Transport of lipids in insects

Open AccessPublished:September 01, 1974DOI:
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      Many insect species are almost completely dependent on lipids for their metabolic needs, although this is usually a function of developmental stage. The primary storage organ is the fat body, which can constitute 50% of the fresh weight of the insect and also acts as the major metabolic center (analogous to the vertebrate adipose tissue and liver). Bathing the fat body (and all other tissues and organs) is the hemolymph, the main functions of which are to transport nutrient substrates to utilization sites and to deliver metabolic wastes to the excretory system.
      Although neutral lipids are stored as triglycerides, in times of need they appear to be endergonically released into the hemolymph as diglycerides in the majority of insects thus far studied (particularly silkmoths and locusts). Indeed, diglycerides constitute the largest neutral lipid fraction in the hemolymph of silkmoths, locusts, cockroaches, bugs, etc. In the hemolymph the diglyceride is found as a constituent of specific lipoproteins, and one specific lipoprotein class (lipoprotein I; high density lipoprotein) appears to be necessary for the transport of diglyceride from the fat body cell into the hemolymph. This particular lipoprotein is also involved in the transport of cholesterol from the gut into the hemolymph. Thus, lipoprotein I appears to be the major neutral lipid and sterol transport agent in the insects studied and, in addition, plays a regulatory role in the release of both diglycerides and sterols. Hemolymph lipoprotein II (very high density lipoprotein) may be important in providing protein and lipid to the insect ovary during oogenesis.
      Ecdysone, the polyhydroxy steroidal insect molting hormone, is probably carried “free” in the hemolymph, although reports exist of specific hemolymph-binding proteins in some species. The other major insect growth hormone, juvenile hormone, is transported by hemolymph lipoproteins in silkmoths and locusts and by a lower molecular weight hemolymph protein in the tobacco hornworm.


        • Gilbert L.I.
        Lipid metabolism and function in insects.
        Advan. Insect Physiol. 1967; 4: 69-211
        • Fast P.G.
        Insect lipids.
        Progr. Chem. Fats Other Lipids. 1970; 2: 181-242
        • Thompson M.J.
        • Kaplanis J.N.
        • Robbins W.E.
        • Svoboda J.A.
        Metabolism of steroids in insects.
        Advan. Lipid Res. 1973; 11: 219-265
        • Doane W.W.
        Role of hormones in insect development.
        in: Counce S.J. Waddington C.A. Developmental Systems: Insects. 2. Academic Press, New York1973: 291-497
        • Gilbert L.I.
        • King D.S.
        Physiology of growth and development: endocrine aspects.
        in: Rockstein M. Physiology of Insec-ta. 1. Academic Press, New York1973: 249-370
        • Wyatt G.R.
        Insect hormones.
        in: Litwack G. Biochemical Actions of Hormones. 2. Academic Press, New York1972: 385-490
        • Gilbert L.I.
        • Schneiderman H.A.
        The content of juvenile hormone and lipid in Lepidoptera: sexual differences and developmental changes.
        Gen. Comp. Endocrinol. 1961; 1: 453-472
        • Domroese K.A.
        • Gilbert L.I.
        The role of lipid in adult development and flight muscle metabolism in Hy-alophora cecropia.
        J. Exp. Biol. 1964; 41: 573-590
        • Liu T.P.
        • Davies D.M.
        Fine structure of fro-zen-etched lipid granules in the fat body of an insect.
        J. Lipid Res. 1972; 13: 115-118
        • Bhakthan N.M.G.
        • Gilbert L.I.
        Studies on the cytophysiology of the fat body of the American silkmoth.
        Z. Zelljorsch. Mikrosk. Anat. 1972; 124: 433-444
        • Bhakthan N.M.G.
        • Gilbert L.I.
        Effects of epinephrine and lipase on the morphology of insect fat body.
        Ann. Entomol. Soc. Amer. 1971; 64: 68-72
        • Tietz A.
        Studies on the biosynthesis of diglycerides and triglycerides in cell free preparations of the fat body of the locust Locusla migratoria.
