RT-LAMP assay: an alternative approach for profiling of bovine heat shock protein 70 gene in PBMC cultured model

Characterization of a putative ribosome binding site at the 5' untranslated region of bovine heat shock protein 90

Untranslated regions (UTRs) of the transcripts play significant roles in translation regulation and continue to raise many intriguing questions in our understanding of cellular stress physiology. Internal ribosome entry site (IRES) mediated alternative translation initiations are emerging as unique mechanisms. Present study is aimed to indentify a functional short 92 base pair length putative sequence located at the 5' untranslated region of bovine heat shock protein 90 AA1 (Hsp90AA1) may interact with ribosomal as well as eukaryotic initiation factor binding site. Here we have predicted both the two and three dimensional structures of bovine Hsp90AA1 IRES (MF400854) element with their respective free energy. Molecular interactions between bovine RPS5 and IRES have been determined after the preparation of docking complex of IRES bound RPS5. Structure of bovine ribosomal translational initiation factor (TIF) has also been determined and docked with IRES. Molecular interaction between bovine TIF and IRES was analyzed from the complex structure. We further detected the relative expression efficiency of the viral (original) in relation with Hsp90AA1 IRES-driven GFP expression, which revealed that efficiency under the control of identified bovine Hsp90AA1 IRES was slightly lower than viral origin. It was also noted that identified bovine HSP90 IRES may increase the expression level of GFP under in vitro heat stressed condition.

Differential expression of microRNAs associated with thermal stress in Frieswal (Bos taurus x Bos indicus) crossbred dairy cattle

Environmental temperature is one of the important abiotic factors that influence the normal physiological function and productive performance of dairy cattle. Temperature stress evokes complex responses that are essential for safeguarding of cellular integrity and animal health. Post-transcriptional regulation of gene expression by miRNA plays a key role cellular stress responses. The present study investigated the differential expression of miRNA in Frieswal (Holstein Friesian × Sahiwal) crossbred dairy cattle that are distinctly adapted to environmental temperature stress as they were evolved by using the temperate dairy breed Holstein Friesian. The results indicated that there was a significant variation in the physiological and biochemical indicators estimated under summer stress. The differential expression of miRNA was observed under heat stress when compared to the normal winter season. Out of the total 420 miRNAs, 65 were differentially expressed during peak summer temperatures. Most of these miRNAs were found to target heat shock responsive genes especially members of heat shock protein (HSP) family, and network analysis revealed most of them having stress-mediated effects on signaling mechanisms. Being greater in their expression profile during peak summer, bta-miR-2898 was chosen for reporter assay to identify its effect on the target HSPB8 (heat shock protein 22) gene in stressed bovine PBMC cell cultured model. Comprehensive understanding of the biological regulation of stress responsive mechanism is critical for developing approaches to reduce the production losses due to environmental heat stress in dairy cattle.