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Fat Body (fat + body)
Terms modified by Fat Body Selected AbstractsA Morphological and 13C NMR Study of the Extramandibular Fat Bodies of the Striped Dolphin (Stenella coeruleoalba)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2007C. Maxia Abstract The molecular and histological structure of the fat bodies covering externally the posterolateral region of the jaw of the striped dolphin (Stenella coeruleoalba) was investigated by means of morphological and nuclear magnetic resonance techniques. The analyses of samples belonging to adult and juvenile individuals were performed with the aim of seeking the presence of age-related differences. In our study, the level of isovalerate (iso5:0) in the extramandibular fat of the juvenile individuals is comparable with those of the adult counterparts; conversely, longer isobranched fatty acids were detected in lower quantities in the juveniles together with a higher degree of unsaturation. The morphologic analyses revealed that, in both adults and juveniles, this fatty tissue is similar to univacuolar adipose tissue. However, in the juveniles, a muscular component was present, whereas only in adult subjects, enlarged and irregularly shaped cavities may be seen within the adipose tissue. These cavities, structurally organized as veins, may regulate blood flow in response to changing water temperature and stabilize thermal gradient within the jaw lipids. These data suggest that the molecular components and the histological organization can indicate a maturation of the organ with age that probably may reflect different sound reception properties. Anat Rec, 2007. © 2007 Wiley-Liss, Inc. [source] Sexual patterns of prebreeding energy reserves in the common frog Rana temporaria along a latitudinal gradientECOGRAPHY, Issue 5 2009K. Ingemar Jönsson The ability to store energy is an important life history trait for organisms facing long periods without energy income, and in particular for capital breeders such as temperate zone amphibians, which rely on stored energy during reproduction. However, large scale comparative studies of energy stores in populations with different environmental constraints on energy allocation are scarce. We investigated energy storage patterns in spring (after hibernation and before reproduction) in eight common frog Rana temporaria populations exposed to different environmental conditions along a 1600,km latitudinal gradient across Scandinavia (range of annual activity period is 3,7,months). Analyses of lean body weight (eviscerated body mass), weight of fat bodies, liver weight, and liver fat content, showed that 1) post-hibernation/pre-breeding energy stores increased with increasing latitude in both sexes, 2) males generally had larger energy reserves than females and 3) the difference in energy stores between sexes decreased towards the north. Larger energy reserves towards the north can serve as a buffer against less predictable and/or less benign weather conditions during the short activity period, and may also represent a risk-averse tactic connected with a more pronounced iteroparous life history. In females, the continuous and overlapping vitellogenic activity in the north may also demand more reserves in early spring. The general sexual difference could be a consequence of the fact that, at the time of our sampling, females had already invested their energy into reproduction in the given year (i.e. their eggs were already ovulated), while the males' main reproductive activities (e.g. calling, mate searching, sexual competition) occurred later in the season. [source] Oral bioavailability and toxicokinetics of 3,3,,4,4,,5-pentachlorobiphenyl in northern leopard frogs, Rana pipiensENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2000Yue-wern Huang Abstract This study is the first report on oral bioavailability, whole-body elimination, and distribution of a specific polychlorinated biphenyl (PCB) congener on an amphibian species, northern leopard frogs. Each frog was orally dosed once with either 0.35 or 5.0 mg/kg PCB 126 (based on frog wet wt), including tracer 14C-PCB 126 (3,,4,,5,-phenyl-ring- 14C) by force feeding it a cricket injected with the PCB. We found no statistical difference (t = 0.917, df = 5, p = 0.401) in the average 48-h oral bioavailabilities of 0.35- and 5.0-mg/kg dosage groups, which were 84.6 ± 5.8% (mean ± SE, n = 4) and 90.9 ± 1.5% (n = 3), respectively. Statistical analysis indicated that time was the only independent variable affecting the retention of whole-body 14C content. Kinetics were apparently first order because elimination rate was independent of dose. Assuming a single pool and one elimination rate, the t1/2 value for whole-body elimination of PCB-derived 14C was 763 d. Liver, fat bodies (corpora adiposa), carcass (head, bone, cartilage materials, and residues of other tissues), skin, and muscle were the major organs for PCB 126 retention in both dosage groups. The concentrations of 14C residue in fat bodies were relatively constant throughout the experiment. However, total residues in fat bodies declined throughout the experiment in both dosage groups in correlation with declining masses of fat bodies. Gonad, kidney, stomach, intestine, and a tissue pool including esophagus, lung, spleen, heart, and cloacal materials each accumulated <1% of the initial total 14C residue. The egg follicles in 19 females contained 1 to 23% of the initial total 14C residue, with an average of 10.0 ± 9.2% (mean ± SE, n = 19). [source] Cloning and molecular characterization of two invertebrate-type lysozymes from Anopheles gambiaeINSECT MOLECULAR BIOLOGY, Issue 3 2008S. M. Paskewitz Abstract We sequenced and characterized two novel invertebrate-type lysozymes from the mosquito Anopheles gambiae. Alignment and phylogenetic analysis of these and a number of related insect proteins identified through bioinformatics strategies showed a high degree of conservation of this protein family throughout the Class Insecta. Expression profiles were examined for the two mosquito genes through semiquantitative and real-time PCR analysis. Lys i-1 transcripts were found in adult females in the fat body and Malpighian tubules, whereas Lys i-2 was detected only in fat bodies. Blood-feeding resulted in significantly increased transcript abundance for both genes in the midguts. Neither gene was upregulated following bacterial challenge. [source] A tapeworm molecule manipulates vitellogenin expression in the beetle Tenebrio molitorINSECT MOLECULAR BIOLOGY, Issue 4 2006E. Warr Abstract Metacestodes of Hymenolepis diminuta secrete a molecule that decreases vitellogenin (Vg) synthesis in the beetle host, Tenebrio molitor. The 5608 bp T. molitor Vg cDNA represents a single-copy gene encoding a single open reading frame of 1821 amino acids with a predicted molecular mass of 206 kDa. Northern blot analysis revealed detectable levels of transcripts only in adult females. In vivo, Vg mRNA abundance was significantly higher in fat bodies from infected females compared with control females at all but the earliest time point. In vitro, Vg mRNA abundance was significantly increased in fat bodies incubated with live stage I,II parasites. The apparent conflict between increased Vg mRNA abundance and decreased Vg protein in fat bodies from infected females is discussed. [source] Apis mellifera ultraspiracle: cDNA sequence and rapid up-regulation by juvenile hormoneINSECT MOLECULAR BIOLOGY, Issue 5 2004A. R. Barchuk Abstract Two hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH) are key regulators of insect development including the differentiation of the alternative caste phenotypes of social insects. In addition, JH plays a different role in adult honey bees, acting as a ,behavioural pacemaker'. The functional receptor for 20E is a heterodimer consisting of the ecdysone receptor and ultraspiracle (USP) whereas the identity of the JH receptor remains unknown. We have cloned and sequenced a cDNA encoding Apis mellifera ultraspiracle (AMUSP) and examined its responses to JH. A rapid, but transient up-regulation of the AMUSP messenger is observed in the fat bodies of both queens and workers. AMusp appears to be a single copy gene that produces two transcripts (,4 and ,5 kb) that are differentially expressed in the animal's body. The predicted AMUSP protein shows greater sequence similarity to its orthologues from the vertebrate,crab,tick,locust group than to the dipteran,lepidopteran group. These characteristics and the rapid up-regulation by JH suggest that some of the USP functions in the honey bee may depend on ligand binding. [source] Histological and ultrastructural aspects of the nasal complex in the harbour porpoise, Phocoena phocoenaJOURNAL OF MORPHOLOGY, Issue 11 2009Susanne Prahl Abstract During the evolution of odontocetes, the nasal complex was modified into a complicated system of passages and diverticulae. It is generally accepted that these are essential structures for nasal sound production. However, the mechanism of sound generation and the functional significance of the epicranial nasal complex are not fully understood. We have studied the epicranial structures of harbor porpoises (Phocoena phocoena) using light and electron microscopy with special consideration of the nasal diverticulae, the phonic lips and dorsal bursae, the proposed center of nasal sound generation. The lining of the epicranial respiratory tract with associated diverticulae is consistently composed of a stratified squamous epithelium with incomplete keratinization and irregular pigmentation. It consists of a stratum basale and a stratum spinosum that transforms apically into a stratum externum. The epithelium of the phonic lips comprises 70,80 layers of extremely flattened cells, i.e., four times more layers than in the remaining epicranial air spaces. This alignment and the increased number of desmosomes surrounding each cell indicate a conspicuous rigid quality of the epithelium. The area surrounding the phonic lips and adjacent fat bodies exhibits a high density of mechanoreceptors, possibly perceiving pressure differentials and vibrations. Mechanoreceptors with few layers and with perineural capsules directly subepithelial of the phonic lips can be distinguished from larger, multi-layered mechanoreceptors without perineural capsules in the periphery of the dorsal bursae. A blade-like elastin body at the caudal wall of the epicranial respiratory tract may act as antagonist of the musculature that moves the blowhole ligament. Bursal cartilages exist in the developmental stages from fetus through juvenile and could not be verified in adults. These histological results support the hypothesis of nasal sound generation for the harbor porpoise and display specific adaptations of the echolocating system in this species. J. Morphol. 