Identification of histone modifications reveals an association of H2b monoubiquitination with gonadal transdifferentiation

Gonadal trans-differentiation from ovary to testis occurs in a same individual, suggesting a role of epigenetic regulation. However, histone modifications concerning the sex reversal process remain elusive. Here, we report a developmental atlas of histone modifications in the gonadal differentiation, including acetylation, methylation, and ubiquitination, using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We provided a detail distribution map of these modification sites including novel histone modifications along histones H2a, H2b, H3, and H4, and revealed their relationship with types of gonadal differentiation. We then determined a testis-enriched histone modification site, H2b monoubiquitination at K120, and its association with spermatogenesis. ChIP-seq demonstrated that the modification was highly enriched in the male sex-determining gene dmrt1, in particular association with its exon regions, suggesting its role in transcriptional elongation of dmrt1 in testis. Together, these data not only provide a new resource for epigenetic study in gonadal development, but also define an association of histone modifications in gonadal differentiation from ovary to testis. Overall design: ChIP-seq of histone H2BK120ub in ovary and testis of Monopterus albus