title: Genomic imprinting of a placental lactogen gene in Peromyscus.
abstract: The mammalian genome contains over 30 genes whose expression is dependent upon their parent-of-origin. Of these imprinted genes the majority are involved in regulating the rate of fetal growth. In this report we show that in the deer mouse Peromyscusthe placental lactogen-1-variant ( pPl1-v) gene is paternally expressed throughout fetal development, whereas the linked and closely related pPl1gene is expressed in a biallelic manner. Neither the more distantly related pPl2Agene, nor the Mus Pl1gene displays any preferential expression of the paternal allele, suggesting that the acquisition of imprinting of pPl1-v is a relatively recent event in evolution. Although pPl1 expression is temporally mis-regulated in the dysplastic placentae of hybrids between two Peromyscus species, its over-expression cannot account for the aberrant phenotypes of these placentae. We argue that the species-specific imprinting of pPl1-v, encoding a growth factor that regulates nutrient transfer from mothers to their offspring, is consistent with the parent-offspring conflict model that has been proposed to explain the evolution of genomic imprinting.
authors.affiliation: Howarh Hughes Medical Institute and Department of Molecular Biology, Princeton University, NJ 08544, USA. pvrana@uci.edu
authors.forename: P B
authors.initials: PB
authors.lastname: Vrana
authors.forename: P G
authors.initials: PG
authors.lastname: Matteson
authors.forename: J V
authors.initials: JV
authors.lastname: Schmidt
authors.forename: R S
authors.initials: RS
authors.lastname: Ingram
authors.forename: A
authors.initials: A
authors.lastname: Joyce
authors.forename: K L
authors.initials: KL
authors.lastname: Prince
authors.forename: M J
authors.initials: MJ
authors.lastname: Dewey
authors.forename: S M
authors.initials: SM
authors.lastname: Tilghman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019143:Evolution, Molecular; D015870:Gene Expression; D018392:Genomic Imprinting; D006824:Hybridization, Genetic / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D010542:Peromyscus; D010802:Phylogeny; D010920:Placenta / Q000378:metabolism; D010928:Placental Lactogen / Q000235:genetics*; D017385:Sequence Homology
chemical_list: D010928:Placental Lactogen