Construction of a physical and transcript map flanking the imprinted MEST/PEG1 region at 7q32

MEST/PEG1, a gene expressed paternally in mesodermal derivatives in early e mbryonic stages, is the first imprinted gene mapped to chromosome 7q32. Sin ce imprinted genes are clustered in general at a chromosomal region, we spe culated that a similar imprinted-gene cluster may exist at chromosome regio n 7q32 and that the functions of some such genes may contribute to the phen otype of Silver-Russell syndrome including maternal uniparental disomy for chromosome 7 (maternal UPD7). As an initial step toward the isolation of im printed genes at 7q32, we adopted an integrated approach involving the cons truction of a PAC contig and ESTs mapping in the vicinity of MEST. Here, we have constructed a complete contig of PAC and BAC clones and a transcript map spanning the entire similar to 1-Mb region between D7S530 and D7S649. W e developed 60 novel STSs and precisely mapped 47 genes/ESTs. This map cont ains a putative autistic disorder locus that has been suggested to be local ized near markers D7S530 and D7S684. This integrated physical and transcrip t map provides a valuable resource for identification of an imprinted gene( s) in this region as well as a candidate gene(s) for autistic disorder. (C) 2000 Academic Press.