Retrotransposon Silencing by DNA Methylation Can Drive Mammalian Genomic Imprinting
2007

How DNA Methylation Affects Genomic Imprinting in Mammals

publication Evidence: moderate

Author Information

Author(s): Suzuki Shunsuke, Ono Ryuichi, Narita Takanori, Pask Andrew J, Shaw Geoffrey, Wang Changshan, Kohda Takashi, Alsop Amber E, Marshall Graves Jennifer A., Kohara Yuji, Ishino Fumitoshi, Renfree Marilyn B, Kaneko-Ishino Tomoko

Primary Institution: Department of Epigenetics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan

Hypothesis

Did genomic imprinting arise as a by-product of a DNA methylation mechanism that silences foreign DNAs?

Conclusion

The study provides evidence that retrotransposon insertion can drive the evolution of genomic imprinting in mammals.

Supporting Evidence

  • PEG10 is an essential placental gene in eutherians.
  • Tammar PEG10 is the first example of a differentially methylated region associated with genomic imprinting in marsupials.
  • The presence of PEG10 in marsupials but not in monotremes suggests its role in the evolution of placentation.
  • Imprinting in marsupials is restricted to PEG10, unlike in eutherians where it includes neighboring genes.

Takeaway

This study shows that a gene important for the placenta in some mammals has a special way of being turned on or off based on which parent it comes from, and this might have started because of a DNA change.

Methodology

Comparative analysis of PEG10 in marsupials and monotremes, along with DNA sequencing and expression analysis.

Limitations

The exact mechanism of how DNA methylation regulates PEG10 imprinting in marsupials remains unclear.

Participant Demographics

Tammar wallabies and platypus were used as representative species.

Statistical Information

P-Value

p<0.01

Statistical Significance

p<0.01

Digital Object Identifier (DOI)

10.1371/journal.pgen.0030055

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