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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Morphological aspects of yolk sac from rodents of Hystricomorpha subordem: paca (Agouti paca) and agouti (Dasyprocta aguti)

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Author(s):
Rogério Arcuri Conceição [1] ; Carlos Eduardo Ambrósio [2] ; Daniele S. Martins [3] ; Ana Flávia Carvalho [4] ; André Luis R. Franciolli [5] ; Marcia Rita F. Machado [6] ; Moacir F. Oliveira [7] ; Maria Angélica Miglino [8]
Total Authors: 8
Affiliation:
[1] Fundação de Ensino Octávio Bastos. Centro Universitário. Setor de Anatomia dos Animais Domésticos e Silvestres - Brasil
[2] Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Cirurgia - Brasil
[3] Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Cirurgia - Brasil
[4] Fundação de Ensino Octávio Bastos. Centro Universitário. Setor de Anatomia dos Animais Domésticos e Silvestres - Brasil
[5] Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Cirurgia - Brasil
[6] Unesp-Jaboticabal. Departamento de Morfologia e Fisiologia Animal - Brasil
[7] Universidade Federal Rural do Semi-Árido. Departamento de Ciências Animais - Brasil
[8] Universidade de São Paulo. Faculdade de Medicina Veterinária e Zootecnia. Departamento de Cirurgia - Brasil
Total Affiliations: 8
Document type: Journal article
Source: Pesquisa Veterinária Brasileira; v. 28, n. 5, p. 253-259, 2008-05-00.
Abstract

The study aimed to characterize gross and microscopic features of the yolk sac in paca (Agouti paca) and agouti (Dasyprocta aguti) in early gestation. Fragments of the yolk sac of 3 paca and 3 agouti fetuses at early gestation were taken and processed for histological and ultrastructural analyses. Gross features of the vitelline placenta in both species showed its insertion over the main placenta surface and projections to the embryos/fetuses. Microscopically, the vitelline placenta was constituted by endoderm epithelium and mesenchyme, in which vitelline vessels are abundant. The ultrastructure of the samples showed that the visceral yolk sac of the paca was formed by endodermic cells with nuclei in the median region, and that the visceral yolk sac of the agouti was formed by nuclei arranged apically; other characteristic was the large number of mitochondrias, eletrodense vesicles with microvilosities We conclude that (1) the vitelline placenta of the two species presents insertion in the surface of the main placenta; (2) the vitelline placenta of paca rests on the Reichert's membrane, whereas the agouti vitelline placenta does not have this membrane; (3) the chorion and allantoic are fusioned; and (4) the chorioallantoic placenta and the yolk sac in both species are reversed and vascularized. (AU)