2009. © 2009 Wiley-Liss, Inc. [source] When does a reproducing female viper (Vipera aspis) ,decide' on her litter size?JOURNAL OF ZOOLOGY, Issue 2 2003Olivier Lourdais Abstract Some organisms rely on stored energy to fuel reproductive expenditure (capital breeders) whereas others use energy gained during the reproductive bout itself (income breeders). Most species occupy intermediate positions on this continuum, but few experimental data are available on the timescale over which food intake can affect fecundity. Mark,recapture studies of free-ranging female aspic vipers Vipera aspis have suggested that reproductive output relies not only on the energy in fat bodies accumulated in previous years, but also on food intake immediately before ovulation. A simple experiment was conducted to test this hypothesis, maintaining female snakes in captivity throughout the vitellogenic period and controlling their food intake. The energy input of a female strongly influenced the amount of mass that she gained and the number of ova that she ovulated. Multiple regression showed that litter size in these snakes was affected both by maternal body condition in early spring (an indicator of foraging success over previous years) and by food intake in the spring before ovulation. Our experimental data thus reinforce the results of descriptive studies on free-ranging snakes, and emphasize the flexibility of energy allocation patterns among vipers. Reproducing female vipers may combine energy from ,capital' and ,income' to maximize their litter sizes in the face of fluctuating levels of prey abundance. [source] Lipid dynamics in the viperine snake, Natrix maura, from the Ebro Delta (NE Spain)OIKOS, Issue 1 2004Xavier Santos Body reserves play a major role in several aspects of vertebrate biology. Accurate identification and quantification of body reserves constitute a useful contribution to the better understanding of the energetic costs of reproduction and the implication of food availability in life history traits of organisms. In this study, lipid content in fat bodies, liver and muscle of the viperine snake (Natrix maura) were measured along an active season. Samples were collected monthly from a natural population of the Ebro Delta Natural Park (NE Spain). This methodology pointed out that lipids stored in fat bodies were the main energetic source during reproduction. In addition, lipids stored in liver appeared to be critical for vitellogenesis, while lipids stored in muscle turned out to be a supplementary energetic resource to fuel reproductive effort. Relationships between changes in body reserves and prey availability in canals of the Ebro Delta were also considered. In males, lipid reserves presented a positive correlation with food availability. On the contrary, lipid reserves in female viperine snakes decreased during vitellogenesis even though food availability increased in this period, which suggests a quick transfer of body lipids to clutch. In April, when rice fields of the Ebro Delta were dry and aquatic prey was scarce for viperine snakes, males and females presented a lower lipid content in fat bodies, liver and muscle than they did in other months, showing a clear link between prey availability and body reserves during food shortage. Thus, patterns of variation in fat levels indicated that Natrix maura is a capital breeder since it acquires resources in advance and stores them until they are invested during the reproductive period. Nevertheless, the shortage in April forces Natrix maura to turn into a facultative income breeder to fuel vitellogenesis. Finally, fat reserves in body components were compared with an estimate of body condition calculated by the residuals from the regression of body mass on body length. In male viperine snakes, the estimate of body condition was correlated with fat levels, revealing that this index is useful to measure condition in living individuals. On the contrary, body condition in females was not correlated with fat levels, which suggests that it is not appropriate to infer condition in female viperine snakes since it depends on the reproductive status of the individuals. [source] A Morphological and 13C NMR Study of the Extramandibular Fat Bodies of the Striped Dolphin (Stenella coeruleoalba)THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 7 2007C. Maxia Abstract The molecular and histological structure of the fat bodies covering externally the posterolateral region of the jaw of the striped dolphin (Stenella coeruleoalba) was investigated by means of morphological and nuclear magnetic resonance techniques. The analyses of samples belonging to adult and juvenile individuals were performed with the aim of seeking the presence of age-related differences. In our study, the level of isovalerate (iso5:0) in the extramandibular fat of the juvenile individuals is comparable with those of the adult counterparts; conversely, longer isobranched fatty acids were detected in lower quantities in the juveniles together with a higher degree of unsaturation. The morphologic analyses revealed that, in both adults and juveniles, this fatty tissue is similar to univacuolar adipose tissue. However, in the juveniles, a muscular component was present, whereas only in adult subjects, enlarged and irregularly shaped cavities may be seen within the adipose tissue. These cavities, structurally organized as veins, may regulate blood flow in response to changing water temperature and stabilize thermal gradient within the jaw lipids. These data suggest that the molecular components and the histological organization can indicate a maturation of the organ with age that probably may reflect different sound reception properties. Anat Rec, 2007. © 2007 