SRA

Germ cells have evolved unique mechanisms to ensure an everlasting transmission of their genetic and epigenetic information to future generations, whose alteration compromises germ cell immortality. In many instances, epigenetic factors play fundamental roles in these mechanisms. Despite H3K36 and H3K27 methyltransferases shape and propagate over generations a pattern of histone methylation essential for C. elegans germ cell maintenance, the role of respective histone demethylases in this context remains mainly unexplored. Here, we show that jmjd-5 regulates the level of H3K36me2 and H3K27me3, preserves germ cell immortality at high temperature and protects germ cell identity by controlling somatic and germline gene expression. Strikingly, the biological and transcriptional effects of jmjd-5 loss can be hindered by the removal of demethylases for H3K27, indicating that H3K36/K27 demethylases act in a transcriptional framework and promote the accurate balance between H3K36 and H3K27 methylation required for the maintenance of germ cell immortality. Furthermore, we found that in wild-type, but not in jmjd-5 mutant animals, alterations of H3K27 and H3K36 methylation and transcription occur at high temperature, suggesting a role for jmjd-5 in adaptation to environmental changes. Overall design: Elucidate the role of jmjd-5 in safeguarding germline immortality