GENETIC DIVERSITY OF SELECTED CHICKEN BREEDS IN NIGERIA, SEGREGATING AT THE CHICKEN GROWTH HORMONE GENE LOCUS

Résumé

The study was carried out to evaluate genetic diversity of selected chicken breeds in Nigeria focussing on the chicken growth hormone gene locus. The chickens studied were: Fulani ecotype, FUNAAB Alpha, frizzled feathered, Noiler and Cobb 500 broilers chicken. Genomic DNA was extracted from blood samples collected from 50 chickens (10/chicken breed). The extracted DNA was amplified using PCR and the gene sequenced. The sequenced data was used to evaluate genetic diversity and to carry out phylogenetic analysis. Results showed that the mean number of alleles (Na), mean number of effective alleles (Ne), mean Shannon information index (I), mean observed heterozygosity (Ho), mean expected heterozygosity (He), mean unbiased expected heterozygosity (uHe), mean fixation index (F) and % polymorphic locus were 2.000±0.000, 1.956±0.014, 0.682±0.004, 0.449±0.067, 0.489±0.004, 0.516±0.004, 0.083±0.138 and 100%, respectively. The gene flow (Nm) for all the population was 13.141. Results of Analysis of Molecular Variance (AMOVA) showed that the percentage of molecular variance among and within individuals was 13 and 87%, respectively. Phylogenetic analysis divided the five chickens into two broad claves; Noiler and the frizzled feathered occupied one while, the Fulani ecotype, FUNAAB Alpha and Cobb 500 occupied the other. It was concluded that great genetic diversity exists in the chicken breeds which could be exploited for further improvement especially in the more native breeds.