MOLECULAR GENETIC ANALYSIS OF DIVERSITY IN VILLAGE CHICKENS IN NIGERIA

Résumé

Indigenous chickens obtained from the central and northern parts of Nigeria were evaluated for incidence and frequencies of endogenous viral, ev, genes 1, 3, 15 and 21 using blood samples collected by branchial venipuncture from free ranging adult birds of both sexes. Results indicated that 60.7% of the birds do not carry any of the four ev elements and that none of the birds carried genes for ev I. The frequencies ev 1, 3, 15 and 21 genes were 0.00, 0.07, 0.07 and 0.24. Significantly (P<0.05) higher frequencies of birds carrying the homozygous negative genes for each of the four ev elements are expected among the local chicken. Significantly (P<0.05) higher frequency of birds carrying the heterozygous than the homozygous positive forms for ev 3, 15 and 21 are also expected. The obtained negative genotypes agree closely with the expected, although slightly lower frequencies were obtained for ev 3 and 15 and higher frequeney for ev 21 than expected. However, there were no birds carrying the homozygous positive forms for ev 3 and ev 15 and slightly lower frequency for ev 21 than expected. The frequencies for the heterozygotes, though slightly lower for ev 21 and higher for ev 3 and 15, agree closely with the expected. Analysis of the DNA finger print, DFP, bands from RFLP studies indicated that the level of genetic diversity in the local chicken in Nigeria is only about 52%. The study suggests that there may be true genetic differences in the Nigerian local chicken population and hence the slightly high variation in genetic differences could be exploited for genetic improvement.