Promoter-specific imprinting of the human insulin-like growth factor-II gene

摘要: GENOMIC imprinting is a mechanism whereby only one of the two parental alleles expressed. Loss or relaxation genomic has been proposed as an epigenetic for oncogenesis in variety human tumours1–6. Although unknown, differential CpG methylation implicated7–12. The insulin-like growth factor-II (IGF2) gene, which transcribed from four promoters, P1–P4 (ref. 13), imprinted fetal liver14,15 but biallelic expression occurs adult liver16. Like most tissues, liver uses primarily promoters P3 and P4 17). Adult liver, however, transcribes IGF2 promoter P1, it suggested that recruitment P1 may be responsible absence choroid plexus leptomeninges18. We report here chondrocytes, transcripts are always derived both alleles, whereas P2, allele. These findings demonstrate lack can occur within single gene tissue, suggesting regional factors important.