SIN3 acts in distinct complexes to regulate the germline transcriptional program in C. elegans [sin-3(tm1276)]

The SIN3 transcriptional coregulator influences gene expression through multiple interactions that include histone deacetylases (HDACs). Haploinsufficiency and mutations in SIN3 are the underlying cause of Witteveen-Kolk syndrome and related intellectual disability (ID)/autism syndromes, emphasizing its key role in development. However, little is know on its complexity of interactions and functions in developmental processes. Here we show that loss of SIN-3, the single SIN3 homologue in Caenorhabditis elegans, results in maternal effect sterility associated with deregulation of the germline transcriptome, including derepression of X-linked genes. Using proteomics analysis we identify at least two SIN3 complexes containing distinct HDACs and differentially contributing to fertility. Single cell smFISH reveals that loss of sin-3 stochastically derepresses X linked genes in individual germ cells. We further identify acetylation marks whose abundance depends on SIN3. Together, this work provides a powerful paradigm for the in vivo study of SIN3 and associated proteins. Overall design: Gene expression profiling of germlines from young adults sin-3(tm1276) mutant and wild-type (wt) worms (used as control)