• International Journal of Industrial Entomology and Biomaterials
• /
• v.21 no.2
• /
• pp.163-167
• /
• 2010

[ $\alpha$ ]Glucosidase (EC 3.2.1.20) is a glycosidase that hydrolyzes disaccharides, oligosaccharides, and polysaccharides resulting in the release of α-D-glucose. In this study, $\alpha$-glucosidase activity in the hemolymph and midgut of the mulberry silkworm Bombyx mori and Japanese oak silkmoth Antheraea yamamai was measured using maltose, sucrose, trehalose, and p-nitrophenyl $\alpha$-D-glucopyranoside as substrates. In general, hemolymph $\alpha$-glucosidase activity was higher in B. mori than in A. yamamai. In contrast, midgut $\alpha$-glucosidase activity was higher in A. yamamai than in B. mori for all of the substrates tested. $\alpha$-Glucosidase activity in the midgut of both B. mori and A. yamamai showed similar responses to changes in pH and temperature for all of the substrates tested. Native (7.5%) PAGE of hemolymph and midgut proteins from B. mori and A. yamamai followed by staining with 4-methylumbelliferyl $\alpha$-D-glucoside (MUG) indicated that the $\alpha$-glucosidases of these related lepidopterans are functionally similar but structurally different. In comparison to $\alpha$-glucosidase activity from A. yamamai, $\alpha$-glucosidase activity from B. mori was generally less sensitive to the $\alpha$-glucosidase inhibitors, 1-deoxynojirimycin (DNJ), acarbose, and voglibose when the activity was determined using maltose, sucrose, and trehalose.

• Korean journal of applied entomology
• /
• v.15 no.4 s.29
• /
• pp.169-178
• /
• 1976

The concentration of amino acids, total nitrogen, trehalose, lipids and the activities of respiratory, acid$\cdot$alkaline phosphatase, glutamic oxalozcetic transaminase and glutamic pyruvic transaminase during larval stage in Pine leaf gall midge, Thecodiplosis janensis Uchi. et Inouye were measured using Paper chromatographic method, micro-Kjeldahl method, Thin layer chromatographic method, Warburg's manometric method, Bessey-Lowry method and Reitman-Frankel method, respectively. Healthy specimens )yore chosen as samples of each larval stages; alrva in gall and larva in soil. Amino acids present in the alcoholic extracts were alanine, glutamic acid, glycine, histidine, methionine, proline, threonine, tryptophan and valine. The total nitrogen concentration reached to 31.348mg/g during the larva in gall and the larval stage in soil of the value was decreased to 29.027mg/g. The hemolymph sugar, trehalose value for larva in soil was about two times of the value for larva in gall. Total lipid, phospholipid,monoacylglycerol, triacylglycerol, sterol, free fatty acid and ester cholesterol were identified at larval stages in gall and soil. Triacylglycerol concentration reached high level in contrast with other lipid contents during larvae in gall and larva in soil. Free fatty acid, sterol except decreased lipids during larval stage in soil. Endogenous respiration, succinate of respiratory activities decreased at larval stage in soil compare with larva in gall. The activities of acid phosphatase decreased larval stage in soil but the activities of alkaline phosphatase increased remarkably. The activities of glutamic oxaloacetic transaminase and glutamic pyruvic transaminase reached high level of the larva in gall.

• Molecules and Cells
• /
• v.41 no.6
• /
• pp.603-611
• /
• 2018

Triglyceride homeostasis is a key process of normal development and is essential for the maintenance of energy metabolism. Dysregulation of this process leads to metabolic disorders such as obesity and hyperlipidemia. Here, we report a novel function of the Drosophila flightless-I (fliI) gene in lipid metabolism. Drosophila fliI mutants were resistant to starvation and showed increased levels of triglycerides in the fat body and intestine, whereas fliI overexpression decreased triglyceride levels. These flies suffered from metabolic stress indicated by increased levels of trehalose in hemolymph and enhanced phosphorylation of eukaryotic initiation factor 2 alpha ($eIF2{\alpha}$). Moreover, upregulation of triglycerides via a knockdown of fliI was reversed by a knockdown of desat1 in the fat body of flies. These results indicate that fliI suppresses the expression of desat1, thereby inhibiting the development of obesity; fliI may, thus, serve as a novel therapeutic target in obesity and metabolic diseases.

• Korean journal of applied entomology
• /
• v.59 no.3
• /
• pp.185-202
• /
• 2020

The diapause induction season in Ostrinia furnacalis (Lepidoptera: Crambidae) was estimated in Suwon. Three batches of adult generations were observed, the first one from early May to early July, the second from early or mid-July to early or mid-August, and the third from mid-August to October. In outdoor larval rearing, colony rearing occurring from mid-July to mid-August produced both non-overwintering and overwintering larvae, whereas late-reared colonies produced only overwintering larvae. Larvae collected during July and August in maize fields produced both non-overwintering and overwintering larvae, whereas late-collected larvae produced only overwintering larvae. The results indicated that O. furnacalis has a bi- or trivoltine complex life cycle in this area. In the laboratory, when larvae of all instars within 9 h after molting were first treated to a diapause induction condition (11:13 h = light:dark photoperiod and 20℃), almost all larvae were induced to diapause. However, when similar treatments were conducted age-specifically for the 5th instar larvae, diapause induction rates in 3- and 4-day-old larvae of the 5th instar decreased. In contrast, when larvae were subjected to the diapause induction treatment only during the periods from the hatching stage to the 2nd, 3rd, and 4th instar, almost all larvae were not induced to diapause. The results suggest that the early age of the 5th larval instar is the last stage for sensitivity to diapause induction stimuli. In the diapause-induced larvae, hemolymph trehalose content increased and body supercooling points dropped, compared with those in non-diapause larvae.