The Biochemistry of the Insect Fat Body

Kilby, B. A.

doi:10.1016/s0065-2806(08)60175-7

Cited by 138 publications

(43 citation statements)

References 131 publications

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“…Although the PAS technique is used for the identification of aminoacids that contain free OH groups adjacent to carbon chains (1:2 glycol), it does not guarantee specificity, and several sugars, such as amides, cellulose, and glycogen (Pearse, 1960) can give a positive reaction. Since glycogen is the main carbohydrate stored in the fat body of insects (Kilbe, 1963;Keeley, 1985), the strong positive reactions obtained for PAS in the trophocytes of P. villosa might indicate the presence of this carbohydrate. Carbohydrates, one of the main metabolites synthesized and liberated into the hemolymph from the fat body, serve as an energy source for all tissues (Keeley, 1985).…”

Section: Discussionmentioning

confidence: 95%

Ultramorphology and histochemistry of fat body cells from last Instar larval of the Pachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)

Zara

Caetano

2004

Braz. J. Biol.

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The fat body cells of Pachycondyla (=Neoponera) villosa are disposed in a single layer between the cuticle and the digestive tract, forming a group of cells enclosed by a thin membrane. Histological studies have revealed three different cellular types: trophocyte (more abundant), urate, (located among the trophocytes), and oenocyte (the scarcest), usually observed laying near the cuticle. Histochemically, the trophocytes showed a positive reaction for basic proteins in the nucleus and cytoplasm, as well as a strong positive reaction in the cytoplasmic granules. The test for carbohydrates showed a strong positive reaction throughout the cytoplasm, while the test for lipids was positive for the cytoplasmic vesicles. The urate cells showed a positive reaction for basic proteins in the nucleus and in the areas of the cytoplasm surrounding the vesicles. These cells did not react to the PAS test or to Sudan Black B. The oenocytes showed a weak positive reaction to PAS and a strong positive reaction to Sudan Black B and Mercuric-bromophenol Blue.Key words: Pachycondyla, fat body, histochemistry, histology, larva. RESUMO Ultramorfologia e histoquímica do corpo gorduroso de larvas de último estágio dePachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)As células do corpo gorduroso de Pachycondyla (=Neoponera) villosa distribuem-se como uma única camada entre a cutícula e o trato digestivo, formando um conjunto de células agrupadas e recobertas por uma fina membrana. Não foram identificados tipos celulares distintos por meio da ultramorfologia, porém a histologia revelou três tipos celulares distintos: os trofócitos, mais abundantes, as células de urato, distribuídas por entre os trofócitos, e os enócitos, menos abundantes que os demais. Os enócitos são comumente observados próximos da cutícula. Histoquimicamente, os trofócitos apresentaram reação positiva para proteínas básicas no núcleo e no citoplasma e reação fortemente positiva nos grânulos citoplasmáticos. O teste para carboidratos foi fortemente positivo em todo o citoplasma, enquanto para os lipídeos observouse reação positiva nas vesículas citoplasmáticas. Em relação às células de urato, estas apresentaram reação positiva para proteínas básicas no núcleo e citoplasma, por entre as vesículas. Essas células não apresentaram reação para o teste de PAS e Sudan Black B. Quanto aos enócitos, estes apresentaram citoplasma fracamente positivo ao PAS e fortemente positivo ao Sudan Black B e para o azul de bromofenol.

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Section: Discussionmentioning

confidence: 95%

Ultramorphology and histochemistry of fat body cells from last Instar larval of the Pachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)

Zara

Caetano

2004

Braz. J. Biol.

