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PubMed1981

Genetics of insect hemolymph beta-N-acetylglucosaminidase in the silkworm, Bombyx mori.

The distribution of insect hemolymph beta-N-acetylglucosaminidase was investigated in the silkworm, Bombyx mori. Activity in 115 varieties was 6.92 +/- 3.22 units/ml, ranging from 1.4 to 17.0 units/ml. No enzyme-deficient individuals were observed. By selecting individuals showing either high or low enzyme activities, homozygotes were separated with activities varying 10-fold between isolates. No differences in activity of alpha-mannosidase and beta-galactosidase were observed. Thus, it appears that high- or low-enzyme silkworms (High or Low lines) shared the same genetic background except for the gene concerning the activity of beta-N-acetylglucosaminidase. Studies on the heredity of the enzyme indicated that the synthesis of the enzyme protein was controlled by an autosomal allele. Examination by immunotitration and CM52-cellulose column chromatography revealed that the difference in activity between High and Low lines was due to the amount of the active enzyme, but not to an endogeneous activator or inhibitor. Furthermore, there was no isozymic difference in beta-N-acetylglucosaminidase. Slab gel electrophoresis on polyacrylamide showed a species of enzyme (A) that stained more intensely in the High line. For the second species of enzyme (B), the converse was true. This evidence suggests that enzyme levels in hemolymph are under the control of a gene affording association of enzyme subunits to the active enzyme molecule.

Acetylglucosaminidase↗

PubMed1984

Genetic variants of protease inhibitors against fungal protease and alpha-chymotrypsin from hemolymph of the silkworm, Bombyx mori.

Many electrophoretic variants of hemolymph inhibitors of proteases from Aspergillus melleus and pancreatic alpha-chymotrypsin were found using 126 silkworm strains. Six inhibitors of the fungal protease were detected and eight of chymotrypsin; the distribution of inhibitors among Japanese, Chinese, and European races was investigated. Comparison of electrophoretic patterns from F1 hybrids and parents showed that the offspring produce inhibitors of both parental types. Segregation in F2 and backcrossing suggest that the expression of each inhibitor is controlled in most cases by a pair of alleles which are responsible for strong and null bands. Two bands of fungal protease inhibitors C and D were controlled by codominant alleles. These results suggest that polymorphism of hemolymph protease inhibitors in the silkworm would be a useful experimental system for the study of the genetic control of protease inhibitors.

Animals↗

PubMed1991

Partial purification and some properties of a hemolymph lectin from Panstrongylus megistus (Hemiptera, Reduviidae).

Hemagglutinating activity was studied in homogenates of three embryonic stages, and in the hemolymph of most instar larvae and in adult insects of Panstrongylus megistus, an important Chagas' disease vector in Brazil. A hemolymph lectin from the 5th instar larvae of P. megistus was purified through a biospecific adsorption by using formaldehyde-treated erythrocytes. The lectin fraction was desorbed with 0.2M D-galactose in 0.15M NaCl. The lectin fraction activity was inhibited by L-rhamnose, D-lactose, raffinose, D-galactose, and D-fucose. The electrophoretic pattern to native and acidic proteins resolved lectin fraction in two main bands with lectin activity. These bands were considered as multiple molecular forms or isoforms of P. megistus lectin. Under denaturating conditions, isoform 1 showed one band with apparent mol wt (MW) of 64 kDa while isoform 2 was resolved in two bands with MW of 64 and 33 kDa.

Adsorption↗

PubMed2002

The coagulation of insect hemolymph.

In contrast to both vertebrates and non-insect arthropods, little is known about the coagulation of hemolymph (hemostasis) in insects. We discuss the integration of the hemostatic response with other branches of the insect immune system. We also describe the present stage in the characterization of both soluble and cellular factors that contribute to hemostasis in insects. The factors of the well-characterized clotting cascades of vertebrates, primitive chelicerates and crustaceans are used to assess the implications of sequencing the whole Drosophila genome for searching candidate genes involved in hemostasis. Some striking similarities between blood clotting in vertebrates and the reaction of insect cells involved in hemolymph coagulation have implications for a phylogenetic comparison of hemostasis between divergent animal classes.

Animals↗

PubMed1996

Ultrastructural localization of a sialic acid-specific hemolymph lectin in the hemocytes and other tissues of the hard tick Ixodes ricinus (Acari; Chelicerata).

