Development Genes and Evolution

, Volume 226, Issue 2, pp 79–85

Allelic expression of mammalian imprinted genes in a matrotrophic lizard, Pseudemoia entrecasteauxii

  • Oliver W. Griffith
  • Matthew C. Brandley
  • Katherine Belov
  • Michael B. Thompson
Original Article

Abstract

Genomic imprinting is a process that results in the differential expression of genes depending on their parent of origin. It occurs in both plants and live-bearing mammals, with imprinted genes typically regulating the ability of an embryo to manipulate the maternal provision of nutrients. Genomic imprinting increases the potential for selection to act separately on paternally and maternally expressed genes, which increases the number of opportunities that selection can facilitate embryonic control over maternal nutrient provision. By looking for imprinting in an independent matrotrophic lineage, the viviparous lizard Pseudemoia entrecasteauxii (Scincidae), we test the hypothesis that genomic imprinting facilitates the evolution of substantial placental nutrient transport to embryos (matrotrophy). We sequenced transcriptomes from the embryonic component of lizard placentae to determine whether there are parent-of-origin differences in expression of genes that are imprinted in mammals. Of these genes, 19 had sufficiently high expression in the lizard to identify polymorphisms in transcribed sequences. We identified bi-allelic expression in 17 genes (including insulin-like growth factor 2), indicating that neither allele was imprinted. These data suggest that either genomic imprinting has not evolved in this matrotrophic skink or, if it has, it has evolved in different genes to mammals. We outline how these hypotheses can be tested. This study highlights important differences between mammalian and reptile pregnancy and the absence of any shared imprinting genes reflects fundamental differences in the way that pregnancy has evolved in these two lineages.

Keywords

Viviparity Parent-offspring conflict Pseudemoia Placenta Placentotrophy Lizard Scincidae Genomic imprinting 

Supplementary material

427_2016_531_MOESM1_ESM.docx (66 kb)
ESM 1(DOCX 65 kb)

Copyright information

© Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  1. 1.School of Life and Environmental SciencesUniversity of SydneySydneyAustralia
  2. 2.Department of Ecology and Evolutionary BiologyYale UniversityNew HavenUSA
  3. 3.New York University – SydneyThe RocksAustralia

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