Ciliary control of meiotic chromosomal pairing mechanics and germ cell morphogenesis in zebrafish and mouse

A hallmark of meiosis is chromosomal pairing, which requires telomere tethering and rotation on the nuclear envelope via microtubules, driving chromosome homology searches. Telomere pulling towards the centrosome forms the “zygotene chromosomal bouquet”. Here, we identified the “zygotene cilium” in oocytes. This cilium providess a cable system for the bouquet machinery, extending throughout the germline cyst. Using zebrafish mutants and live manipulations, we demonstrate that the cilium anchors the centrosome to counterbalance telomere pulling. The cilium is essential for bouquet and synaptonemal complex formation, oogenesis, ovarian development, and fertility. Thus, a cilium represents a conserved player in zebrafish and mouse meiosis, which sheds light on reproductive aspects in ciliopathies, and suggests that cilia can control chromosomal dynamics.