A novel gene, ITM, located between p57KIP2 and IPL, is imprinted in mice.
We searched for new imprinted genes using a positional cloning method in a region of human chromosome 11p15.5, which contains several imprinted genes including p57KIP2 and IPL, and found a novel ITM gene located between p57KIP2 and IPL. We also obtained the mouse homologue Itm in its syntenic region of mouse chromosome 7. In humans, its location is 17 kb centromeric to p57KIP2 and 3 kb telomeric to IPL, and in mice, 15 kb and 2.5 kb, respectively. They are expressed in most tissue, but especially in the kidney and liver, and moderately in the heart, lung and testis. Mice exhibit a functional imprinting resulting in higher expression of maternal alleles in fetal, newborn and most adult tissues, but it is biallelically expressed in the adult kidney and liver where expression is the highest. In addition to the discrepancy between the level of expression and the strength of the imprint, Itm has several unusual features for an imprinted gene, including large introns, moderate GC content and the absence of direct repeats. Our results will be helpful in understanding the intricate regulatory mechanism of imprinted genes.
Morisaki
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H
Department of Bioscience, National Cardiovascular Center Research Institute, Suita, Osaka, Japan. hirokom@ri.ncvc.go.jp
Hatada
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I
Morisaki
T
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Mukai
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D050761:Cyclin-Dependent Kinase Inhibitor p57; D018076:DNA, Complementary; D018392:Genomic Imprinting; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*; D013045:Species Specificity
C493964:CDKN1C protein, human; C493965:Cdkn1c protein, mouse; D050761:Cyclin-Dependent Kinase Inhibitor p57; D018076:DNA, Complementary; D009687:Nuclear Proteins; D011506:Proteins; C109277:TSSC3 protein