Paternal influence on apoptosis, and expression of BCL2, BAX, TP53, heat shock protein-70 and interferon tau genes in bovine preimplantation embryo

Abstract

The bull effects on apoptosis, and BAX, BCL2, TP53, heat shock protein 70 (HSPA1A) and interferon tau (IFNT) gene expression in in vitro produced embryos were investigated. The degree of correlation of this effect with the 60- to 90-d non-return rates was also investigated. Standard in vitro fertilization and embryo culture were performed using frozen semen from six genetically unrelated bulls. Live, apoptotic, and dead cell percentages in blastocysts were determined, after staining with annexin V, propidium iodide, and bisbenzamide. BAX, BCL2, TP53, HSPA1A and IFNT gene expression levels in blastocysts were determined by RT-PCR. The non-return rate data for all experimental bulls were obtained from a local artificial insemination center. Apoptotic, live and dead blastomere percentages, and HSPA1A and IFNT expression levels in blastocysts were different (P < 0.01) among bulls. BAX, BCL2 and TP53 expression levels were not different among bulls. The non-return rate was highly correlated (P < 0.05) with BCL2 (r = -0.93) or the ratio of BAX to BCL2 (r = 0.84) gene expression. None of the other in vitro fertility parameters were correlated with non-return rate. This study concluded that the development, apoptosis, and HSPA1A and IFNT gene expression of in vitro produced embryos are influenced by individual bulls. Key words: Bovine, embryo, fertility, apoptosis, gene expression, interferon