Wiley-Liss, Inc. [source] Prostaglandin E2 modulates the expression of antimicrobial peptides in the fat body and midgut of Anopheles albimanusARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2008F.L. García Gil de Muñoz Abstract Prostaglandins (PGs) participate in the regulation of vertebrate and in at least six insect orders' immune responses. We identified PGE2 in midgut, fat body, Malpighian tubules, and ovarioles of Anopheles albimanus (Aa) mosquitoes. Our data indicate that PGE2 synthesis in cultured midguts responds to the presence of two bacterial species, Micrococcus luteus and Klebsiella pneumoniae. The production of mRNA coding for antimicrobial peptides Aa -Attacin, Aa -Cecropin, and Aa -Gambicin was observed in cultured fat bodies and midguts. The production of these messengers was reduced in the presence of dexamethasone, and this effect was reversed by arachidonic acid. Adding PGE2 to cultures resulted in increased Aa -cecropin mRNA and decreased Aa -attacin and Aa -gambicin mRNAs. Arch. Insect Biochem. Physiol. 68:14,25, 2008. © 2008 Wiley-Liss, Inc. [source] Disruption of insulin pathways alters trehalose level and abolishes sexual dimorphism in locomotor activity in DrosophilaDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2006Yesser Hadj Belgacem Abstract Insulin signaling pathways are implicated in several physiological processes in invertebrates, including the control of growth and life span; the latter of these has also been correlated with juvenile hormone (JH) deficiency. In turn, JH levels have been correlated with sex-specific differences in locomotor activity. Here, the involvement of the insulin signaling pathway in sex-specific differences in locomotor activity was investigated in Drosophila. Ablation of insulin-producing neurons in the adult pars-intercerebralis was found to increase trehalosemia and to abolish sexual dimorphism relevant to locomotion. Conversely, hyper-insulinemia induced by insulin injection or by over-expression of an insulin-like peptide decreases trehalosemia but does not affect locomotive behavior. Moreover, we also show that in the head of adult flies, the insulin receptor (InR) is expressed only in the fat body surrounding the brain. While both male and female InR mutants are hyper-trehalosemic, they exhibit similar patterns of locomotor activity. Our results indicate that first, insulin controls trehalosemia in adults, and second, like JH, it controls sex-specific differences in the locomotor activity of adult Drosophila in a manner independent of its effect on trehalose metabolism. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2006 [source] Senescence of immune defence in Bombus workersECOLOGICAL ENTOMOLOGY, Issue 2 2002Claudie Doums Abstract 1. Senescence in workers of social insects is a particularly intriguing life-history trait as the future fitness of workers relies primarily on age-dependent survival rate. The pattern of senescence of immune defence traits was investigated under laboratory conditions in workers of two bumble bees: Bombus terrestris and B. lucorum. 2. In both species, there was a significant decrease with age in the ability to encapsulate a foreign object (a global measure of the efficiency of immune systems). This pattern of senescence was observed in all colonies in B. terrestris (seven) and B. lucorum (eight) assayed, even though, for the latter, there was some heterogeneity among colonies. 3. In B. terrestris, two other measures of immune defence were taken: the relative percentage of fat body in the abdomen and the concentration of haemocytes (the immune defence cells). The quantity of fat body increased only slightly with age and there was no effect for the concentration of haemocytes. Interestingly, the concentration of haemocytes decreased strongly after an encapsulation response, regardless of the age of workers. 4. The importance of the senescence pattern observed for the immune defence traits is discussed in the context of the social biology of workers. [source] Purification and cDNA Cloning of Lysozyme II from Cabbage Butterfly, Artogeia rapae LarvaeENTOMOLOGICAL RESEARCH, Issue 4 2005BANG In Seok ABSTRACT Last instar larvae of cabbage butterfly Artogeia rapae respond to injection of bacteria with a set of inducible antibacterial peptides/proteins. The inducible peptides/proteins are related to the known hinnavins (I and II) and lysozymes (I and II). The lysozyme II has been isolated by heat treatment, cation exchange, and reversed-phase chromatography from immunized hemolymph of last instar larvae. The lysozyme II gene of A. rapae was isolated and its nucleotide sequence was determined by the RACE-PCR from immunized fat body with E. coli. It has an open reading frame of 414 bp nucleotide corresponding to 138 amino acids including an 18 amino acid signal sequence. The molecular weight and the isoelectric point of Artogeia lysozyme II without a signal peptide were 13,649.38 Da and 9.11, respectively. It is great similarity with Manduca lysozyme among other lepidopteran. [source] An ecdysteroid-inducible insulin-like growth factor-like peptide regulates adult development of the silkmoth Bombyx moriFEBS JOURNAL, Issue 5 2009Naoki Okamoto Insulin-like growth factors (IGFs) play essential roles in fetal and postnatal growth and development of mammals. They are secreted by a wide variety of tissues, with the liver being the major source of circulating IGFs, and regulate cell growth, differentiation and survival. IGFs share some biological activities with insulin