Detection of toxic metabolites in the hemolymph ofBeauveria bassiana infectedSpodoptera exigua larvae

Highly active metabolites have been detected in the hemolymph of the lepidopteranSpodoptera exigua infected with the mycopathogen,Beauveria bassiana. A combination of phenyl sepharose and CM ion exchange chromatography was utilized to extract the active metabolites from infected hemolymph samples. The active in vivo metabolites, having a molecular mass greater than 10 KDa, were thermolabile and were inactivated by proteinase K. These metabolites were characterized by their ability to disrupt metamorphosis, killing treated larvae at the wandering or pupal stage. Additionally, injection ofS. exigua larvae with active samples caused a reduction in the number of filopodial-producing hemocytes. The biological activities and biochemical properties suggest that novel compounds are produced duringB. bassiana mycosis.     

Freezing-tolerance in the woodroachCryptocercus punctulatus (Scudder)

Summary Winter-acclimatedCryptocercus punctulatus are able to withstand ice crystal formation within their bodies (freeze-tolerant), and contain hemolymph plasma ice nucleating factors (INF's) throughout the year. In addition, ribitol, a sugar alcohol accumulates in their hemolymph during winter. This represents a new report of INF's occurring in the Dictyoptera, and the presence of ribitol in the hemolymph of the Insecta.Department of Entomology     

Effect of the juvenoid methoprene on the hemolymph composition of the cabbage maggotDelia radicum (Diptera: Anthomyiidae)

Summary Treatment of post-feeding larvae of the cabbage maggotDelia radicum with methoprene did not affect the capacity of the insect to pupate, but suppressed eclosion to the adult stage. The concentration of hemolymph trehalose was significantly decreased by methoprene treatment, although hemolymph protein and amino nitrogen levels were unaffected.19 December 1986The authors are grateful to D. C. Read of the Research Centre, Agriculture Canada, Charlottetown, P.E.I., Canada for supplying eggs ofD. radicum for the stock colony. TheD. radicum colony was maintained at the Agriculture Canada Research Station, St. John's West, Newfoundland, Canada. The sample of methoprene was donated by Zoecon Corp., Palo Alto, California, U.S.A. This research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (Operating grant A6679).     

Cholinergic control of extracardiac pulsations in insects

Summary The autonomic nerve system which controls extracardiac pulsations of hemolymph pressure appears to be quite susceptible to cholinesterase inhibitors (physostigmine, organophosphorus insecticides). In pupae ofTenebrio molitor L. andGalleria mellonella L., the treatment induced large peaks in hemolymph pressure (over 4 kPa). The peaks were repeated at more-or-less constant, 30-s intervals for several hours or days. Removal of the pupal brain neither affected extracardiac pulsations nor influenced the specific responses to the investigated drugs or insecticides.     

Partial sequence of the gene for a serine protease from a halophilic archaeumhaloferax mediterranei R4, and nucleotide sequences of 16S rRNA encoding genes from several halophilic archaea

A part of the gene coding for a halophilic serine protease from a halophilic archaeumHaloferax mediterranei R4 was amplified by PCR and its 672 nucleotide sequence was determined. Tentative translation to the amino acid sequence suggested that the enzyme was quite similar to halolysin produced by another halophilic archaeum strain 172P1. Nucleotide sequences of 16S rRNA encoding genes from 9 halophilic archaea were determined. Alignment of 19 sequences known so far showed that there are more than 20 positions carrying bases or deletions specific for each halobacterial genus:Halobacterium, Haloarcula, Haloferax, andHalococcus.     

Immunochemical similarities among the hemolymph juvenile hormone binding proteins of moths

The hemolymph from various species of moths was analyzed for cross-reactivity with a panel of six monoclonal antibodies made against the hemolymph juvenile hormone binding protein ofManduca sexta. With the exception of one antibody, the immunoreactivity was limited to the sphingid family. One monoclonal antibody cross-reacted with a number of lepidopteran species; however, families such as Noctuidae and Pyralidae, known to have high affinity, low molecular weight juvenile hormone binding proteins, did not cross-react. Immunological cross-reactivity withManduca sexta juvenile hormone binding protein in several primitive moth families supports the current model of phylogenetic relationships in the order Lepidoptera.     

A specific protein in the genusRhynchosciara (Diptera,Sciaridae)

Summary Proteins immunologically related toRhynchosciara americana larval protein 10 occur in the hemolymph and ovaries of five different fly species of the genusRhynchosciara. Electrophoretic analyses showed these proteins to have a mol.wt similar to that of theR. americana protein 10 (43,000), e.g. theR. hollanderi protein 44,300, theR. milleri protein 45,500.     

