Neuropeptide FF indirectly affects testicular morphogenesis and functions in medaka.

Testicular morphogenesis and functions are considered to be under the control of neural and endocrine systems. However, the available literature is mainly limited to mammals, and it remains unclear how they are regulated in teleost species. Here, we demonstrated that neuropeptide FF (NPFF) in the brain is responsible for the follicle-stimulating hormone expression in the pituitary, which facilitates the testicular morphogenesis and androgen synthesis, and subsequently contributes to successful spermatogenesis. The present findings give us important insights into the neuroendocrine regulatory mechanisms underlying the testicular morphogenesis and functions in teleosts.