Investigation of heat shock protein 70 gene polymorphism in Khuzestan native chickens

 Heat shock protein 70 (Hsp70) are a family of molecular chaperones, which promote protein folding and participate in many cellular functions. The purpose of the study was to identify the polymorphisms of heat shock protein 70 gene of Khuzestan native chickens using SSCP technique. 

For this purpose, blood samples were collected from 130 native chicken from Shosh, Ramhormoz, Andimeshk cities and Jihad native chicken breeding station (Bavi city). After DNA extraction, the target area (892 base pair) was amplified using polymerase chain reaction (PCR) method and sequenced.    

PCR-SSCP analysis of these regions indicated the presence of polymorphisms in the beginning of the coding region and the sequencing of the PCR products confirmed and identified two polymorphic sites in this region: a transition A → G in position +259 (A259G) and a transversion C→G in position +277 (C277G). The results showed that Hsp70 gene is polymorphic in the studied area. Moreover, using the chi-square (X2) showed that the locus allele frequencies is not in Hardy-Weinberg equilibrium. Furthermore, the observed heterozygosity and the effective number of alleles demonstrated high diversity in the population. Moreover, Haplotype H3 has the highest frequency in the population. It occurs A259G mutants in this haplotype.   

Thus, these valuable gene pools should be conserved to be used in the future if needed. The selection at Jihad native chicken breeding station (Bavi city) has led to increased inbreeding and, as a result, the abundance of haplotype H3 in the population.