Effect of cadmium chloride on steroidogenic enzymes in the Bidder's organ of the toad (Bufo melanostictus)

Summary Injection of cadmium chloride in a toad increases both the ⁵-3-hydroxy-steroid dehydrogenase and 17-hydroxysteroid dehydrogenase activities in Bidder's organ.     

Effect of cadmium chloride on steroidogenic enzymes in the Bidder's organ of the toad (Bufo melanostictus)

Injection of cadmium chloride in a toad increases both the delta 5-3 beta-hydroxy-steroid dehydrogenase and 17 beta-hydroxysteroid dehydrogenase activities in Bidder's organ.     

Effects of gonadotropin-releasing hormone (LH-RH) on the pars distalis and testis of the Skipper frog,rana cyanophlyctis (Schn.)

Summary Administration of LH-RH to adult male Skipper frogs resulted in marked hypertrophy and degranulation of basophils-2 (B2) in the pars distalis of the pituitary and a significant increase in their nuclear and cellular area. Concomitantly, there is a significant increase in the relative weight of the testes, in the number of cell nests containing secondary spermatogonia and primary spermatocytes, and in the nuclear diameter of the Leydig cells. There is also an increase in the ⁵-3-hydroxysteroid dehydrogenase and glucose-6-phosphate dehydrogenase activities in the Leydig cells. The results indicate that the B2 cells are gonadotrops and the hormone(s) secreted by B2 cells regulate the spermatogenetic and steroidogenic activity of the testis inR. cyanophlyctis.The free gift of LH-RH from NIH is gratefully acknowledged. Authors are grateful to CSIR, New Delhi, for the award of a SRF to the first author and to Karnatak University, Dharwad for providing laboratory facilities.     

Effects of diapause and host species on some morphometric characters inTrichogramma (Hym.: Trichogrammatidae)

Adult morphology ofTrichogramma is modified by environmental conditions during the preimaginal development. For instance, the low temperatures inducing diapause cause a decrease of the ratio length of longest seta on male flagellum/width of flagellum inT. evanescens. The species of the host also influences numerous body ratios. So, in females, the development of tibiae with regard to wings is more important withScotia ipsilon than withGalleria mellonella. These results confirm the necessity of performing comparative morphological studies on individuals reared in the same conditions.     

Studies onHolothuria polii (Echinodermata) antibacterial proteins. I. Evidence for and activity of a coelomocyte lysozyme

Summary Lysozyme activity has been detected in coelomocyte lysate of the echinodermHolothuria polii. The bacteriolytic reaction was stable when the lysate was heated in acidic buffer but heat-labile in alkaline medium. An incubation temperature of 35°C, acidic pH values (5.2 and 6.2) and an ionic strength of 0.175 were found to be the best conditions for the coelomocyte enzymatic activity. A low level of lysozyme was also evidenced in cell-free coelomic fluid where it could represent a basal defense level of bacteriolytic molecules released by the coelomocytes.Acknowledgments. This work was supported in part by a grant from MRES (C. C.). The authors thank M. Lasségues and F. Lassalles for their help and criticism.     

The prey consumption and prey preference of the larvae of the mosquitoCulex (Lutzia) raptor on the larvae ofCulex quinquefasciatus

The maximum consumption of the larvae of the pest and vector mosquitoCulex quinquefasciatus by the predatory mosquitoCulex (Lutzia) raptor was studied at various instars of both the predator and the prey. The prey preferences of the predator when given lavae of different instars were also investigated. The IVth instar of the predator consumed the maximum number of Ist instar and the maximum biomass of IVth instar larvae of the prey. Instars I and II of the predator preferred the Ist of the prey; instars III and IV of the predator preferred instars II and III of the prey respectively.The predator consumed an average of 157.1 larvae during its whole larval period, when each instar of the predator was given its preferred instar of the prey.     

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     

Origin and identification of bacteria which produce kairomones in the frass ofAcrolepiopsis assectella (Lep., Hyponomeutoidea)

The volatiles used by the parasitoidDiadromus pulchellus to find its host, the leek moth, are produced by the bacteria developing in the frass of the host larvae. The origin and the nature of these bacteria were investigated. Samples were taken from healthy leeks and from infested leeks in the field, as well as from the frass of larvae reared in the laboratory either on the host plant or on an artificial diet. The various species of bacteria identified were cultured in the presence of precursors of leek sulphur volatiles and their volatile emissions were analysed.Klebsiella oxytoca and variousBacillus, common decomposers of plant matter, were the principal species producing active volatiles which were alkyl disulphides.     

