PRESENCE OF AN ADDITIONAL PSTI FRAGMENT IN INTRON-1 OF THE CHICKEN GROWTH HORMONE-ENCODING GENE

A previously unreported 196-bp PstI fragment was found in intron 1 of the gene encoding chicken growth hormone (cGH) when a PCR assay for an MspI restriction fragment length polymorphism was established. A pair of PCR primers was designed according to the published cGH sequence a nd used to amplify a fragment which contained two MspI sites, one poly morphic and another non-polymorphic. However, amplification of genomic DNA from two strains of meat-type chickens and three strains of White Leghorn chickens yielded a PCR product which was about 200 bp larger than expected. The fragment from one of the meat-type chickens was sub cloned into the vector pCR-Script SK+, and sequenced. It revealed the presence of an extra fragment of 196 bp which was flanked by the PstI sites and occurred at nt +308 of the previously reported cGH sequence.