Purification of adultDrosophila melanogaster lipophorin and its role in hydrocarbon transport

Abstract

Lipophorin was isolated from homogenized adult Drosophila melanogaster. It is stained by Sudan Black and has a native molecular mass of 640 kD and a density of 1.12 g/ml. It consists of two glycosylated apoproteins of 240 and 75 kDa. Gas chromatography and mass spectrometry showed that lipophorins isolated separately from virgin 3‐day‐old male and female flies were associated with specific hydrocarbons, and that these were the same hydrocarbons found in male and female cuticles, respectively. Moreover, a pool of internal hydrocarbons was demonstrated for the first time, with chain lengths similar to those of the cuticular pool. Studies on the fate of the hydrocarbons synthesized de novo after topical applications of radiolabelled fatty acid precursors showed a decrease of the internal pool of hydrocarbons with time, concomitant with an increase of the cuticular pool. These results suggest that hydrocarbons synthesized at an internal site, possibly in oenocytes, may be transported to the cuticle of the flies by lipophorin. © 1996 Wiley‐Liss, Inc.

Control of metabolic adaptation to fasting by dILP6-induced insulin signaling in Drosophila oenocytes

“…This function is consistent with the IIS-dependent induction of lipophorin receptor 2 (LpR2) in oenocytes of fasting flies. Lipophorin functions as the main lipid transport protein in the hemolymph of both larvae and adults (44)(45)(46), and lipophorin receptor is involved in the uptake of neutral lipids in various tissues (44,47). Interestingly, inhibiting IIS activity in oenocytes is sufficient to cause metabolic imbalance in flies even under fed conditions (Fig.…”

Lipophorin of female Blattella germanica (L.): characterization and relation to hemolymph titers of juvenile hormone and hydrocarbons

“…It has been purified and characterized from the hemolymph of insect species in the Diptera (Sarcophaga bullata, Van Mellaert et al, 1985;Aedes aegypti, Van Heusden et al, 1997;Drosophila melanogaster, Fernando-Warnakulasuriya and Wells, 1988), Hymenoptera (Apis mellifera, de Kort and Koopmanschap, 1986), Coleoptera (Leptinotarsa decemlineata, de Kort and Koopmanschap, 1987), Lepidoptera (several species, see review: Soulages and Wells, 1994), Hemiptera (Triatoma, Ganzalez et al, 1991;Rhodnius, Coelho et al, 1997), Orthoptera (Locusta migratoria, Chino and Kitazawa, 1981), Isop-HDLp facilitates absorption of neutral and polar lipids from the gut, and it transports diacylglycerols from the fat body to muscle to fuel flight (Chino, 1985;Van der Horst et al, 1993;Blacklock and Ryan, 1994;Soulages and Wells, 1994). Lipophorin also delivers pheromones to the cuticle (Gu et al, 1995;Pho et al, 1996) and specialized pheromone glands (Schal et al, 1998a), hydrocarbons to the epicuticle, fat body, and ovaries (Chino et al, 1977;Chino, 1985;Katagiri and de Kort, 1991;Gu et al, 1995;Schal et al, 1998b), and retinoids to yet undetermined locations (Kutty et al, 1996). It has specific, high-affinity binding sites for juvenile hormone (JH) III in species in the Coleoptera, Isoptera, Diptera, Hymenoptera and Dictyoptera (Trowell, 1992; and, in this context, the primary functions of HDLp are thought to be facilitation of transport of the hydrophobic hormone from the site of synthesis to target tissues (Whitmore and Gilbert, 1972) and protection of the hormone from enzymatic degradation by hemolymph esterases and epoxide hydrolases (Sanburg et al, 1975a, b;Hammock et al, 1975;Goodman, 1990;Lanzrein et al, 1993;Touhara et al, 1996).…”

Site of synthesis, tissue distribution, and lipophorin transport of hydrocarbons in Blattella germanica (L.) nymphs

“…Grooming does provide an opportunity for insects to redistribute cuticular waxes, but several studies implicate a hemolymph transport pathway (Chino, 1985;Soulages and Wells, 1994;Schal et al, 1998). HC contained in the hemolymph of many insect species, including locusts, beetles, bees, flies, and cockroaches, is qualitatively similar to the respective epicuticular HC Chino, 1982, 1984;Blomquist et al, 1987;Pho et al, 1996;see Schal et al, 1998 for other examples). In adult B. germanica all of the hemolymph HC is associated with lipophorin, a hemolymph lipoprotein that transports HC to both the epicuticle and developing oöcytes (Gu et al, 1995).…”