The isolation,identification and synthesis of the alarm pheromone ofVespula squamosa (Drury) (Hymenoptera: Vespidae) and associated behavior

Summary A material that elicits alarm and attack behavior byVespula squamosa (Drury) workers was isolated from venom extracts and identified by spectroscopic methods as N-3-methylbutylacetamide. This compound elicited attack responses from worker wasps identical to those responses observed when venom was applied at the same dosage. This is the first behavioral role reported for this compound.The authors thank E. Adamak, R. Murphy and F. Takken for technical assistance. This article reports the results of research only. Mention of a proprietary product does not constitute an endorsement or the recommendation for its use by USDA.     

Effects of diflubenzuron and tunicamycin on N-acetylglucosaminyl transferases in prepupae of the stable fly (Stomoxys calcitrans)

Summary Tunicamycin, an antibiotic, and diflubenzuron, an insect growth regulator, were tested to determine their effects on N-acetylglucosaminyl transferase fromS. calcitrans prepupae. Diflubenzuron had no effect, but tunicamycin inhibited the transfer of GlcNAc-1-P from UDP-GlcNAc to dolicholmonophosphate with an I₅₀ of 1.5–4 ng/ml.     

The influence of ethylene on primary attraction of the olive beetle,Phloeotribus scarabaeoides (Bern.) (Col., Scolytidae)

Two experiments have been carried out to verify the effect of ethylene on the primary attraction ofPhloeotribus scarabaeoides under both laboratory and field conditions. The experiments were based on the enhancement of ethylene production by olive branches and trunks after the application of (2-chloroethyl)phosphonic acid. Under laboratory conditions, the beetles' response was strongly stimulated on the treated branches. Under field conditions, the treatment aided the location of the olive wood by the flying beetles, and the attack density was significantly greater in the treated wood at the end of the experiment.     

Structure revision and cytotoxicity of the germacranolide,stizolicin, fromStizolophus balsamitus (Asteraceae)

Summary The structure of the cytotoxic sesquiterpene lactone, stizolicin, reisolated fromStizolophus balsamitus (Centaurea b.) was revised to atrans, trans germacranolide (1) on the basis of simultaneous application of lanthanide shift reagent and NOE in the NMR.The authors acknowledge the use of the Purdue University Biomedical Magnetic Resonance Laboratory (NIH grant No. RR01077). Support of contract No. N01-CM-97296 and Grant No. CA-33326 from the National Cancer Institute, HHS is gratefully acknowledged. This is paper 18 in the series Potential Antitumor Agents.     

The gross morphology of the stinging and non-stinging states of the antTetramorium caespitum L. (Hymenoptera,Formicidae, Myrmicinae)

Summary The change in sting morphology ofTetramorium caespitum is described in detail. The sting-tip may protrude/retract from the sting-ending during its stinging/non-stinging process respectively. A possible trail laying function of the stings terminal membranous sheath is proposed.     

The male pheromone of the old house borerHylotrupes bajulus (L.) (Coleoptera: Cerambycidae): Identification and female response

We report here the identification of the long-range, male-produced sex pheromone of the Old house borerHylotrupes bajulus. Chemical analysis of hexane extracts obtained by surface extraction from dissected prothoracic glands and from headspace samples of the two sexes, revealed male-specific compounds: (3R)-3-hydroxy-2-hexanone, 2-hydroxy-3-hexanone, the diastereomeric diols (2R, 3R)-2,3-hexanediol and (2S, 3R)-2,3-hexanediol, 2,3-hexanedione, as well as 1-butanol.In wind tunnel bioassays we tested the influence of these male-specific compounds from the prothoracal glands on the behaviour of unmated and mated females. Specific behavioural sequences of the tested females (activity, running behaviour, searching, cleaning, flying, extension of ovipositor) were recorded. Unmated females were attracted by male beetles, headspace extracts of males, synthetic blends of the major pheromone compounds as well as by the components (3R)-3-hydroxy-2-hexanone, and the diastereomeric diols. Hexane, female beetles and 2,3-hexanedione did not attract unmated females. The reactions of mated females to male beetles and headspace samples did not differ significantly from those of the controls.The results of the bioassays show that the two-stage premating behaviour is initiated by emission of a long-range sex pheromone from the male prothoracal glands, which functions as an activator, attractant, and possibly aphrodisiac for unmated females.     

