Imprinted X chromosome inactivation in marsupials
This research examines the contrasting mechanisms of eutherian and marsupial X chromosome inactivation (XCI) by investigating one of the key differences: paternal imprinting in marsupials. Analysis of DNA methylation patterns on the marsupial X chromosome during spermatogenesis revealed that genes o...
| Autores: | , , , , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Autònoma de Barcelona |
| Repositorio: | Dipòsit Digital de Documents de la UAB |
| Idioma: | inglés |
| OAI Identifier: | oai:ddd.uab.cat:317822 |
| Acceso en línea: | https://ddd.uab.cat/record/317822 https://dx.doi.org/urn:doi:10.1073/pnas.2412185121 |
| Access Level: | acceso abierto |
| Palabra clave: | DNA methylation Marsupial Imprinting X chromosome inactivation Spermatogenesis |
| Sumario: | This research examines the contrasting mechanisms of eutherian and marsupial X chromosome inactivation (XCI) by investigating one of the key differences: paternal imprinting in marsupials. Analysis of DNA methylation patterns on the marsupial X chromosome during spermatogenesis revealed that genes on the paternal X chromosome exhibit a DNA methylation profile akin to the "silent" profile of genes on inactive X chromosomes in female somatic cells. This observation suggests a preexisting, silent DNA methylation landscape on the paternal X chromosome upon fertilization, which we hypothesize is the long sought-after imprint governing paternal XCI in marsupials. X chromosome inactivation (XCI) is an epigenetic process that results in the transcriptional silencing of one X chromosome in the somatic cells of females. This phenomenon is common to both eutherian and marsupial mammals, but there are fundamental differences. In eutherians, the X chosen for silencing is random. DNA methylation on the eutherian inactive X is high at transcription start sites (TSSs) and their flanking regions, resulting in universally high DNA methylation. This contrasts XCI in marsupials where the paternally derived X is always silenced, and in which DNA methylation is low at TSSs and flanking regions. Here, we examined the DNA methylation status of the tammar wallaby X chromosome during spermatogenesis to determine the DNA methylation profile of the paternal X prior to and at fertilization. Whole genome enzymatic methylation sequencing was carried out on enriched flow-sorted populations of premeiotic, meiotic, and postmeiotic cells. We observed that the X displayed a pattern of DNA methylation from spermatogonia to mature sperm that reflected the inactive X in female somatic tissue. Therefore, the paternal X chromosome arrives at the egg with a DNA methylation profile that reflects the transcriptionally silent X in adult female somatic tissue. We present this epigenetic signature as a candidate for the long sought-after imprint for paternal XCI in marsupials. |
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