Lectins have been suggested to function as pattern-recognition molecules in invertebrate immune mechanisms. A lectin from the hemolymph of the tick Ixodes ricinus with main specificity for sialic acid was characterized and antibodies directed against this lectin were prepared. In this study, these antibodies were used to localize the lectin in the tissues of I. ricinus. Immunoreactivity with poly- and monoclonal antibodies was detected in the granules of both types of granular hemocytes, at the membrane of hemocytes, and at the basal laminae surrounding the hemocoel. Furthermore, cells attached to the midgut, invaginations of Géné's organ, and granular inclusions of nephrocytes were labeled. The immunoreactivity detected in hemocytes and the hemocoel lining supports the idea that the hemolymph lectin may function as a recognition molecule in the immune system of I. ricinus. Another function could be protection of eggs that are coated with secretions by Géné's organ. The lectin activity could also be involved in transmission of Borrelia burgdorferi, the causative agent of Lyme borreliosis, and the tick-borne encephalitis virus.

Animals↗

PubMed2004

Reduced cysteine protease activity of the hemolymph of Bombyx mori larvae infected with fp25K-inactivated bombyx mori nucleopolyhedrovirus results in the reduced postmortem host degradation.

We previously reported that the FP25K gene (fp25K) product of the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) is involved in postmortem host degradation. Here, we investigated the mechanism by which reduced postmortem host degradation is caused after the infection of fp25K-mutated BmNPVs. Firstly, we investigated gene expression levels of vcath and chiA both of which products are involved in postmortem host degradation. We found that transcriptional levels of these genes infp25K-mutated BmNPV-infected BmN cells were comparable to those in cells infected with wild-type (wt) BmNPV. Next, we examined the cysteine protease activity in fp25K-mutated BmNPV-infected BmN cells. Although the cysteine protease activity in BmN cells infected with fp25K-mutated BmNPVs was comparable to that of wt BmNPV-infected cells, the released activity in the culture medium is dramatically reduced in that of cells infected with fp25K mutants. We also found that the cysteine protease activity in the hemolymph of fp25K-mutated BmNPV-infected B. mori larvae is drastically reduced compared to that of wt BmNPV-infected larvae. These results show that the release of cysteine protease into the hemolymph of B. mori larvae infected with fp25K-mutated BmNPVs is reduced and, as a consequence, postmortem host degradation of infected insects is lessened.

Amino Acid Substitution↗

PubMed1985

Apparent multiple catalytic sites involved in the ester hydrolysis of juvenile hormones by the hemolymph and by an affinity-purified esterase from Manduca sexta Johannson (Lepidoptera: Sphingidae).

The esterases which metabolize juvenile hormone (JH) in some insects may be important in regulating the hormone titer. The JH ester-hydrolyzing activity (JHE) in the larval hemolymph of the tobacco hornworm (Manduca sexta) was found to be attributed to two forms of esterase with almost equivalent activity based on selectivity and kinetics of inhibition by two 3-substituted thio-1,1,1-trifluoropropan-2-ones and a phosphoramidothioate. Neither of the two forms were inhibited by diisopropyl phosphorofluoridate or iodoacetamide. Steady-state kinetics of JH II hydrolysis supported the inhibition studies and showed that the two forms were widely different in their affinity for JH II. The activity of the hemolymph was found to be bound selectively to an affinity column synthesized by the reaction of epoxy-activated Sepharose with 3-(4'-mercaptobutylthio)-1,1,1-trifluoropropan-2-one. This column offered a quantitative, one-step purification of JH esterase with a purification factor of approximately 800 and specific activity of approximately 573 nmol JH III hydrolyzed min-1 mg protein-1. The purified protein showed only a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with a molecular weight of approximately 65,000. However, the purified enzyme apparently revealed the same two kinetic forms as the native enzyme, which indicates that two sites of the same protein are likely to be involved in JH hydrolysis.

Acetone↗

PubMed1984

Purification of a human alternative complement pathway inhibitor from hemolymph of larval fall armyworm (Spodoptera frugiperda).

Larval Spodoptera frugiperda hemolymph contains a specific inhibitor of the alternative pathway of human complement. This inhibitor was purified from larval hemolymph (HL) by 50% (NH4)2SO4 precipitation, DEAE-Sephacel chromatography and sequential gel-filtration on Bio-Gel 1.5m, 0.5m and Sephacryl S-200. Purified HL protein (Mr = 110,000) was composed of two Mr 55,000 polypeptide chains. Addition of purified HL protein to human complement resulted in a dose-dependent inhibition of RaRBC lysis and clumping of cells. The protein inhibitor provides a new tool for investigating the regulation of human alternative complement pathway.

Amino Acids↗

PubMed1988

Acetylcholinesterase (EC 3.1.1.7), a neurotransmitter enzyme in scorpion hemolymph.

