre
33

Utilising embryonic and extra-embryonic stem cells to model early mammalian embryogenesis in vitro

Harrison, Sarah Ellys January 2018 (has links)
Successful mammalian development to term requires that embryonic and extra-embryonic tissues communicate and grow in coordination, to form the body. After implanting into the uterus, the mouse embryo is comprised of three cell lineages: first, the embryonic epiblast (EPI) that forms the embryo proper, second, the extra-embryonic ectoderm (ExE) which contributes to the foetal portion of the placenta, and third, the visceral endoderm (VE) that contributes to the yolk sac. These three tissues form a characteristic ‘egg-cylinder’ structure, which allows signals to be exchanged between them and sets the stage for body axis establishment and subsequent tissue patterning. The mechanisms underlying this process are difficult to study in vivo because a different genetically manipulated mouse line must be generated to investigate each factor involved. This difficulty has prompted efforts to model mammalian embryogenesis in vitro, using cell lines, which are more amenable to genetic manipulation. The pluripotent state of the EPI can be captured in vitro as mammalian embryonic stem cells (ESCs). Although mouse ESCs have been shown to contribute to all adult tissues in chimeric embryos, they cannot undertake embryogenesis when allowed to differentiate in culture. Previous studies have shown that ESCs formed into three-dimensional (3D) aggregates, called embryoid bodies, can become patterned and express genes associated with early tissue differentiation. However, embryoid bodies cannot recapitulate embryonic architecture and therefore may not accurately reflect what happens in the embryo. In this study, a new technique was developed to model early mouse development which is more faithful to the embryo. ESCs were co-cultured with stem cells derived from the ExE, termed trophoblast stem cells (TSCs), embedded within extracellular matrix (ECM). These culture conditions lead to the self-assembly of embryo-like structures with similar architecture to the mouse egg cylinder. They were comprised of an embryonic compartment derived from ESCs abutting an extra-embryonic compartment derived from TSCs, and hence were named ‘ETS-embryos’. These structures developed a continuous cavity at their centre, which formed via a similar sequence of events to those that lead to pro-amniotic cavity formation in the mouse embryo, and required active Nodal/Activin signalling. After cavitation, ‘ETS-embryos’ developed regionalised mesodermal tissue and primordial germ cell-like cells originating at the boundary between embryonic and extra-embryonic compartments. Inhibitor studies revealed that this occurred in response to endogenous Wnt and BMP signalling, pathways which also govern these tissue specification events in the early mouse embryo. To demonstrate that ‘ETS-embryos’ were comparable to mouse embryos at the global transcriptional level, RNA-sequencing was then performed on different tissue regions of ‘ETS-embryos’ and the resulting transcriptomes were compared to datasets from mouse embryos. These data showed that ‘ETS-embryos’ were highly similar to mouse embryos at post-implantation stages in their overall gene expression patterns. Taken together, these results indicate that ‘ETS-embryos’ are an accurate in vitro model of mammalian embryogenesis, which can be used to complement studies undertaken in vivo to investigate early development.
34

Efeitos da somatotropina recombinante bovina na taxa de concepção, composição celular do corpo lúteo e morfometria das glândulas endometriais em vacas de corte

Costa, Natália Paulozzi [UNESP] 21 August 2014 (has links) (PDF)
Made available in DSpace on 2015-10-06T13:02:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-21. Added 1 bitstream(s) on 2015-10-06T13:19:11Z : No. of bitstreams: 1 000849269.pdf: 1092196 bytes, checksum: 4d8dae3ac98fc445a758ca678690e98a (MD5) / cows treated with recombinant bovine somatotropin (bST) have higher conception rate. It was found that maternal and embryonic components are positively affected by the design favoring bST. However, few investigations have been done on beef cows. It was hypothesized that beef cows treated with bST, the day timed AI (TAI) or seven days after TAI, have higher conception rates and the morphology of the endometrial glands and the proportion of steroidogenic luteal cells are altered by such treatment. The present study aimed to evaluate the effect of bST at a dose of 250 or 500mg, the day of TAI, the conception rate at 30 days of gestation (Experiment 1); verify the effects of application of 500mg of bST, seven days after TAI, the conception rate at 30 days of gestation (Experiment 2) and investigate the effects of bST in the proportion of steroidogenic luteal cells and morphometry of the endometrial glands (Experiment 3). In Experiment 1, Nelore cows (n=587) received an intravaginal device containing progesterone (1g; DIB®) associated with an intramuscular (IM) injection of estradiol benzoate (2mg; Gonadiol®). The devices were removed after eight days, when cows were treated with D-cloprostenol (0.530 mg; Ciosin®) and equine chorionic gonadotropin (300UI; Novormon®) and after 24 hours received estradiol benzoate (1 mg; Gonadiol®), via IM. After 30 hours of the last injection (D0) females were inseminated and received 5ml of saline (Control Group; n=194) or somatotropin (Boostin®) at a dose of 250mg (Group bST 250; n=197) or 500mg (Group bST 500; n=196), subcutaneously (SC). Pregnancy diagnosis was performed 30 days after TAI by ultrasonography. In Experiment 2, Nelore cows (n=243) received the Experimento1 similar protocol and were inseminated on D0. In D7 received 5ml of saline (Control Group; n=124) or somatotropin (Boostin®) at a dose of 500mg (Group bST 500; n =119) subcutaneously...(Complete abastract click eletrononic acess below)
35

