Genetic diversity of different indigenous chicken ecotypes using highly polymorphic MHC-linked and non-MHC microsatellite markers

The study investigated the genetic make-up of different ecotypes of indigenous chickens (ICs) in Kenya based on major histocompatibility complex (MHC)-linked and non-MHC microsatellite markers. Blood samples were collected from eight regions (48 birds per region) of Kenya: Kakamega (KK), Siaya (BN), West Pokot (WP), Turkana (TK), Bomet (BM), Narok (NR), Lamu (LM) and Taita-Taveta (TT) and genotyped using two MHC-linked and ten non-MHC markers. All MHC-linked and non-MHC markers were polymorphic with a total of 140 alleles, of which 56 were identified in MHC-linked markers. Mean number of alleles (Na and Ne), private alleles, heterozygosity and genetic distances were higher for MHC-linked markers compared with non-MHC markers. The ad hoc statistic ¿K detected the true numbers of clusters to be three for MHC-linked markers and two in non-MHC markers. In conclusion, Kenyan ICs belong into two to three genetically distinct groups. Different markers systems have different clustering system. MHC-linked markers divided ICs into three mixed clusters, composing of individuals from the different ecotypes whereas non-MHC markers grouped ICs into two groups. These IC ecotypes host many and highly diverse MHC-linked alleles. Higher allelic diversity indicated a huge amount of genetic variation in the MHC region of ICs and supported their reputation of being hardy and resistant to diseases.