Association between HSP70 Genotypes and Oocytes Development on In vitro Maturation/Fertilization in Pig

Abstract

This study was performed to clarify whether the variation of stress related heat shock protein 70 (HSP70) (GenBank X68213) gene was associated with the nuclear morphological change of in vitro maturation and in vitro capacitation in oocytes of pig ovaries obtained at the slaughterhouse. The nucleic acid substitution of C to G at the 483rd position was found out in HSP70 K1 (290-512) from X68213. The ovaries were categorized into CC, CG, and GG genotypes using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) (BsiHKA I). After the second in vitro maturation of immature fresh oocytes, the relation of nuclear morphological change in oocytes with the genotype of HSP70 K1 gene was such that the MII ratios of the genotype GG and CG (46.93% and 42.20%, respectively) were significantly higher than that of the CC genotype (10.71%) (p<0.05). With respect to in vitro maturation of frozen-thawed oocytes by an open pulled straw (OPS) method, the percentage of oocytes matured to MII stage of the CG genotype showed a higher trend than CC and GG genotypes. After the in vitro maturation of immature fresh oocytes and frozen-thawed oocytes by the OPS method, the relation of the pronuclei change in oocytes matured in vitro with HSP70 genotype was assessed, and the result showed that the enlarged sperm heads (ESH) of matured fresh oocytes and frozen-thawed oocytes were 80.0% and 60.0% in the CC genotype, respectively. The CC genotype group had a significantly higher rate of ESH than the CG and the GG genotype group (p<0.05). The ratios of polyspermic invasion were not different among HSP70 of the three genotypes. It was considered that the rate of in vitro maturation of fertilized oocytes was expected to differ according to genotype of the stress related gene.

HSP70 Gene Expression Pattern in Peripheral Blood Mononuclear Cells during Different Seasons in Pandharpuri Buffaloes

“…Relative expression of HSP70 genes varied markedly among the heat-and cold-adapted goat breeds with a moderate variation between breeds and showed a good response to increased or decreased ambient temperature (Banerjee et al, 2014, in caprine PBMCs (Gupta et al, 2013, leukocytes of buffalo (Pawar et al, 2014), Murrah buffalo (Mishra et al, (2010), dermal fibroblasts of cattle (Singh et al, 2014). In addition, it is speculated that heat shock stress effects on the early embryo directly and it also influences the development to the late embryo (Wee et al, 2008). Heat stress in farm animals, such as cattle and buffalo during summer and post-summer seasons is a problem for livestock producers.…”