Acetylcholinesterase (AchE: EC 3.1.1.7) was identified and purified from the hemolymph of the scorpion Heterometrus bengalensis. The purity of the enzyme was determined by polyacrylamide gel electrophoresis (PAGE). The molecular weight of the enzyme, determined by sodium dodecyl sulfate-PAGE, was 80,000. The purified AchE hydrolysed acetylthiocholine iodide, but it did not react with butyrylthiocholine iodide. BW284C51, a specific inhibitor of AchE, strongly inhibited the enzyme. The known inhibitor (tetramonoisopropylpyrophosphortetramide) of pseudocholinesterase did not produce any inhibition of the enzyme activity. The purified AchE of scorpion hemolymph was vulnerable to high substrate concentration. The presence of Cu2+ and Ni2+ reduced the enzyme activity, whereas the metal ion, Sn2+, enhanced AchE activity. Ca2+ produced neither inhibition nor activation. (Na+, K+)-ATPase and Mg2+-ATPase activities were greatly enhanced by the purified AchE.

Acetylcholinesterase↗

PubMed1985

Plasmodium gallinaceum: sporozoite activity in immune mosquito hemolymph.

Sporozoites of Plasmodium gallinaceum are relatively inactive in Hanks' balanced salt solution or in the hemolymph of the susceptible Aedes aegypti mosquito. They become agitated and very active in the presence of the hemolymph of the innately immune mosquito, Culex pipiens. Sporozoites from the latter are more infective in chicks than the former. This behavior is likely the result of stimulation or irritation by the adverse environment.

Aedes↗

PubMed1984

Cytophysiological correlations between prothoracic gland activity and hemolymph ecdysteroid concentrations in Rhodnius prolixus during the fifth larval instar: further studies in normal and decapitated larvae.

Hemolymph ecdysteroid titers in fifth instar larvae of Rhodnius prolixus were determined by radioimmunoassay, and their prothoracic glands were excised and examined by electron microscopy. During the last larval instar, the titer of ecdysteroid increased between the head-critical period until Day 13, at which time the peak titer was 3100 pg 20-hydroxyecdysone equivalents/microliter. The activation of secretory cells at the time of the second period of prothoracicotropic hormone release was correlated with the development of major cellular organelles. The smooth endoplasmic reticulum first appeared at the head-critical period and then proliferated in close relation to the increase in ecdysteroid titer until Day 13, after which time it disappeared. Mitochondria expand and develop tubular cristae. They are closely associated with the smooth endoplasmic reticulum. When insects were decapitated, hemolymph ecdysteroid titer remained below 10 pg/microliter and the prothoracic gland cells failed to develop smooth endoplasmic reticulum. We conclude that in the prothoracic gland cells as well as other steroidogenic tissues the smooth endoplasmic reticulum in association with mitochondria is involved in ecdysone biosynthesis.

Animals↗

PubMed1985

Elimination of the allatotropic activity in locusts by microsurgical and immunological methods: evidence for humoral control of the corpora allata, hemolymph proteins, and ovary development.

Transection of the nervous connections (NCC I) between the brain and the corpus cardiacum (group 1) and injection of anti-brain antibodies inhibited vitellogenin synthesis and ovary development in virgin Locusta migratoria females. Removal of the neurosecretory material by these methods changed the titer and the electrophoretic pattern of hemolymph proteins, including vitellogenin. Transection of NCC I at some distance from the brain resulted in bulbs with 30-200 micron diameter which were filled with stainable neurosecretory material (group 2). Oocyte maturation was delayed in group 2 but normal eggs were laid. The same happened if group 1 animals received daily injections of JH-III. It is concluded that a humoral factor is involved in the activation of JH-III biosynthesis. The factor is transported through the NCC I and is released into the hemolymph as allatotropin.

Animals↗

PubMed1989

Sex differences in the profiles of prothoracic gland synthetic activity and of hemolymph ecdysteroid titers during development in the last larval instar of Rhodnius prolixus (Hemiptera).

The synthesis of ecdysteroids by prothoracic glands (PGs) of Rhodnius prolixus was measured in vitro by radioimmunoassay in both male and female larvae following initiation of development in the last larval instar by a blood meal. Neither ecdysteroid synthesis nor hemolymph titer differ between the sexes during the first few days following a blood meal. However, on Day 4 the PGs of female larvae commence a surge of increased synthesis, while in males this surge does not commence until Day 5. This 1 day difference is attributed to different times of activation of the PGs by prothoracicotropic hormone in male and female larvae. From Day 4 onward, differences between male and female larvae are described for both ecdysteroid synthesis and titer, both of which are more complex than a 1-day displacement of duplicate profiles. Both temporal and quantitative differences are detailed between males and females during Days 4-16 of development; ecdysteroid synthesis by PGs varies between males and females by up to fourfold on the same day. The hemolymph ecdysteroid titer profile closely follows that of PG synthesis for each sex. Both PG activity and titer in females decline 1 day ahead of males. The declining titer is known to influence the timing of ecdysis, and it was found that the median ecdysis time of females occurs 1 day before that of males even when males and females are synchronized with each other using a developmental marker on Day 14. We conclude that male and female PGs possess the intrinsic ability to synthesize ecdysteroids in a sex-specific pattern during development.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Ecdysteroids in relation to the molt cycle of the American lobster, Homarus americanus. I. Hemolymph titers and metabolites.

