Molecular factors shaping small RNA content in mouse sperm
Year: 2026
Type: preprint
Abstract: In mammalian reproduction, sperm and oocytes fuse to generate embryos. In contrast to maternally inherited small RNAs, sperm-borne small RNAs have been implicated in embryo viability but remain incompletely understood. Unanswered questions about molecular forces shaping small RNA content in sperm and sources of reporting discrepancies hinder a deeper understanding of their post-fertilization roles. Here, we investigate the dynamics and protein association of small RNAs in C57BL/6 mice during spermiogenesis and sperm capacitation. Using unique molecular identifiers and spike-ins to minimize technical biases in low-input sequencing, we demonstrate a selective sperm small RNA repertoire derived from a subset of spermatogenic small RNAs that remains malleable during capacitation. Retained PIWI-interacting RNAs persist despite widespread RNA decay and are insensitive to capacitation, which may be partly attributed to their association with MIWI proteins. Our data reveal RNA species susceptible to PCR duplicate-related abundance overestimation and uncover biological and technical factors shaping experimentally observed sperm small RNA profiles. These findings refine our understanding of sperm-borne RNAs and inform future functional studies and medically assisted reproduction.
Language: English
Subfield: Reproductive Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7171972166