OXA and OX1R are expressed in mice testes throughout the postnatal development. OXA and OX1R are localized in both tubular and interstitial compartments of testis. Expression for both increases at mRNA and protein level from birth until adulthood. Adult testis shows maximal expression for OXA and OX1R at mRNA and protein level. Binding of OXA to OX1R may help in testicular cell development and spermatogenesis.