title: Allelic expression of IGF2 in live-bearing, matrotrophic fishes.
abstract: The parental conflict, or kinship, theory of genomic imprinting predicts that parent-specific gene expression may evolve in species in which parental investment in developing offspring is unequal. This theory explains many aspects of parent-of-origin transcriptional silencing of embryonic growth regulatory genes in mammals, but it has not been tested in any other live-bearing, placental animals. A major embryonic growth promoting gene with conserved function in all vertebrates is insulin-like growth factor 2 (IGF2). This gene is imprinted in both eutherians and marsupials, as are several genes that modulate IGF2 activity. We have tested for parent-of-origin influences on developmental expression of IGF2 in two poeciliid fish species, Heterandria formosa and Poeciliopsis prolifica, that have evolved placentation independently. We found IGF2 to be expressed bi-allelically throughout embryonic development in both species.
authors.affiliation: Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA.
authors.forename: Betty R
authors.initials: BR
authors.lastname: Lawton
authors.forename: Leila
authors.initials: L
authors.lastname: Sevigny
authors.forename: Craig
authors.initials: C
authors.lastname: Obergfell
authors.forename: David
authors.initials: D
authors.lastname: Reznick
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: O'Neill
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Neill
mesh_terms: D000483:Alleles; D000818:Animals; D003433:Crosses, Genetic; D004625:Embryo, Nonmammalian; D005260:Female; D005399:Fishes / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D018392:Genomic Imprinting; D006133:Growth Substances / Q000235:genetics*; D007335:Insulin-Like Growth Factor II; D008297:Male; D011506:Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D006133:Growth Substances; C035170:IGF2 protein, human; D011506:Proteins; D007335:Insulin-Like Growth Factor II