title: Nucleotide sequence of a 28-kb mouse genomic region comprising the imprinted Igf2 gene.
abstract: The mouse insulin-like growth factor II gene (Igf2) is physically linked to the insulin II gene (Ins2) and both are subject to tissue-specific genomic imprinting. The paternal-specific expression of Igf2 has been associated with hypermethylation of some CpG sites in the 5' flanking region and in the body of the gene. As a first step in analyzing the structural features of this imprinted locus, we here report the complete nucleotide sequence of Igf2, including all introns and the intergenic region adjacent to Ins2. This 28-kb segment of mouse chromosome 7 exhibits 80% overall identity with the corresponding rat sequence and has a high GC content of 52%. In addition to the known CpG island within the second Igf2 promoter, another island was identified approximately 2 kb 5' to the first exon. Other features of this locus include a 35-fold tandem repeat of an 11-bp sequence that overlaps Igf2 pseudo-exon 2, and a B2 repeat element in the intergenic region between Ins2 and Igf2. The GC-richness and the presence of CpG islands associated with tandem repeats are common features of imprinted genes and thus may play a role in the imprinting mechanism.
authors.affiliation: Division of Disease Genes, Kyushu University, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sasaki
authors.forename: K
authors.initials: K
authors.lastname: Shimozaki
authors.forename: M
authors.initials: M
authors.lastname: Zubair
authors.forename: N
authors.initials: N
authors.lastname: Aoki
authors.forename: K
authors.initials: K
authors.lastname: Ohta
authors.forename: N
authors.initials: N
authors.lastname: Hatano
authors.forename: T
authors.initials: T
authors.lastname: Moore
authors.forename: R
authors.initials: R
authors.lastname: Feil
authors.forename: M
authors.initials: M
authors.lastname: Constancia
authors.forename: W
authors.initials: W
authors.lastname: Reik
authors.forename: P
authors.initials: P
authors.lastname: Rotwein
mesh_terms: D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping / Q000379:methods; D018899:CpG Islands / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics*; D008040:Genetic Linkage; D018392:Genomic Imprinting / Q000235:genetics*; D007328:Insulin / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data
chemical_list: D007328:Insulin; D007335:Insulin-Like Growth Factor II