Assisted reproduction techniques have improved agricultural breeding in the bovine. However, important development steps may differ from the situation in vivo and there is a high mortality rate during the first trimester of gestation. To better understand these events, we investigated the development of embryos and fetal membranes following fixed-time AI (FTAI), IVF and nuclear transfer (NT). The onset of yolk-sac development was not normal in cloned embryos. Later steps differed from conditions in vivo in all three groups; the yolk-sac was yellowish and juxtaposed with the amniotic membrane. Vascularisation of the chorioallantoic membrane was relatively late and low in NT gestations, but normal in the others. The overall development of the embryos was normal, as indicated by morphology and regression analysis of growth rate. However, NT conceptuses were significantly smaller, with the livers in some embryos occupying the abdominal cavity and others exhibiting heart abnormalities. In conclusion, the yolk-sac and the cardiovascular system seem to be vulnerable to morphogenetic alterations. Future studies will focus on gene expression and early vascularisation processes to investigate whether these changes may be responsible for the high incidence of intrauterine mortality, especially in clones.

Although assisted reproductive techniques are commonly applied in humans and animals, they are frequently associated with major developmental deficits and reduced viability. To explore abnormalities associated with cloning or nuclear transfer (NT) as the most invasive of these methods, we used a bovine model to characterize abnormalities. Detailed necropsy examinations were done on 13 calves that died soon after birth; in addition, we included data from embryos and fetuses (produced by NT) that terminated prematurely. Bovine clones that survived until the neonatal period differed quantitatively and qualitatively from in-vivo-derived cattle. Although alterations affected a variety of organs (e.g. heart, lung and liver), there was a clear association with abberant vascular developmental during the early intrauterine phase. Therefore, we concluded that vascular problems were key alterations induced by cloning (presumably via epigenetic modifications).

IMorfologia e desenvolvimento ultraestrutural do sistema renal de embriões bovinos com idade gestacional entre 10 e 50 diasMorphology and ultrastructural development of renal system in bovine embryos with gestational age between 10 and 50 days

A convivência vinda através da embriologia me trouxe a alegria de conhecêlo, foi plantada então uma semente, a AMIZADE, e o tempo jamais irá conseguir cobri-la! Como sempre disse... Meu Anjo de Candura... Foi Aristóteles... quando me ensinou que devemos ver as coisas crescerem desde o início, assim teremos melhor visão delas; Foi Pai... quando teve paciência para ouvir minhas palavras de desespero e acalmar, fazendo com que em minutos eu pudesse enxergar o outro lado do problema, a solução; Foi Orientador... sanou sempre da melhor forma todas minha dúvidas, sem nunca reclamar, levantar a voz ou fazer cara feia; Foi Professor... me ensinou a aprender, e todo seu conhecimento foi transferido de forma a me fazer entender o conteúdo, instigando sempre a querer saber mais;

ResumoEstudou-se a morfologia da traquéia de gansos domésticos, caracterizando seus aspectos macroscópicos e morfométricos. Para tanto, foram utilizados 31 gansos domésticos adultos, machos e fêmeas, oriundos de criadouros comerciais, os quais foram eutanasiados por meio de inalação de clorofórmio, seguindo-se fi xação em solução aquosa de formol a 10%. A traquéia foi dissecada desde seu início, caudalmente à laringe, até sua bifurcação já na cavidade celomática. Os resultados mostraram que a traquéia dos gansos é composta por 144r12 anéis cartilagíneos completos, e em média possui 33r2,7 cm de comprimento. A luz da traquéia apresenta-se ovalada, com um ligeiro achatamento dorso-ventral, tornando-se cilíndrica caudalmente a partir do seu terço médio. Os valores morfométricos obtidos para machos e fêmeas adultos não mostraram diferenças estatísticas signifi cativas (p<0,05), sugerindo que não há dimorfi smo sexual evidente para as características analisadas. Unitermos: traquéia, gansos, sistema respiratório AbstractMorphologic and morphometric aspects of the domestic geese trachea. The tracheal morphology of 31 domestic geese was studied in order to characterize the morphometric and macroscopic aspects. Domestic geese, adult, male and female, from regular breeders, were utilized. The animals were euthanized by chloroform inhalation and fi xed in 10% formaldehyde in aqueous solution. The trachea was dissected, beginning caudal at Biotemas, 21 (2): 91-96, junho de 2008

Congenital malformations correspond to one of the main causes of embryonic loss during the gestational process. They result from interaction of several factors such as multifactor heredity, chromosomal and genetic alterations and environmental agents; however, unknown aetiology also can be present. In this article, we have used 10 embryos, from a frigorific area of Dracena, SP, Brazil, which were fixed in Bouin solution for a macro- and micro-scopic description. We could verify the presence of an encephalic tissue mass on the embryo's dorsal cranial area, resulting from the non-formation of part of the cranial cap and from the non-closing of cephalic neuropore and consequent neuroepithelial cells disorganization. In the abdominal area, the embryos did not show the complete fusion of the body lateral pleats during the abdominal wall formation, and the liver extruded into the amniotic cavity without involvement of the intestine.

RESUMOEstudou-se a ossificação endocontral de 18 embriões e 12 fetos de até três meses de gestação, os quais foram coletados de úteros gestantes em frigoríficos e abatedouros. Os úteros foram dissecados e, em seguida, realizou-se uma incisão dorsal até o cérvix para avaliações macroscópicas dos embriões e fetos. Para o estudo microscópico foram realizadas técnicas de inclusão, seguidas de marcação dos depósitos de cálcio e fósforo, responsável pela ossificação dos moldes de cartilagem. Foram identificados hipertrofia da cartilagem e morte dos condrócitos e aumento da área de depósito de cálcio e fósforo, por volta da 10 a semana gestacional (74 dias). Durante a 11 a semana de gestação (81 dias), os grupamentos de carbonato de cálcio e fósforo espalharam-se por todo o osso, sendo mais intenso na diáfise.

We studied the development of respiratory tract in bovine embryos by light microscopy and transmission electronic microscopy. This process was observed formation of laryngeal-tracheal tube in embryos that present crown-rump (CR) length of 9.0 mm (20/21 days of pregnancy) at around the fourth gestational week; the organ wall appears to be formed of epithelium comprising several cell layers and supported by mesenchyme. Within the lungs, the areas subjacent to epithelium present condensed mesenchyme, while more distal areas loose mesenchyme, in which blood vessels beginn to form, as the organ is in a pseudo-glandular phase. Ultra-structurally, the mesenchyme cells present irregular shapes, having a stellar or fusiform appearance and are united by desmosomes, where the cytoskeleton attaches to the cellular membrane, forming a connection. The bifurcation of trachea caudal portion in the main bronchia is simultaneous to the appearance of the tracheal bronchi, during the fifth gestational week.