Evolution of X Inactivation in Mammals
Author Information
Author(s): Julie Chaumeil, Paul D. Waters, Edda Koina, Clément Gilbert, Terence J. Robinson, Jennifer A. Marshall Graves
Primary Institution: The Australian National University
Hypothesis
Whether the histone marks associated with XCI in human and mouse were also found in distantly related placental mammals, and in marsupials without the XIST gene.
Conclusion
The study reveals that marsupial XCI displays a unique profile of repressive marks that differ from placental mammals, suggesting an ancestral mechanism of X inactivation.
Supporting Evidence
- The inactive X chromosome in marsupials shows a unique pattern of histone modifications.
- XIST is absent in marsupials, suggesting a different mechanism of X inactivation.
- Histone marks associated with transcription are excluded from the inactive X chromosome in both marsupials and placental mammals.
Takeaway
This study looks at how female mammals turn off one of their X chromosomes and finds that marsupials do it differently than placental mammals, using different chemical markers.
Methodology
Immunofluorescence analysis of histone modifications in interphase nuclei of various mammalian species.
Limitations
The study primarily focuses on a limited number of marsupial and placental species, which may not represent all variations in XCI.
Participant Demographics
The study includes female cells from tammar wallaby, opossum, and elephant.
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website