Torpor expression is associated with differential spermatogenesis in hibernating eastern chipmunks

Area of Science:

• Reproductive Biology
• Animal Physiology
• Hibernation Research

Background:

• Hibernation involves suppressed physiology, but its impact on male reproduction is unclear.
• Deep torpor may impair spermatogenesis and increase oxidative stress, potentially damaging sperm.

Purpose of the Study:

• To investigate how torpor expression affects sperm production and reproductive readiness in male eastern chipmunks.
• To determine the relationship between torpor depth and spermatogenesis during hibernation.

Main Methods:

• Assessed torpor depth using temperature data loggers in captive chipmunks.
• Examined spermatogenic progression, cell division, sperm counts, maturity, and DNA damage.
• Compared reproductive parameters between deep and shallow hibernators.

Main Results:

• Deep hibernators largely halted spermatogenesis, while shallow hibernators maintained it.
• No differences in sperm progression, numbers, or maturity were found in spring.
• Shallow hibernators had higher DNA damage during hibernation, reversing in spring.

Conclusions:

• Deep torpor suppresses spermatogenesis, but sperm production recovers post-hibernation.
• Deep hibernators may experience increased sperm DNA damage during spring mating season.
• Torpor expression influences reproductive physiology and potentially sperm quality.