        Israel J. Med. Sci. 1969; 5: 10071017
        • Thompson S.N.
        A review and comparative characterization of the fatty acid compositions of seven insect orders.
        Comp. Biochem. Physiol. 1973; 45B: 467-482
        • Suzuki M.
        • Kobayashi M.
        • Kekawa N.I.
        Variation of triglycerides and fatty acid methyl esters in silkworm eggs during embryonic development.
        Lipids. 1970; 5: 539544
        • McFarlane J.E.
        Fatty acids, methyl esters and insect growth.
        Comp. Biochem. Physiol. 1968; 24: 377-384
        • Stephen Jr., W.F.
        • Gilbert L.I.
        Fatty acid biosynthesis in the silkmoth, Hyalophora cecropia.
        J. Insect Physiol. 1969; 15: 1833-1854
        • Chino H.
        • Gilbert L.I.
        Studies on the interconversion of carbohydrate and fatty acid in Hyalophora cecropia.
        J. Insect Physiol. 1965; 11: 287-295
        • Chino H.
        • Gilbert L.I.
        Lipid release and transport in insects.
        Biochim. Biophys. Acta. 1965; 98: 94-110
        • Wimer L.T.
        • Lumb R.H.
        Lipid composition of the developing larval fat body of Phormia regina.
        J. Insect Physiol. 1967; 13: 889-898
        • Tietz A.
        Fat transport in the locust: the role of diglycerides.
        Eur. J. Biochem. 1967; 2: 236-242
        • Chippendale G.M.
        Fat body and haemolymph lipids of the southwestern corn borer, Diatraea grandiosella, during metamorphosis.
        Insect Biochem. 1971; 1: 39-46
        • Stevenson E.
        Haemolymph lipids and fat body lipases of the southern armyworm moth.
        J. Insect Physiol. 1972; 18: 1751-1756
        • Thomas K.K.
        Lipid composition of the fat body and haemolymph and its relation to lipid release in Oncopellus fasciatus.
        J. Insect Physiol. 1974; 20: 845-858
        • Gilbert L.I.
        • Chino H.
        • Domroese K.A.
        Lipolytic activity of insect tissues and its significance in lipid transport.
        J. Insect Physiol. 1965; 11: 1057-1070
        • Stevenson E.
        Monoglyceride lipase in moth flight muscle.
        J. Insect Physiol. 1969; 15: 1537-1550
        • Krysan J.L.
        • Guss P.L.
        Lipase from egg of southern corn rootworm.
        Lipids. 1973; 8: 369-373
        • Krysan J.L.
        • Guss P.L.
        On the regulation of lipolysis in an insect egg. Observations in vitro.
        Biochim. Biophys. Acta. 1973; 296: 466-470
        • Dutkowski A.B.
        • Ziajka B.
        Synthesis and degradation of glycerides in fat body of normal and ovariotecto-mized females of Galleria mellonella.
        J. Insect Physiol. 1972; 18: 1351-1367
        • Dutkowski A.B.
        Sex differences in the lipolytic activity of Galleria mellonella fat body.
        J. Insect Physiol. 1973; 19: 1721-1726
        • Dutkowski A.B.
        • Sarzala-Drabikowska M.G.
        Some aspects of regulation of fat body lipolytic activity in Galleria mellonella.
        J. Insect Physiol. 1973; 19: 1341-1350
        • Wigglesworth V.B.
        ‘Catalysomes’ or enzyme caps on lipid droplets: an intracellular organelle.
        Nature. 1966; 210: 759
        • Thomas K.K.
        • Gilbert L.I.
        Phospholipid synthesis during flight muscle development in the American silkmoth, Hyalophora cecropia.
        Comp. Biochem. Physiol. 1967; 21: 279-290
        • Chan S.K.
        • Margoliash E.
        Properties and primary structure of the cytochrome c from the flight muscles of the moth, Sarnia cynthia.
        J. Biol. Chem. 1966; 241: 335-348
        • Chino H.
        • Gilbert L.I.
        Diglyceride release from insect fat body.
        Science. 1964; 143: 359-361
        • Nayar J.K.
