MORPHOLOGICAL ANALYSIS OF THE EXTRA-EMBRYONIC MEMBRANES OF DOMESTIC PIG (Sus scrofa) AT 20 DAYS OF GESTATION
BERTASSOLI BRUNO MACHADO *
Department of Morphology, Biological Sciences Institute of the Federal University of Minas Gerais, (Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais - ICB/UFMG), Brazil.
SANTOS AMILTON CÉSAR
Department of Surgery, College of Veterinary Medicine and Animal Science (Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo– FMVZ/USP), Brazil.
FRATINI PAULA
Department of Surgery, College of Veterinary Medicine and Animal Science (Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo– FMVZ/USP), Brazil.
WILL SONIA ELISABETE ALVES DE LIMA
Department of Surgery, College of Veterinary Medicine and Animal Science (Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo– FMVZ/USP), Brazil.
ASSIS NETO ANTÔNIO CHAVES
Department of Surgery, College of Veterinary Medicine and Animal Science (Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo– FMVZ/USP), Brazil.
*Author to whom correspondence should be addressed.
Abstract
The first 4 weeks period of gestation is the most critical for nutrition, development, uterine spacing and implantation of the embryos to the uterus and the majority of prenatal losses occurs in pigs during this period. The aim of the present study was to describe the pig embryo (n=20) and its extra-embryonic membranes (amnion, chorion, allantois and yolk sac) at both macroscopic and microscopic level and determine those cells with endodermal origins. The pig fetal membranes were very similar to those of other domestic mammals. The allantois membrane was responsible for vascularizing the chorion. The yolk sac produced the first blood cells in the conceptus. The epithelial cells of the yolk sac, amnion and chorion originated from the endoderm.
Keywords: Allantois, amnion, chorion, morphology, yolk sac, pig