Análise morfológica de embriões ovinos produzidos em laboratório a partir de oócitos aspirados de doadoras multíparas, primíparas e pré - púberes da raça Santa Inês

Abstract

This work aimed to analyze the morphology of embryos at seven days of development, produced in the laboratory from oocytes aspirated from three different classes of donors of the Santa Inês race (multiparous, primiparous and prepubertal). The analyzed embryos had a discoid shape and were delimited by the pellucid zone (ZP). In the morula and initial blastocyst stages, the ZP measured from 5 to 10 μm in thickness, revealing to be thinner in the expanded blastocyst phase. In general, the structure and ultrastructure of Santa Inês sheep embryos, originating from in vitro fertilization (IVF) and evaluated in this study, corroborate many of the observations by Colarco and Mclaren (1976), Ferrer et al. (1995) and Coccero et al. (2002). The most striking aspect was the intense uniform distribution of lipid inclusions in the cytoplasm of the blastomeres, both in the internal cell mass and in the trophoblastic cells, regardless of the origin of the oocyte, suggesting that the morphology seems to be conditioned mainly to the culture system employed, which seems to favor the accumulation of intracellular lipids.