Efeitos do agente modificador epigenético (Tricostatina A) no desenvolvimento embrionário pré-implantacional de embriões fêmeas de bovinos /

Silva, Bruna Mazeti. January 2011 (has links)
Resumo: A acetilação das histonas é um dos principais mecanismos de reprogramação epigenética do genoma dos gametas a fim de estabelecer um estado totipotente para o desenvolvimento normal. O objetivo deste trabalho foi avaliar o efeito da utilização da Tricostatina A (TSA) sobre os níveis de acetilação das histonas e o desenvolvimento embrionário, avaliando-se a contagem do número de células da massa celular interna (MCI), trofectoderma (TE), e células totais, e os níveis da reação de imunocitoquímica para H3K9ac. Para isso, três experimentos foram delineados. No primeiro experimento, verificou-se que o grupo tratado com 5nM de TSA por 144h durante o cultivo in vitro (CIV) aumentou (p<0,01) o nível de H3K9ac em relação ao grupo controle. A taxa de clivagem e o desenvolvimento embrionário foram avaliados em um segundo experimento, e o grupo tratado com 5nM de TSA não apresentou diferença na produção de embriões comparado ao grupo controle. No experimento 3, o tratamento com a TSA não apresentou efeitos significativos em relação ao número de células da MCI, porém houve redução (p<0,01) tanto do número de células da TE quanto de células totais comparado ao grupo controle. Portanto, conclui-se que o tratamento com TSA não altera o desenvolvimento embrionário pré-implantacional de embriões fêmeas de bovinos, mostrando efeito negativo sobre o desenvolvimento dos embriões tratados / Abstract: Histone acetylation is one of the major mechanisms of epigenetic reprogramming of gamete genome to establish a totipotent state for normal development. The aim of this work was to evaluate the use of Trichostatin A (TSA) on the levels of histone acetylation and embryonic development, the assessment of counting the cell number of inner cell mass (ICM), trophectoderm (TE), and total cells, and the levels of H3K9ac for immunocytochemical reaction. Therefore, three experiments were designed. In the first experiment, it was verified that the group treated with TSA for 5nM for 144h during in vitro culture (IVC) increased (p <0.01) the level of H3K9ac in the control group. Cleavage rate and embryo development were evaluated in a second experiment, and the group treated with 5nM TSA showed no difference in embryo production compared to control. In Experiment 3, treatment with TSA had no significant effect on the cell number of ICM, but decreased (p <0.01) both the cell number of TE and total cells as compared to control. Therefore, it is concluded that treatment with TSA does not alter the preimplantation embryonic development female bovine embryos, showing a negative effect on the development of embryos treated / Orientador: Jeffrey Frederico Lui / Coorientador: Joaquim Mansano Garcia / Banca: Gilson Hélio Toniollo / Banca: Sandro Henrique Antunes Ribeiro / Mestre
36

Porovnání embryonálního vývoje původních a nepůvodních druhů raků / Comparison of embryonic Development of Native and Non-native Crayfish

KOUBA, Antonín January 2007 (has links)
The embryonic and early postembryonic development of all crayfish occurring open water of the Czech Republic were studied under controlled conditions.
37

Estudo da expressão imunoistoquimica de SPLUNC1, SPLUNC2 e LPLUNC1 nas glandulas salivares, lingua e palato de fetos humanos / Immunohistochemical expression study of SPLUNC1, SPLUNC2 and LPLUNC1 in salivary glands, tongue and palate of human fetus

