Abstract
The development and function of male gametes is critically dependent on a dynamic microtubule network, yet how this is regulated remains poorly understood. We have recently shown that microtubule severing, via the action of the meiotic AAA ATPase protein clade, plays a critical role in this process. Here, we sought to elucidate the roles of spastin, an as yet unexplored member of this clade in spermatogenesis. Using a SpastKO/KO mouse model, we reveal that spastin loss resulted in a complete loss of functional germ cells. Spastin plays a critical role in the assembly and function of the male meiotic spindle, and in its absence, apoptosis is significantly increased. Consistent with meiotic failure, round spermatid nuclei were enlarged, indicating aneuploidy, but were still able to enter spermiogenesis. During spermiogenesis, we observed extreme abnormalities in manchette structure, supernumerary acrosome formation, and commonly, a loss of nuclear integrity. This work defines a novel and essential role for spastin in regulating microtubule dynamics during spermatogenesis and is of potential relevance to patients carrying Spastin variants and to the medically assisted reproductive technology industry.
Summary statement We identify an essential role for the microtubule severing enzyme spastin in the regulation of microtubule dynamics during spermatogenesis.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Contact information: moira.obryan{at}unimelb.edu.au and Jessica.dunleavy{at}unimelb.edu.au
To include supplemental data.