        • Van Handel E.
        Flight performance and metabolism of the moth, Spodoptera Jrugiperda.
        J. Insect Physiol. 1971; 17: 2475-2479
        • Van Handel E.
        • Nayar J.K.
        Turn-over of diglycerides during flight and rest in the moth Spodoptera Jrugiperda.
        Insect Biochem. 1972; 2: 8-12
        • Bhakthan N.M.G.
        • Gilbert L.I.
        Studies on lipid transport in Manduca sexta (Insecta).
        Comp. Biochem. Physiol. 1970; 33: 705-706
        • Tietz A.
        Fat transport in the locust.
        J. Lipid Res. 1962; 3: 421-426
        • Allen W.V.
        Lipid transport in the dungeness crab, Cancer magister Dana..
        Comp. Biochem. Physiol. 1972; 43B: 193-207
        • Starratt A.N.
        • Osgood C.E.
        An oviposition pheromone of the mosquito Culex larsalis: diglyceride composition of the active fraction.
        Biochim. Biophys. Acta. 1972; 280: 187-193
        • Cook B.J.
        • Eddington L.C.
        The release of triglycerides and free fatty acids from the fat body of the cockroach, Periplaneta americana.
        J. Insect Physiol. 1967; 13: 1361-1372
        • Gilbert L.I.
        Changes in lipid content during the reproductive cycle of Leucophaea maderae and effects of the juvenile hormone on lipid metabolism in vitro.
        Comp. Bio-chem. Physiol. 1967; 21: 237-257
        • Downer R.G.H.
        • E-Steele J.
        Hormonal stimulation of lipid transport in the American cockroach, Periplaneta americana.
        Gen. Comp. Endocrinol. 1972; 19: 259-265
        • Martin j. S
        Lipid composition of fat body and its contribution to the maturing oocytes in Pyrrhocoris apterus.
        J. Insect Physiol. 1969; 15: 1025-1045
        • Martin J.S.
        Studies on assimilation, mobilization, and transport of lipids by the fat body and haemolymph of Pyrrhocoris apterus.
        J. Insect Physiol. 1969; 15: 2319-2344
        • Wlodawer P.
        • Wisniewska A.
        Lipids in the haemolymph of waxmoth larvae during starvation.
        J. Insect Physiol. 1965; 11: 11-20
        • Wlodawer P.
        • Lagwinska E.
        • Baranska J.
        Esterification of fatty acids in the wax moth haemolymph and its possible role in lipid transport.
        J. Insect Physiol. 1966; 12: 547-560
        • Wlodawer P.
        • Lagwinska E.
        Uptake and release of lipids by the isolated fat body of the wax moth larva.
        J. Insect Physiol. 1967; 13: 319-331
        • Beenakkers A.M.T.
        • Gilbert L.I.
        The fatty acid composition of fat body and haemolymph lipids in Hy-alophora cecropia and its relation to lipid release.
        J. Insect Physiol. 1968; 14: 481-494
        • Zinder O.
        • Eisenberg E.
        • Shapiro B.
        Compart-mentation of glycerides in adipose tissue cells. I. The mechanism of free fatty acid release.
        J. Biol. Chem. 1973; 248: 76737676
        • Beenakkers A.M.T.
        Influence of flight on lipid metabolism in Locusta migratoria.
        Insect Biochem. 1973; 3: 303308
        • Beenakkers A.M.T.
        Transport of fatty acids in Locusta migratoria during sustained flight.
        J. Insect Physiol. 1965; 11: 879-888
        • Mayer R.J.
        • Candy D.J.
        Changes in haemolymph lipoproteins during locust flight.
        Nature. 1967; 215: 987
        • Wiens A.W.
        • Gilbert L.I.
        Regulation of cockroach fat-body metabolism by the corpus cardiacum in vitro.
        Science. 1965; 150: 614-616
        • Mayer R.J.
        • Candy D.J.
        Control of haemolymph lipid concentration during locust flight: an adipoki-netic hormone from the corpora cardiaca.
        J. Insect Physiol. 1969; 15: 611-620
        • Goldsworthy G.J.
