Martín-Vega, Daniel; Simonsen, Thomas J; Wicklein, Martina; Hall, Martin J R
Minimum post-mortem interval (minPMI) estimates often rely on the use of developmental data from blow flies (Diptera: Calliphoridae), which are generally the first colonisers of cadavers and, therefore, exemplar forensic indicators. Developmental data of the intra-puparial period are of particular importance, as it can account for more than half of the developmental duration of the blow fly life cycle. During this period, the insect undergoes metamorphosis inside the opaque, barrel-shaped puparium, formed by the hardening and darkening of the third instar larval cuticle, which shows virtually no external changes until adult emergence. Regrettably, estimates based on the intra-puparial period are severely limited due to the lack of reliable, non-destructive ageing methods and are frequently based solely on qualitative developmental markers. In this study, we use non-destructive micro-computed tomography (micro-CT) for (i) performing qualitative and quantitative analyses of the morphological changes taking place during the intra-puparial period of two forensically relevant blow fly species, Calliphora vicina and Lucilia sericata, and (ii) developing a novel and reliable method for estimating insect age in forensic practice. We show that micro-CT provides age-diagnostic qualitative characters for most 10% time intervals of the total intra-puparial period, which can be used over a range of temperatures and with a resolution comparable to more invasive and time-consuming traditional imaging techniques. Moreover, micro-CT can be used to yield a quantitative measure of the development of selected organ systems to be used in combination with qualitative markers. Our results confirm micro-CT as an emerging, powerful tool in medico-legal investigations.
Hou, Qiu-Li; Jiang, Hong-Bo; Gui, Shun-Hua; Chen, Er-Hu; Wei, Dan-Dan; Li, Hui-Min; Wang, Jin-Jun; Smagghe, Guy
Corazonin (Crz) is a neuropeptide hormone, but also a neuropeptide modulator that is internally released within the CNS, and it has a widespread distribution in insects with diverse physiological functions. Here, we identified and cloned the cDNAs of Bactrocera dorsalis that encode Crz and its receptor CrzR. Mature BdCrz has 11 residues with a unique Ser(11) substitution (instead of the typical Asn) and a His in the evolutionary variable position 7. The BdCrzR cDNA encodes a putative protein of 608 amino acids with 7 putative transmembrane domains, typical for the structure of G-protein-coupled receptors. When expressed in Chinese hamster ovary (CHO) cells, the BdCrzR exhibited a high sensitivity and selectivity for Crz (EC50 ≈ 52.5 nM). With qPCR, the developmental stage and tissue-specific expression profiles in B. dorsalis demonstrated that both BdCrz and BdCrzR were highly expressed in the larval stage, and BdCrzR peaked in 2-day-old 3rd-instar larvae, suggesting that the BdCrzR may play an important role in the larval-pupal transition behavior. Immunochemical localization confirmed the production of Crz in the central nervous system (CNS), specifically by a group of three neurons in the dorso-lateral protocerebrum and eight pairs of lateral neurons in the ventral nerve cord. qPCR analysis located the BdCrzR in both the CNS and epitracheal gland, containing the Inka cells. Importantly, dsRNA-BdCrzR-mediated gene-silencing caused a delay in larval-pupal transition and pupariation, and this phenomenon agreed with a delayed expression of tyrosine hydroxylase and dopa-decarboxylase genes. We speculate that CrzR-silencing blocked dopamine synthesis, resulting in the inhibition of pupariation and cuticular melanization. Finally, injection of Crz in head-ligated larvae could rescue the effects. These findings provide a new insight into the roles of Crz signaling pathway components in B. dorsalis and support an important role of CrzR in larval-pupal transition and
Hou, Qiu-Li; Jiang, Hong-Bo; Gui, Shun-Hua; Chen, Er-Hu; Wei, Dan-Dan; Li, Hui-Min; Wang, Jin-Jun; Smagghe, Guy
Corazonin (Crz) is a neuropeptide hormone, but also a neuropeptide modulator that is internally released within the CNS, and it has a widespread distribution in insects with diverse physiological functions. Here, we identified and cloned the cDNAs of Bactrocera dorsalis that encode Crz and its receptor CrzR. Mature BdCrz has 11 residues with a unique Ser11 substitution (instead of the typical Asn) and a His in the evolutionary variable position 7. The BdCrzR cDNA encodes a putative protein of 608 amino acids with 7 putative transmembrane domains, typical for the structure of G-protein-coupled receptors. When expressed in Chinese hamster ovary (CHO) cells, the BdCrzR exhibited a high sensitivity and selectivity for Crz (EC50 ≈ 52.5 nM). With qPCR, the developmental stage and tissue-specific expression profiles in B. dorsalis demonstrated that both BdCrz and BdCrzR were highly expressed in the larval stage, and BdCrzR peaked in 2-day-old 3rd-instar larvae, suggesting that the BdCrzR may play an important role in the larval-pupal transition behavior. Immunochemical localization confirmed the production of Crz in the central nervous system (CNS), specifically by a group of three neurons in the dorso-lateral protocerebrum and eight pairs of lateral neurons in the ventral nerve cord. qPCR analysis located the BdCrzR in both the CNS and epitracheal gland, containing the Inka cells. Importantly, dsRNA-BdCrzR-mediated gene-silencing caused a delay in larval-pupal transition and pupariation, and this phenomenon agreed with a delayed expression of tyrosine hydroxylase and dopa-decarboxylase genes. We speculate that CrzR-silencing blocked dopamine synthesis, resulting in the inhibition of pupariation and cuticular melanization. Finally, injection of Crz in head-ligated larvae could rescue the effects. These findings provide a new insight into the roles of Crz signaling pathway components in B. dorsalis and support an important role of CrzR in larval-pupal transition and
Dubey, Anil Kumar; Ramamurthy, V V
Aleuropositus Dubey gen. n., Australeurodes Dubey gen. n. and Septemaleurodes Dubey gen. n. are proposed with their respective type species as A. sinus Dubey sp. n. from India, D. operculobata Martin & Carver from Australia, and D. swainei Martin from Australia. A. sinus sp. n. is described from Kerala, India, illustrated with line drawings, microphotographs and SEM images. The puparia are asymmetric in taxonomic characters and shape, and variation in puparia associated with a single host is discussed. A generic diagnosis of Dialeurolonga is provided based on SEM study of the type species, D. elongata. Australian species placed in this genus have puparial characteristics that distinguish them from Afrotropical assemblages, and are here referred to two new genera.
