Chromatin compaction mediates progenitor to post-mitotic cell transitions and modulates gene expression programs, yet the mechanisms are poorly defined. Snf2h and Snf2l are ATP-dependent chromatin remodelling proteins that assemble, reposition and space nucleosomes, and are robustly expressed in the brain. Here we show that mice conditionally inactivated for Snf2h in neural progenitors have reduced levels of histone H1 and H2A variants that compromise chromatin fluidity and transcriptional programs within the developing cerebellum. Disorganized chromatin limits Purkinje and granule neuron progenitor expansion, resulting in abnormal post-natal foliation, while deregulated transcriptional programs contribute to altered neural maturation, motor dysfunction and death. However, mice survive to young adulthood, in part from Snf2l compensation that restores Engrailed-1 expression. Similarly, Purkinje-specific Snf2h ablation affects chromatin ultrastructure and dendritic arborization, but alters cognitive skills rather than motor control. Our studies reveal that Snf2h controls chromatin organization and histone H1 dynamics for the establishment of gene expression programs underlying cerebellar morphogenesis and neural maturation.
Bibliographical noteFunding Information:
We are grateful to Dr Diane Lagace and Mirela Hasu at the University of Ottawa Behavioral Core for assistance with behavioural experiments and expert discussions. We thank Dr Alexandra Joyner for pan-Engrailed antibodies. M.A.-S. thanks D.J.P. for funding and Dr Peter Becker for expert discussions. This work was funded by operating grants GACR P305/12/1033 and UNCE 20421 to T.S.; NIH grant R01 CA079057 to A.I.S.; and CIHR grants MOP97764 and MOP84412 to D.J.P.