Level of ecdysteroids in the hemolymph of the freshwater prawn,Macrobrachium rosenbergii (Crustacea: Decapoda) in relation to the phenomenon of cheliped autotomy in males

Summary Ecdysteroid titers were determined in the hemolymph of adult freshwater prawn,Macrobrachium rosenbergii, during various stages of the molt cycle, using radioimmunoassay. A comparison was made between hormone levels in males which undergo normal molt and dominant males of the population which periodically commit cheliped autotomy. The latter is a recently discovered phenomenon whereby a male voluntarily sheds off both its long claws at molt, once the ratio between body length and combined claw length reaches a ceiling level of about 13. Shortly before an autotomizing molt, hormone levels were about three times higher than on the eve of a normal molt.10 November 1986     

Head critical period and juvenile hormone titre during the last larval instar of the cockroach,Periplaneta americana

From neck ligation experiments with last instar larvae of the cockroachPeriplaneta americana it was concluded that the head critical period is reached around day 17, which corresponds to 59% of the last larval stage. At the same stage the juvenile hormone III titre in the hemolymph dropped to undectable levels.     

Juvenile hormone I is the principal juvenile hormone in a hemipteran insect,Riptortus clavatus

Juvenile hormone I (JH I) was identified by combined gas chromatography/mass spectrometry as the predominant JH in the hemolymph of female adults of the bean bug,Riptortus clavatus (Thunberg) (Hemiptera: Alydidae). Among JH I, II, and III, JH I was the most effective hormone for inducing the synthesis of yolk proteins in diapause adults.     

Is ATP synthesized by a vacuolar-ATPase in the extremely halophilic bacteria?

The proton-dependent synthesis of ATP was demonstrated in representative members of the generaHalobacterium, Haloarcula, andHaloferax. In all cases, synthesis was not inhibited by nitrate or N-ethylmaleimide, inhibitors of the vacuolar-like ATPase found in Archaea, but was affected by azide, an inhibitor of F₀F₁-ATP syntheses. These observations extend the earlier observations withHalobacterium saccharovorum and suggest that ATP synthesis in these organisms is brought about by an F₀F₁-APT synthase.     

Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III throughout the life cycle of a hemimetabolous insect,the ovoviviparous cockroachNauphoeta cinerea

Summary Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III were measured in whole body extracts or hemolymph of embryos, first, penultimate and last stadium nymphs, and adult females ofNaupoheta cinerea. We used a gas-chromatography/mass spectrometry method for quantifying juvenile hormone and a radio-immunoassay for ecdysteroid determination. Juvenile hormone III is particularly abundant in the embryonic stage (up to 960 ng/g), at a low level in first and penultimate stadium nymphs (2–10 ng/ml) and almost absent in the last nymphal stadium; in the adult female the juvenile hormone titer rises to 180 ng/ml in hemolymph during rapid oocyte growth. The titers of ecdysone and 20-hydroxyecdysone undergo similar fluctuations in the embryonic and nymphal stages, being highest at the time of cuticle formation in the embryo and a few days before the nymphal and adult molts (around 100–200 ng/ml for exdysone and 2–4 g/ml for 20-hydroxyecdysone).Acknowledgments. We thank Mrs A. Tschan for rearing the cockroaches, Mr M. Kaltenrieder for drawing the graphs, Mr G.C. Jamieson and Mrs C. Reuter for GC/MS analyses. We are also grateful to the Swiss National Science Foundation (grant no. 3.291-0.82 to B. Lanzrein) and the United States National Science Foundation (grant no. PCM 82-08665 to D.A. Schooley) for their financial support.     

Effects of the pyrimidine-containing cytochrome P-450 inhibitor,fenarimol, on the formation of 20-OH ecdysone in flies

Summary The effect of fenarimol, a pyrimidine-containing cytochrome P-450 inhibitor, was tested in vitro on brain-ring gland complexes ofCalliphora vicina (Dipt., Calliphoridae), and on microsomes prepared from the fat body of 0-h wandering stage larvae ofNeobellieria bullata (Dipt., Sacrophagidae). Fenarimol had no influence on the formation of ecdysone, but it was an effective inhibitor of cytochrome P-450-dependent ecdysone 20-monooxygenase.     