Methyl farnesoate (MF) and juvenile hormone (JH III), which respectively bind to the receptors USP and MET, and bisepoxy JH III (bisJHIII) were assessed for several activities during Drosophila larval development, and during prepupal development to eclosed adults. Dietary MF and JH III were similar...
Braga, Marina Vianna; Pinto, Zeneida Teixeira; de Carvalho Queiroz, Margareth Maria; Matsumoto, Nana; Blomquist, Gary James
The external surface of all insects is covered by a species-specific complex mixture of highly stable, very long chain cuticular hydrocarbons (CHCs). Gas chromatography coupled to mass spectrometry was used to identify CHCs from four species of Sarcophagidae, Peckia (Peckia) chrysostoma, Peckia (Pattonella) intermutans, Sarcophaga (Liopygia) ruficornis and Sarcodexia lambens. The identified CHCs were mostly a mixture of n-alkanes, monomethylalkanes and dimethylalkanes with linear chain lengths varying from 23 to 33 carbons. Only two alkenes were found in all four species. S. lambens had a composition of CHCs with linear chain lengths varying from C23 to C33, while the other three species linear chain lengths from 24 to 31 carbons. n-Heptacosane, n-nonacosane and 3-methylnonacosane, n-triacontane and n-hentriacontane occurred in all four species. The results show that these hydrocarbon profiles may be used for the taxonomic differentiation of insect species and are a useful additional tool for taxonomic classification, especially when only parts of the insect specimen are available. PMID:23932943
Braga, Marina Vianna; Pinto, Zeneida Teixeira; de Carvalho Queiroz, Margareth Maria; Matsumoto, Nana; Blomquist, Gary James
The external surface of all insects is covered by a species-specific complex mixture of highly stable, very long chain cuticular hydrocarbons (CHCs). Gas chromatography coupled to mass spectrometry was used to identify CHCs from four species of Sarcophagidae, Peckia (Peckia) chrysostoma, Peckia (Pattonella) intermutans, Sarcophaga (Liopygia) ruficornis and Sarcodexia lambens. The identified CHCs were mostly a mixture of n-alkanes, monomethylalkanes and dimethylalkanes with linear chain lengths varying from 23 to 33 carbons. Only two alkenes were found in all four species. S. lambens had a composition of CHCs with linear chain lengths varying from C23 to C33, while the other three species linear chain lengths from 24 to 31 carbons. n-Heptacosane, n-nonacosane and 3-methylnonacosane, n-triacontane and n-hentriacontane occurred in all four species. The results show that these hydrocarbon profiles may be used for the taxonomic differentiation of insect species and are a useful additional tool for taxonomic classification, especially when only parts of the insect specimen are available.
F., Beckwith W., Sandman C., Eds.), Ann. NY Acad. Sci., 1997, 814, 67-72.  Nachman R.J., Zdarek J., Hayes T.K., Holman G.M., in: Neuropeptides...in Development and Aging, (Strand F., Beckwith W., Sandman C., Eds.), Ann. NY Acad. Sci., 1997, 814, 73-9.  Nachman R.J., Strey A., Zubrzak P
Diapause hormone (DH) effectively terminated pupal diapause in Helicoverpa zea. This effect was temperature-dependent, with an optimum of 21 degrees C. The dose-response curve indicated an ED50 of DH for diapause termination of approximately 100 pmol. The core sequence and essential amino acids w...
Malan, Antoinette P; Manrakhan, Aruna
The potential of entomopathogenic nematodes, Heterorhabditis bacteriophora, Heterorhabditis zealandica and Steinernema khoisanae, to infect pupariating larvae, pupae and adults of Ceratitis capitata and Ceratitis rosa was investigated in laboratory bioassays. Pupariating larvae and adult flies were susceptible to nematode infection, with no infection recorded for the pupae. Pupariating larvae of C. capitata were generally more susceptible to infection than those of C. rosa. Significantly more larvae of C. capitata were infected by H. bacteriophora. For C. rosa, highest infectivity of larvae was obtained with H. zealandica. In contrast, adults of both species were highly infected by S. khoisanae.
Sukontason, Kom; Piangjai, Somsak; Siriwattanarungsee, Sirisuda; Sukontason, Kabkaew L
The larval morphology and developmental rate of Chrysomya megacephala (F.) and Chrysomya rufifacies (Macquart), the two most forensically important blowfly species in Thailand, are presented. Morphological comparison of the third instar of both species revealed different characteristics (e.g., body appearance, cephalopharyngeal skeleton, dorsal cuticular spines between the prothorax and mesothorax, and feature of the posterior spiracle), thereby, allowing correct identification. A data analysis was conducted in Chiang Mai province, Northern Thailand during 2000-2001 on the developmental rate of both flies under natural ambient temperature and a natural light-dark photoperiod. The results indicated that larvae of C. megacephala developed more rapidly in April, pupariation initiated at 84 h at temperatures averaging 31.4 degrees C, and the larvae grew slower in the rainy season and winter. Similarly, rapid development of C. rufifacies larvae appeared in the summer, with a pupariation period as short as 96 h in June (average temperature 27.4 degrees C). Analysis of the median body length of C. megacephala and C. rufifacies larvae in different seasons of the years 2000-2001 in Thailand revealed that both species developed rapidly in the summer; pupariation of C. rufifacies initiated at 144 h, while C. megacephala initiated pupariation at 156 h. This information is potentially useful for estimating the postmortem interval of a corpse in forensic investigations, where the corpse becomes infesting with these fly species.
Andersen, Svend Olav
during sample hydrolysis. Mono- and dichlorotyrosine are also present in cuticular samples from other insect species, such as the beetle, Tenebrio molitor, the moth Hyalophora cecropia, the cockroach Blaberus craniifer, and the bug Rhodnius prolixus, but not in the sclerotized puparial cuticle...... of the blowfly, Calliphora vicina, or in sclerotized ootheca from the cockroach, Periplaneta americana. Cuticular sclerotization and formation of chlorotyrosines occur simultaneously in locust legs; sclerotized cuticles tend to have a higher content of chlorotyrosines than unsclerotized cuticles...
