Phenotypic and Genetic Diversity, and HSP70 Gene Polymorphism of the Helmeted Guinea fowl in Kenya

Abstract

Little is known about the origin and genetic background of helmeted Guinea fowls despite their importance as a source of food, income, gifts, sacrifices, payment of dowries as well of being a source of manure. Heat stress is also one of the main problems affecting poultry production, especially affecting birds in the final phase of rearing causing mortality and economic losses. Understanding of genetic diversity in poultry provides information that would be used to conserve beneficial genotypes in the face of uncertainties brought about by global challenges such as climate change responsible for drought and heat stress in poultry. This study aimed to characterize local domesticated and wild helmeted Guinea fowls in selected regions in Kenya based on primary phenotypic traits, mitochondrial DNA (mtDNA) D-loop variations and polymorphisms in the heat shock protein 70 (HSP70) gene associated. Ninety (n=90) Guinea fowls selected from four domestic populations (n=70) in Western Kenya and a wild population (n=20) were scored for primary phenotypic characteristics. DNA was also extracted from blood collected from five populations of Guinea fowls comprising 13-21 individuals. Other than the wattle colour and head size, there is no marked difference between domestic and wild helmeted Guinea fowls of Kenya for the primary phenotypic traits considered. The 90 sequences were assigned to 25 distinct mtDNA and 4 HSP70 haplotypes. Most mtDNA haplotypes of the domesticated helmeted Guinea fowls were grouped into two main haplogroups; HgA and HgB. The wild population grouped into distinct haplogroups. Two haplotypes dominated across all populations of domesticated helmeted Guinea fowls; Hap2 and Hap4. The lack of population structure could suggest intensive genetic intermixing between the domestic populations. The differentiation of the wild population may be due to a clearly distinct demographic history that shaped its genetic profile. Overall, there was no significant (P<0.05) correlation between genetic variations and the geographic location in helmeted Guinea fowl populations in Kenya, indicating lack of a population structure within Kenya’s domesticated helmeted Guinea fowls. Analysis of the Kenyan Guinea fowl population structure and history based on mtDNA D-loop variations complimented by archaeological and linguistic evidence supports the hypothesis that most domesticated helmeted Guinea fowls in Kenya are related to the West African domesticated helmeted Guinea fowls. More molecular work is recommended on a larger sample size to validate this work and identify more haplogroups not identified in this study.