Meiotic divisions and round spermatid formation do not require centriole duplication in mice

Abstract Authors: Meiotic divisions and round spermatid formation do not require centriole duplication in mice

Marnie W. Skinner^1,2,3; Paula B. Nhan²; Carter J. Simington¹; Philip W. Jordan^1,2,4,*

1. Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA

2. Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA

3. The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA


4. School of Biomedicine, The University of Adelaide, Adelaide, SA, 5000, Australia

Abstract Text: Centrosomes, composed of centrioles and pericentriolar matrix, are traditionally viewed as essential microtubule-organizing centers (MTOCs) that facilitate bipolar spindle formation and chromosome segregation during spermatogenesis. In this study, we investigated the role of centrioles in male germ cell development by using a conditional knockout (cKO) of Sas4, a critical component of centriole biogenesis, in mouse spermatocytes. We found that while centriole duplication was impaired in Sas4 cKO spermatocytes, these cells were still capable of progressing through meiosis I and II. Chromosome segregation was able to proceed through the formation of a non-centrosomal MTOC, indicating that centrioles are not required for meiotic divisions. However, spermatids that inherited fewer than two centrioles exhibited severe defects in spermiogenesis, including improper manchette formation, mislocalized perinuclear rings, disrupted acrosome morphology, and failure to form flagella. Consequently, Sas4 cKO males were infertile due to the absence of functional spermatozoa. Our findings demonstrate that while centrioles are dispensable for meiosis in male germ cells, they are essential for spermiogenesis and sperm maturation. This work provides key insights into the role of centrosomes in male fertility and may have implications for understanding certain forms of male infertility associated with centriole defects.