        • Mordue W.
        • Guthkelch J.
        Studies on insect adipokinetic hormones.
        Gen. Comp. Endocrinol. 1972; 18: 545-551
        • Bhakthan N.M.G.
        • Gilbert L.I.
        Effects of some vertebrate hormones on lipid mobilization in the insect fat body.
        Gen. Comp. Endocrinol. 1968; 11: 186-197
        • Downer R.G.H.
        • Steele J.E.
        Hormonal control of lipid concentration in fat body and hemolymph of the American cockroach, Periplaneta americana.
        Proc. Entomol. Soc. Ontario. 1969; 100: 113-116
        • Downer R.G.H.
        • Steele J.E.
        Haemolymph lipase activity in the American cockroach, Periplaneta americana.
        J. Insect Physiol. 1973; 19: 523-532
        • Downer R.G.H.
        Interspecificity of lipid-regulating factors from insect corpus cardiacum.
        Can. J. Zool. 1972; 50: 63-65
        • Vroman H.E.
        • Kaplanis J.N.
        • Robbins W.E.
        Effect of allatectomy on lipid biosynthesis and turnover in the female American cockroach, Periplaneta americana (L.).
        J. Insect Physiol. 1965; 11: 897-904
        • Walker P.R.
        • Bailey E.
        Effect of allatectomy on fat body lipid metabolism of the male desert locust during adult development.
        J. Insect Physiol. 1971; 17: 813-821
        • Walker P.R.
        • Bailey E.
        Effect of allatectomy on fat body lipogenic enzymes of the male desert locust during adult development.
        J. Insect Physiol. 1971; 17: 1359-1369
        • Walker P.R.
        • Bailey E.
        Effect of allatectomy on the growth of the male desert locust during adult development.
        J. Insect Physiol. 1971; 17: 1125-1137
        • Hill L.
        Hormones and the control of metabolism in insects.
        Gen. Comp. Endocrinol. Suppl. 1972; 3: 174-183
        • Chino H.
        • Sudo A.
        • Harashima K.
        Isolation of diglyceride-bound lipoprotein from insect hemolymph.
        Bio-chim. Biophys. Acta. 1967; 144: 177-179
        • Chino H.
        • Murakami S.
        • Harashima K.
        Diglyceride-carrying lipoproteins in insect hemolymph. Isolation, purification and properties.
        Biochim. Biophys. Acta. 1969; 176: 1-26
        • Thomas K.K.
        • Gilbert L.I.
        Isolation and characterization of the hemolymph lipoproteins of the American silkmoth, Hyalophora cecropia.
        Arch. Biochem. Biophys. 1968; 127: 512-521
        • Thomas K.K.
        • Gilbert L.I.
        The hemolymph lipoproteins of the silkmoth Hyalophora gloveri: studies on lipid composition, origin and function.
        Physiol. Chem. Phys. 1969; 1: 293-311
        • Scanu A.M.
        Structural studies on serum lipoproteins.
        Biochim. Biophys. Acta. 1972; 265: 471-508
        • Scanu A.M.
        • Wisdom C.
        Serum lipoproteins structure and function.
        Annu. Rev. Biochem. 1972; 41: 703-730
        • Whitmore E.
        • Gilbert L.I.
        Hemolymph proteins and lipoproteins in Lepidoptera—a comparative electrophoretic study.
        Comp. Biochem. Physiol. 1974; 47B: 63-78
        • Harashima K.
        Carotenoids in haemolymph of a silkworm, Philosamia cynthia pryeri Butler: occurrence of 3-hydroxy-3'-keto-a-carotene.
        Int. J. Biochem. 1970; 1: 523-531
        • Dejmal R.K.
        • Brookes V.J.
        Insect lipovitellin: chemical and physical characteristics of a yolk protein from the ovaries of Leucophaea maderae.
        J. Biol. Chem. 1972; 247: 869-874
        • Peled Y.
        • Tietz A.
        Fat transport in the locust, Locusta migratoria: the role of protein synthesis.