Hallman, Guy J; Thomas, Donald B
Methyl bromide fumigation is widely used as a phytosanitary treatment. Mexican fruit fly, Anastrepha ludens (Loew) (Diptera: Tephritidae), is a quarantine pest of several fruit, including citrus (Citrus spp.), exported from Texas, Mexico, and Central America. Recently, live larvae have been found with supposedly correctly fumigated citrus fruit. This research investigates the efficacy of the previously approved U.S. Department of Agriculture-Animal and Plant Health Inspection Service treatment schedule: 40 g/m3 methyl bromide at 21-29.4 degrees C for 2 h. Tolerance ofA. ludens to methyl bromide in descending order when fumigated in grapefruit (Citrus X paradisi Macfad.) is third instar > second instar > first instar > egg. Two infestation techniques were compared: insertion into fruit of third instars reared in diet and oviposition by adult A. ludens into fruit and development to the third instar. Inserted larvae were statistically more likely to survive fumigation than oviposited larvae. When fruit were held at ambient temperature, 0.23 +/- 0.12% of larvae were still observed to be moving 4 d postfumigation. Temperatures between 21.9 and 27.2 degrees C were positively related to efficacy measured as larvae moving 24 h after fumigation, pupariation, and adult emergence. Coating grapefruit with Pearl Lustr 2-3 h before fumigation did not significantly affect the proportion of third instars moving 24 h after fumigation, pupariating, or emerging as adults. In conclusion, fumigation with 40 g/m3 methyl bromide for 2 h at fruit temperatures >26.7 degrees C is not found to be inefficacious for A. ludens. Although a few larvae may be found moving >24 h postfumigation, they do not pupariate.
Kathryn E Dean
Full Text Available The transition of Drosophila third instar larvae from feeding, photo-phobic foragers to non-feeding, photo-neutral wanderers is a classic behavioral switch that precedes pupariation. The neuronal network responsible for this behavior has recently begun to be defined. Previous genetic analyses have identified signaling components for food and light sensory inputs and neuropeptide hormonal outputs as being critical for the forager to wanderer transition. Trio is a Rho-Guanine Nucleotide Exchange Factor integrated into a variety of signaling networks including those governing axon pathfinding in early development. Sequoia is a pan-neuronally expressed zinc-finger transcription factor that governs dendrite and axon outgrowth. Using pre-pupal lethality as an endpoint, we have screened for dominant second-site enhancers of a weakly lethal trio mutant background. In these screens, an allele of sequoia has been identified. While these mutants have no obvious disruption of embryonic central nervous system architecture and survive to third instar larvae similar to controls, they retain forager behavior and thus fail to pupariate at high frequency.
Thibert, Julien; Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François
Animals ubiquitously use chemical signals to communicate many aspects of their social life. These chemical signals often consist of environmental cues mixed with species-specific signals-pheromones-emitted by conspecifics. During their life, insects can use pheromones to aggregate, disperse, choose a mate, or find the most suitable food source on which to lay eggs. Before pupariation, larvae of several Drosophila species migrate to food sources depending on their composition and the presence of pheromones. Some pheromones derive from microbiota gut activity and these food-associated cues can enhance larval attraction or repulsion. To explore the mechanisms underlying the preference (attraction/repulsion) to these cues and clarify their effect, we manipulated factors potentially involved in larval response. In particular, we found that the (i) early exposure to conspecifics, (ii) genotype, and (iii) antibiotic treatment changed D. melanogaster larval behavior. Generally, larvae-tested either individually or in groups-strongly avoided food processed by other larvae. Compared to previous reports on larval attractive pheromones, our data suggest that such attractive effects are largely masked by food-associated compounds eliciting larval aversion. The antagonistic effect of attractive vs. aversive compounds could modulate larval choice of a pupariation site and impact the dispersion of individuals in nature.
Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François
Insects use chemosensory cues to feed and mate. In Drosophila, the effect of pheromones has been extensively investigated in adults, but rarely in larvae. The colonization of natural food sources by Drosophila buzzatii and Drosophila simulans species may depend on species-specific chemical cues left in the food by larvae and adults. We identified such chemicals in both species and measured their influence on larval food preference and puparation behaviour. We also tested compounds that varied between these species: (i) two larval volatile compounds: hydroxy-3-butanone-2 and phenol (predominant in D. simulans and D. buzzatii, respectively), and (ii) adult cuticular hydrocarbons (CHs). Drosophila buzzatii larvae were rapidly attracted to non-CH adult conspecific cues, whereas D. simulans larvae were strongly repulsed by CHs of the two species and also by phenol. Larval cues from both species generally reduced larval attraction and pupariation on food, which was generally--but not always--low, and rarely reflected larval response. As these larval and adult pheromones specifically influence larval food search and the choice of a pupariation site, they may greatly affect the dispersion and survival of Drosophila species in nature.
Wang, Jiangfeng; Li, Zhigang; Chen, Yuchuan; Chen, Qiangsheng; Yin, Xiaohong
The succession of insect communities on carrion varies at local and global spatial scales. As such, ecological succession data obtained from corpses at one geographic location cannot necessarily be applied to other locations. Our study describes this succession in the far southern part of China to provide such data for forensic cases in this region. A total of 18 pig carcasses were placed in the field in four seasons, and the timing of the following events were recorded: appearance of larvae, onset of larval wandering, when most larvae had wandered, onset of pupariation, when most larvae had pupariated, onset of eclosion and end of eclosion. Our results indicated that all of the evaluated events could be used as accurate indicators of postmortem interval (PMI). The carcasses decayed fairly quickly in spring, summer and autumn, taking 225+/-75 h, 183+/-44 h, and 247+/-70 h, respectively, to decay from the fresh stage to skeletonisation. In winter, carcasses needed longer (1180+/-291) to decay as much. Carcasses attracted 47 species of insect, with flies predominating. The larvae were mainly Chrysomya megacephala (Fabricius), Chrysomya rufifacies (Macquart) and Hydrotaea (Ophyra) spinigera (Stein). Most necrophagous insects were found all year around, and there were no marked differences in species among the four seasons, except that Dermestes maculatus (De Geer) was absent in winter. Blowflies produced only one generation on a carcass before it became skeletonised, which simplified the estimation of PMIs.