Multiple roles of the DSCR1 (Adapt78 or RCAN1) gene and its protein product Calcipressin 1 (or RCAN1) in disease

The DSCR1 (Adapt78) gene¹ is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer’s disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases. ¹Please note that the mammalian DSCR1 gene is also called Adapt78 or RCAN1, and its protein products have been named Calcipressin1, MCIP1 and RCAN1. A proposal to adopt a single gene name of RCAN1 and a protein name RCAN1 (for Regulator of Calcineurin) has been endorsed by the HUGO Gene Nomenclature Committee, but final approval must await agreement from a majority of researchers in the field. Received 2 March 2005; received after revision 27 May 2005; accepted 19 July 2005     

Inhibitory effect of bacterial ubiquinones on the settling of barnacle,Balanus amphitrite

In an attempt to clarify the influence of marine bacteria on the settling of fouling invertebrate larvae, we screened for inhibitors, produced by marine bacteria, of settling by cyprids of the barnacle,Balamus amphitrite. We found that the culture broth ofAlteromonas sp. strain number KK10304, which was associated with the marine sponge,Halichondria okadai, effectively inhibited settling of the cyprids. Bioassay-guided isolation indicated ubiquinone-8 (1) as an effective inhibitor of cyprid settling. As ubiquinones are widely distributed in bacteria, several related compounds were also tested.     

Endogenous suppression of pheromone production in virgin female moths

Summary Sexual receptivity generally is reduced in moths after mating. We found that even in virginHeliothis zea females the titer of pheromone declines after the third night of adult life, although the number of eggs laid increases. Reduction in pheromone titer is not due to reduced amounts of pheromone biosynthesis activating neuropeptide. We have discovered that a substance present in the bursa, ovaries and hemolymph of senescing virgins suppresses pheromone production. A similar factor was found in 2-day-old mated females indicating that both virgin and mated females use this factor to suppress pheromone production.     

Green leaf volatiles interrupt aggregation pheromone response in bark beetles infesting southern pines

Summary Green leaf volatiles were shown to interrupt responses to aggregation pheromones of three species of bark beetles (Coleoptera: Scolytidae) which infest pines in the southern United States [the southern pine beetle,Dendroctonus frontalis Zimm.; the four-spined engraver,Ips avulsus (Eichhoff); and the five-spined engraver,Ips grandicollis (Eichhoff)]. The order of effectiveness of the compounds tested for each species was hexanal>hexanal+hexan-1-ol>hexan-1-ol. Neither hexanal, hexan-1-ol nor hexanal+hexan-1-ol was as effective in interrupting pheromone responses ofD. frontalis as verbenone, a known inhibitor of this species. Other than interspecific chemical signals, this is the first report of an interruptant forIps species, and the only report of a pheromone interruptant active for bothIps andDendroctonus species.     

Microtubule inhibitors block the morphological changes induced inDrosophila blood cells by a parasitoid wasp factor

Summary The shape change ofDrosophila melanogaster blood cells (lamellocytes) from discoidal to bipolar that is caused by a factor from the female parasitoidLeptopilina heterotoma is blocked by the tubulin inhibitors vinblastine and vincristine in vitro. The actin inhibitor, cytochalasin B, causes arborization ofDrosophila lamellocytes and acts synergistically with the wasp factor to alter lamellocyte morphology. Lamellocyte arborization induced by cytochalasin B is blocked by simultaneous treatment with vinblastine. These observations indicate that the changes in lamellocyte shape induced by both the wasp factor and cytochalasin B require microtubule assembly.     

Structural diversity of trypsin from different mosquito species feeding on vertebrate blood

Summary Mosquito trypsin was purified using a combination of ion exchange and affinity chromatography with the ligand soybean trypsin inhibitor. ThreeAedes and threeAnopheles species were tested, all of which are specialized in the digestion of vertebrate blood. Amino-terminal sequences of HPLC-purified trypsins fromAedes aegypti andAnopheles quadrimaculatus revealed homologies of 30–40% with vertebrate and other invertebrate proteases previously identified as serine-proteases. The purified mosquito trypsins have molecular masses between 25 kDa and 36 kDa, as determined by denaturing polyacrylamide electrophoresis, and are heterogeneous in size and number in the various species. The number of SDS-bands varies between 3 and 6 inAedes and between 1 and 3 inAnopheles. The specific activities, determined with the substrate TAME, range from 240 U/mg inAedes aegypti to 1065 U/mg inAnopheles quadrimaculatus. All mosquito trypsins tested have acidic isoelectric points between pH 3.5 and pH 5.4. No alkaline proteases were detected. Polyclonal antisera againstAedes aegypti andAnopheles albimanus trypsin do not cross-react with bovine trypsin. Cross-reactivity of the two sera with trypsin from six mosquito species suggests the presence of at least 2 enzyme families.     

Studies on the fungal phytotoxin victorin: Structures of three novel amino acids from the acid hydrolyzate

Summary The host-selective phytotoxin victorin, produced by the fungusCochliobolus victoriae, was found to be at least partially peptidic in nature, and did not contain victoxinine. The exact mass of the M-H ion was measured by FABMS as 795.1877. Derivatives of three major acid hydrolysis products were isolated. The structures of the corresponding amino acids were assigned as 2S,3R-3-hydroxyleucine, 5,5-dichloroleucine, and 3-hydroxylysine. A into victorin by the fungus in vivo.