For most species, the male accessory glands are mesodermal derivatives. Their form is as varied as are the functions of the secretion they produce. The post-embryonic development and differentiation of the glands, like those of other tissues, appear to be regulated by the interaction of juvenile hormone (JH) and ecdysteroid, the former inhibiting and the latter promoting these processes. Post-eclosion accessory gland activity (i.e. production of secretion), for most species examined, is regulated by JH. However, the precise mechanism of control and the site of action are not at all clear. A limited amount of in vitro work indicates a direct action of JH on the accessory glands though only for Drosophila melanogaster Meigen has a JH-receptor protein been identified. The JH promotes the synthesis of specific proteins in the accessory gland secretion, and two proposals have been made for the site and mode of action of the hormone. In the first it is suggested that the hormone affects membrane permeability, thereby influencing the supply of protein precursors; in the second a more direct action of JH at the gene level is proposed, namely, the promotion of translation.
The involvement of ecdysteroids in accessory gland activity is virtually unexplored though there have been a few demonstrations that these hormones can stimulate protein synthesis. An hypothesis worth further consideration suggests that ecdysteroids may have a role in those species that eclose in a sexually mature condition, i.e. where the accessory glands have both differentiated and produced their secretion in the pupal or pharate adult stage, presumably in the absence of JH.