Full Text Available Kumchura (Kaempferia galangal L. rhizome has been known to posses bioactivity to melon fly in its crude form. Extract preparation from the same plant part was tested against melon fly Bactrocera cucurbitae Coquillet’s eggs and larvae to investigate its toxicity and activity. Toxicity test was done by diluting the rhizome’s methanolic extract and incorporating the solution to larval diet. Based on the toxicity test, sublethal concentrations were then tested to determine the extract activity to egg and larval survivals, larval stage duration, puparial weight and length, extracts’ repellency to larvae and extracts’ hormonal activity to larvae. The result showed that kumchura extract toxicity was only considered “slightly toxic”, but sublethal concentration as low as 0.3125% (to eggs and 2.5% (to larvae significantly affected the fly’s survival, while the same concentration to egg and 0.625% concentration to larvae significantly prolonged larval stage durations. Extracts’ repellency to larvae was siginificant in sublethal concentration as low as 0.3125%, but kumchura extract has no significant effect on puparial weight and length, and did not contain any hormonal activities toward melon fly. Key words: kumchura extract, melon fly, bioactivity
Segal, Dagan; Dhanyasi, Nagaraju; Schejter, Eyal D; Shilo, Ben-Zion
Indirect flight muscles (IFMs) in Drosophila are generated during pupariation by fusion of hundreds of myoblasts with larval muscle templates (myotubes). Live observation of these muscles during the fusion process revealed multiple long actin-based protrusions that emanate from the myotube surface and require Enabled and IRSp53 for their generation and maintenance. Fusion is blocked when formation of these filopodia is compromised. While filopodia are not required for the signaling process underlying critical myoblast cell-fate changes prior to fusion, myotube-myoblast adhesion appears to be filopodia dependent. Without filopodia, close apposition between the cell membranes is not achieved, the cell-adhesion molecule Duf is not recruited to the myotube surface, and adhesion-dependent actin foci do not form. We therefore propose that the filopodia are necessary to prime the heterotypic adhesion process between the two cell types, possibly by recruiting the cell-adhesion molecule Sns to discrete patches on the myoblast cell surface.
Olekšáková, Tereza; Žurovcová, Martina; Klimešová, Vanda; Barták, Miroslav; Šuláková, Hana
Several methods of DNA extraction, coupled with 'DNA barcoding' species identification, were compared using specimens from early developmental stages of forensically important flies from the Calliphoridae and Sarcophagidae families. DNA was extracted at three immature stages - eggs, the first instar larvae, and empty pupal cases (puparia) - using four different extraction methods, namely, one simple 'homemade' extraction buffer protocol and three commercial kits. The extraction conditions, including the amount of proteinase K and incubation times, were optimized. The simple extraction buffer method was successful for half of the eggs and for the first instar larval samples. The DNA Lego Kit and DEP-25 DNA Extraction Kit were useful for DNA extractions from the first instar larvae samples, and the DNA Lego Kit was also successful regarding the extraction from eggs. The QIAamp DNA mini kit was the most effective; the extraction was successful with regard to all sample types - eggs, larvae, and pupari.
Katsuyama, Tomonori; Comoglio, Federico; Seimiya, Makiko; Cabuy, Erik; Paro, Renato
Regeneration of fragmented Drosophila imaginal discs occurs in an epimorphic manner involving local cell proliferation at the wound site. After disc fragmentation, cells at the wound site activate a restoration program through wound healing, regenerative cell proliferation, and repatterning of the tissue. However, the interplay of signaling cascades driving these early reprogramming steps is not well-understood. Here, we profiled the transcriptome of regenerating cells in the early phase within 24 h after wounding. We found that JAK/STAT signaling becomes activated at the wound site and promotes regenerative cell proliferation in cooperation with Wingless (Wg) signaling. In addition, we showed that the expression of Drosophila insulin-like peptide 8 (dilp8), which encodes a paracrine peptide to delay the onset of pupariation, is controlled by JAK/STAT signaling in early regenerating discs. Our findings suggest that JAK/STAT signaling plays a pivotal role in coordinating regenerative disc growth with organismal developmental timing.
Carbonell, Albert; Mazo, Alexander; Serras, Florenci; Corominas, Montserrat
The molting hormone ecdysone triggers chromatin changes via histone modifications that are important for gene regulation. On hormone activation, the ecdysone receptor (EcR) binds to the SET domain-containing histone H3 methyltransferase trithorax-related protein (Trr). Methylation of histone H3 at lysine 4 (H3K4me), which is associated with transcriptional activation, requires several cofactors, including Ash2. We find that ash2 mutants have severe defects in pupariation and metamorphosis due to a lack of activation of ecdysone-responsive genes. This transcriptional defect is caused by the absence of the H3K4me3 marks set by Trr in these genes. We present evidence that Ash2 interacts with Trr and is required for its stabilization. Thus we propose that Ash2 functions together with Trr as an ecdysone receptor coactivator.
Walker, Jane; Kwon, So Yeon; Badenhorst, Paul
The Elongator complex has been implicated in several cellular processes, including gene expression and tRNA modification. We investigated the biological importance of the Elp3 gene in Drosophila melanogaster. Deletion of Elp3 results in larval lethality at the pupal stage. During early development......, larval growth is dramatically impaired, with progression to the third instar delayed for ~24 hr, and pupariation occurring only at day 14 after egg laying. Melanotic nodules appear after 4 days. Microarray analysis shows that stress response genes are induced and ecdysone-induced transcription factors...... are severely repressed in the mutant. Interestingly, the phenotypes of Elp3 flies are similar to those of flies lacking the domino gene, encoding a SWI/SNF-like ATP-dependent chromatin-remodeling enzyme. Indeed, the gene expression profiles of these mutants are also remarkably similar. Together, these data...
Guilin R Ren
Full Text Available The neuroendocrine peptides CCHamide-1 and -2, encoded by the genes ccha1 and -2, are produced by endocrine cells in the midgut and by neurons in the brain of Drosophila melanogaster. Here, we used the CRISPR/Cas9 technique to disrupt the ccha1 and -2 genes and identify mutant phenotypes with a focus on ccha-2 mutants. We found that both larval and adult ccha2 mutants showed a significantly reduced food intake as measured in adult flies by the Capillary Feeding (CAFE assay (up to 72% reduced food intake compared to wild-type. Locomotion tests in adult flies showed that ccha2 mutants had a significantly reduced locomotor activity especially around 8 a.m. and 8 p.m., where adult Drosophila normally feeds (up to 70% reduced locomotor activity compared to wild-type. Reduced larval feeding is normally coupled to a delayed larval development, a process that is mediated by insulin. Accordingly, we found that the ccha2 mutants had a remarkably delayed development, showing pupariation 70 hours after the pupariation time point of the wild-type. In contrast, the ccha-1 mutants were not developmentally delayed. We also found that the ccha2 mutants had up to 80% reduced mRNA concentrations coding for the Drosophila insulin-like-peptides-2 and -3, while these concentrations were unchanged for the ccha1 mutants. From these experiments we conclude that CCHamide-2 is an orexigenic peptide and an important factor for controlling developmental timing in Drosophila.
