ASSESSMENT OF GENETIC DIVERSITY AND EVOLUTIONARY RELATIONSHIP OF GROWTH DIFFERENTIATION FACTOR 8 GENE OF FOUR BROILER CHICKEN GENOTYPES

This experiment was designed to estimate genetic diversity and analyse evolutionary relationship of exon 1 Growth differentiation factor 8 gene in Arbor Acre, Abor Acre Plus, Cobb and Ross. Two-hundred-day-old chicks of mixed sexes were assigned into five equal-sized cells, each containing forty birds with ten birds per strain. Blood samples were collected via brachial vein of selected birds for molecular analysis. The amplified products were sequenced and genetic diversity was estimated by DNA sequence polymorphism software and phylogeny was analysed by molecular evolutionary genetic analysis software. The analysis revealed polymorphic sites of 7 in Ross and 4 each in Arbor Acre, Abor Acre Plus and Cobb. Ross had 5 haplotypes and other strains had 3 each. Ross exhibited highest haplotype and nucleotide diversity. Positive Tajima’s D was revealed in Arbor Acre while negative Tajima’s D occurred in Abor Acre Plus, Cobb and Ross. Arbor Acre and Abor Acre Plus were closely related in breeding lineage. The clustering of Cobb and Ross in distinct phylogenetic branches suggested unique ancestral origins. In that high genetic diversity is advantageous for breeding programme since it provides a wider genetic pool for selection, resilience against inbreeding depression and better adaptability to environmental changes. However, Ross is the most promising for breeding improvement.