Study of polymorphisms in the introns 1 and 4 chicken growth hormone gene in the native fowls of Isfahan and Mazandaran

The chicken growth hormone (cGH) is a polypeptide hormone which is involved in a wide variety of physiological functions. To investigate the growth hormone gene polymorphism, 217 samples (129 samples of Isfahan and 88 samples of mazandaran) for intron 1 and 134 samples (91 samples of Isfahan and 43 samples of mazandaran) for intron 4 were analyzed. The genomic DNA was extracted using salting out technique. The quantity and the quality of the extracted DNA was examined using spectrophotometery and then analyzed on a 0.8% agarose gel electrophoresis. A fragment with the size of 776 bp from the intron 1 and a fragment with the size of 1170 bp from the intron 4 were amplified using two pair of specific primers and polymerase chain reaction. The PCR products digested with MspI restriction enzyme and then it analyzed on %2.5 agarose gel. The allelic frequency of intron 1 locus for M, N and O alleles in Isfahan native fowls was 0.60, 0.21 & 0.19 respectively and in Mazandaran populations was 0.28, 0.05, 0.67 respectively. The allelic frequency of intron 4 for A, B and C alleles in Isfahan native fowls populations were 0.28, 0.31 & 0.41 respectively and in Mazandaran population were 0.37, 0.24 & 0.37 respectively. Also D and E alleles were observed in Mazandaran population solely with 0.01 frequency for each allele. The result of current study indicated that the introns 1 and 4 of cGH is relatively highly polymorphic in Isfahan and Mazandaran native fowls.