GENETIC BACKGROUND AND HSP70 GENE POLYMORPHISMS FOR HEAT TOLERANCE IN INDIGENOUS CHICKENS OF KENYA

Abstract

It is postulated that chickens were first domesticated in Asia around 8000 years ago and spread to the rest of the world. This study investigated the origins, phenotypes as well as polymorphisms at a candidate gene implicated for heat-tolerance in indigenous chickens from four agro climatic zones of Kenya (Lamu archipelago, the Turkana basin, Victoria basin and the Mount Elgon Catchment). Phenotypic traits for heat tolerance were collected using the ODK collect suite and recorded. DNA was extracted from 296 indigenous chickens. Mitochondrial DNA d-loop region and the heat shock protein 70(HSP70) gene were amplified using an optimized PCR protocol. Analysis of the HSP70 revealed the presence of three heterozygous and three homozygous sequences. The ancestral red jungle fowl was used as the reference sequence. DnaSP generated 28 mtDNA haplotypes. Our samples clustered into four of the five reference haplogroups downloaded from GenBank. Most of our samples clustered into Haplogroup E. Haplogroup E. This study characterized the phenotypes of indigenous chickens, characterized the origins and HSP70 gene functional polymorphisms in the various climatic regions of Kenya