Genomic imprinting of a placental lactogen gene in Peromyscus.
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.
Vrana
P B
PB
Howarh Hughes Medical Institute and Department of Molecular Biology, Princeton University, NJ 08544, USA. pvrana@uci.edu
Matteson
P G
PG
Schmidt
J V
JV
Ingram
R S
RS
Joyce
A
A
Prince
K L
KL
Dewey
M J
MJ
Tilghman
S M
SM
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
D010928:Placental Lactogen