ACTRT1 and spermatogenic failure 16: Heid et al. (2002) used immunofluorescence staining to show that ACTRT1 is mainly expressed in the calyx and pericentriolar material (PCM) of bull spermatozoa (Heid et al., 2002). Centrioles are an indispensable component of the HTCA, and the dysfunction of sperm centriole-associated proteins can cause acephalic spermatozoa syndrome (Chemes and Rawe, 2010; Kim et al., 2018; Reina et al., 2018; Sha et al., 2020). These data indicate that ACTRT1 may play a role in fastening the sperm head and flagellum.