Hypothalamic transplantation repair of reproductive defects in hypogonadal mice

The defect of the hypogonadal mouse, resulting in infantile reproductive organs and severely reduced gonadotropin levels, is due to a truncation of the gene encoding for preprogonadotropinreleasing hormone. The hypogonadal mouse bearing a graft containing normal gonadotropin-releasing hormone neurons may show testicular development, seminal vesicle growth, and increased gonadotropin production in males. Normalization of gonadotropin levels in females is frequently associated with the capacity for a reflex ovulation followed by pregnancy and bearing of live young. All of these phenomena are dependent on the outgrowth of gonadotropin-releasing hormone axons from the graft to the host median eminence and the hypophysial portal capillaries.