Activities of natural methyl farnesoids on pupariation and metamorphosis of Drosophila melanogaster

Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum

“…Meanwhile, in TcJHAMT knockdown animals, FA could be epoxidized into JH acid, which may have had some JH activity in the embryonic stage as discussed above; however, JH acid may not be potent in terms of maintaining the larval status. In D. melanogaster, the continuous exposure of larvae to MF prevented normal pupariation, and MF was as potent as JH III (Harshman et al, 2010;Jones et al, 2010). In contrast, a B. mori mutant strain lacking CYP15C1 function underwent precocious larva-pupa metamorphosis (Daimon et al, 2012), although MF appeared to be produced in this mutant since JHAMT was able to methylate FA and JH acid (Shinoda and Itoyama, 2003).…”

How does juvenile hormone control insect metamorphosis and reproduction?

“…Ultraspiracle from Drosophila melanogaster binds JH III with intermediate affinity (K d = 2 Â 10 À7 M), whereas it binds methyl farnesoate with the high nanomolar affinity expected for a hormone receptor [31]. Methyl farnesoate is found in larvae, but is 100 times less active than JH III in preventing metamorphosis when applied at the time of pupariation [32]. When synthesis of methyl farnesoate and thus of all JHs is prevented in Drosophila by expression of HMGCoA reductase RNAi, most larvae die during the molt to the 3rd larval stage [30].…”

Precocene-I inhibits juvenile hormone biosynthesis, ovarian activation, aggression and alters sterility signal production in bumble bee (Bombus terrestris) workers

“…Samples were stored at −20°C until shipping. Hemolymph was sent to the USDA-ARS laboratory in Gainesville, Florida, where it was processed according to a described protocol (Teal et al, 2000;Teal and Proveaux, 2006;Jones et al, 2010;Niño et al, 2012). Immediately after hemolymph extraction, the bees were killed by freezing on dry ice and stored at −20°C until dissections and analyses.…”