but are secreted in distinct physiological and developmental contexts, having specific functions. Although recent analyses of invertebrate genomes have revealed the presence of multiple insulin family peptide genes in each genome, little is known about functional diversification of the gene products. Here we show that a novel insulin family peptide of the silkmoth Bombyx mori, which was purified and sequenced from the hemolymph, is more like IGFs than like insulin, in contrast to bombyxins, which are previously identified insulin-like peptides in B. mori. Expression analysis reveals that this IGF-like peptide is predominantly produced by the fat body, a functional equivalent of the vertebrate liver and adipocytes, and is massively released during pupa,adult development. Studies using in vitro tissue culture systems show that secretion of the peptide is stimulated by ecdysteroid and that the secreted peptide promotes the growth of adult-specific tissues. These observations suggest that this peptide is a Bombyx counterpart of vertebrate IGFs and that functionally IGF-like peptides may be more ubiquitous in the animal kingdom than previously thought. Our results also suggest that the known effects of ecdysteroid on insect adult development may be in part mediated by IGF-like peptides. [source] Characterization of a novel silkworm (Bombyx mori) phenol UDP-glucosyltransferaseFEBS JOURNAL, Issue 3 2002Teresa Luque Sugar conjugation is a major pathway for the inactivation and excretion of both endogenous and exogenous compounds. We report here the molecular cloning and functional characterization of a phenol UDP-glucosyltransferase (UGT) from the silkworm, Bombyx mori, which was named BmUGT1. The complete cDNA clone is 1.6 kb, and the gene is expressed in several tissues of fifth-instar larvae, including fat body, midgut, integument, testis, silk gland and haemocytes. The predicted protein comprises 520 amino acids and has ,,30% overall amino-acid identity with other members of the UGT family. The most conserved region of the protein is the C-terminal half, which has been implicated in binding the UDP-sugar. BmUGT1 was expressed in insect cells using the baculovirus expression system, and a range of compounds belonging to diverse chemical groups were assessed as potential substrates for the enzyme. The expressed enzyme had a wide substrate specificity, showing activity with flavonoids, coumarins, terpenoids and simple phenols. These results support a role for the enzyme in detoxication processes, such as minimizing the harmful effects of ingested plant allelochemicals. This work represents the first instance where an insect ugt gene has been associated with a specific enzyme activity. [source] BhSGAMP-1, a gene that encodes an antimicrobial peptide, is developmentally regulated by the direct action of 20-OH ecdysone in the salivary gland of Bradysia hygida (Diptera, Sciaridae)GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 12 2009Gabriela Morilha Zanarotti Abstract Recently we have shown that BhSGAMP-1 is a developmentally regulated reiterated gene that encodes an antimicrobial peptide (AMP) and is expressed exclusively in the salivary glands, at the end of the larval stage. We show, for the first time, that a gene for an AMP is directly activated by 20-OH ecdysone. This control probably involves the participation of short-lived repressor(s). We also found that the promoter of BhSGAMP-1 is not equipped with elements that respond to infection, provoked by the injection of microorganisms, in the salivary glands or in the fat body. We produced polyclonal antibodies against the synthetic peptide and found that the BhSGAMP-1 peptide is secreted in the saliva. The BhSGAMP-1 gene was also activated during the third larval molt. These facts confirm our hypothesis that this preventive system of defense was selected to produce an environment free of harmful microorganisms in the insect's immediate vicinity, during molts. genesis 47:847,857, 2009. © 2009 Wiley-Liss, Inc. [source] Cloning and characterization of Dorsal homologues in the hemipteran Rhodnius prolixusINSECT MOLECULAR BIOLOGY, Issue 5 2009R. Ursic-Bedoya Abstract Rhodnius prolixus is an ancient haematophagous hemipteran insect capable of mounting a powerful immune response. This response is transcriptionally regulated in part by transcription factors of the Rel/Nuclear Factor kappa B (Rel/NF-,B) family. We have cloned and characterized three members of this transcription factor family in this insect. Dorsal 1A is primarily expressed in early developmental stages. In contrast, dorsal 1B and 1C, both differentially spliced products of dorsal 1A, are expressed primarily in the adult fat body in response to septic injury, suggesting their exclusive role in immunity. Additionally, we identified putative ,B binding sites in the 5, upstream regions of target genes known to be involved in the innate immune response of insects. [source] Molecular cloning, characterization, expression pattern and cellular distribution of an ovarian lipophorin receptor in the cockroach, Leucophaea maderaeINSECT MOLECULAR BIOLOGY, Issue 3 2009M. Tufail Abstract A cDNA that encodes a lipophorin receptor (LpR) with a predicted structure similar to that of the low density lipoprotein receptor (LDLR) gene superfamily was cloned from ovaries of the cockroach, Leucophaea maderae (Lem) and characterized. This is the first LpR sequenced from the order Dictyoptera. The cDNA has a length of 3362 bp coding for an 888-residue mature protein with a