PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

DNA polymorphism at B-LβII region of chicken Major Histocompatibility Complex (MHC) was studied in Nigerian locally adapted chicken genotypes, namely: Normal-feathered, Frizzled-feathered and Naked neck with much less history of selection for economic traits, though, previously selected for response to sheep red blood cell (SRBC). Response to SRBC (1% suspension, i/v) was estimated by haemagglutination (HA) test 5 days post inoculation (dpi). Thereafter, high and low responding groups were generated. DNA was isolated from high and low responders at second generation of selection as well as randomly selected individuals from the locally adapted chicken population. The B-LβII was amplified with specific primers and an amplicon of 277 bp obtained in each sample was digested with three restriction enzymes (RE) viz., MspI, BseRI and TaqI individually. While the PCR-RFLP of B-LβII with MspI and BseRI had no cutting sites, TaqI RE exhibited monomorphic pattern with genotypes AA and at frequency 1.0 in the divergently selected groups. The Nigerian locally adapted chicken is known for high disease resistance. The monomorphic could be as a result of fixation of naturally selected genotype AA.