Control of copulation‐enhanced protein synthesis in the long hyaline gland of the male grasshopper, Melanoplus sanguinipes

Abstract

AbstractControl of copulation‐enhanced protein synthesis in the accessory reproductive gland of the male grasshopper, Melanoplus sanguinipes, has been studied by measurement of in vivo incorporation of [35S]methionine into a juvenile hormone (JH)‐regulated Mr 72,000 glycoprotein, long hyaline protein I (LHPI). In normal males, incorporation into LHPI was enhanced within 4 h of the commencement of mating and had increased even further when measured 24 h later. Short (15 min) copulations, in which small amounts of LHPI were discharged, stimulated incorporation into LHPI but brief genital contact did not. Neither severance of the nervi corporis allati nor allatectomy (CA−) on day 1 prevented copulation‐enhancement of incorporation into LHPI. Decapitation after 15 min of copulation also failed to prevent copulation‐enhanced incorporation into LHPI. This suggests that neither the CA nor the corpus cardiacum/brain complex is essential for the response. There was, however, a strong positive correlation between the amount of LHPI lost at copulation and the subsequent rate of incorporation into LHPI. These results suggest that control of copulation‐enhanced incorporation of amino acids into LHPI is peripheral and linked to the extent of gland emptying.