predicted molecular mass of ~99.14 kDa and a pI value of 4.68. The deduced amino acid sequence showed that the LemLpR harbours eight ligand-binding repeats (LBRs) at the N-terminus similar to the other insect LpRs, and thus resembles vertebrate VLDLRs. In addition to eight tandemly arranged LBRs, the five-domain receptor contains an O -linked sugar region and the classic LDLR internalization signal, FDNPVY. Northern blot analysis revealed the presence of ~4.0 kb ovarian mRNA that was transcribed throughout oogenesis with its peak especially during late previtellogenic and vitellogenic periods (from days 3 to 11). LpR transcript(s) or homologues of LDLRs were also detected in the head, midgut, Malpighian tubules, muscles and in the fat body. RNA in situ hybridization and immunocytochemistry localized the LpR mRNA and protein to germ line-derived cells, the oocytes, and revealed that LpR gene transcription and translation starts very early during oocyte differentiation in the germarium. LpR protein was evenly distributed throughout the cytoplasm during previtellogenic periods of oogenesis. However, during vitellogenic stages, the receptor was accumulated mainly in the cortex of the oocyte. Immunoblot analysis probed an ovarian LpR protein of ~115 and 97 kDa under reducing and nonreducing conditions, respectively. The protein signal appeared on day 2, increased every day and was high during vitellogenic periods from day 4 to day 7. Southern blot analysis suggested the presence of a single copy of the LpR gene in the genome of Le. maderae. [source] Prolonged gene knockdown in the tsetse fly Glossina by feeding double stranded RNAINSECT MOLECULAR BIOLOGY, Issue 1 2009D. P. Walshe Abstract Reverse genetic studies based on RNA interference (RNAi) have revolutionized analysis of gene function in most insects. However the necessity of injecting double stranded RNA (dsRNA) inevitably compromises many investigations particularly those on immunity. Additionally, injection of tsetse flies often causes significant mortality. We demonstrate, at transcript and protein level, that delivering dsRNA in the bloodmeal to Glossina morsitans morsitans is as effective as injection in knockdown of the immunoresponsive midgut-expressed gene TsetseEP. However, feeding dsRNA fails to knockdown the fat body expressed transferrin gene, 2A192, previously shown to be silenced by dsRNA injection. Mortality rates of the dsRNA fed flies were significantly reduced compared to injected flies 14 days after treatment (Fed: 10.1%± 1.8%; injected: 37.9% ± 3.6% (Mean ± SEM)). This is the first demonstration in Diptera of gene knockdown by feeding and the first example of knockdown in a blood-sucking insect by including dsRNA in the bloodmeal. [source] Cloning and molecular characterization of two invertebrate-type lysozymes from Anopheles gambiaeINSECT MOLECULAR BIOLOGY, Issue 3 2008S. M. Paskewitz Abstract We sequenced and characterized two novel invertebrate-type lysozymes from the mosquito Anopheles gambiae. Alignment and phylogenetic analysis of these and a number of related insect proteins identified through bioinformatics strategies showed a high degree of conservation of this protein family throughout the Class Insecta. Expression profiles were examined for the two mosquito genes through semiquantitative and real-time PCR analysis. Lys i-1 transcripts were found in adult females in the fat body and Malpighian tubules, whereas Lys i-2 was detected only in fat bodies. Blood-feeding resulted in significantly increased transcript abundance for both genes in the midguts. Neither gene was upregulated following bacterial challenge. [source] Characterization of Phosphatase and Tensin Homolog expression in the mosquito Aedes aegypti: Six splice variants with developmental and tissue specificityINSECT MOLECULAR BIOLOGY, Issue 3 2007Michael A. Riehle Abstract Phosphatase and tensin homologue (PTEN), an inhibitor of insulin signalling, was characterized in Aedes aegypti. Surprisingly, six splice variants were identified: three with alternative terminal exons (AaegPTEN2 : 3 : 6) and three formed by intron retention (AaegPTEN1 : 4 : 5). All variants encoded active phosphatase domains. Variants with alternative terminal exons also encoded C2 and COOH-domains, and AaegPTEN6 encoded a PDZ binding motif. These three variants also had unique expression patterns. AaegPTEN2 was expressed primarily in the ovary. AaegPTEN3 was predominant in heads and midguts, and throughout development, except early embryogenesis. AaegPTEN6 was expressed in fat body, ovaries, and throughout development. Intron retention variants were weakly expressed in most samples. These expression patterns suggest that AaegPTEN variants play unique roles in regulating insulin's pleiotropic effects. [source] Genomic organization and functional characterization of the alcohol dehydrogenase locus of Ceratitis capitata (Medfly)INSECT MOLECULAR BIOLOGY, Issue 3 2006Saverio Brogna Abstract Approximately 30 kb of genomic DNA enclosing the Adh locus from the medfly, Ceratitis capitata have been cloned and about 15 kb has been structurally and functionally characterized. The locus consists of two genes, Adh-1 and Adh-2, separated by an intergenic region, which is polymorphic in size ranging from , 6.4 kb to 8.1 kb. Both genes consist of three exons and two introns. The introns are below 200 bp in size, except the 1st intron of Adh-1, which is unexpectedly long, variable in size and contains a deleted mariner -like element (postdoc). The two genes are transcribed in different orientations. The Adh-2 gene shows the typical pattern of transcription seen in the homologous genes of Drosophilidae presenting high levels of expression in the fat body, gut and ovaries. The Adh-1 gene is only expressed in the body muscle tissues of embryos, larvae and adult flies, raising the question of what its biological function may be. A DNA fragment containing bases ,102 to ,1666 relative to the first base of the initiating ATG of Adh-1 is sufficient to drive the expression of a reporter gene in body muscles of Drosophila melanogaster embryos, larvae and adult flies. The study provides further insights into the evolution of the Adh genes of higher diptera. [source] Immulectin-4 from the tobacco hornworm Manduca sexta binds to lipopolysaccharide and lipoteichoic acidINSECT MOLECULAR BIOLOGY, Issue 2 2006X.-Q. Yu Abstract Insect C-type lectins function as pattern recognition receptors in innate immunity. In the tobacco hornworm Manduca sexta, we have previously isolated three C-type lectins named immulectins, which are involved in innate immune responses. Here, we report a new member of the immulectin family, immulectin-4 (IML-4). IML-4 mRNA was detected in the fat body of control larvae and was induced in the fat body when larvae were injected with bacteria. Recombinant IML-4 bound to bacterial lipopolysaccharide (LPS) and lipoteichoic acid (LTA), and the binding activity was not affected by addition of calcium or EGTA. IML-4 agglutinated bacteria and yeast, and agglutination of Escherichia coli by IML-4 was concentration- and calcium-dependent. IML-4 also enhanced haemocyte encapsulation and melanization. [source] The accumulation of specific mRNAs following multiple blood meals in Anopheles gambiaeINSECT MOLECULAR BIOLOGY, Issue 1 2005X. Nirmala Abstract One approach to genetic control of transmission of the parasites that cause human malaria is based on expressing effector genes in mosquitoes that disable the pathogens. Endogenous mosquito promoter and other cis -acting DNA sequences are needed to direct the optimal tissue-, stage- and sex-specific expression of the effector molecules. The mRNA accumulation profiles of eight different genes expressed specifically in the midgut, salivary glands or fat body tissues of the malaria vector, Anopheles gambiae, were characterized as a measure of their suitability to direct the expression of effector molecules designed to disable specific stages of the parasites. RT-PCR techniques were used to determine the abundance of the gene products and their duration following multiple blood meals. Transcription from the midgut-expressed carboxypeptidase-encoding gene, AgCP, follows a cyclical, blood-inducible expression pattern with maximum accumulation every 3 h post blood meal. Other midgut-expressed genes encoding a trypsin and chymotrypsin, Antryp2 and Anchym1, respectively, and the fat body-expressed genes, Vg1 and Cathepsin, also show a blood-inducible pattern of expression with maximum accumulation 24 h after every blood meal. Expression of the Lipophorin gene in the fat body and apyrase and D7-related genes (AgApy and D7r2) in the salivary glands is constitutive and not significantly affected by blood meals. Promoters of the midgut- and fat body-expressed genes may lead to maximum accumulation of antiparasite effector molecule transcripts after multiple blood meals. The multiple feeding behaviour of An. gambiae thus can be an advantage to express high levels of antiparasite effector molecules to counteract the parasites throughout most of adult development. [source] Toxoneuron nigriceps polydnavirus encodes a putative aspartyl protease highly expressed in parasitized host larvaeINSECT MOLECULAR BIOLOGY, Issue 1 2003Patrizia Falabella Abstract Toxoneuron nigriceps (Viereck) (Hymenoptera: Braconidae) is an endophagous parasitoid of larval stages of the tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae). This parasitoid is associated with a polydnavirus (TnBV), injected at oviposition along with the egg, and involved in the disruption of host immune reaction and endocrine balance. This paper reports the molecular characterization of TnBV2, one of the most abundant genes in the TnBV genome. TnBV2 expression produces a mature 0.6 kb transcript in fat body, prothoracic glands and haemocytes, as early as 6 h after parasitoid oviposition. Only in haemocytes a specific longer transcript of 2.5 kb is found 24 h after parasitization. The putative translation product of TnBV2 contains a retroviral type aspartyl protease domain. The possible origin and functional role of this TnBV gene are discussed. [source] Aedes aegypti transducing densovirus pathogenesis and expression in Aedes aegypti and Anopheles gambiae larvaeINSECT MOLECULAR BIOLOGY, Issue 5 2001T. W. Ward Abstract Aedes aegypti densovirus (AeDNV) is a small DNA virus that has been developed into an expression and transducing vector for mosquitoes [Afanasiev et al. (1994) Exp Parasitol 79: 322,339; Afanasiev et al. (1999) Virology 257: 62,72; Carlson et al. (2000) Insect Transgenesis: Methods and Applications (Handler, A.M. & James, A.A., eds), pp. 139,159. CRC Press, Boca Raton]. Virions carrying a recombinant genome expressing the GFP gene were used to characterize the pathogenesis of the virus in 255 individual Aedes aegypti larvae. The anal papillae of the larvae were the primary site of infection confirming previous observations (Afanasiev et al., 1999; Allen-Muira et al. (1999) Virology 257: 54,61). GFP expression was observed in most