Alves, Daniel Berretta Moreira, 1982- 15 August 2018 (has links)
Orientador: Pablo Agustin Vargas / Dissertação (mestrado) - Universidade Estadual de Campinas. Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T12:35:10Z (GMT). No. of bitstreams: 1 Alves_DanielBerrettaMoreira_M.pdf: 2353528 bytes, checksum: c4fc62eb44bbd4f300dbdb9d7dc74cd6 (MD5) Previous issue date: 2010 / Resumo: INTRODUÇÃO: As proteínas da família PLUNC ("palate, lung and nasalepithelium clone"), as quais são expressas no trato aéreo superior e na cavidade bucal humana, podem ser responsáveis por mediar a resposta imune inata e interagir com a superfície bacteriana. Entretanto, sabe-se muito pouco sobre a expressão destas proteínas nas glândulas salivares durante o período embrionário humano. OBJETIVO: O objetivo do presente estudo foi analisar a expressão imunoistoquímica de SPLUNC1, SPLUNC2 e LPLUNC1 em glândulas salivares maiores e menores, língua e palato de fetos humanos. MATERIAIS e MÉTODOS: A amostra do presente estudo foi composta por 26 fetos humanos com idade variando entre 12 e 25 semanas de vida intra-uterina. As glândulas parótidas (n=7), submandibulares (n=13) e sublinguais (n=5) e as glândulas salivares menores [lábio (n=18), palato (n=9) e língua (n=6)] foram classificadas de acordo com os estágios de morfodiferenciação. A marcação imunoistoquímica citoplasmática das glândulas salivares, epitélio respiratório palatino e epitélio lingual, foi avaliada como positiva ou negativa. RESULTADOS: Dentre os 26 fetos avaliados, 13 (50%) apresentaram positividade para SPLUNC1 nos plugues de mucina dos ductos estriados e no citoplasma dos ácinos mucosos. Os dois casos positivos para LPLUNC1 apresentaram expressão citoplasmática na porção apical das células do ducto estriado primitivo. Nenhum dos casos apresentou marcação positiva para os anticorpos SPLUNC2A e SPLUNC2B. Os estágios de morfodiferenciação avançados (estágio canalicular e broto terminal) prevaleceram entre os fetos que apresentaram positividade para SPLUNC1. Tecidos que estavam adjacentes as glândulas salivares avaliadas, como células do epitélio respiratório associado à região do palato (n=6) e curiosamente, do epitélio escamoso de superfície da língua associado às glândulas salivares menores da região lingual (n=3), também apresentaram marcação positiva para SPLUNC1. Os resultados do presente estudo sugerem que a expressão de SPLUNC2 em glândulas salivares inicia na vida pós-natal. A expressão da proteína LPLUNC1 nas células ductais durante a vida intra-uterina precisa ser melhor estudada, visto que apenas dois casos foram positivos para esta proteína. CONCLUSÕES: A proteína SPLUNC1 inicia sua expressão durante a vida intra-uterina, nas glândulas salivares em estágio de morfodiferenciação avançado (estágio canalicular e broto terminal). Estudos com métodos mais sensíveis devem ser realizados para avaliar e quantificar a expressão de SPLUNC1 e LPLUNC1 em glândulas salivares maiores e menores de fetos humanos, visando entender melhor a função destas proteínas na vida intra-uterina. / Abstract: OBJECTIVES: The expression of PLUNC proteins in human fetal tissue has not been previously studied. The aim of this study, therefore, was to determine expression in major and minor salivary glands, tongue and palate throughout fetal development and thus gain further insight into the function of these proteins. MATERIALS AND METHODS: 26 human fetuses (12 to 25 intra-uterine weeks) were collected retrospectively. Parotid (n=7), submandibular (n=13), sublingual (n=5) and minor salivary glands [lips (n=18)], palate (n=9) and tongue (n=6)] were classified according to their morphodifferentiation stage. Immunohistochemical analysis of three PLUNC proteins (SPLUNC1, SPLUNC2 and LPLUNC1) was performed and immunoreactivity was assessed as positive or negative. RESULTS: Mucin plugs in striated ducts and mucous cells of submandibular (n=4, 30.77%), sublingual (n=4, 80%) and minor salivary glands (n=9, 27.27%) were positive for SPLUNC1. The apical portion of primitive striated duct cells of submandibular and sublingual salivary glands was positive for LPLUNC1 (n=2). SPLUNC1 was detected in late morphodiferentiation stages (canalicular stage and terminal bud stage) of salivary glands. Tissues adjacent to the minor salivary glands, such as respiratory epithelial cells located in the palate (n=6) and squamous epithelial cells of the tongue surface (n=3), were also positive for SPLUNC1. All cases (n=26) were negative for SPLUNC2. CONCLUSIONS: Our results suggest that SPLUNC2, the major PLUNC protein in adult salivary glands, is either expressed very late in fetal development or only in adult tissues. Only 2 cases of LPLUNC1 protein in fetal duct cells were positive; further studies are needed to confirm expression. Salivary glands expressed SPLUNC 1 only in late morphodifferentiation stages (canalicular and terminal bud stages). Further studies using other sensitive methods, such as in situ hybridization, should be performed to assess and quantify the expression of SPLUNC 1 and LPLUNC1 in major and minor salivary glands, tongue and palate in order to better understand their function in intra-uterine life. / Mestrado / Estomatologia / Mestre em Estomatopatologia
38

