Juvenile hormone (JH) is a sesquiterpenoid of vital importance for insect development, yet the molecular basis JH signaling remains obscure, mainly because bona fide receptor has not been identified. Mounting evidence points to basic helix–loop–helix (bHLH)/Per-Arnt-Sim (PAS) domain protein Methoprene-tolerant (Met) as best candidate. However, details how Met transduces hormonal signal are missing. Here, we demonstrate that specifically binds III and its biologically active mimics,...

Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In case juvenile hormone (JH) prevents metamorphosis until a larva has attained appropriate phase of development. holometabolous insects, JH acts its putative receptor Methoprene-tolerant (Met) regulate Krüppel-homolog 1 (Kr-h1) Broad-Complex (BR-C) genes. While Met Kr-h1 prevent precocious in pre-final larval instars, BR-C specifies the stage....

Juvenile hormones (JHs) play a major role in controlling development and reproduction insects other arthropods. Synthetic JH-mimicking compounds such as methoprene are employed potent insecticides against significant agricultural, household disease vector pests. However, receptor mediating effects of JH its insecticidal mimics has long been the subject controversy. The bHLH-PAS protein Methoprene-tolerant (Met), along with Drosophila melanogaster paralog germ cell-expressed (Gce), emerged...

Besides being a spectacular developmental process, metamorphosis is key to insect success. Entry into controlled by juvenile hormone (JH). In larvae, JH prevents pupal and adult morphogenesis, thus keeping the in its immature state. How signals preclude poorly understood, receptor remains unknown. One candidate for role Methoprene-tolerant (Met) Per-Arnt-Sim (PAS) domain protein [also called Resistance JH, Rst (1)JH], whose loss confers tolerance mimic methoprene fruit fly Drosophila...

Metamorphosis of holometabolous insects, an elaborate change form between larval, pupal and adult stages, offers ideal system to study the regulation morphogenetic processes by hormonal signals. involves growth differentiation, tissue remodeling death, all which are orchestrated morphogenesis-promoting ecdysteroids antagonistically acting juvenile hormone (JH), whose presence precludes metamorphic changes. How target tissues interpret this combinatorial effect two cues is poorly understood,...

The transcription factor Broad-Complex (BR-C) is required for differentiation of adult structures as well the programmed death obsolete larval organs during metamorphosis fruit fly Drosophila melanogaster . Whether BR-C has a similar role in other holometabolous insects could not be proven without loss-of-function genetic test, performed non-drosophilid species. Here we use recombinant Sindbis virus tool to silence expression silkmoth Bombyx mori expressing antisense RNA fragment reduced...

In temperate regions, the shortening day length informs many insect species to prepare for winter by inducing diapause. The adult diapause of linden bug, Pyrrhocoris apterus , involves a reproductive arrest accompanied energy storage, reduction metabolic needs, and preparation withstand low temperatures. By contrast, nondiapause animals direct nutrient muscle activity reproduction. photoperiod-dependent switch from reproduction is systemically transmitted throughout organism juvenile hormone...

Macrophage-mediated phagocytosis and cytokine production represent the front lines of resistance to bacterial invaders. A key feature this pro-inflammatory response in mammals is complex remodeling cellular metabolism towards aerobic glycolysis. Although function bactericidal macrophages highly conserved, metabolic insect remains poorly understood. Here, we used adults fruit fly Drosophila melanogaster investigate changes that occur during acute resolution phases Streptococcus-induced...

Insect metamorphosis boasts spectacular cases of postembryonic development when juveniles undergo massive morphogenesis before attaining the adult form and function; in moths or flies larvae do not even remotely resemble their parents. A selective advantage complete (holometaboly) is that within one species two forms with different lifestyles can exploit diverse habitats. It was environmental adaptation specialization larvae, primarily delay internalization wing development, eventually...

cDNAs were isolated from Manduca sexta that encode two isoforms of an ultraspiracle (USP) homologue MsUSP‐1 and MsUSP‐2 with different N‐terminal A/B regions. The cDNA predicts a protein 97% 45% amino acid identities in the DNA‐ ligand‐binding domains respectively to Drosophila USP 89% overall identity Bombyx mori CF1 (an homologue). Northern blot hybridizations probes specific showed transcripts approximately equal size (4.5 kb), but diverse developmental profiles epidermis during final...

Integration of metabolic and immune responses during animal development ensures energy balance, permitting both growth defense. Disturbed homeostasis causes organ failure, retardation, disorders. Here, we show that the Drosophila melanogaster activating transcription factor 3 (Atf3) safeguards system homeostasis. Loss Atf3 results in chronic inflammation starvation mounted primarily by larval gut epithelium, while fat body suffers lipid overload, causing imbalance death. Hyperactive...

Methyl farnesoate (MF) plays hormonal regulatory roles in crustaceans. An epoxidated form of MF, known as juvenile hormone (JH), controls metamorphosis and stimulates reproduction insects. To address the evolutionary significance MF epoxidation, we generated mosquitoes completely lacking either two enzymes that catalyze last steps MF/JH biosynthesis respectively: JH acid methyltransferase (JHAMT) P450 epoxidase CYP15 (EPOX). jhamt-/- larvae both died at onset metamorphosis. Strikingly,...

Background Nuclear receptors are essential players in the development of all metazoans. The nematode Caenorhabditis elegans possesses more than 200 putative nuclear receptor genes, several times number known any other organism. Very few these transcription factors conserved with components steroid response pathways vertebrates and arthropods. Ftz‐F1, one evolutionarily oldest types, is required for steroidogenesis sexual differentiation mice segmentation metamorphosis Drosophila . Results We...

MHR3, a homolog of the retinoid orphan receptor (ROR), is transcription factor in nuclear hormone family that induced by 20-hydroxyecdysone (20E) epidermis tobacco hornworm, Manduca sexta. Its 2.7-kb 5′ flanking region was found to contain four putative ecdysone response elements (EcREs) and monomeric (GGGTCA) binding site. Activation this promoter fused chloramphenicol acetyltransferase (CAT) reporter 2 μg 20E per ml GV1 cells similar endogenous with detectable CAT 3 h. When B1 (EcR-B1)...

Steroid signaling underlies developmental processes in animals. Mutations that impair steroidogenesis the fruit fly Drosophila melanogaster provide tools to dissect steroid hormone action genetically. The widely used temperature-sensitive mutation ecdysoneless(1) (ecd(1)) disrupts production of ecdysone, and causes reproductive defects. These defects cannot be satisfactorily interpreted without analysis ecd gene. Here, we show encodes an as yet functionally undescribed protein is conserved...

The homolog of the ecdysteroid-induced transcription factor E75A inDrosophila melanogasterwas cloned from tobacco hornworm,Manduca sexta,and its developmental expression and hormonal regulation were analyzed. Both E75B mRNAs found in abdominal epidermis during both larval pupal molts, with appearing before E75B, coincident rise ecdysteroid. Exposure either fourth or fifth instar to 20Ein vitrocaused rapid, transient induction RNA a peak at 6 3 h, respectively, followed by maintenance low...

The sesquiterpenoid juvenile hormone (JH) is vital to insect development and reproduction. Intracellular JH receptors have recently been established as basic helix-loop-helix transcription factor (bHLH)/PAS proteins in Drosophila melanogaster known germ cell–expressed (Gce) its duplicate paralog, methoprene-tolerant (Met). Upon binding JH, Gce/Met activates target genes. Insects possess multiple native homologs whose molecular activities remain unexplored, diverse synthetic compounds...