cases to spread from the anal papillae to cells of the fat body, and subsequently to many other tissues including muscle fibers and nerves. Infected anal papillae were also observed to shrink, or melanize and subsequently fall off in a virus dependent manner. Three to four day-old larvae were less susceptible to viral infection and, if infected, were more likely to survive into adulthood, with 14% of them still expressing GFP as adults. Higher salt concentrations of 0.10,0.15 m inhibited viral infection. Anopheles gambiae larvae also showed infection of the anal papillae (17%) but subsequent viral dissemination did not occur. The persistence of the reporter gene expression into adulthood of Aedes aegypti indicates that transduction of mosquito larvae with recombinant AeDNV may be a means of introducing a gene of interest into a mosquito population for transient expression. [source] Molecular characterization of a prophenoloxidase cDNA from the malaria mosquito Anopheles stephensiINSECT MOLECULAR BIOLOGY, Issue 2 2000L. Cui Abstract Some refractory anopheline mosquitoes are capable of killing Plasmodium, the causative agent of malaria, by melanotic encapsulation of invading ookinetes. Phenoloxidase (PO) appears to be involved in the formation of melanin and toxic metabolites in the surrounding capsule. A cDNA encoding Anopheles stephensi prophenoloxidase (Ans-proPO) was isolated from a cDNA library screened with an amplimer produced by reverse transcriptase polymerase chain reaction (RT-PCR) with degenerate primers designed against conserved proPO sequences. The 2.4-kb-long cDNA has a 2058 bp open reading frame encoding Ans-proPO of 686 amino acids. The deduced amino acid sequence shows significant homology to other insect proPO sequences especially at the two putative copper-binding domains. In A. stephensi, Ans-proPO expression was detected in larval, pupal and adult stages. The Ans-proPO mRNA was detected by RT-PCR and in situ hybridization in haemocytes, fat body and epidermis of adult female mosquitoes. A low level of expression was detected in the ovaries, whereas no expression was detected in the midguts. Semi-quantitative RT-PCR analysis of Ans-proPO mRNA showed that its expression was similar in adult female heads, thoraxes and abdomens. No change in the level of Ans-proPO expression was found in adult females after blood feeding, bacterial challenge or Plasmodium berghei infection. However, elevated PO activity was detected in P. berghei -infected mosquitoes, suggesting that in non-selected permissive mosquitoes PO may be involved in limiting parasite infection. Genomic Southern blot and immunoblots suggest the presence of more than one proPO gene in the A. stephensi genome, which is consistent with the findings in other Diptera and Lepidoptera species. The greatest similarity in sequence and expression profile between Ans-proPO and A. gambiae proPO6 suggests that they might be homologues. Our results demonstrate that Ans-proPO is constitutively expressed through different developmental stages and under different physiological conditions, implying that other factors in the proPO activation cascade regulate melanotic encapsulation. [source] cDNA of an arylphorin-type storage protein from Pieris rapae with parasitism inducible expression by the endoparasitoid wasp Pteromalus puparumINSECT SCIENCE, Issue 3 2009Jia-Ying Zhu Abstract, This report presents the cDNA cloning of a storage protein, PraAry, from Pieris rapae and investigates its expression regulated by parasitism of an endoparasitoid wasp Pteromalus puparum. The full-length cDNA of PraAry is 2 270 nucleotides and contains a 2 121 nucleotide open reading frame encoding 707 amino acids with calculated molecular weights of approximately 83 kDa. Analysis of the primary protein sequence revealed that it possesses a signal peptide of 16 amino acids at the N-terminus and contains two highly conserved storage protein signature motifs. According to both phylogenetic analysis and the criteria for amino acid composition, PraAry belongs to the subfamily of arylphorin-type storage protein (1.42% methionine and 18.82% aromatic amino acids). Reverse transcription , polymerase chain reaction analysis indicated that the transcriptional level of PraAry mRNA in P. rapae pupae fat body is inducible in response to parasitism by P. puparum. [source] Analysis of the structure and expression of the 30K protein genes in silkworm, Bombyx moriINSECT SCIENCE, Issue 1 2007QUAN SUN Abstract A group of lipoproteins with molecular sizes of approximately 30 kDa, referred to as 30K proteins, are synthesized in fat body cells in the fifth instar larvae of silkworm, Bombyx mori. Analyzing the silkworm genome and its expressed sequence tags (ESTs), we found 10 genes encoding 30K proteins, which are mainly distributed in three subfamilies. Of these, seven coding proteins were found to harbor the degrading sites of 30kP protease A, although the number of degrading sites may be different. As some potential core promoters and regulatory elements were supposed to be essential for gene transcription, the expression profiles of these genes were examined by semi-quantitative reverse transcription polymerase chain reaction. Eight 30K protein genes were detected to express luxuriantly in the fat body, while two were hardly expressed. Such results suggest that these 30K proteins may have different functions, and their adjacent regulatory elements play a crucial role in regulating their transcription. [source] | |||||||||||||||||||||||||||||||