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Divergent genetic and epigenetic post-zygotic isolation mechanisms in Mus and Peromyscus

Item Type:Article
Title:Divergent genetic and epigenetic post-zygotic isolation mechanisms in Mus and Peromyscus
Creators Name:Zechner, U. and Shi, W. and Hemberger, M. and Himmelbauer, H. and Otto, S. and Orth, A. and Kalscheuer, V. and Fischer, U. and Elango, R. and Reis, A. and Vogel, W. and Ropers, H. and Rueschendorf, F. and Fundele, R.
Abstract:Interspecific hybridization in the rodent genera Peromyscus and Mus results in abnormal placentation. In the Peromyscus interspecies hybrids, abnormal allelic interaction between an X-linked locus and the imprinted paternally expressed Peg3 locus was shown to cause the placental defects. In addition, loss-of-imprinting (LOI) of Peg3 was positively correlated with increased placental size. As in extreme cases this placental dysplasia constitutes a post-zygotic barrier against interspecies hybridization, this finding was the first direct proof that imprinted genes may be important in speciation and thus in evolution. In the Mus interspecies hybrids, a strong role of an X-linked locus in placental dysplasia has also been detected. However, here we show by backcross and allele specific expression analyses that neither LOI of Peg3 nor abnormal interactions between Peg3 and an X-linked locus are involved in generating placental dysplasia in Mus hybrids, although the placental phenotypes observed in the two genera seem to be identical. In contrast to this, another dysgenesis effect common to Peromyscus and Mus hybrids, altered foetal growth, is caused at least in part by the same X-chromosomal regions in both genera. These findings first underline the strong involvement of the X-chromosome in the genetics of speciation. Secondly, they indicate that disruption of epigenetic states, such as LOI, at specific loci may be involved in hybrid dysgenesis effects in one group, but not in another. Thus, we conclude that even in closely related groups divergent molecular mechanisms may be involved in the production of phenotypically similar post-zygotic barriers against hybridization.
Keywords:Hybrid Dysgenesis, Interspecies Hybridization, Loss-of-Imprinting, Mus, Peromyscus, Placentation, Animals, Mice
Source:Journal of Evolutionary Biolog
Publisher:Blackwell Publishing
Page Range:453-460
Date:1 January 2004
Official Publication:https://doi.org/10.1046/j.1420-9101.2003.00656.x
PubMed:View item in PubMed

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