Moeller, Morten E.; Danielsen, E. Thomas; Herder, Rachel; O’Connor, Michael B.; Rewitz, Kim F.
Steroid hormones trigger the onset of sexual maturation in animals by initiating genetic response programs that are determined by steroid pulse frequency, amplitude and duration. Although steroid pulses coordinate growth and timing of maturation during development, the mechanisms generating these pulses are not known. Here we show that the ecdysone steroid pulse that drives the juvenile-adult transition in Drosophila is determined by feedback circuits in the prothoracic gland (PG), the major steroid-producing tissue of insect larvae. These circuits coordinate the activation and repression of hormone synthesis, the two key parameters determining pulse shape (amplitude and duration). We show that ecdysone has a positive-feedback effect on the PG, rapidly amplifying its own synthesis to trigger pupariation as the onset of maturation. During the prepupal stage, a negative-feedback signal ensures the decline in ecdysone levels required to produce a temporal steroid pulse that drives developmental progression to adulthood. The feedback circuits rely on a developmental switch in the expression of Broad isoforms that transcriptionally activate or silence components in the ecdysone biosynthetic pathway. Remarkably, our study shows that the same well-defined genetic program that stimulates a systemic downstream response to ecdysone is also utilized upstream to set the duration and amplitude of the ecdysone pulse. Activation of this switch-like mechanism ensures a rapid, self-limiting PG response that functions in producing steroid oscillations that can guide the decision to terminate growth and promote maturation. PMID:24173800
Moreau, S J.M.; Dingremont, A; Doury, G; Giordanengo, P
The impact of parasitism by Asobara tabida on Drosophila melanogaster larval development, survival features and larval activity has been investigated using two strains of the parasitoid. The successful parasitism rate of the A1 strain was four times greater than that of the WOPV strain. Both strains induced equivalent mortality rates but hosts parasitized by A1 predominantly died as pupae. The time necessary for the host pupariation and emergence, and the larval weight at 72, 96 and 120 h post-parasitization were measured. Parasitized larvae exhibited longer periods of development and lower weights than controls, especially when parasitized by A1. These results suggest that hosts underwent physiological costs varying with respect to the outcome of the parasitic relationship. Of the parasitoid factors possibly responsible for these costs, we examined venoms for their impact on host mortality. Artificial injections of WOPV venoms induced higher mortality rates than did A1 venoms. Venoms were also found responsible for the induction of a transient paralysis, naturally occuring after parasitization. Again, the strongest effect was observed after parasitization by WOPV or injections of its venoms. This study gives new insights into the intriguing features of A. tabida and constitutes the first report of the paralysing properties of the venoms.
Full Text Available The circadian clock provides the temporal framework for rhythmic behavioural and metabolic functions. In the modern era of industrialization, work and social pressures, the clock function is often jeopardized, resulting in adverse and chronic effects on health. Understanding circadian clock function, particularly individual variation in diurnal phase preference (chronotype, and the molecular mechanisms underlying such chronotypes may lead to interventions that could abrogate clock dysfunction and improve human (and animal health and welfare. Our preliminary studies suggested that fruitflies, like humans, can be classified as early rising ‘larks’ or late rising ‘owls’, providing a convenient model system for these types of studies. We have identified strains of flies showing increased preference for morning emergence (Early or E from the pupal case, or more pronounced preference for evening emergence (Late or L. We have sampled pupae the day before eclosion (4th day after pupariation at 4 h intervals in the E and L strains, and examined differences in gene expression by RNAseq. We have identified differentially expressed transcripts between the E and L strains which provide candidate genes for studies of Drosophila chronotypes and their human orthologues.
Migeon, J C; Garfinkel, M S; Edgar, B A
We identified a new Drosophila gene, peter pan (ppan), in a screen for larval growth-defective mutants. ppan mutant larvae do not grow and show minimal DNA replication but can survive until well after their heterozygotic siblings have pupariated. We cloned the ppan gene by P-element plasmid rescue. ppan belongs to a highly conserved gene family that includes Saccharomyces cerevisiae SSF1 and SSF2, as well as Schizosaccharomyces pombe, Arabidopsis, Caenorhabditis elegans, mouse, and human homologues. Deletion of both SSF1 and SSF2 in yeast is lethal, and depletion of the gene products causes cell division arrest. Mosaic analysis of ppan mutant clones in Drosophila imaginal disks and ovaries demonstrates that ppan is cell autonomous and required for normal mitotic growth but is not absolutely required for general biosynthesis or DNA replication. Overexpression of the wild-type gene causes cell death and disrupts the normal development of adult structures. The ppan gene family appears to have an essential and evolutionarily conserved role in cell growth.
Mazzanti, Morena; Alessandrini, Federica; Tagliabracci, Adriano; Wells, Jeffrey D; Campobasso, Carlo P
Puparial cases are common remnants of necrophagous flies in crime investigations. They usually represent the longest developmental time and, therefore, they can be very useful for the estimation of the post-mortem interval (PMI). However, before any PMI estimate, it is crucial to identify the species of fly eclosed from each puparium associated with the corpse. Morphological characteristics of the puparium are often distinctive enough to permit a species identification. But, even an accurate morphological analysis of empty puparia cannot discriminate among different species of closely related flies. Furthermore, morphological identification may be impossible if the fly puparia are poorly preserved or in fragments. This study explores the applicability of biomolecular techniques on empty puparia and their fragments for identification purposes. A total of 63 empty puparia of necrophagous Diptera resulting from forensic casework were examined. Samples were divided into three groups according to size, type and time of eclosion in order to verify whether the physical characteristics and puparia weathering can influence the amount of DNA extraction. The results suggest that a reliable genetic identification of forensically important flies may also be performed from empty puparia and/or their fragments. However, DNA degradation can deeply compromise the genetic analysis since the older the fly puparia, the smaller are the amplified fragments.
