RNA-seq REVEALS CONTRIBUTION OF HISTONE UBIQUITINATION TO POSTTRANSLATIONAL REGULATION OF HEAT SHOCK PROTEINS AND CYTOKINES OF CATTLE AFTER EXPOSURE TO HEAT SHOCK

Abstract

Epigenetics is the study of post translational changes in gene expression/function without corresponding alteration in the DNA sequence of a particular body phenotype. Ubiquitin, Histone and DNA methylations are the evidence of epigenetics involving gene modulations in eukaryotes. In this study, we isolated peripheral blood monoclonal cells (PBMCs) from twelve (12) India Gir zebu cattle and exposed them to different doses of in vitro assault of thermal condition. RNAs isolated from the heat-shocked PBMCs were processed for production of enriched mRNA library for RNA-seq. We performed RNA-seq analyses followed by transcriptional expression of mRNAs for differential gene expression and gene ontology term enrichment analyses. Our findings showed that thermal stress stimulation of our PBMCs impinged heat shock on the bovine cellular system thereby activating expression of histones, ubiquitin and heat shock protein genes. Further to the above, we found direct relationship between the expression of histone (H2A1), ubiquitin and heat shock protein genes. We concluded therefore that, ubiquitination of histone protein (H2A1) plays an epigenetic role in post-translational regulation/overexpression of heat shock proteins (HSPs) including HSPs 70, 90, small HSPs (HSPB11, HSPB6, HSP22, HSP1L1, HSP27) and cytokines (IL1A, IL18) in zebu cattle and this may permit joint regulation of expression and function of these target proteins (HSPs and cytokines) for their thermotolerance and immune-competence potentials in bovine species upon exposure to heat shock/thermal assault.