Hormonal control of vitellogenesis in the gypsy moth, Lymantria dispar (L.): Suppression of haemolymph vitellogenin by the juvenile hormone analogue, methoprene

Juvenile hormone downregulates vitellogenin production in Ectatomma tuberculatum (Hymenoptera: Formicidae) sterile workers

“…The different response of the fat body and haemolymph linked to the JH dose may be due to the delay between gene transcription in the fat body and protein release to the haemolymph, as reported in other insects (Glinka and Wyatt, 1996). Furthermore, changes in the circulating vitellogenin in the haemolymph after topical application of JH has been reported to be dose responsive (Davis et al, 1990;Hiremath and Jones, 1992).…”

Dynamics of juvenile hormone-mediated gonadotropism in the lepidoptera

“…These authors further suggested that ecdysteroids not only likely initiate Vg synthesis in the fat body, but also enhance patency of the follicular epithelium to allow Vg sequestration by oocytes. In L. dispar, JH represses transcription of the Vg gene (Davis et al, 1990;Hiremath and Jones, 1992;Adamczyk et al, 1996). In these species, adult male emergence precedes female emergence by several Hodges (1983). hours to days, i.e., these species are protandrous.…”

“…Based on various reproductive characteristics, lepidopterans may be divided broadly into four groups (Table 1). The first group includes species such as Hyalophora cecropia (Saturniidae) (Williams, 1952), Malacosoma pluviale (Lasiocampidae) (Sahota, 1969), Bombyx mori (Bombycidae) (Ohnishi, 1987), and Lymantria dispar (Lymantriidae) (Davis et al, 1990). These species exhibit an indirect or direct requirement for ecdysteroids; egg development is initiated and completed only during the larval or early pupal stage, in concert with developmental/metamorphic processes.…”

Molecular Evolution of Juvenile Hormone Signaling

“…In this case, JH signaling is necessary to promote 20E competence in the fat body, the site of post-blood meal vitellogenin synthesis. In contrast, vitellogenesis is retarded by JH treatment in the gypsy moth, Lymantria dyspar (Davis et al, 1990). Thus, there is variation in hormonal control in insects.…”