Richards, Cameron S; Simonsen, Thomas J; Abel, Richard L; Hall, Martin J R; Schwyn, Daniel A; Wicklein, Martina
We demonstrate how micro-computed tomography (micro-CT) can be a powerful tool for describing internal and external morphological changes in Calliphora vicina (Diptera: Calliphoridae) during metamorphosis. Pupae were sampled during the 1st, 2nd, 3rd and 4th quarter of development after the onset of pupariation at 23 °C, and placed directly into 80% ethanol for preservation. In order to find the optimal contrast, four batches of pupae were treated differently: batch one was stained in 0.5M aqueous iodine for 1 day; two for 7 days; three was tagged with a radiopaque dye; four was left unstained (control). Pupae stained for 7d in iodine resulted in the best contrast micro-CT scans. The scans were of sufficiently high spatial resolution (17.2 μm) to visualise the internal morphology of developing pharate adults at all four ages. A combination of external and internal morphological characters was shown to have the potential to estimate the age of blowfly pupae with a higher degree of accuracy and precision than using external morphological characters alone. Age specific developmental characters are described. The technique could be used as a measure to estimate a minimum post-mortem interval in cases of suspicious death where pupae are the oldest stages of insect evidence collected.
Musah, Rabi A.; Espinoza, Edgard O.; Cody, Robert B.; Lesiak, Ashton D.; Christensen, Earl D.; Moore, Hannah E.; Maleknia, Simin; Drijfhout, Falko P.
A high throughput method for species identification and classification through chemometric processing of direct analysis in real time (DART) mass spectrometry-derived fingerprint signatures has been developed. The method entails introduction of samples to the open air space between the DART ion source and the mass spectrometer inlet, with the entire observed mass spectral fingerprint subjected to unsupervised hierarchical clustering processing. A range of both polar and non-polar chemotypes are instantaneously detected. The result is identification and species level classification based on the entire DART-MS spectrum. Here, we illustrate how the method can be used to: (1) distinguish between endangered woods regulated by the Convention for the International Trade of Endangered Flora and Fauna (CITES) treaty; (2) assess the origin and by extension the properties of biodiesel feedstocks; (3) determine insect species from analysis of puparial casings; (4) distinguish between psychoactive plants products; and (5) differentiate between Eucalyptus species. An advantage of the hierarchical clustering approach to processing of the DART-MS derived fingerprint is that it shows both similarities and differences between species based on their chemotypes. Furthermore, full knowledge of the identities of the constituents contained within the small molecule profile of analyzed samples is not required.
Full Text Available Reciprocal cross effects with respect to larval salivary secretory protein levels were studied in the interspecific fertile reciprocal hybrids by crossing Drosophila nasuta nasuta, and Drosophila nasuta albomicans. These proteins are produced copiously during the third larval instar stage and are believed to play a role in the attachment of pupa to the substratum prior to pupariation as well as in insect immunity. Quantitative variations were encountered among the reciprocal hybrids. Significant heterosis was observed between D. n. nasuta and the F1 hybrid female of a cross between D. n. albomicans female and D. n. nasuta male (21.39% while the F1 hybrids of a cross between D. n. nasuta female and D. n. albomicans male showed a marginal increase (4.24% from the mid parent level. The glue secretions were correlated to total cell number but independent of gland size. SDS PAGE revealed a considerable heterosis with respect to X-linked protein fractions. Here we report sex specific biochemical heterosis. However the X-linked fractions undergo dosage compensation in both parents and hybrids indicating strict regulatory control.
Mary A.Sorensen; C.Mae Chase-Dunn; John T.Trumble
Environmental contamination with metals Such as manganese(Mn)and nickel (Ni)often results in elevated concentrations of these metals in plant tissues.At high concentrations.these metals are known to have detrimental effects on certain insect herbivores.Using laboratory bioassays and artificial diet,We investigated the development and survival of a cosmopolitan insect detritivore.Megaselia scalaris(Diptera:Phoridae),exposed to concentrations of Mn and Ni reaching 2 600 mg Mn/kg and 5 200 mg Ni/kg dry mass(dm)in artiflcial diet.Surprisingly,Ni and Mn at the concentrations tested did not harm this fly.Treatment groups from diets with 260-2 600 mg Mn/kg dm and 1300-5 200 mg Ni/kg dm had significantly shorter lalval development times.overail times to adult emergence,and both pupariation and pupal eclosion times compared to a control group.Wing length of females.a correlate of adult fitness,was also greater in metal treatment groups.Other measures including rate of egg hatch,percentage of emerging flies that were female,and wing length of male flies,were not significantly different in metal treatment groups.We conclude that Megaselia scalaris is tolerant of exceptionally high levels of Mn and Ni.
Follett, Peter A; Armstrong, John W; Zee, Francis T
Forced infestation studies were conducted to determine whether northern or southern highbush blueberries, Vaccinium corymbosum L., are hosts for the invasive tephritid fruit flies in Hawaii. Fruit were exposed to gravid female flies of Bactrocera dorsalis Hendel (oriental fruit fly), Ceratitis capitata (Wiedemann) (Mediterranean fruit fly), or Bactrocera cucurbitae Coquillet (melon fly) in screen cages outdoors for 6 h and then held on sand in the laboratory for 2 wk for pupal and adult emergence. The number of puparia, number of puparia per gram, and percentage of adult emergence on 'Bluecrop' blueberry were significantly higher for B. dorsalis and C. capitata than B. cucurbitae; B. dorsalis, C. capitata, and B. cucurbitae produced an average of 1.06, 0.60, and 0.09 pupae per g fruit and had 5.8, 54.1, and 12.7% adult emergence, respectively. 'Berkeley' blueberries produced an average of only 0.06, 0.02, and 0.0 pupae per g fruit for B. dorsalis, C. capitata, and B. cucurbitae, respectively. Similarly, six blueberry cultivars were harvested weekly for 10 wk, exposed to Bactrocera latifrons (Hendel) in cages, and held for pupal and adult emergence on either sand or artificial diet. In total, 2,677 blueberries were exposed to 2681 B. latifons and held on sand, and no pupariation or adult emergence was observed. Small numbers of B. latifrons puparia and adults emerged from the artificial diet treatment in all cultivars. Results from rearing on sand and diet indicate that blueberry is an acceptable oviposition host for B. latifrons but not an adequate developmental host. These data suggest blueberry is potentially a good host for B. dorsalis and C. capitata, and an adequate host for Bactrocera cucurbitae, but that there may be significant variation in resistance among cultivars. Blueberry seems to be a nonhost for B. latifrons.
