The growth hormone gene (cGH) polymorphism was studied in relation to growth and production traits in Bantam, White leghorn and Bantamised White leghorn chicken. Two cGH regions, intron I (770 bp) and inttron IV (1216 bp) were amplified which exhibited size variation from the homologous region (1163 and 756 bp, rcspectively) in Yellow Wai Chow strain of chicken. PCR-RFLP of cGH showed an additional Sac I restriction site at 628 bp in 12 I6 bp fragment and Msp I restriction site at 529 bp position in 770 bp fragment. A2 and A3 cGHI/Sac I RFLP alleles were absent in BNT and WLH while only A2 allele was absent in BWLH. The allele A was found in highest frequency in BNT (0.5357) and WLH (0.5968) groups, while allele Al was at highest frequency in BWLH (0.7766) group. The WLH population significantly (P<0.05) deviated from genetic equilibrium at this locus. For eGH2/Msp I locus, the allele frequencies of AI and A3 alleles were found intermediate in BNT genetic group. Al allele showed higher frequency (0.8878) in BWLH while WLH group showed lack of polymorphism with only AI allele present. BNT and BWLH genetic groups were in genetic equilibrium (P<0.01). The phylogenetic tree constructed from cGHI and cGH2 motifs showed that WLH was at equidistance from BWLH and BNT. Statistical analysis revealed non-significant effect of genotypes at cGHI/SacI and cGH2/MspIlocus on BW-8, BW-20, BW-40, TEN-40. EW-40 and TFC-40 traits.
GH gene polymorphism, RFLP, phylogenetic, Bantam, White leghorn
