Project description:Decades of work in placental (eutherian) species have constructed a paradigm of mammalian development, wherein the genome-wide erasure of parental DNA methylation is required for embryogenesis. Whether such DNA methylation reprogramming is, in fact, conserved in other mammals is unknown. To resolve this point, we generated base-resolution DNA methylation maps in gametes, embryos and adult tissues of the opossum marsupial Monodelphis domestica, revealing extensive variations from the eutherian-derived model. In stark contrast with eutherians, the marsupial genome remains hypermethylated during the cleavage stages and in the embryo proper of the blastocyst. In the extra-embryonic trophectoderm DNA methylation is reduced, suggesting an important evolutionary conserved function for DNA hypomethylation in formation of the mammalian placenta. Furthermore, unlike in eutherians, the inactive X chromosome becomes globally DNA hypomethylated during embryogenesis. Using our DNA methylation profiles, we identify a candidate mechanism for imprinted X-inactivation in marsupials, via maternal promoter DNA methylation of the Xist-like non-coding RNA RSX11. How mammalian embryos employ DNA methylation to regulate their development is therefore more mechanistically diverse than current models can accommodate.
Project description:Decades of work in placental (eutherian) species have constructed a paradigm of mammalian development, wherein the genome-wide erasure of parental DNA methylation is required for embryogenesis1-10. Whether such DNA methylation reprogramming is, in fact, conserved in other mammals is unknown. To resolve this point, we generated base-resolution DNA methylation maps in gametes, embryos and adult tissues of the opossum marsupial Monodelphis domestica, revealing extensive variations from the eutherian-derived model. In stark contrast with eutherians, the marsupial genome remains hypermethylated during the cleavage stages and in the embryo proper of the blastocyst. In the extra-embryonic trophectoderm DNA methylation is reduced, suggesting an important evolutionary conserved function for DNA hypomethylation in formation of the mammalian placenta. Furthermore, unlike in eutherians, the inactive X chromosome becomes globally DNA hypomethylated during embryogenesis. Using our DNA methylation profiles, we identify a candidate mechanism for imprinted X-inactivation in marsupials, via maternal promoter DNA methylation of the Xist-like non-coding RNA RSX11. How mammalian embryos employ DNA methylation to regulate their development is therefore more mechanistically diverse than current models can accommodate.
Project description:Decades of work in placental (eutherian) species have constructed a paradigm of mammalian development, wherein the genome-wide erasure of parental DNA methylation is required for embryogenesis1-10. Whether such DNA methylation reprogramming is, in fact, conserved in other mammals is unknown. To resolve this point, we generated base-resolution DNA methylation maps in gametes, embryos and adult tissues of the opossum marsupial Monodelphis domestica, revealing extensive variations from the eutherian-derived model. In stark contrast with eutherians, the marsupial genome remains hypermethylated during the cleavage stages and in the embryo proper of the blastocyst. In the extra-embryonic trophectoderm DNA methylation is reduced, suggesting an important evolutionary conserved function for DNA hypomethylation in formation of the mammalian placenta. Furthermore, unlike in eutherians, the inactive X chromosome becomes globally DNA hypomethylated during embryogenesis. Using our DNA methylation profiles, we identify a candidate mechanism for imprinted X-inactivation in marsupials, via maternal promoter DNA methylation of the Xist-like non-coding RNA RSX11. How mammalian embryos employ DNA methylation to regulate their development is therefore more mechanistically diverse than current models can accommodate.
Project description:Decades of work in placental (eutherian) species have constructed a paradigm of mammalian development, wherein the genome-wide erasure of parental DNA methylation is required for embryogenesis1-10. Whether such DNA methylation reprogramming is, in fact, conserved in other mammals is unknown. To resolve this point, we generated base-resolution DNA methylation maps in gametes, embryos and adult tissues of the opossum marsupial Monodelphis domestica, revealing extensive variations from the eutherian-derived model. In stark contrast with eutherians, the marsupial genome remains hypermethylated during the cleavage stages and in the embryo proper of the blastocyst. In the extra-embryonic trophectoderm DNA methylation is reduced, suggesting an important evolutionary conserved function for DNA hypomethylation in formation of the mammalian placenta. Furthermore, unlike in eutherians, the inactive X chromosome becomes globally DNA hypomethylated during embryogenesis. Using our DNA methylation profiles, we identify a candidate mechanism for imprinted X-inactivation in marsupials, via maternal promoter DNA methylation of the Xist-like non-coding RNA RSX11. How mammalian embryos employ DNA methylation to regulate their development is therefore more mechanistically diverse than current models can accommodate.
Project description:STRT-N is a newly optimized single-cell RNA sequencing method for studies of early genome activation in mammalian preimplantation development. Here, single embryos from the oocyte, 2-cell, 4-cell, 8-cell, blastocyst, and morula stages were sampled for experiments and were sequenced using STRT-N method.
Project description:Single-nucleus RNA sequencing (snRNA-seq) was used to profile the transcriptome of 9,926 nuclei in opossum adult testis. This dataset includes three samples from three different individuals. This dataset is part of a larger evolutionary study of adult testis at the single-nucleus level (97,521 single-nuclei in total) across mammals including 10 representatives of the three main mammalian lineages: human, chimpanzee, bonobo, gorilla, gibbon, rhesus macaque, marmoset, mouse (placental mammals); grey short-tailed opossum (marsupials); and platypus (egg-laying monotremes). Corresponding data were generated for a bird (red junglefowl, the progenitor of domestic chicken), to be used as an evolutionary outgroup.