Developmental rates of immatures of three Chrysomya species (Diptera: Calliphoridae) under the effect of methylphenidate hydrochloride, phenobarbital, and methylphenidate hydrochloride associated with phenobarbital.
Rezende, Fábio; Alonso, Marcela A; Souza, Carina M; Thyssen, Patrícia J; Linhares, Arício X
Entomotoxicology is focused on obtaining data on necrophagous entomofauna, for criminal investigations purposes. This study aimed to evaluate the effect of different concentrations of methylphenidate hydrochloride, phenobarbital, and their association on the developmental rate, larval and pupal survivorship, and the interval of emergence of adults of Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius), and Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae). Considering the therapeutic dose (TD) of methylphenidate hydrochloride (0.29 mg/Kg), the concentrations tested were 10× TD, 50× TD, and 100× TD. For phenobarbital, the concentrations used were 1× TD (=150 mg/Kg), 3.3× TD, and 6.7× TD. For the association of the drugs, the combinations used were 10× TD-methylphenidate hydrochloride plus 1× TD-phenobarbital, 50× TD-methylphenidate hydrochloride plus 3.3× TD-phenobarbital, and 100× TD-methylphenidate hydrochloride plus 6.7× TD-phenobarbital. The control group, without addition of drug, was maintained under the same conditions of temperature (25 ± 1 °C), humidity (70 ± 10%), and photoperiod (12 h). Specimens of each group were weighed every 12 h until pupariation. The developmental rate of the three Chrysomya species immatures was monitored. For C. albiceps the developmental time was delayed in 24 h for methylphenidate hydrochloride group and in 12 h for the phenobarbital and the drugs association groups. The effect was observed only at specific ages for C. megacephala, without altering the developmental time. For C. putoria, the developmental time was delayed in 12 h for methylphenidate hydrochloride group and in 24 h for the phenobarbital and the drugs association groups. The emergence interval was similar among all experimental groups, but larval and pupal viabilities were affected in different ways.
Sawadogo, B; Rayaisse, J B; Adakal, H; Kabre, A T; Bauer, B
In order to assess the residual effects of fipronil 1% on tsetse fly survival, male Glossina palpalis gambiensis were released on non-treated and treated cattle, with 0.1 ml of fipronil/kg b.w. as a pour-on formulation. In a second trial, the female fecundity performances were evaluated by feeding teneral females on the same cattle. These females were then mated and their production parameters monitored, as well as the survival of freshly emerged flies. Fipronil had a significant effect on tsetse fly survival (p < 0.001). Over a period of 30 days, up to 40% of tsetse fly mortality was observed within 72 h after tsetse were released. The residual effects ranged between 51 and 74 days when tsetse flies were released twice within a 15-day interval in the presence of a treated animal. When tsetse flies were fed on treated cattle through a parafilm membrane, 92 days after the treatment, no significant effect of fipronil was observed on the reproductive performance of females, i.e., as well as on fecundity (p = 0.948) and emergence rates (p = 0.743), or puparial weight (p = 0.422). This was also the case for the survival of young flies, with no difference observed between the two groups. After this study, it is confirmed that fipronil is highly effective against tsetse flies. Its efficacy in controlling ticks is already known but other externalities such as the control of biting insects add value to its use.
De Loof, Arnold
In the recent decade, tremendous progress has been realized in insect endocrinology as the result of the application of a variety of advanced methods in neuropeptidome- and receptor research. Hormones of which the existence had been shown by bioassays four decades ago, e.g. bursicon (a member of the glycoprotein hormone family) and pupariation factor (Neb-pyrokinin 2, a myotropin), could be identified, along with their respective receptors. In control of diurnal rhythms, clock genes got company from the neuropeptide Pigment Dispersing Factor (PDF), of which the receptor could also be identified. The discovery of Inka cells and their function in metamorphosis was a true hallmark. Analysis of the genomes of Caenorhabditis elegans, Drosophila melanogaster and Apis mellifera yielded about 75, 100 and 200 genes coding for putative signaling peptides, respectively, corresponding to approximately 57, 100 and 100 peptides of which the expression could already be proven by means of mass spectrometry. The comparative approach invertebrates-vertebrates recently yielded indications for the existence of counterparts in insects for prolactin, atrial natriuretic hormone and Growth Hormone Releasing Hormone (GRH). Substantial progress has been realized in identifying the Halloween genes, a membrane receptor(s) for ecdysteroids, a nuclear receptor for methylfarnesoate, and dozens of GPCRs for insect neuropeptides. The major remaining challenges concern the making match numerous orphan GPCRs with orphan peptidic ligands, and elucidating their functions. Furthermore, the endocrine control of growth, feeding-digestion, and of sexual differentiation, in particular of males, is still poorly understood. The finding that the prothoracic glands produce an autocrine factor with growth factor-like properties and secrete proteins necessitates a reevaluation of their role in development.
Mason-Suares, Heather; Tie, Feng; Yan, Christopher; Harte, Peter J.
