Development and morphology of the inverted yolk sac in the guinea pig (Cavia porcellus)

Autor(es)

Vasconcelos, Bruno Gomes ^[1] ; Favaron, Phelipe Oliveira ^[1] ; Miglino, Maria Angelica ^[1] ; Mess, Andrea Maria ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sch Vet Med & Anim Sci, Dept Surg, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Theriogenology; v. 80, n. 6, p. 636-641, OCT 1 2013.
• Citações Web of Science: 6

Resumo

Although the guinea pig is an important animal model for human placentation, aspects of fetal nutrition are not fully understood, especially in regard to the yolk sac that is regarded to be essential for early development of the embryo. We investigated differentiation by means of histology, histochemistry, immunohistochemistry, and transmission electron microscopy. Data suggest that the guinea pig's yolk sac was not sufficiently developed to facilitate substantial fetal nutrition in early pregnancy. On Day 12, it was a flat, inverted, but avascular structure. This was followed by differentiation to form the typical, highly villous and vascularized condition of advanced gestation. Finally, the yolk sac degenerated toward term. We suggest that the guinea pig and other caviomorphs rely predominantly on hemotrophic nutrition via the placenta even in very early pregnancy. In contrast to the general pattern of mammals, histiotrophic nutrition via yolk sac routes seems to be most essential during mid-gestation. (C) 2013 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 11/10714-5 - Plano de visita pesquisador exterior Andrea Maria Mess novembro 2011/novembro 2012
• Beneficiário: Maria Angelica Miglino
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisador Visitante - Internacional