Androglobin, a chimeric mammalian globin, is required for male fertility.

Spermatogenesis is a highly specialised differentiation process driven by a dynamic gene expression program and ending with the production of mature spermatozoa. Whereas hundreds of genes are known to be essential for male germline proliferation and differentiation, the contribution of several genes remains uncharacterized. The predominant expression of the latest globin family member, androglobin (Adgb), in mammalian testis tissue prompted us to assess its physiological function in spermatogenesis. Adgb knockout mice display male infertility, reduced testis weight, impaired maturation of elongating spermatids, abnormal sperm shape and ultrastructural defects in microtubule and mitochondrial organisation. Epididymal sperm from Adgb knockout animals display multiple flagellar malformations including coiled, bifid or shortened flagella, and erratic acrosomal development. Following immunoprecipitation and mass spectrometry, we could identify septin 10 (Sept10) as interactor of Adgb. The Sept10-Adgb interaction was confirmed both in vivo using testis lysates, and in vitro by reciprocal co-immunoprecipitation experiments. Furthermore, absence of Adgb leads to mislocalisation of Sept10 in sperm, indicating defective manchette and sperm annulus formation. Finally, in vitro data suggest that Adgb contributes to Sept10 proteolysis in a calmodulin (CaM)-dependent manner. Collectively, our results provide evidence that Adgb is essential for murine spermatogenesis and further suggest that Adgb is required for sperm head shaping via the manchette and proper flagellum formation.

eLife. 2022 Jun 14 [Epub ahead of print]

Anna Keppner, Miguel Correia, Sara Santambrogio, Teng Wei Koay, Darko Maric, Carina Osterhof, Denise V Winter, Angèle Clerc, Michael Stumpe, Frédéric Chalmel, Sylvia Dewilde, Alex Odermatt, Dieter Kressler, Thomas Hankeln, Roland H Wenger, David Hoogewijs

Department of Endocrinology, Metabolism and Cardiovascular system, University of Fribourg, Fribourg, Switzerland., Institute of Physiology, University of Zurich, Zurich, Switzerland., Institute for Organismic and Molecular Evolutionary Biology, University of Mainz, Mainz, Germany., Department of Pharmaceutical Sciences, University of Basel, Basel, Switzerland., Department of Biology, University of Fribourg, Fribourg, Switzerland., University of Rennes, Inserm, UMR_S 1085, Rennes, France., Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium.