Lipid digestion in the tsetse fly, Glossina morsitans

Langley, P. A.; Ogwal, L.M.; Felton, T.; Stafford, Kathryn

doi:10.1016/0022-1910(87)90011-4

Cited by 21 publications

(12 citation statements)

References 20 publications

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“…Insects have the tendency to accumulate cholesterol in the body during feeding stages (Svoboda et al ., 1982; Beydon & Lafont, 1987; Jouni et al ., 2002). Studies have indicated that the midgut and possibly the foregut are the sites of cholesterol absorption in insects (Langley et al ., 1987; Kuthiala & Ritter, 1988; Komnick & Giesa, 1994; Jouni et al ., 2002). It is not surprising that insects have evolved multiple genes encoding low molecular weight SCP‐2 domain‐containing proteins that may be involved in intracellular sterol transport (Fig.…”

Section: Discussionsupporting

confidence: 59%

Identification of two sterol carrier protein‐2 like genes in the yellow fever mosquito, Aedes aegypti

Vyazunova

Wessley

Kim

et al. 2007

Insect Molecular Biology

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Section: Discussionsupporting

confidence: 59%

Identification of two sterol carrier protein‐2 like genes in the yellow fever mosquito, Aedes aegypti

Vyazunova

Wessley

Kim

et al. 2007

Insect Molecular Biology

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“…It has been shown that adults of the tsetse fly, GEussi~a morsituns mursitans, use all components of the blood lipids except cholesterol; ca. 50% of the ingested cholesterol was found in the excreta [6]. Similar findings were reported for the stable fly [7]; ca.…”

Section: Introductionsupporting

confidence: 81%

Hydrolysis of sphingomyelin and phosphatidylcholine by midgut homogenates of the stable fly

Spates¹,

Bull²,

Chen³

1990

Arch Insect Biochem Physiol

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Qualitative and quantitative analyses were made to characterize the enzymatic degradation of sphingomyelin and phosphatidylcholine by midgut homogenates of the adult stable fly, Stomoxys calcitrans (L.). The results indicated that sphingomyelin was hydrolyzed by an enzyme with sphingomyelinase-like properties, and that phosphatidylcholine was hydrolyzed by an enzyme with properties similar to phospholipase C. The optimum pH for the sphingomyelinase was 7.6, and the rate of hydrolysis of sphingomyelin at that pH was linear from 1 to 4 nmol of substrate and 5 to 25 micrograms of enzyme preparation. Dialysis of the homogenates against Tris-HCl and imidazole buffers resulted in a decrease of sphingomyelinase activity by 59% and 98%, respectively, and the original activity was not restored with the addition of Ca++, Mg++, or Mn++.

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“…Our observations that the yeast and phospholipid components of the diet stimulate PLA 2 secretion by hornworm midguts are in accord with similar work on other species. In hematophagous insects, midgut proteolytic activity increases in response to blood meals, but not to sugar or saline solutions (Langley, 1966;Yang and Davies, 1968;Garcia and Garcia, 1977;Stiles et al, 1991). These observations, coupled with the point that enzyme secretion can be stimulated in isolated midguts, support the hypothesis that prandial and/or paracrine mechanisms are responsible for regulating digestive enzyme secretion.…”

Section: Discussionmentioning

confidence: 64%

In vitro secretion of digestive phospholipase A2 by midguts isolated from tobacco hornworms,Manduca sexta

Rana

Stanley

1999

Arch. Insect Biochem. Physiol.

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We report on secretion of phospholipase A2 (PLA2) by in vitro preparations of midguts isolated from tobacco hornworms, Manduca sexta. This enzyme is responsible for hydrolysis of fatty acids from the sn‐2 position of phospholipids, a necessary step in fatty acid absorption. The in vitro midgut preparations are competent to secrete PLA2 into incubation buffer. Secretion began within the first 30 min of incubation and increased to a maximum at 8 h. We selected 2 h incubations because substantial loss of tissue integrity was observed after 8 h incubations. Using 2 h incubations, we recorded increased secretion of digestive PLA2 from midguts incubated in buffer amended with diet or with yeast as a component of the diet. We also recorded small increases in secretion of PLA2 from midguts incubated in buffer amended with a specific phospholipid, phosphatidylcholine. Midguts incubated in buffer amended with increased concentrations of phospholipid did not yield higher levels of PLA2 activity. Lepidopteran midguts can be divided into three regions, and we recorded the highest secretion of PLA2 from the middle region and lowest secretion from the anterior region. Because isolated midguts responded to food chemicals with increased secretion of digestive PLA2, we suggest that secretion of digestive enzymes in tobacco hornworms is regulated by a prandial and/or paracrine mechanism, as suggested for digestive proteases in other insect species. Arch. Insect Biochem. Physiol. 42:179–187, 1999 .© 1999 Wiley‐Liss, Inc.

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Lipid digestion in the tsetse fly, Glossina morsitans

Cited by 21 publications

References 20 publications

Identification of two sterol carrier protein‐2 like genes in the yellow fever mosquito, Aedes aegypti

Identification of two sterol carrier protein‐2 like genes in the yellow fever mosquito, Aedes aegypti

Hydrolysis of sphingomyelin and phosphatidylcholine by midgut homogenates of the stable fly

In vitro secretion of digestive phospholipase A2 by midguts isolated from tobacco hornworms,Manduca sexta

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