Do Insects Really Have a Homeostatic Hypotrehalosaemic Hormone?

Veenstra, Jan A.

doi:10.1111/j.1469-185x.1989.tb00678.x

Cited by 8 publications

(6 citation statements)

References 63 publications

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“…Trehalose is thus present in both the hemolymph and the intracellular fat body space. In flies, the total compartment containing trehalose is ϳ30% volume/body wt (34). Thus we can estimate from the observed total quantities of trehalose an approximate hemolymph trehalose concentration of 2.5 mM for flies from which the AKH cells have been ablated vs. 5 mM for control flies.…”

Section: Discussionmentioning

confidence: 99%

“…Because the release of carbohydrates from the crop in flies seems to be effected via a neural mechanism (see Ref. 34 and references therein), while AKH is released as a hormone, it remains unclear as to whether, in Drosophila, AKH can affect hemolymph trehalose. Indeed, in honeybees, which also use carbohydrates stored in the digestive system as fuel for flight, it has been reported that AKH is without effect on hemolymph trehalose (16).…”

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confidence: 99%

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AKH-producing neuroendocrine cell ablation decreases trehalose and induces behavioral changes inDrosophila

Isabel¹,

Martin²,

Chidami

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

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195

226

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Adipokinetic hormone (AKH) is a metabolic neuropeptide principally known for its mobilization of energy substrates, notably lipid and trehalose during energy-requiring activities, such as flight and locomotion. Drosophila melanogaster AKH cell localization in corpora cardiaca, as in other insect species, was confirmed by immunoreactivity and by a genetic approach using the UAS/GAL4 system. To assess AKH general physiological rules, we ablated AKH endocrine cells by specifically driving the expression of apoptosis transgenes in AKH cells. Trehalose levels were decreased in larvae and starved adults, when the stimulation by AKH of the production of trehalose from fat body glycogen is no longer possible. Moreover, we show that these adults without AKH cells become progressively hypoactive. Finally, under starvation conditions, those hypoactive AKH-knockout cell flies survived approximately 50% longer than control wild-type flies, suggesting that the slower rate at which AKH-ablated flies mobilize their energy resources extends their survival.

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

AKH-producing neuroendocrine cell ablation decreases trehalose and induces behavioral changes inDrosophila

Isabel¹,

Martin²,

Chidami

et al. 2005

American Journal of Physiology-Regulatory, Integrative and Comp

Self Cite

195

226

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“…Although insect insulins can lower hemolymph carbohydrates (Satake et al 1997), such studies do not demonstrate that these insect insulins are homeostatic hormones (Veenstra 1989a;Satake et al 1997). Just as the diapause hormone lowers trehalose in pupae destined to make diapause eggs in the silk worm (Yamashita et al 1981), one can expect growth-stimulating hormones to stimulate the uptake of glucose in growing cells and thus lower glucose concentrations in the hemolymph.…”

Section: Functions Of Midgut Endocrine Cellsmentioning

confidence: 95%

“…No convincing studies demonstrate that insulin-like peptides act as homeostatic hypoglycemic or hypotrehalosemic hormones (for a review, see Veenstra 1989a). Although insect insulins can lower hemolymph carbohydrates (Satake et al 1997), such studies do not demonstrate that these insect insulins are homeostatic hormones (Veenstra 1989a;Satake et al 1997).…”

Section: Functions Of Midgut Endocrine Cellsmentioning

confidence: 98%

“…Many attempts have been made to localize insulin immunoreactivity in the insect midgut, but these experiments and their conclusions have been severely criticized (e.g., Yalow and Eng 1981;Teller and Pilc 1985;Veenstra 1989a). Within this context, we consider it to be of interest to investigate the possible expression of the Drosophila insulin genes in the midgut.…”

Section: Peptide Identificationmentioning

confidence: 99%

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Regulatory peptides in fruit fly midgut

