Expression pattern of heat shock protein genes in sheep

Objective: To recognize the expression patterns of HSP70 and HSP90 genes in two local breeds of Sheep.
Design: Descriptive study.
Animals:  Fifty ewes (25 Barki and 25 Abu Dlik).
Procedures: This investigation was carried out on fifty sheep at the northwest coast and southeast of triangle Halayeb and Shalateen during the months of March and May 2018 and 2019 (average day time temperatures: 25–35 ^◦C; relative humidity: 55–65%). Total RNA was extracted using easy-RED™ Total RNA Extraction Kit. The primers for qPCR were designed on the basis of prior sequence information available at National Center for Biotechnology Information (NCBI) for the target HSP70 and 90 genes. The Glyceraldehyde-3-phosphate dehydrogenase (GAPDH)) gene, housekeeping gene, was used for normalization of qPCR data. The desired genes were amplified for relative expression measurements.  Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1 β, IL-6, IL-10, IL-12) were assayed.  
Results: The expression levels of the HSP70 and HSP90 genes and the genes in Abu Dlik sheep were observed to be relatively up-regulated than those in Barki sheep. Abu Dlik breed exhibited an up-regulated mRNA level of Hsp70 and Hsp90 genes (1.70440938 vs 1.362954) while the Barki breed showed a down-regulated pattern (0.8550442 vs 0.4289764). In Abu Dlik ewes HSP70 gene exhibited a higher mRNA level than HSP90 mRNA.
Conclusion and clinical relevance: Gene expression patterns of HSP70 and HSP90, as well as cytokines modulations can be used as a biological marker and a reference point in sheep to identify, manipulate and cross-breed for improving the genetic potential and adaptability to tolerate harsh environmental conditions, especially heat stress.