Sperm Storage Mechanisms in Female Reproductive Systems

Female sperm storage represents a suite of anatomical, physiological and molecular adaptations that allow internal fertilisation to be decoupled from copulation. Across vertebrate groups – notably birds, reptiles, amphibians and some mammals – specialised regions of the oviduct form sperm reservoirs, often in the form of tubular crypts or glands embedded in the mucosal epithelium. Within these reservoirs, spermatozoa are maintained in a metabolically quiescent state by combinations of low oxygen tension, acidified microenvironments and selective ion balances. Concurrently, the female immune response is locally modulated to tolerate foreign gametes while endocrine signals, including androgens in some reptiles, influence reservoir function and sperm viability. Recent molecular studies have revealed gene networks and signalling pathways that govern sperm adhesion, survival and timed release, with practical implications for conservation of endangered species, optimisation of artificial insemination in agriculture and understanding of fertility disorders in diverse taxa.

Research from Nature Portfolio

Genome‐wide association studies in domestic hens have identified multiple single‐nucleotide polymorphisms linked to the duration‐of‐fertility trait, mapping key loci to genes involved in steroid signalling, extracellular matrix composition and cell adhesion. Validation of candidate loci highlighted differential expression of CYP2D6, ESR1 and TGFBR3 in individuals exhibiting extended post‐insemination fertility. Separate work has elucidated the biochemical basis of sperm quiescence in avian sperm storage tubules, demonstrating that elevated lactic acid concentrations and hypoxia in the tubule lumen drive cytoplasmic acidification of sperm and inactivation of dynein ATPase, thereby preserving flagellar integrity over weeks at body temperature.

Sperm Storage Mechanisms in Female Reproductive Systems publication trend

The graph below shows the total number of articles in sperm storage mechanisms in female reproductive systems across all publications each year (not limited to Nature Index journals).

Technical terms

Sperm storage tubules (SSTs): specialised invaginations or crypts in the oviductal epithelium where spermatozoa are sequestered and maintained in a quiescent state.

Duration‐of‐fertility trait: the interval, measured in days, between copulation (or insemination) and the last egg laid that remains fertilisable.

Quiescence: a reversible state of reduced motility and metabolic activity adopted by stored sperm to prolong viability.

RNA‐seq and Ribo‐seq: high‐throughput sequencing methods that quantify transcript levels and ribosome‐protected mRNA fragments, respectively, to assess gene expression and translation dynamics.

Immunomodulation: local suppression or alteration of immune responses in the oviduct to prevent rejection of stored spermatozoa.

References

1. Investigating the genetic determination of duration-of-fertility trait in breeding hens. Scientific Reports (2024).
2. Lactic acid is a sperm motility inactivation factor in the sperm storage tubules. Scientific Reports (2015).
3. Identification of genes associated with sperm storage capacity in hens at different times after insemination by RNA-seq and Ribo-seq. BMC Genomics (2024).
4. Physiological factors influencing female fertility in birds. Royal Society Open Science (2021).
5. Detrimental effects of excessive fatty acid secretion on female sperm storage in chickens. Journal of Animal Science and Biotechnology (2020).
6. Androgen-related sperm storage in oviduct of Chinese Soft-Shelled Turtle in vivo during annual cycle. Scientific Reports (2016).