Differential expression of heat shock protein genes and their splice variants in bovine preimplantation embryos

Abstract

Heat shock proteins (HSP) are among the first proteins produced during embryonic development and are crucial to cell function; their activities include folding, unfolding, transport, and localization of proteins and differentiation and regulation of the embryonic cell cycle. Although HSP have been extensively studied in humans and mice, limited information exists on the roles of these genes in bovine embryos. As such, the objectives of this study were to profile the expression of HSP and their splice variants in bovine embryos (degenerates vs. blastocysts) and to carry out association analysis with fertility traits. Quantitative real time PCR analysis revealed differences in expression that ranged from 1.5- to 7.6-fold in degenerate embryos compared with blastocysts. Interestingly, all members of the HSP40 family were found to be upregulated in degenerate embryos. Analysis of current bovine Ensembl data showed that 13 HSP genes have 1 transcript each, 2 genes have 2 transcripts each, and 2 have 3 transcripts each. Some splice variants show differential expression between degenerate embryos and blastocysts, whereas others were not expressed at all in embryos, which implies different functions of these transcripts in embryonic development. The most significant differentially expressed genes were further investigated for association with fertility and development traits. Single nucleotide polymorphisms in DNAJC15 and DNAJC27 were found to be associated with blastocyst rate and fertilization rate, respectively. Collectively, the roles of HSP in fertilization and early development of cattle embryos are important.

Integrating Omics and Alternative Splicing Reveals Insights into Grape Response to High Temperature

“…Lund et al (2001) observed that forms of HSP22 resulted from alternative intron splicing in maize (Zea mays). Zhang et al (2011) reported that 13 HSP genes had one transcript each, two genes had two transcripts each, and two had three transcripts each in bovine. Heat stress-AS occurs in transcripts for specific functions.…”

Effects of diagnostic ultrasound on HSP70 expression in chorionic villi in rats during early pregnancy and the role of HSP70 in apoptosis in chorionic villi

“…Previous studies have indicted that HSPs may play important protective roles in animal embryonic development. Zhang et al (19) found that more than ten HSP genes had differential expression between degenerate cattle embryos and blastocysts, whereas others were not expressed at all. This suggests the important roles of HSPs in fertilization and early development of the embryo.…”

PHYSIOLOGY AND ENDOCRINOLOGY SYMPOSIUM: The current status of heat shock in early embryonic survival and reproductive efficiency1,2

“…In cattle, performance differences have been identifi ed in Bos indicus breeds and genetic polymorphisms in HSP70 have been associated with reproductive performance (Rosenkrans et al, 2010). In Holstein cows, differences in expression of genes in the HSP40 family have been associated with improved early embryonic development in vitro, indicating that these proteins may have a greater role in reproductive effi ciency than thought, even in animals not adapted to a tropical environment and not placed in a heat stress situation (Zhang et al, 2011). The speakers at this Physiology and Endocrinology Symposium were identifi ed to address these topics based on their research.…”