title: The placental imprintome and imprinted gene function in the trophoblast glycogen cell lineage.
abstract: Imprinted genes represent a unique class of autosomal genes expressed from only one of the parental alleles during development. The choice of the expressed allele is not random but rather is determined by the parental origin of the allele. Consequently, the mouse genome contains more than 100 genes expressed preferentially or exclusively from the maternally or the paternally inherited allele. Current research efforts are focused on understanding the molecular mechanism of this epigenetic phenomenon as well as the biological functions of the genes under its regulation. Both theoretical considerations and experimental results support a role for genomic imprinting in the regulation of embryonic growth and placental biology. In this review, recent efforts to establish the complete set of genes showing imprinted expression in the mouse placenta are first discussed. Then, the evidence suggesting that imprinted genes might be implicated in the emergence, maintenance and function of trophoblast glycogen cells is presented. Although the origin and functions of this trophoblast cell lineage are currently unknown, the analysis of mutations in imprinted genes in the mouse are providing new insights into these issues. The implications of this work for placental pathologies in human are also discussed.
authors.affiliation: Department of Medical Genetics, Molecular Epigenetics Group, Life Sciences Institute, University of British Columbia, Vancouver, Canada. louis.lefebvre@ubc.ca
authors.forename: Louis
authors.initials: L
authors.lastname: Lefebvre
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000096:biosynthesis; D019070:Cell Lineage / Q000235:genetics; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000096:biosynthesis; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting / Q000502:physiology*; D006003:Glycogen / Q000378:metabolism*; D006801:Humans; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis; D051379:Mice; D009035:Mothers; D009687:Nuclear Proteins / Q000096:biosynthesis; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D020543:Proteome / Q000096:biosynthesis; D014327:Trophoblasts / Q000378:metabolism*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D050761:Cyclin-Dependent Kinase Inhibitor p57; D006003:Glycogen; D007335:Insulin-Like Growth Factor II; D009687:Nuclear Proteins; D020543:Proteome; C489311:Ascl2 protein, mouse; C493965:Cdkn1c protein, mouse; C513121:IGF2 protein, mouse; C109277:TSSC3 protein