Turner, K A; Fishman, Emi L; Asadullah, Mariam; Ott, Brooke; Dusza, Patrick; Shah, T A; Sindhwani, Puneet; Nadiminty, Nagalakshmi; Molinari, Emanuela; Patrizio, Pasquale; Saltzman, Barbara S; Avidor-Reiss, Tomer
A large proportion of infertility and miscarriage causes are unknown. One potential cause is a defective sperm centriole, a subcellular structure essential for sperm motility and embryonic development. Yet, the extent to which centriolar maladies contribute to male infertility is unknown due to the lack of a convenient way to assess centriole quality. We developed a robust, location-based, ratiometric assay to overcome this roadblock, the Fluorescence-based Ratiometric Assessment of Centrioles (FRAC). We performed a case series study with semen samples from 33 patients, separated using differential gradient centrifugation into higher-grade (pellet) and lower-grade (interface) sperm fractions. Using a reference population of higher-grade sperm from infertile men with morphologically standard sperm, we found that 79% of higher-grade sperm of infertile men with substandard sperm morphology have suboptimal centrioles ( = 0.0005). Moreover, tubulin labeling of the sperm distal centriole correlates negatively with age ( = 0.004, = -0.66). These findings suggest that FRAC is a sensitive method and that patient age and sperm morphology are associated with centriole quality.