Seasonal and age-related changes in sperm quality of farmed arctic charr (Salvelinus alpinus)

• Published in: BMC Genomics
• Main Authors: Khrystyna Kurta, Henrik Jeuthe, Rakan Naboulsi, Dirk-Jan de Koning, Christos Palaiokostas
• Format: Article in Journal/Newspaper
• Language: English
• Published: BMC 2023
• Subjects: Arctic charr; Sperm concentration; Motility; Season; Age; Whole-genome sequencing; Biotechnology; TP248.13-248.65; Genetics; QH426-470; Arctic; Salvelinus alpinus
• Online Access: https://doi.org/10.1186/s12864-023-09614-9; https://doaj.org/article/e2bbeacbad944c6cb0d86ad42245ce8a

Abstract Background Substantial variation in male fertility is regularly observed in farmed Arctic charr. However, detailed investigations of its fluctuation during a reproductive season and across years are lacking. Furthermore, information about the effect of underlying genetic factors influencing sperm quality is scarce. The current study focused on seasonal and age-related factors that may affect sperm quality characteristics in males reared in natural and delayed photoperiods. Animals were sampled three times for two consecutive years, and sperm quality parameters were recorded using a computer-assisted sperm analysis (CASA) system. Thereafter, high-throughput sequencing technologies were applied, aiming to identify genomic regions related to the variation of sperm quality throughout the reproductive season. Results An across-season variation in the recorded sperm quality parameters was evident. Overall, 29% and 42% of males from the natural and delayed spawning groups had a highly variable total progressive motility. Males at four years of age showed significantly higher sperm motility and velocities during the early October and November recordings compared to the following year when the same animals were five years of age. On the other hand, the opposite was observed regarding sperm concentration during the last sampling. A genome-wide F ST scan detected SNP differentiation among males with high and low variability in total progressive motility (PM) on eight chromosomes (F ST > 0.17), Genome wide windows with the highest F ST contained SNPs in proximity (within 250 kb up- and downstream distance) to 16 genes with sperm quality biological functions in mammalian species. Conclusion Our findings provide a detailed view of seasonal, age-related, and genetic effects on sperm quality and can be used to guide decisions on broodstock selection and hatchery management.