| Texto completo | |
| Autor(es): |
de Oliveira, Moacir Franco
[1]
;
Favaron, Phelipe Oliveira
[2]
;
Ambrosio, Carlos Eduardo
[3]
;
Miglino, Maria Angelica
[2]
;
Mess, Andrea Maria
[2]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [1] Univ Fed Rural do Semiarido, Dept Anim Sci, Mossoro, RN - Brazil
[2] Univ Sao Paulo, Dept Surg, Fac Vet Med, BR-05508270 Sao Paulo - Brazil
[3] Univ Sao Paulo, Fac Anim Sci & Food Engn, BR-05508270 Sao Paulo - Brazil
Número total de Afiliações: 3
|
| Tipo de documento: | Artigo Científico |
| Fonte: | JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION; v. 318B, n. 1, p. 13-25, JAN 15 2012. |
| Citações Web of Science: | 16 |
| Resumo | |
The evolutionary history of Hystricognathi is associated with major transformations in their placental system. Data so far indicate that key characters are independent from size dimensions in medium to very large species. To better understand the situation in smaller species, we analyzed placental development in a spiny rat, Thrichomys laurentinus. Fourteen individuals ranging from early implantation to near term were investigated by histology, immunohistochemistry, proliferation activity and electron microscopy. Placentation in Thrichomys revealed major parallels to the guinea pig and other hystricognath rodents with respect to the early and invasive implantation, the process of trophoblast invasion, the internal organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta. In contrast to systematically related small-sized species, the placental regionalization in Thrichomys was characterized by a remarkable lobulated structure and associated growing processes. Reverse to former perspectives, these conditions represented ancient character states of hystricognaths. The subplacenta was temporarily supplied by both the maternal and fetal blood systems, a rare condition among hystricognaths. The extraplacental trophoblast originating from the subplacenta was partly proliferative in mid gestation. In conclusion, the presented results indicated that only minor variations occurred in small-sized hystricognath species, independent of their systematic interrelationships. Previous views were supported that placentation in hystricognaths followed an extraordinary stable pattern, although the group had distinct habitats in South America and Africa that were separated 30-40 million years ago. J. Exp. Zool. (Mol. Dev. Evol.) 318:13-25, 2012. (C) 2011 Wiley Periodicals, Inc. (AU) | |
| Processo FAPESP: | 07/51491-3 - Placentação em roedores da família Cricetidae-Sigmodontinae |
| Beneficiário: | Phelipe Oliveira Favaron |
| Modalidade de apoio: | Bolsas no Brasil - Mestrado |