Imprinting analysis of 10 genes and/or transcripts in a 1.5-Mb MEST-flanking region at human chromosome 7q32.

MEST is one of the imprinted genes in human. With the assistance of our integration map and the complete sequence in the registry, we mapped a total of 16 genes/transcripts at the 1.5-Mb MEST-flanking region at 7q32. This region has been suggested to form an imprinted gene cluster, because MEST and its three flanking genes/transcripts (MESTIT1, CPA4, and COPG2IT1) were reported to be imprinted, although two (TSGA14 and COPG2) were shown to escape imprinting. In this study, 10 other genes/transcripts were examined for their imprinting status in human fetal tissues. The results indicated that 8 genes/transcripts (NRF1, UBE2H, HSPC216, KIAA0265, FLJ14803, CPA2, CPA1, and DKFZp667F0312) were expressed biallelically. The imprinting status of two (TSGA13 and CPA5) was not conclusive, because of their weak and/or tissue-specific expression and inconstant results. These findings provided evidence that only 4 of the 16 genes/transcripts located to the region show monoallelic expression, while others are not involved in imprinting. Therefore, it is less likely that the MEST-flanking 7q32 region forms a large imprinted domain.