AÃÃo farmacolÃgica das vitaminas A & E na produÃÃo de oÃcitos e embriÃes bovinos. / Pharmacological action of vitamins A & E in the production of bovine oocytes and embryos.

JoÃo Josà Ferreira Evangelista 07 January 2010 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Na produÃÃo in vitro (PIV) de embriÃes bovinos vÃrios fatores contribuem para as variÃveis na produÃÃo e qualidade dos oÃcitos e embriÃes. Avaliou-se o uso parenteral de vitamina A (VA) e vitamina E (VE) na produÃÃo de oÃcitos colhidos por aspiraÃÃo folicular (OPU) e embriÃes por produÃÃo in vitro (PIV) em de vacas (n=22), sendo: Simental (S) (n=2); Nelore (N) (n=4); Brahma (B) (n=5) e Gir (G) (n=11). Todos os animais foram alocados na fase prÃ-tratamento (F1) (n=22) (nÃo receberam vitaminas) e os mesmos animais utilizados para a fase pÃs-tratamento (F2) (receberam 1.000.000 UI de vitamina A e 1g de vitamina E). A primeira OPU foi na F1, logo em seguida foi aplicado 1.000.000 UI de VA e 1g de VE, e apÃs 12 dias realizou-se nova OPU para fazer a F2. Os oÃcitos (CCO) foram maturados, fecundados e cultivados in vitro. As 44 OPU produziram 520 oÃcitos, 217 (F1) e 303 (F2), havendo efeito significativo, com acrÃscimo de 86 oÃcitos, obtendo mÃdia e desvio padrÃo 9,86Â5,53 F1 e 13,77Â2,0 F2, (*p<0,0219). Quando separada as raÃas NBG (Nelore, Brahma e Gir) (n=20) houve acrÃscimo de 95 oÃcitos, obtendo mÃdia e desvio padrÃo 9,90Â5,81 F1-NBG e 14,65Â9,44 F2-NBG, (*p<0,0085). As 44 PIV produziram 224 embriÃes, sendo 93 F1 e 131 F2, obtendo mÃdia e desvio padrÃo 4,23Â3,09 F1 e 5,95Â4,05 F2, (*p<0,0228). Quando separada as NBG a produÃÃo foi de 214 embriÃes, havendo acrÃscimo de 38 embriÃes, obtendo valores de 4,45Â3,15 F1 e 6,25Â4,09 F2, (*p<0,0285). Houve um efeito significativo na quantidade produzida de oÃcitos (n=22) e oÃcitos NBG (n=20). Houve efeito na produÃÃo de embriÃes de todas as raÃas (n=22) e embriÃes NBG (n=20). A suplementaÃÃo com VA e VE aumentou o nÃmero de oÃcitos totais (1,7Â0,7); oÃcitos NBG (1,8Â0,8); embriÃes totais (3,9Â1,6) e embriÃes NBG (4,7Â1,6). A resposta da F2 comparado com a F1 na produÃÃo de oÃcitos e embriÃes foi significativa quando todas as raÃas estavam agrupadas e tambÃm quando foi agrupado apenas as Bos taurus indicus (NBG). O uso das vitaminas A e E pode ser usada para maior recuperaÃÃo oÃcitÃria e embrionÃria em raÃas ZebuÃnas. / The in vitro (IVP) bovine embryos production has several factors that contribute to the variables in the production and quality of oocytes and embryos. We evaluated the parenteral use of vitamin A (VA) and vitamin E (VE) in the production of oocytes collected by follicular aspiration (OPU) and embryos by in vitro production (IVP) in cows (n = 22), where: Simmental (S) (n = 2), Nelore (N) (n = 4), Brahma (B) (n = 5) and Gir (G) (n = 11). All animals were allocated in the pre-treatment (F1) (n = 22) (not receiving vitamins) and the same animals used for post-treatment (F2) (received 1,000,000 IU of vitamin A and vitamin 1g E). The first OPU was in F1, soon after 1,000,000 IU was administered 1 g of VE and VA, and after 12 days was held to make the new OPU F2. Oocytes (COC) were matured, fertilized and cultured in vitro. The OPU 44 yielded 520 oocytes, 217 (F1) and 303 (F2), with significant effect, an increase of 86 oocytes, obtaining mean and standard deviation 9.86 Â 5.53 13.77 Â 2.0 F1 and F2, (*p <0.0219). When separate races NBG (Nelore, Brahman and Gir) (n = 20) there was an increase of 95 oocytes, obtaining mean and standard deviation 9.90 Â 5.81 and 14.65 NBG F1-F2-NBG Â 9.44, (*p <0.0085). The 44 IVP embryos produced 224, 93 F1 and 131 F2, getting mean and standard deviation 4.23 Â 3.09 5.95 Â 4.05 F1 and F2, (*p <0.0228). When separated from the NBG production was 214 embryos, with an increase of 38 embryos, obtaining values of 4.45 Â 3.15 6.25 Â 4.09 F1 and F2, (*p <0.0285). There was a significant effect on the quantity produced of oocytes (n = 22) and NBG oocytes (n = 20). It was an increased in all breeds embryos production (n = 22) and NBG embryos (n = 20). Supplementation with VE and VA increased the total number of oocytes (1.7 Â 0.7); NBG oocytes (1.8 Â 0.8); total embryos (3.9 Â 1.6) and embryos NBG (4 7 Â 1.6). The response of the F2 compared to F1 in the production of oocytes and embryos was significant when all races were grouped together and also when it was grouped only Bos taurus indicus (NBG). The use of vitamins A and E can be used to greater oocyte recovery and embryo in Zebu breeds.
39

