Dual control of midgut trehalase activity by 20-hydroxyecdysone and an inhibitory factor in the bamboo borer Omphisa fuscidentalis Hampson

Tatun, Nujira; Singtripop, Tippawan; Sakurai, Shunsuke

doi:10.1016/j.jinsphys.2007.10.006

Cited by 70 publications

(47 citation statements)

References 17 publications

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“…In the larval Omphisa fuscidentalis, for instance, at the end of diapause, trehalase activity is stimulated by ecdysone, probably by induction of its expression (Tatun et al, 2008). Our data indicate that the R. prolixus midgut is the main organ responsible for the hydrolysis of hemolymph trehalose.…”

Section: Discussionmentioning

confidence: 65%

Synthesis and mobilization of glycogen and trehalose in adult male Rhodnius prolixus

Mariano

Santos

Gonzalez

et al. 2009

Arch Insect Biochem Physiol

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The vector of Chagas' disease, Rhodnius prolixus, feeds exclusively on blood. The blood meals are slowly digested, and these insects wait some weeks before the next meal. During the life of an insect, energy-requiring processes such as moulting, adult gonadal and reproductive growth, vitellogenesis, muscular activity, and fasting, lead to increased metabolism. Carbohydrates are a major source of energy and their mobilization is important. We determined the amounts of glycogen, trehalose, and glucose present in the fat body and/or hemolymph of adult males of R. prolixus and recorded the processes of accumulation and mobilization of these carbohydrates. We also tested our hypothesis that these processes are under endocrine control. The amount of glycogen in the fat body progressively increased until the fourth day after feeding (from 9.3+/-2.2 to 77. 3+/-7.5 microg/fat body), then declined to values around 36.3+/-4.9 microg/fat body on the fifteenth day after the blood meal. Glycogen synthesis was eliminated in decapitated insects and head-transplanted insects synthesized glycogen. The amount of trehalose in the fat body increased until the sixth day after feeding (from 16. 6+/-1.7 to 40. 6+/-5.3 nmol/fat body), decreased abruptly, and stabilized between days 7 and 15 at values ranging around 15-19 nmol/fat body. Decapitated insects did not synthesize trehalose after feeding, and this effect was reversed in head-transplanted insects. The concentration of trehalose in the hemolymph increased after the blood meal until the third day (from 0.07+/-0.01 to 0.75+/-0.05 mM) and at the fourth day it decreased until the ninth day (0.21+/-0.01 mM), when it increased again until the fourteenth day (0.79+/-0.06 mM) after the blood meal, and then declined again. In decapitated insects, trehalose concentrations did not increase soon after the blood meal and at the third day it was very low, but on the fourteenth day it was close to the control values. The concentration of glucose in the hemolymph of untreated insects remained low and constant (0.18+/-0.01 mM) during the 15 days after feeding, but in decapitated insects it progressively increased until the fifteenth day (2.00+/-0.10 mM). We recorded the highest trehalase activity in midgut, which was maximal at the eighth day after feeding (2,830+/-320 nmol of glucose/organ/h). We infer that in Rhodnius prolixus, the metabolism of glycogen, glucose, and trehalose are controlled by factors from the brain, according to physiological demands at different days after the blood meal.

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Section: Discussionmentioning

confidence: 65%

Synthesis and mobilization of glycogen and trehalose in adult male Rhodnius prolixus

Mariano

Santos

Gonzalez

et al. 2009

Arch Insect Biochem Physiol

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“…During this period, hemolymph ecdysteroid titer peaks on Day 8 in preparation for pupation, drops during pupation, and then increases again before adult differentiation (Mizoguchi et al, 2001). In the bamboo borer O. fuscidentalis, exogenous 20E decreases the inhibitory activity of a proteinaceous trehalase inhibitor in larval hemolymph (Tatun et al, 2008a). If this is also the case in B. mori, the high 20E concentration before pupation may decrease inhibitor-P concentration, while low 20E concentrations during feeding and at pupation may allow the inhibitor to increase.…”

Section: Two Types Of Trehalase Inhibitor and Two Types Of Trehalasementioning

confidence: 99%

“…Long-term regulation has been studied from the perspective of hormonal control of trehalase activities (Steele and Paul, 1985), i.e., hyperglycemic hormone for homeostatic regulation (Gäde et al, 1997) and 20-hydroxyecdysone (Yaginuma and Happ, 1989;Oda et al, 2000;Tatun et al, 2008a) for regulation during larval growth and larval-pupal transformation. However, hormonal regulation appears to be an insufficient explanation for long-term changes in hemolymph trehalose concentration.…”

Section: Introductionmentioning

confidence: 99%

Possible involvement of proteinaceous and non-proteinaceous trehalase inhibitors in the regulation of hemolymph trehalose concentration in Bombyx mori

Tatun

Singtripop

Osugi

et al. 2009

Appl. Entomol. Zool.

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The midgut of the silkworm Bombyx mori contains two types of trehalase: soluble and membrane-bound. The trehalose concentration in larval hemolymph remains substantially high through the feeding period of the last (fifth) larval instar, despite appreciable trehalase activity through this period. We found that B. mori larval hemolymph contains two types of trehalase inhibitor, a proteinaceous inhibitor (inhibitor-P) and an inhibitor that is extractable with methanol and ethanol (inhibitor-M). Both inhibit the two types of trehalase, but with different sensitivities. Inhibitor-P inhibited soluble trehalase (ST) more effectively than membrane-bound trehalase (MT), while inhibitor-M inhibited MT slightly more than ST. The inhibitory activity of inhibitor-M was high during the early to middle feeding period, followed by a sudden decrease during the late feeding period. Inhibitor-P activity increased throughout the feeding period, and markedly decreased 2 days after gut purge. Thus, the two inhibitors exhibited stage-specific changes in the hemolymph, indicating coordinated inhibitory activity. Therefore, trehalose concentration regulation in the hemolymph appears to be complex, consisting of at least two inhibitors and two types of trehalase.

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“…In insects, it plays a crucial role in flight metabolism (Clegg and Evans, 1961;Wegener et al, 2003), chitin synthesis during molting (Tatun et al, 2008a;Chen et al, 2010), development (Tatun et al, 2008b;Santos et al, 2012), locomotion (Tang et al, 2014) and cold tolerance (Tatun et al, 2008b). Trehalases occur in two forms in insects: soluble trehalase (encoded by Treh-1 gene) and membrane-bound trehalase (encoded by Treh-2 gene) (Becker et al, 1996;Yaginuma et al, 1996;Thompson, 2003).…”

Section: Introductionmentioning

confidence: 99%

Molecular cloning and expression analysis of soluble and membrane-bound trehalase genes in the cotton bollworm, Helicoverpa armigera

Dai

et al. 2015

Journal of Asia-Pacific Entomology

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Dual control of midgut trehalase activity by 20-hydroxyecdysone and an inhibitory factor in the bamboo borer Omphisa fuscidentalis Hampson

Cited by 70 publications

References 17 publications

Synthesis and mobilization of glycogen and trehalose in adult male Rhodnius prolixus

Synthesis and mobilization of glycogen and trehalose in adult male Rhodnius prolixus

Possible involvement of proteinaceous and non-proteinaceous trehalase inhibitors in the regulation of hemolymph trehalose concentration in Bombyx mori

Molecular cloning and expression analysis of soluble and membrane-bound trehalase genes in the cotton bollworm, Helicoverpa armigera

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