Sexually dimorphic cell-cycle progression regulates asymmetric neural progenitor division

Sex differences in neuron number, neural circuit organisation and behaviour exist across the animal kingdom. Quiescent glia cells act as neural progenitors across species but whether and how sex-specific cell-cycle progression is controlled and coupled to asymmetric neuronal cell fate specification remains unclear. We have shown that a class of glial cells, present in both sexes of C. elegans, are sexually dimorphic neural progenitors. They undergo a male-specific asymmetric cell division leading to self-renewal and the generation of a class of interneurons required for a male-only associative learning behaviour. We have uncovered a multi-step, sexually dimorphic genetic programme that regulates quiescence exit and tightly links cell cycle progression to asymmetric neural progenitor division. Our work identifies principles by which cell‑cycle architecture can generate sexually dimorphic neural outcomes.