DNA methyltransferases expression in bovine embryos cultured in the presence of oviductal fluid

BARRERA, DANIEL; JIMENEZ DÍAZ, MARIA; GARCIA, ELINA VANESA; RIZO, GABRIELA; PALMA, GUSTAVO; SINOWATZ, FRED; MICELI, DORA C.

Tafí del Valle

Jornada; XXVII Jornadas Científicas de la Asociación de Biología de Tucumán; 2010

Asociación de Biología de Tucumán

Early development of bovine embryo requires a coordinate gene expression. During this period, the gene transcription is regulated by epigenetic modifications. One of these includes DNA methylation by DNA methyltransferases (DNMTs). These modifications can be inherited but some are reversible and could be affected by the environment. Considering this fact, the study of the influence of oviductal microenvironment on embryo could be used to develop optimal culture media. The aim of the present work was to analyze mRNA expression of DNMT1, DNMT3a and DNMT3b in bovine embryos cultured in medium supplemented with oviductal fluid (OF). Ovaries and oviducts were collected from abattoir. The OF was obtained by aspiration from oviducts at metestrus and early diestrus stages. Cumulus-oocyte complexes were aspirated from ovarian follicles, maturated and fertilized using standard procedures. The presumptive zygotes were cultured in TCM-199 + BSA (6 mg/ml) (A) and TCM-199 + OF (6 mg/ml) (B) media at 38.5 °C and 5% CO2. Total RNA isolated from pools of 20 four-cell embryos was used to synthesize cDNA. Real time-PCR analysis showed that expression levels of DNMT1, 3a and 3b were increased in embryos cultured in TCM-199 + OF compared with that of embryos cultured in TCM-199 + BSA.