[Screening genes related to 'black' character in wu-ding chicken by delta differential display]

The 'black' character is a cardinal character of black chicken that is very important to the medical value and economical value of black chicken. The study compared gene expression between black chicken and non-black chicken by delta differential display method, and obtained twenty-nine expressed sequence tags(ESTs) by extraction, amplification, purification, northern blotting, cloning and sequencing of gel-embedded DNA. Of twenty-nine ESTs, eight ESTs have high similarity rate with known gene in chicken-beta-trepomyosin gene, cardiac myosin alkali light chain gene, insertionally activated c-Ha-ras oncogene, fra-2 oncogene, 16S rRNA gene and mitochondrion genome sequence, respectively, with similarity rate 97%,100%, 98%, 98%, 98%, 99%, 99% and 97%. Five ESTs have high similarity rate with human TTN gene, human phosphoglucomutase 5 gene, human or mouse signal recongnition particle 54 kD gene, human or mouse ribonuclease/angiogenin inhibitor gene, respectively, with similarity rate 82%, 82%, 87%, 99% and 99%. Their homologous genes in chicken are still not cloned. Thirteen ESTs are novel gene fragments. Of thirteen ESTs, nine ESTs have high similarity with ESTs in database. Four ESTs have not high similarity with any EST in database. The results of gene expression analysis show that one known gene (insertionally activated c-Ha-ras oncogene) fragment and one novel gene fragment are expressed in all non-black chicken and are not expressed in all black chicken, and that one known gene (signal recongnition particle 54 kD gene) fragment is expressed in all black chicken and is not expressed in all non-black chicken. According to these results, we conclude that the expression of insertionally activated c-Ha-ras oncogene, signal recongnition particle 54 kD gene and one novel gene are related to the 'black' character in chicken.