Hemolymph ecdysteroid (Ecd) titers were measured using radioimmunoassay (RIA) during the molt cycle of the American lobster, Homarus americanus. Individual animals showed small, transitory rises of Ecds which increased in magnitude with the onset of premolt and culminated in a large premolt peak at morphological stages D2(2)-D3(1). Male lobsters had significant postmolt peaks and late premolt titers that remained high until ecdysis. In females, postmolt peaks were absent and late premolt titers reached basal levels before ecdysis. At least seven different Ecd metabolites were identified by high-performance liquid chromatography-RIA analyses. High polarity products (HP) were the most abundant metabolites in virtually every molt stage. Titers of HP were significantly higher in males during late postmolt-early intermolt and in late premolt. Levels of 20-hydroxyecdysone (20E) were equivalent in both sexes and correlated with the morphological changes associated with premolt. Evidence was also obtained for the presence of ecdysone, ponasterone A, and other as yet unidentified metabolites. The pattern of Ecd metabolites in the hemolymph supports other data indicative of 20E as the major molting hormone. Metabolism of 20E is primarily toward more polar compounds, including conjugates.

Animals↗

PubMed1990

Antibacterial activity in the hemolymph of myriapods (Arthropoda).

The hemolymphs of two diplopod (Chicobolus sp. and Rhapidostreptus virgator) and two chilopod species (Lithobius forficatus and Scolopendra cingulata) were tested for the presence of antibacterial substances using Petri dish tests. The native hemolymph of all species had substances acting on living Micrococcus luteus, whereas only Rhapidostreptus, Scolopendra, and Lithobius were effective against lyophilized Micrococcus. The antibacterial activity against living Micrococcus increased after inoculation with bacteria (Enterobacter cloacae beta-12) in Chicobolus and Rhapidostreptus and also against lyophilized Micrococcus in the latter. Thus, these effects appear to be inducible. None of the myriapods tested had any bacteriostatic effect on Escherichia coli D-31 whereas the growth of gram-negative E. cloacae was inhibited. The antibacterial substances in the diplopod species were unstable when heated but were resistant to freezing. At least two antibacterial substances (a lysozyme-like one and another substance) are considered to occur in Myriapoda.

Animals↗

PubMed1980

A new operational approach to PCO2 determination in crustacean hemolymph.

A new method of calculating PCO2 based on mathematical expressions derived from a measured 'Davenport diagram' is described. The measured 'Davenport diagram' is constructed from in vitro buffer curves relating total CO2 to pH at PCO2 levels which adequately encompass the in vivo range of the acid-base status for the species in question. The 'Davenport diagram' is described by three linear equations such that PCO2 can be accurately calculated from in vivo measured CCO2 and pH. The equations are specific for a given species at a given temperature and hemolymph ionic strength, as are the constants in the more classical Henderson-Hasselbalch equation. The accuracy of the method is equal to calculations using the Henderson-Hasselbalch equation with corrected values for pK1' and alpha CO2 and in vivo PCO2 measured directly. This procedure is equally applicable to fluids with dissolved pigments such as hemolymph from freshwater and marine crustaceans and to human blood. The major benefit of this method of calculating PCO2 is that correction nomograms for the constants in the Henderson-Hasselbalch equation are not required.

Acid-Base Equilibrium↗

PubMed1985

Enkephalin-degrading activity in arthropode hemolymphe.

Enkephalin and related peptides are rapidly inactivated in Astacus fluviatilis and Limulus polyphemus hemolymphe. At least three different enzymes, an aminopeptidase, a carboxypeptidase and a peptidyl-dipeptidase, acting concomitantly on the peptide substrates have been identified. The properties of these enzymes were characterized and they were compared to similar enzymes of the vertebrate blood. The opioid peptides appear to be extremely short lived in invertebrate hemolymphe, which presumably is a metabolic barrier to the action of active peptides stronger than vertebrate blood.

Amino Acids↗

PubMed1984

Identification of hemagglutinating protein and bactericidal activity in the hemolymph of adult Sarcophaga peregrina on injury of the body wall.

When the body wall of adult Sarcophaga peregrina (flesh-fly) was injured with a hypodermic needle, hemagglutinating activity and antibacterial activity were induced in the hemolymph simultaneously. The hemagglutinating activity was shown to be due to the same lectin that was found previously in the hemolymph of injured larvae. Thus, larval and adult Sarcophaga respond in the same way to injury of the body wall.

Animals↗