Hemolymph

Bacillus thuringiensis produces a variety of organic compounds which are toxic to the larvae of certain susceptible insect hosts. Among the toxic entities are proteinaceous crystals, probably three soluble toxins, and certain enzymes. The protein material is the major toxin active in killing lepidopterous larvae. The protein is formed by the cells apparently in close synchrony with sporulation, and its nature is a constant function of bacterial strain. The mode of action of the protein is under study. The sequence of events in the pathology observed is probably solubilization of the crystal (enzymatic or physical)—>liberation of toxic unit—>alteration of permeability of larval gut wall— change in hemolymph pH—>invasion of hemolymph by spores or vegetative cells of the bacterium. 

Trehalose Fungi and yeasts. The major sugar of insect hemolymph. ... 

Martel, R.R. and Law, J.H., Purification and properties of an ommochrome-binding protein from the hemolymph of the tobacco homworm, Manduca sexta, J. Biol. Chem., 266, 21392, 1991. 

Kanost MR, Zepp MK, Ladendorff NE, Andersson LA 1994 Isolation and characterization of a hemocyte aggregation inhibitor from hemolymph of Manduca sexta larvae. Arch Insect Biochem Physiol 27 123—136... 

FIGURE 24.1 The pathway of carotenoid transport in the silkworm. Carotenoids are absorbed from dietary mulberry leaves into the intestinal mucosa, transferred to the hemolymph (1), transported in the hemolymph by plasma lipoproteins (2), and accumulated in the silk gland (3). 

The hemolymphal transport of carotenoids by lipophorin has been elucidated and documented (Law and Wells 1989, Tsuchida et al. 1998, Arrese et al. 2001, Canavoso et al. 2001), as has plasma transport by mammalian lipoproteins (Paker 1996, Yeum and Russell 2002). Lipophorin serves as a shuttle that moves carotenoids from one tissue to another without itself entering the cells, in stark contrast to the vertebrate low-density lipoprotein (LDL) (Brown and Goldstein 1986), which is endocytosed and metabolized in the cell. Here, we focus on the recent biochemical and genetic studies of the intracellular CBP of the silkworm, which mainly transports lutein. We hope this review provides insights into the studies of CBPs in other organisms. 

Acp Light yellow hemolymph, even though individuals have Yand I... 

FIGURE 24.6 Model of the molecular function of CBP. CBP moves in the cytosol and relays carotenoid in combination with the lipophorin in the hemolymph. At the membrane, other factors might be involved in the carotenoid transport (magnification, see the text for explanation). 

We consider that there must be CBPs other than CBP in the silkworm. Lipophorin binds carotenoids (Tsuchida et al. 1998). Fujii et al. isolated a CBP of 60kDa from the larval hemolymph, and... 

Chino, H. 1985. Lipid transport Biochemistry of hemolymph lipophorin. In Comprehensive Insect Physiology, Biochemistry, and Pharmacology, eds. Kerkut G. A. and Gilbert L. I., Oxford Pergamon Press, 10 115-134. 

Fujii, H., Morooka, J., Tochihara, S., Kawaguchi, Y., and Sakaguchi, B. 1988a. Existence of carotenoids binding protein in larval hemolymph of the yellow blood strain of Bombyx mori. J. Seric. Sci. Jpn., 57(2) 94-99. 

Tsuchida, K., Katagiri, C., Tanaka, Y. et al. 2004b. The basis for colorless hemolymph and cocoons in the Y-gene recessive Bombyx mori mutants A defect in the cellular uptake of carotenoids. J. Insect Physiol., 50(10) 975-983. 

The site of pheromone production in flies and cockroaches that utilize hydrocarbons is similar to that of the moths. Oenocyte cells produce the hydrocarbon pheromone which is transported by lipophorin in the hemolymph to epidermal cells throughout the body for release from the cuticular surface in general [20,21]. 

Several families of moths utilize hydrocarbons or epoxides of hydrocarbons as their sex pheromone. Oenocyte cells produce hydrocarbons that are transported through the hemolymph by lipophorin [71]. In a study using arctiid moths it was shown that sex pheromone hydrocarbons are transported on the same lipophorin particle as the hydrocarbons destined for the cuticular surface [ 17]. Therefore, specific uptake of the sex pheromone hydrocarbon occurred in pheromone glands [17]. Similar findings have been found with other moths [72-74]. The mechanism behind this specific uptake of one hydrocarbon from a potential pool of other hydrocarbons is unknown. 

The biosynthesis of Me3,Mel 1-29 H takes place in oenocyte cells, released into the hemolymph and transported by lipophorin to peripheral tissues (Fig. 7) [71, 231, 232]. Direct evidence for oenocytes biosynthesizing hydrocarbon has come recently with the dissociation of oenocytes from epidermal cells and in vitro incubation with labeled propionate [233]. Differential uptake of some hydrocarbons in different tissues has also been documented although the exact mechanism behind the differential placement of hydrocarbons is unknown [20,128,230,232,234]. Although the biosynthesis of hydrocarbons may not be under direct endocrine regulation supply of precursor hydrocarbon that is converted to the sex pheromone is a requirement. 

As with the other insects studied that utilize hydrocarbon sex pheromones, once Z9-23 H is produced by oenocyte cells it is released into the hemolymph. Lipophorin is the transport protein that will move the hydrocarbon to cuticu-lar tissue [21]. It was found that about 24 h were required once Z9-23 H was induced to actual deposition on the cuticular surface [237]. As is the case with other insects selective partitioning of the sex pheromone was observed with relatively larger proportions of Z9-23 H being found on the cuticular surface than in other tissues [21]. 

Apis mellifera Q-MG Delays worker foraging ontogeny reduces tbeir hemolymph JH titre (2E)-9-Oxodec-2-enoic acid 52, (2 E)-9-hydroxydec-2-enoic acid (71% (R)-(-)) 53, methyl 4-hydroxybenzoate 54, 4-hydroxy-3-methoxyphenylethanol 55 (collectively called queen mandibular pheromone QMP ) [138]... 

Larva Delays onset of worker foraging suppresses JH titre in worker hemolymph Ten component blend of brood pheromone [124]... 

Temporary decrease in hemolymph glucose levels in the freshwater prawn Macrobrachium lamarrei surviving 1840 pg/L Cr+6 for 96 h (Murti et al. 1983)... 

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