Retrotransposon silencing by DNA methylation can drive mammalian genomic imprinting

Date

2007-04-13

Authors

Suzuki, Shunsuke
Ono, Ryuichi
Narita, Takanori
Pask, Andrew J
Shaw, Geoffrey
Wang, Changshan
Kohda, Takashi
Alsop, Amber
Graves, Jennifer
Kohara, Yuji

Journal Title

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Volume Title

Publisher

Public Library of Science

Abstract

Among mammals, only eutherians and marsupials are viviparous and have genomic imprinting that leads to parent-of-origin-specific differential gene expression. We used comparative analysis to investigate the origin of genomic imprinting in mammals. PEG10 (paternally expressed 10) is a retrotransposon-derived imprinted gene that has an essential role for the formation of the placenta of the mouse. Here, we show that an orthologue of PEG10 exists in another therian mammal, the marsupial tammar wallaby (Macropus eugenii), but not in a prototherian mammal, the egg-laying platypus (Ornithorhynchus anatinus), suggesting its close relationship to the origin of placentation in therian mammals. We have discovered a hitherto missing link of the imprinting mechanism between eutherians and marsupials because tammar PEG10 is the first example of a differentially methylated region (DMR) associated with genomic imprinting in marsupials. Surprisingly, the marsupial DMR was strictly limited to the 5′ region of PEG10, unlike the eutherian DMR, which covers the promoter regions of both PEG10 and the adjacent imprinted gene SGCE. These results not only demonstrate a common origin of the DMR-associated imprinting mechanism in therian mammals but provide the first demonstration that DMR-associated genomic imprinting in eutherians can originate from the repression of exogenous DNA sequences and/or retrotransposons by DNA methylation.

Description

Keywords

Keywords: animal cell; animal tissue; article; bacterial artificial chromosome; controlled study; DNA methylation; DNA sequence; fetus; gene; gene locus; gene silencing; gene structure; genome imprinting; mammalian genetics; marsupial; nonhuman; nucleotide sequence

Citation

PLoS Genetics 3.4 e55 (2007): 0531-0537

Source

PLoS Genetics

Type

Journal article

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