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Biology subjects

Heuer, R. A.

Publications and source records attributed to Heuer, R. A..

2 recordsLinked to original sources

Paternal regulation of H3K4 methylation supports tumor suppressor networks in mammals intergenerationally

Paternally-inherited epigenetic information can influence phenotype in offspring (1). Here, we identify a critical mechanistic contribution of KDM6A (UTX), an X-linked histone modifier and tumor suppressor, in regulating transmissible epigenetic information in mammalian sperm. Paternal loss of KDM6A increases cancer risk in genetically wild type offspring, but how Kdm6a knockout sperm transmit this effect at the molecular level is unknown (2). We find that KDM6A functions in spermatogenesis to promote methylation of histone H3 lysine 4 (H3K4) via selective interaction with the COMPASS complex methyltransferase KMT2C (MLL3). KMT2C and KDM6A are coordinately recruited to promoters of active genes in spermatogenic cells, contrasting with recruitment to intergenic enhancers in other cell types (3, 4). Loss of KDM6A disrupts H3K4 methylation at promoters of tumor suppressor genes in spermatogonia, and some of these defects persist in epididymal sperm and correspond to impaired expression in preimplantation embryos. These genes are also misregulated in normal and malignant hematopoietic tissue of genetically wild type offspring, indicating that impaired H3K4 methylation in KDM6A-deficient male germ cells may preferentially alter regulation of tumor suppressor gene networks in development across generations.

genetics↗

Protamine lacunae preserve the paternal chromatin landscape in sperm

The transmission of the paternal genome requires extensive chromatin reorganization, in which nucleosomes are largely replaced by protamines that drive extreme condensation of the genome in the sperm head. Using Fiber-seq, we resolve patterns of paternal chromatin repackaging in sperm at single-molecule resolution, revealing the interplay between protamination and nucleosome retention. We find that nucleosome retention is probabilistic, with no locus universally occupied. Although promoters of spermatogenic genes preferentially harbor retained nucleosomes, the predominant carrier of paternal epigenetic information is protamine lacunae, accessible discontinuities in the protamine coat that preferentially mark critical regulatory elements. By contrast, centromere kinetochore binding regions robustly retain CENP-A mono-nucleosomes, providing a mechanism for the focal transmission of paternal centromeres. Finally, we find that paternal chromatin repackaging is altered in low-motility sperm. Together, these findings reveal distinct modes of paternal chromatin epigenetic inheritance with broad implications for development and infertility.

genomics↗