Heterochromatin characterization and distribution in the chromosomes of two populations ofIdotea baltica basteri Audouin, 1826 (Isopoda,Valvifera)

Two mediterranean populations ofIdotea baltica basteri from Messina and Naples showed a set of chromosomes composed by 58 all-biarmed chromosomes. The heterochromatin was located in the pericentromeric region of the chromosomes, and its composition appeared heterogeneous. In fact, not all the homologs showed heterochromatin resistant to digestion with three restriction enzymes (Alu I, Hae III and Sau 3A). Moreover, the two populations showed polymorphism in a band of G+C-rich telomeric heterochromatin, which was present only in the population from Messina. It is hypothesized that chromosomal polymorphism might reflect the geographical isolation of the two populations. It is also suggested that a process of diversification is taking place.     

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).     

Preliminary results on the action of a plant growth regulator (Ethrel) in reducing the attack ofPrays oleae Bern. on olive fruits

Summary Preliminary experiments carried out in the Granada province of Southern spain over three years and in three different habitats have shown that a single application of Ethrel (2 chloro-ethyl phosphonic acid) to the olive tree at the beginning of fruit formation is sufficient to reduce significantly attack byPrays oleae Bern. and subsequent damage to the fruit. At the same time the treatment did not cause any detrimental change to the trees and had no measurable effect on the activity of beneficial insects such as Chrysopids (Neuroptera), which are known to be importantP. oleae egg predators in the study area.     

Molecular characterization and expression of the antimicrobial peptide defensin from the housefly (Musca domestica)

A 430-bp cDNA encoding the insect antimicrobial peptide defensin was cloned from the housefly, and designated Musca domestica defensin (Mdde). The open reading frame of the cDNA encoded a 92-amino acid peptide with an N-terminal signal sequence followed by a propeptide that is processed by cleavage to a 40-amino acid mature peptide. Northern analysis and in situ hybridization identified the corresponding mRNA in the fat body of bacterially challenged houseflies and in the epidermis of the body wall of naive and challenged houseflies. The Gram-negative bacterium (Escherichia coli) is a strong inducer of the gene. By RT-PCR, Mdde mRNA was also detected in naive and challenged insects. These findings suggest that the defensin gene is constitutively expressed in the epidermis of the housefly body wall. The predicted mature form of Mdde was expressed as a recombinant peptide in E. coli and Pichia pastoris. The recombinant Mdde expressed in Pichia was active against Gram-positive and some Gram-negative bacteria. Received 20 June 2006; received after revision 3 October 2006; accepted 30 October 2006     

Growth ofNostoc muscorum mutants in the presence of diuron (DCMU) and L-methionine-DL-sulfoximine

Summary Diuron (DCMU) is inhibitory to the photoautotrophic and photoheterotrophic growth of the N₂-fixing blue-green algaNostoc muscorum at concentrations of 1.0×10^–5 M and 2.0×10^–5 M, respectively. A mutant of this organism resistant to 5.0×10^–5 M DCMU under its photoheterotrophic growth conditions, with the ability to utilize DCMU as a carbon and nitrogen source for growth, and complete inability to grow photoautotrophically has been isolated. With the apparent defect in its photosynthetic ability, it is suggested that theDCMU ^r mutant lacks the step inhibited by 1.0×10^–5 M DCMU, and metabolizes DCMU by an existing enzyme system in the absence of such inhibition. That this enzyme may be glutamine synthetase (GS) is explained with the help of a L-methionine-DL-sulfoximine (MSO)-resistant mutant ofN. muscorum which is able to grow faster with 2.0×10^–5 DCMU and is known to contain an altered GS.Thanks are due to the Council of Scientific and Industrial Research, CSIR Complex, Govt. of India, New Delhi-110012, for appointing the author to the Scientists' Pool for undertaking researches on the physiological and genetic controls of nitrogen metabolism in blue-green algae, a part of which is presented in this literature.