Spermatozoa centriole quality determined by FRAC may correlate with zygote nucleoli polarization-a pilot study

Spermatozoa centriolar defects can result in abnormal zygote functions. Recently, a method to quantify spermatozoa centriolar defects was developed named Fluorescence-Based Ratiometric Analysis of Sperm Centrioles (FRAC). However, whether spermatozoa centriolar defects identified by FRAC can result in abnormal zygote functions was not tested.

Here, we quantified spermatozoa centriolar defects using FRAC, and zygote centriole function was assessed by imaging Nucleolus Precursor Body (NPB) polarization which was based on the pattern of NPB polarization. Data was analyzed at couple and embryo levels. Subjects were divided into two groups: seven couples and 62 embryos with normal spermatozoa centrioles versus eight couples and 78 embryos with abnormal spermatozoa centrioles (140 embryos from 15 couples in total).

Patterned NPB polarization was statistically significant in both couple- and embryo-level analyses (p < 0.0001 and p = 0.0024). These results suggest that the abnormal spermatozoa centrioles identified by FRAC may correlate with abnormal zygote centrosome function via NPB polarization scoring.

This study provides a foundation for more extensive studies to test for FRAC's utility in assessing spermatozoa centriole quality.