ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

The chicken growth hormone (GHR) gene has an important function in chicken growth and reproduction. Polymorphisms are the most frequently found DNA sequence variations in the animal genome and can be used as genetic markers for association analysis with economic traits. Native chicken in every province are valuable genetic recourses. Iraq local chicken is the one of importance genetic resources that because of adapting to environment and disease also every projected to improvement that conducted in this fowl there is no effected on structural gene.. In order to study and investigation growth hormone receptor gene polymorphism in Iraqi local chicken. Blood samples were collected from 93 individuals of female native Iraqi chicken and genomic DNA was extracted using salting out technique DNA fragment with 718 bp growth hormone receptor gene was amplified using polymerase chain reaction (PCR). PCR product was digested with restriction enzymes HindIII and subsequently electrophoreses on 1.5% agarose gel with ethidium bromide on 50 voltage in 2 hours.
The study introns in this research obtained genotypes percentage of HindIII enzyme on 718 bp fragment for GG and RR genotypes were 78.64 and 21.36 % respectively the frequency of G and R alleles were 0.79 and 0.21 respectively. Also there was study between polymorphism growth hormone gene and age at sexual maturity , first egg weight, body weight at sexual maturity , egg production at 100 days, egg mass, feed consummation and live body weight there was no significant between them but The genotype GG recorded highly significant (P<0.01) on RR genotype for egg weight characters interval 31-34 weeks. According to the results, GHR genes could be candidate gene that can affected some production traits in Iraq local chicken therefore we can used growth hormone receptor gene polymorphism as genetic marker for selection program.