Abstract: This paper was conducted to study the methylation of bcl-2 gene and its death relevance with the hybrids of chicken-quail in early embryonic stage.The CpG island methylation status of bcl-2 gene promoter region was detected by the methylation-specific PCR in seven different chicken quail and its hybrid fetation stages(60, 66, 72, 84, 96, 108 and 120 h). The results showed that the hypermethylation (60, 66, 72 and 120 h) and unmethylation (84 h, 96 h) was detected in the chicken and quail embryos;the hypermethylation of bcl-2 gene promoter CpG islands was detected in the chicken and quail embryos treated by M.sssⅠ enzyme. Compared with the chicken and quail, the abnormal methylation appears in chicken-quail hybrid embryos, and methylation or unmethylation was detected in some sample (60, 66, 72, 96, 108 and 120 h),undetected in the others. However, unmethylation was tested in 84 h hybrid embryos. An important influence factor in early death of chicken-quail hybrid embryos were probably CpG island abnormal methylation of bcl-2 gene promoter region.

Key words: bcl-2 gene; gene methylation; chicken; quail; hybrid embryos; CpG island