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“…In most insects, the majority of the fatty acids are associated with triacylglycerols that are usually stored within fat body cells (Kilby, 1963;Downer, 1985). Fatty acids are also associated with the phospholipids and sterol ester components of biomembranes.…”

Section: Discussionmentioning

confidence: 99%

Triacylglycerol and phospholipid fatty acids of the silverleaf whitefly: Composition and biosynthesis

Buckner

Hagen

2003

Arch Insect Biochem Physiol

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The identification and composition of the fatty acids of the major lipid classes (triacylglycerols and phospholipids) within Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) nymphs were determined. Comparisons were made to fatty acids from the internal lipids of B. argentifolii adults. The fatty acids, as ester derivatives, were analyzed by capillary gas chromatography (CGC) and CGC-mass spectrometry (MS). All lipid classes contained variable distributions of eight fatty acids: the saturated fatty acids, myristic acid (14:0), palmitic acid (16:0), stearic acid (18:0), arachidic acid (20:0); the monounsaturated fatty acids, palmitoleic acid (16:1), oleic acid (18:1); the polyunsaturated fatty acids, linoleic acid (18:2), linolenic acid (18:3). Fourth instar nymphs had 5-10 times the quantities of fatty acids as compared to third instar nymphs and 1-3 times the quantities from adults. The fatty acid quantity differences between fourth and third instar nymphs were related to their size and weight differences. The percentage compositions for fatty acids from each lipid class were the same for the pooled groups of third and fourth instar nymphs. For nymphs and adults, triacylglycerols were the major source of fatty acids, with 18:1 and 16:0 acids as major components and the majority of the polyunsaturated fatty acids, 18:2 and 18:3 were present in the two phospholipid fractions, phosphatidylethanolamine and phosphatidylcholine. Evidence was obtained that whiteflies indeed synthesize linoleic acid and linolenic acid de novo: radiolabel from [2-(14)C] acetate was incorporated into 18:2 and 18:3 fatty acids of B. argentifolii adults and CGC-MS of pyrrolidide derivatives established double bonds in the Delta(9,12) and Delta(9,12,15) positions, respectively.

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“…There is direct evidence in C. stygia of changing nuclear activity between the periods characterized respectively by synthesis and by uptake of protein in the fat body. This evidence includes sharply defined changes in (a) the morphology of the polytene chromosomes (Thomson 1969);(b) the nature and amount of nuclearinclusion ribonucleoprotein ; (c) the structure of the nuclear-cytoplasmic boundary (Thomson, Rogers, Gunson, and Horn 1970); the pattern of nuclear binding of exogenous moulting hormone (Thomson, Rogers, Gunson, and Horn 1970).…”

Section: (C) Relationship Of Plasma and Fat Body Proteinsmentioning

confidence: 99%

“…The role of the fat body during larval development in holometabolous insects is remarkably complex, involving many aspects of protein, lipid, and carbohydrate metabolism (Kilby 1963). The larval fat body of Calliphora stygia undergoes, during third-instar development, a series of sharply defined changes in function relative to protein synthesis and release:…”

Section: Introductionmentioning

confidence: 99%

Developmental Changes in the Late Larva of Calliphora Stygia Iv. Uptake of Plasma Protein by the Fat Body

Martín¹,

Kinnear²,

Thomson³

1971

Aust. Jnl. Of Bio. Sci.

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The protein content of the larval fat body of O. stygia increases during late third-instar development from 1 ·0 mg at day 7 to 3·4 mg in the white prepupa (day 11). This increase is due predominantly to uptake of protein from the haemolymph, in which there is a concurrent fall in protein concentration. The rate of uptake rises from 0·6 mg/day at days 8-9 to 0·9 mg/day at days 10-11.Five plasma proteins (designated HI5-19) appear to be taken up differentially by the fat body in vivo and in vitro. The uptake of these species occurs without degradation to constituent amino acids, but involves conformational changes which reverse those occurring earlier in the instar when protein is released into the haemolymph from the fat body.

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The Biochemistry of the Insect Fat Body

Cited by 138 publications

References 131 publications

Ultramorphology and histochemistry of fat body cells from last Instar larval of the Pachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)

Ultramorphology and histochemistry of fat body cells from last Instar larval of the Pachycondyla (=Neoponera) villosa (Fabricius) (Formicidae: Ponerinae)

Triacylglycerol and phospholipid fatty acids of the silverleaf whitefly: Composition and biosynthesis

Developmental Changes in the Late Larva of Calliphora Stygia Iv. Uptake of Plasma Protein by the Fat Body

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