2008

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Regulatory peptides were immunolocalized in the midgut of the fruit fly Drosophila melanogaster. Endocrine cells were found to produce six different peptides: allatostatins A, B and C, neuropeptide F, diuretic hormone 31, and the tachykinins. Small neuropeptide-F (sNPF) was found in neurons in the hypocerebral ganglion innervating the anterior midgut, whereas pigment-dispersing factor was found in nerves on the most posterior part of the posterior midgut. Neuropeptide-F (NPF)-producing endocrine cells were located in the anterior and middle midgut and in the very first part of the posterior midgut. All NPF endocrine cells also produced tachykinins. Endocrine cells containing diuretic hormone 31 were found in the caudal half of the posterior midgut; these cells also produced tachykinins. Other endocrine cells produced exclusively tachykinins in the anterior and posterior extemities of the midgut. Allatostatin-immunoreactive endocrine cells were present throughout the midgut. Those in the caudal half of the posterior midgut produced allatostatins A, whereas those in the anterior, middle, and first half of the posterior midgut produced allatostatin C. In the middle of the posterior midgut, some endocrine cells produced both allatostatins A and C. Allatostatin-C-immunoreactive endocrine cells were particularly prominent in the first half of the posterior midgut. Allatostatin B/MIP-immunoreactive cells were not consistently found and, when present, were only weakly immunoreactive, forming a subgroup of the allatostatin-C-immunoreactive cells in the posterior midgut. Previous work on Drosophila and other insect species suggested that (FM)RFamide-immunoreactive endocrine cells in the insect midgut could produce NPF, sNPF, myosuppressin, and/or sulfakinins. Using a combination of specific antisera to these peptides and transgenic fly models, we showed that the endocrine cells in the adult Drosophila midgut produced exclusively NPF. Although the Drosophila insulin gene Ilp3 was abundantly expressed in the midgut, Ilp3 was not expressed in endocrine cells, but in midgut muscle.

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A journey into the world of insect lipid metabolism

Toprak¹,

Hegedus

Doğan³

et al. 2020

Arch Insect Biochem Physiol

119

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Lipid metabolism is fundamental to life. In insects, it is critical, during reproduction, flight, starvation, and diapause. The coordination center for insect lipid metabolism is the fat body, which is analogous to the vertebrate adipose tissue and liver. Fat body contains various different cell types; however, adipocytes and oenocytes are the primary cells related to lipid metabolism. Lipid metabolism starts with the hydrolysis of dietary lipids, absorption of lipid monomers, followed by lipid transport from midgut to the fat body, lipogenesis or lipolysis in the fat body, and lipid transport from fat body to other sites demanding energy. Lipid metabolism is under the control of hormones, transcription factors, secondary messengers and posttranscriptional modifications. Primarily, lipogenesis is under the control of insulin‐like peptides that activate lipogenic transcription factors, such as sterol regulatory element‐binding proteins, whereas lipolysis is coordinated by the adipokinetic hormone that activates lipolytic transcription factors, such as forkhead box class O and cAMP‐response element‐binding protein. Calcium is the primary–secondary messenger affecting lipid metabolism and has different outcomes depending on the site of lipogenesis or lipolysis. Phosphorylation is central to lipid metabolism and multiple phosphorylases are involved in lipid accumulation or hydrolysis. Although most of the knowledge of insect lipid metabolism comes from the studies on the model Drosophila; other insects, in particular those with obligatory or facultative diapause, also have great potential to study lipid metabolism. The use of these models would significantly improve our knowledge of insect lipid metabolism.

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Do Insects Really Have a Homeostatic Hypotrehalosaemic Hormone?

Cited by 8 publications

References 63 publications

AKH-producing neuroendocrine cell ablation decreases trehalose and induces behavioral changes inDrosophila

AKH-producing neuroendocrine cell ablation decreases trehalose and induces behavioral changes inDrosophila

Regulatory peptides in fruit fly midgut

A journey into the world of insect lipid metabolism

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