Autoria: FERREIRA, C. R.; BURGSTALLER, J. P.; PERECIN, F.; GARCIA, J. M.; CHIARATTI, M. R.; MÉO, S. C.; MULLER, M.; SMITH, L. C.; MEIRELLES, F. V.; STEINBORN, R.

Resumo: Ooplasmic transfer (01) has been used in basic mouse research for studying lhe segregation of mtDNA, as well as in human assisted reproduction for improving embryo development in cases of persistent developmental failure. Using cattle as a large-animal model, we demonstrate that lhe moderate amount of mitochondria introduced by OT is transmitted to lhe offspring's oocytes; e.g., modifies lhe germ fine. The danar mtDNA was detectable in 25% and 65% of oocytes collected from two females. Its high variation in heteroplasmic oocytes, ranging from 1.1% to 33.5% and from 0.4% to 15.5%, can be explained by random genetic drift in lhe female germ line. Centrifugation-mediated enrichment of mitochondria il1 lhe pole zone of lhe recipient zygote's ooplasm and its substitution by danar ooplasm led to elevated proportions of danar mtDNA in reconstructed zygotes compared with zygotes produced by standard OT (23.6% :!: 9.6% versus 12.1% :!: 4.5%; P <0.0001). We also characterized lhe proliferation of mitochondria from lhe OT parents-the recipient zygote (Bos primigenius taurus type) and lhe danar ooplasm (B. primigenius indicus type). Regression analysis performed for 57 tissue samples collected from lhe seven OT fetuses at different points during fetal development found a decreasing proportion of donor mt DNA (r2=0.78). This indicates a preferred proliferation of recipient of the OT recipeint expressinf a B. primigenius indicus phenotype.

Ano de publicação: 2010

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Pecuária Sudeste

Palavras-chave: Bovine, DNA, Developmental biology, Embryo, Gamete biology, Ooplasmic