Year: 2026
Type: article
Abstract: Circadian disruption is increasingly associated with male reproductive dysfunction, yet the developmental stages underlying this relationship remain poorly defined. We investigated whether chronic circadian desynchrony disrupts the stage-specific molecular and bioenergetic organization of spermiogenesis and compromises male fertility. Adult Wistar rats were maintained under a standard light-dark cycle or exposed for two months to repeated cycles of constant light, constant darkness, and light-dark conditions. Round spermatids, elongated spermatids, and epididymal spermatozoa were analyzed for clock- and mitochondria-related gene expression and mitochondrial bioenergetics. Under control conditions, spermiogenesis exhibited coordinated stage- and time-dependent transcriptional and bioenergetic organization, with developing spermatids relying predominantly on oxidative phosphorylation. Circadian desynchrony reduced circulating testosterone and the abundance of elongated spermatids and disturbed stage-specific clock and mitochondrial gene expression, with the most pronounced transcriptional alterations in elongated spermatids. Bioenergetic responses were also stage-dependent: ATP levels increased in round spermatids but decreased in elongated spermatids and spermatozoa, accompanied by stage-dependent alterations in mitochondrial homeostasis. Circadian desynchrony impaired the progesterone-induced acrosome reaction and significantly reduced litter size. These findings identify spermiogenesis as a circadian-sensitive developmental process and highlight elongated spermatids as a particularly vulnerable stage, suggesting a link between disrupted temporal organization, mitochondrial dysfunction, and impaired male fertility.
Source: Scientific Reports
Institution: University of Novi Sad
Language: English
Subfield: Reproductive Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,690
OpenAlex ID: W7204473744