Morphological description of the aorta-gonad-mesonéfrica region of bovine embryos of 24-40 days gestation and analysis of cell proliferation and expression of markers

Abstract

For a long time the yolk sac was characterized as the main source of hematopoietic stem cells (HSC), since it was the first place to be seen this type of activity. However, more recent evidence suggests that repopulation of CTH is autonomically generated in a region in the embryonic mesoderm, known as the aorta-gonad-mesonephric region (AGM). AGM region is located near the urogenital system training, generating the development of the gonads, the cortex of the adrenal gland and metanephros. This information reinforces the hypothesis that the endothelium of the AGM region operates in support of renewal and differentiation of CTH. Considering the lack of data on the formation and development of the AGM region in cattle, this project aims to characterize macro and microscopically this region in bovine embryos from natural mating with gestational ages 24-40 days (critical phase for pregnancy loss in bovine). Moreover, it will be verified expression of markers involved in cell proliferation and cell growth and pluripotency in AGM samples analyzed at different ages. Thus our results can significantly contribute to the understanding of organogenesis this important species for the Brazilian economy, and will identify cell niches in proliferation and pluripotency characteristics, which in a second step may be collected and cultured in vitro to obtain different strains of stem cells. (AU)