Restricted water intake influences male reproduction in two strains of house mice (Mus musculus)

Males from two strains of house mice (Mus musculus) were subjected to ten weeks of simulated drought in the laboratory. Water availability was reduced to 50% of ad lib intake for 5 weeks, then further restricted to 25% of ad lib consumption for an additional 5 weeks. Individuals of the highly inbred (CF1) strain were generally unaffected by water restriction. Testicular and epididymal mass of restricted CF1 animals did not change relative to control mice with ad lib access to water. Seminal vesicle mass decrease in water restricted CF1 males, but spermatogenesis was not significantly influenced. Body mass was reduced 25.4% after water restriction. In contrast, male F4 progeny of wild-caught Mus substantially reduced reproductive organ mass after limited water intake. Spermatogenesis was significantly diminished, but no animals became completely aspermatic. Body mass declined 12.6% in water restricted wild-strain Mus as compared to animals with ad lib water availability. These results are discussed in terms of their possible ecological significance.