Desenvolvimento embrionário em Gonyleptidae (Arachnida: Opiliones: Laniatores): um estudo comparativo / Embryonic development in Gonyleptidae (Arachnida: Opiliones: Laniatores): a comparative study

Cristiano Frederico Lerche 15 September 2009 (has links)
Os primeiros trabalhos em desenvolvimento embrionário de opiliões tiveram início no final do século XIX, enfocando principalmente espécies holárticas, e desde o final da década de 1970 o assunto não foi mais abordado. Visando retomar este tema com um componente comparativo, o presente estudo objetivou a descrição do desenvolvimento embrionário de quatro subfamílias de Gonyleptidae (Opiliones Laniatores), a saber: Caelopyginae (Ampheres leucopheus), Goniosomatinae (Goniosoma proximum e Goniosoma spelaeum), Mitobatinae (Longiperna zonata e Promitobates ornatus) e Progonyleptoidellinae (Iporangaia pustulosa). Dados adicionais obtidos para outras espécies foram incluídos com fins comparativos. O desenvolvimento dos embriões foi acompanhado através de fotografias digitais diárias de ovos em diversas desovas de cada espécie. Ovos de ambas as espécies de Goniosomatinae (que apresentam cuidado materno das desovas) são depositados com aproximadamente 1,5 1,6 mm, atingindo 2,1 mm em G. proximum e 2,3 mm in G. spelaeum próximos à eclosão, ao passo que em A. leucopheus e I. pustulosa (que apresentam cuidado paterno) apresentam 1,13 mm e 1,30 mm logo após a deposição, e 1,35 mm e 1,59 mm próximos à eclosão, respectivamente. Foram observadas e descritas diferenças entre as espécies estudadas pelo presente, tanto na coloração do vitelo e transparência do córion como em características morfológicas e na seqüência de eventos, em especial no padrão de pigmentação. A duração do período embrionário foi de 29-56 dias em A. leucopheus, 35-66 dias em I. pustulosa, 3148 dias em G. proximum, 2954 dias em G. spelaeum, 43-64 dias em L. zonata e 35-55 dias in P. ornatus. Dentre as espécies estudadas a duração relativa de cada fase variou bastante, com a clivagem correspondendo a 3-4% do período embrionário, a formação da banda germinativa a 9-14%, a metamerização do prossoma a 3-13%, a inversão do embrião a 21-38%, a organogênese larval a 22-42% e a fase larval no ovo a 7-28%. / The first studies concerning the embryonic development of harvestmen started in the late XIX century, mostly concerning holarctic species, and the last studies appeared during the late 1970s. Aiming at filling a gap of more than 30 years in the study of embryology of harvestmen, and adding a comparative component, this study focused on the embryonic development of species of four subfamilies of Gonyleptidae harvestmen (Laniatores), namely Caelopyginae (Ampheres leucopheus), Goniosomatinae (Goniosoma proximum and Goniosoma spelaeum), Mitobatinae (Longiperna zonata and Promitobates ornatus) and Progonyleptoidellinae (Iporangaia pustulosa). Additional data acquired for other species is also included for comparison purposes. The embryonic development was followed in the field, by taking daily photographs of different eggs from a number of egg batches during about two months. Eggs of both species of the subfamily Goniosomatinae (which present maternal care of batches) are laid with ca. 1.5 1.6 mm in diameter, reaching ca. 2.1 mm in G. proximum and 2.3 mm in G. spelaeum near hatching, whereas recently laid eggs of A. leucopheus and of I. pustulosa (which present paternal care) have approximately 1.13 mm and 1.30 mm in diameter, respectively, reaching diameters of about 1.35 mm and 1.59 mm, respectively, close to hatching. Differences concerning yolk coloration and eggshell transparency were observed and are described for the presently studied species, as well as differing morphological features and sequence of events, particularly in reference to the pigmentation pattern. The duration of the embryonic phase was 29-56 days in A. leucopheus, 35-66 days in I. pustulosa, 3148 days in G. proximum, 29-54 days in G. spelaeum, 43-64 days in L. zonata and 35-55 days in P. ornatus. Amongst the species studied herein relative durations are quite variable, with cleavage corresponding to 3-4% of the embryonic development, germ band formation to 9-14%, prosoma metamerization to 3-13%, the inversion of the embryo to 21-38%, larval organogenesis to 22-42% and the larval phase in the egg to 7-28%.
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Excreção de nitrogênio em embriões de iguana Iguana iguana (Reptilia; Squamata) / Nitrogen excretion in the green iguana (Iguana iguana) embryos (Reptilia; Squamata)

