and negatively regulate JNK signalling during spermatogenesis.

One fundamental property of a stem cell niche is the exchange of molecular signals between its component cells. Niche models, such as the testis, have been instrumental in identifying and studying the conserved genetic factors that contribute to niche molecular signalling. Here, we identify (), an allele of (), which is a core member of the highly conserved Striatin-interacting phosphatase and kinase (STRIPAK) complex. In the developing testis, cell-autonomously regulates the differentiation and morphology of the somatic lineage, and non-cell-autonomously regulates the proliferation and differentiation of the germline lineage. Mechanistically, acts in the somatic lineage with its STRIPAK partner, (), where they negatively regulate the Jun N-terminal kinase (JNK) signalling pathway. Our study reveals a novel role for / in JNK pathway regulation during spermatogenesis within the developing testis.