Dwarf mice as models for reproductive aging research

Abstract Dwarf mice are characterized by extremely long lifespan, delayed ovarian aging, altered metabolism, lower age-related oxidative damage and cancer incidence rate. Snell dwarf mice, Ames dwarf and growth hormone receptor knockout mice are three commonly used models. Despite studies focusing on aging and metabolism, the reproductive features of female dwarf mice have also attracted interest in the last decade. Female Snell and Ames dwarf mice have regular estrous cycles and ovulation rates as in normal mice, but with a larger ovarian reserve and delayed ovarian aging. The primordial follicle reserve in dwarf mice is greater than in normal littermates. Anti-Mullerian hormone level is seven times higher in Ames dwarf mice than in their normal siblings, and ovarian transcriptomic profiling showed distinctive patterns in older Ames dwarf mice, especially enriched in inflammatory and immune response-related pathways. In addition, microRNA profiles also showed distinctive differences in Ames dwarf mice compared with normal control littermates. This review aims to summarize research progress about dwarf mice as models in the reproductive aging field. Investigations focusing on the mechanisms of their reserved reproductive ability are highly required and are expected to provide additional molecular biological bases for the clinical practice of reproductive medicine in women.