Marina Rincon Sartori 18 May 2012 (has links)
Tabelas de estágio embrionário podem ser utilizadas para detectar semelhanças e diferenças de caracteres entre grupos e como ferramenta para estudos baseados na fase embrionária. Neste estudo, ovos do lagarto Iguana iguana foram utilizados para a elaboração de uma tabela de estágios e para determinar o padrão de excreção durante o desenvolvimento. Iguana é um modelo conveniente por produzir numerosas desovas de ovos de tamanho grandes, propiciando um fácil manuseio e um bom número de réplicas. Após a oviposição, 18 estágios embrionários foram determinados durante os quais uréia foi o resíduo nitrogenado principal. Apesar do iguana ser o primeiro lagarto estudado, o padrão ureotélico é comum entre a maioria das espécies reptilianas estudadas até o momento. A casca pergaminácea permite que os ovos dobrem em massa devido à absorção de água, e o mecanismo pelo qual os embriões lidam com a diluição e osmolaridade resultante é um tema interessante para futuros trabalhos e comparações com espécies de cascas rígidas. Há evidência de desenvolvimento heterocrônico dos membros e o desenvolvimento de iguana é similar ao do lagarto Anolis sagrei, também do clado Iguania. Mais estudos de desenvolvimento de lagartos são necessários e a utilização de critérios morfológicos similares para facilitar a comparação de eventos embrionários. / A Table of embryonic stages can be used to detect similarities and differences in developmental features between groups and as a tool for studies based on embryonic phase. In this study, eggs of the lizard Iguana iguana were used to elaborate a staging table and to determine the nitrogen excretion pattern during the development. Iguana is a convenient model for having a large clutch of large eggs, allowing an easy handling and a good number of replicates. After oviposition embryonic stages were determined during which urea was the main nitrogen waste. Although iguana is the first lizard studied, the ureotelic pattern is common among the majority of reptilian species so far studied The pergaminaceous shell allows that the eggs double in mass due to water absorption, and the mechanism and how the egg deals with dilution and resultant osmolarity is an interesting issue for future works and comparisons with species of rigid eggshells. There is evidence of heterocronic development of the limbs and the development of iguana is similar to the lizard Anolis sagrei, also from the clade Iguania. Further studies on lizard evelopment are required and the use of similar morphological approach to facilitate comparisons of embryonic events

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