        Biochim. Biophys. Acta. 1973; 296: 499-509
      1. 76. Peled, Y., and A. Tietz. 1974. Isolation and properties of a lipoprotein from the hemolymph of the locust, Locusta migratoria. Biochim. Biophys. Acta. In press.

        • Thomas K.K.
        Studies on the synthesis of lipoproteins during larval-pupal development of Hyalophora cecropia.
        Insect Biochem. 1972; 2: 107-118
        • Clayton R.B.
        The utilization of sterols by insects.
        J. Lipid Res. 1964; 5: 3-19
        • King D.S.
        • Bollenbacher W.
        • Borst D.
        • Vedeckis W.
        • O'Connor J.D.
        • Ittycheriah P.
        • Gilbert L.I.
        The secretion of a-ecdysone by the prothoracic glands of Manduca sexta.
        Proc. Nat. Acad. Sci. USA. 1974; 71: 793-796
        • Chino H.
        • Sakurai S.
        • Ohtaki T.
        • Ikekawa N.
        • Miyazaki H.
        • Ishibashi M.
        • Abuki H.
        Biosynthesis of a-ecdysone by prothoracic glands in vitro.
        Science. 1974; 183: 529530
        • Emmerich H.
        Uber die Hamolymphproteine von Pyrrhocoris apterus und liber die Bindung von Ecdyson durch Hamolymphproteine.
        J. Insect Physiol. 1970; 16: 725-747
        • Emmerich H.
        Ecdysonbindende Proteinfraktionen in den Speicheldriisen von Drosophila hydei.
        Z. Vergl. Physiol. 1970; 68: 385-402
        • Thamer G.
        • Karlson P.
        Nachweis der Protein-bindung von Ecdyson bei der Schmeissfliege Meigen Cal-liphora erythrocephala..
        Z. Naturforsch. 1972; 27B: 1191-1195
        • Gorell T.A.
        • Gilbert L.I.
        • Tash J.
        The uptake and conversion of a-ecdysone by the pupal tissues of Hyalo-phora cecropia.
        Insect Biochem. 1972; 2: 94-106
        • Chino H.
        • Gilbert L.I.
        • Siddall J.B.
        • Hafferl W.
        Studies on ecdysone transport in insect haemolymph.
        J. Insect Physiol. 1970; 16: 2033-2040
        • Chino H.
        • Gilbert L.I.
        The uptake and transport of cholesterol by haemolymph lipoproteins.
        Insect Biochem. 1971; 1: 337-347
        • Nichols A.V.
        • Smith L.
        Effect of very low-density lipoproteins on lipid transfer in incubated serum.
        J. Lipid Res. 1965; 6: 206-210
        • Margolis S.
        Structure of very low and low density lipoproteins.
        in: Tria E. Scanu A. Structural and Functional Aspects of Lipoproteins in Living Systems. Academic Press, New York1969: 367-424
        • Reibstein D.
        • Law J.H.
        Enzymatic synthesis of insect juvenile hormones.
        Biochem. Biophys. Res. Commun. 1973; 55: 266-272
        • Schooley D.A.
        • Judy K.J.
        • Bergot B.J.
        • Hall M.S.
        • Siddall J.B.
        Biosynthesis of the juvenile hormones of Manduca sexta: labeling pattern from mevalonate, propionate, and acetate.
        Proc. Nat. Acad. Sci. USA. 1973; 70: 2921-2925
        • Whitmore E.
        • Gilbert L.I.
        Haemolymph lipoprotein transport of juvenile hormone.
        J. Insect Physiol. 1972; 18: 1153-1167
        • Emmerich H.
        • Hartmann R.
        A carrier lipoprotein for juvenile hormone in the haemolymph of Locusta mi-gratoria.
        J. Insect Physiol. 1973; 19: 1663-1675
        • Kramer K.J.
        • Sanburg L.L.
        • Kezdy F.J.
        • Law J.H.
        The juvenile hormone binding protein in the hemo-lymph of Manduca sexta Johannson (Lepidoptera: Sphing-idae).
        Proc. Nat. Acad. Sci. USA. 1974; 71: 493-497