Summary EED (embryonic ectoderm development) is a core component of the Polycomb repressive complex 2 (PRC2) which catalyzes the methylation of histone H3 lysine 27 (H3K27) during the process of self-renewal, proliferation, and differentiation of embryonic stem cells. However, its function in the mammalian nervous system remains unexplored. Here, we report that loss of EED in the brain leads to postnatal lethality, impaired neuronal differentiation, and malformation of the dentate gyrus. Overexpression of Sox11 , a downstream target of EED through interaction with H3K27me1, restores the neuronal differentiation capacity of EED-ablated neural stem/progenitor cells (NSPCs). Interestingly, downregulation of Cdkn2a , another downstream target of EED which is regulated in an H3K27me3-dependent manner, reverses the proliferation defect of EED-ablated NSPCs. Taken together, these findings established a critical role of EED in the development of hippocampal dentate gyrus, which might shed new light on the molecular mechanism of intellectual disability in patients with EED mutations.

Metabolites such as crotonyl-CoA and lactyl-CoA influence gene expression by covalently modifying histones, known as histone lysine crotonylation (Kcr) and lysine lactylation (Kla). However, their existence patterns, dynamic changes, biological functions，and associations with histone lysine acetylation and gene expression during mammalian development remain largely unknown. Here, we find that histone Kcr and Kla are widely distributed in the brain and undergo global changes during neural development. By profiling genome-wide dynamics of H3K9ac, H3K9cr and H3K18la in combination with ATAC and RNA sequencing, we reveal that these marks are tightly correlated with chromatin state and gene expression, and extensively involved in transcriptome remodeling to promote cell-fate transitions in the developing telencephalon. Importantly, we demonstrate that global Kcr and Kla levels are not the consequence of transcription and identify histone deacetylase (HDAC)1-3 as novel “erasers” of H3K18la. Using P19 cells as induced neural differentiation system, we find that HDAC1-3 inhibition by MS-275 pre-activates neuronal transcriptional programs through stimulating multiple histone lysine acylations simultaneously. These findings suggest histone Kcr and Kla play critical roles in the epigenetic regulation of neural development.