Polycomb group (PcG) proteins are best known for their role in maintaining stable, mitotically heritable silencing of the homeotic (HOX) genes during development. In addition to loss of homeotic gene silencing, some PcG mutants also have small imaginal discs. These include mutations in E(z), Su(z)12, esc and escl, which encode Polycomb Repressive Complex 2 (PRC2) subunits. The cause of this phenotype is not known, but the human homologs of PRC2 subunits have been shown to play a role in cell proliferation, are over-expressed in many tumors, and appear to be required for tumor proliferation. Here we show that the small imaginal disc phenotype arises, at least in part, from a cell growth defect. In homozygous E(z) mutants, imaginal disc cells are smaller than cells in normally proliferating discs. We show that the Thor gene, which encodes eIF4E-Binding Protein (4E-BP), the evolutionarily conserved inhibitor of cap-dependent translation and potent inhibitor of cell growth, is involved in the development of this phenotype. The Thor promoter region contains DNA binding motifs for transcription factors found in well-characterized Polycomb Response Elements (PREs), including PHO/PHOL, GAGA Factor, and others, suggesting that Thor may be a direct target of Polycomb silencing. We present chromatin immunoprecipitation evidence that PcG proteins are bound to the Thor 5’ region in vivo. The Thor gene is normally repressed in imaginal discs, but Thor mRNA and 4E-BP protein levels are elevated in imaginal discs of PRC2 subunit mutant larvae. Deletion of the Thor gene in E(z) mutants partially restores imaginal disc size toward wild-type and results in an increase in the fraction of larvae that pupariate. These results thus suggest that PcG proteins can directly modulate cell growth in Drosophila, in part by regulating Thor expression. PMID:23523430
Imoulan, Abdessamad; Elmeziane, Abdellatif
The Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae), is the major tephritid pest in Morocco. This pest survives in Moroccan forests Argania spinosa and continually invades the nearest agricultural areas. Entomopathogenic fungi are an interesting tool for fruit fly control and hold a useful alternative to conventional insecticides. However, primary selection of effective pathogens should be taken in laboratory condition prior to applying them in the field. Here, we used third late instar larvae of C. capitata to investigate the effectiveness of 15 local Beauveria bassiana isolates. Results showed that all isolates were able to infect the larval stage, producing a large mortality rate in puparia ranging from 65 to 95 % and caused significant reduction in adult emergence. The fungal treatments revealed that the mycosis occurred also in adults escaping infection as pupariating larvae. The percentage of mycosed puparia was highest in strain TAM6.2 (95 %) followed by ERS4.16 (90 %), therefore they were the most virulent. Median lethal concentration (LC₅₀) was studied for five isolates at four concentrations ranging from 10⁵ to 10⁸ conidia ml⁻¹. The results showed that the slopes of regression lines for B. bassiana ERS4.16 (slope = 0.386) and TAM6.2 (slope = 0.41) were the most important and had the lowest LC₅₀ values (2.85 × 10³ and 3.16 × 10³ conidia ml⁻¹ respectively). This investigation suggests that the soil of Argan forests contains pathogenic B. bassiana isolates and highlights for the first time their potential as biological control toward C. capitata larval stage in Morocco.
George, Kelly A; Archer, Melanie S; Green, Lauren M; Conlan, Xavier A; Toop, Tes
Insect specimens collected from decomposing bodies enable forensic entomologists to estimate the minimum post-mortem interval (PMI). Drugs and toxins within a corpse may affect the development rate of insects that feed on them and it is vital to quantify these effects to accurately calculate minimum PMI. This study investigated the effects of morphine on growth rates of the native Australian blowfly, Calliphora stygia (Fabricius) (Diptera: Calliphoridae). Several morphine concentrations were incorporated into pet mince to simulate post-mortem concentrations in morphine, codeine and/or heroin-dosed corpses. There were four treatments for feeding larvae; T 1: control (no morphine); T 2: 2 microg/g morphine; T 3: 10 microg/g morphine; and T 4: 20 microg/g morphine. Ten replicates of 50 larvae were grown at 22 degrees C for each treatment and their development was compared at four comparison intervals; CI 1: 4-day-old larvae; CI 2: 7-day-old larvae; CI 3: pupae; and CI 4: adults. Length and width were measured for larvae and pupae, and costae and tibiae were measured for adults. Additionally, day of pupariation, day of adult eclosion, and survivorship were calculated for each replicate. The continued presence of morphine in meat was qualitatively verified using high-performance liquid chromatography with acidic potassium permanganate chemiluminescence detection. Growth rates of C. stygia fed on morphine-spiked mince did not differ significantly from those fed on control mince for any comparison interval or parameter measured. This suggests that C. stygia is a reliable model to use to accurately age a corpse containing morphine at any of the concentrations investigated.
Koo, Hyun-Na; Yun, Seung-Hwan; Yoon, Changmann [Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Kim, Gil-Hah, E-mail: firstname.lastname@example.org [Department of Plant Medicine, College of Agriculture, Life and Environment Sciences, Chungbuk National University, Cheongju 361-763 (Korea, Republic of)
The American serpentine leafminer fly, Liriomyza trifolii (Burgess), is one of the most destructive polyphagous pests worldwide. In this study, we determined electron beam doses for inhibition of normal development of the leaf miner and investigated the effect of electron beam irradiation on DNA damage and p53 stability. Eggs (0-24 h old), larvae (2nd instar), puparia (0-24 h old after pupariation) and adults (24 h after emergence) were irradiated with increasing doses of electron beam irradiation (six levels between 30 and 200 Gy). At 150 Gy, the number of adults that developed from irradiated eggs, larvae and puparia was lower than in the untreated control. Fecundity and egg hatchability decreased depending on the doses applied. Reciprocal crosses between irradiated and unirradiated flies demonstrated that males were more radiotolerant than females. Adult longevity was not affected in all stages. The levels of DNA damage in L. trifolii adults were evaluated using the alkaline comet assay. Our results indicate that electron beam irradiation increased levels of DNA damage in a dose-dependent manner. Moreover, low doses of electron beam irradiation led to the rapid appearance of p53 protein within 6 h; however, it decreased after exposure to high doses (150 Gy and 200 Gy). These results suggest that electron beam irradiation induced not only abnormal development and reproduction but also p53 stability caused by DNA damage in L. trifolii. We conclude that a minimum dose of 150 Gy should be sufficient for female sterilization of L. trifolii. - Highlights: > Electron beam irradiation inhibited normal development of the leaf miner. > Electron beam irradiation inhibited normal reproduction of the leaf miner. > Electron beam irradiation increased levels of DNA damage. > Electron beam irradiation induced p53 stability.
Gündner, Anna Lisa; Hahn, Ines; Sendscheid, Oliver; Aberle, Hermann; Hoch, Michael
Phosphoinositide-3-kinase enhancer (PIKE) proteins encoded by the PIKE/CENTG1 gene are members of the gamma subgroup of the Centaurin superfamily of small GTPases. They are characterized by their chimeric protein domain architecture consisting of a pleckstrin homology (PH) domain, a GTPase-activating (GAP) domain, Ankyrin repeats as well as an intrinsic GTPase domain. In mammals, three PIKE isoforms with variations in protein structure and subcellular localization are encoded by the PIKE locus. PIKE inactivation in mice results in a broad range of defects, including neuronal cell death during brain development and misregulation of mammary gland development. PIKE -/- mutant mice are smaller, contain less white adipose tissue, and show insulin resistance due to misregulation of AMP-activated protein kinase (AMPK) and insulin receptor/Akt signaling. here, we have studied the role of PIKE proteins in metabolic regulation in the fly. We show that the Drosophila PIKE homolog, ceng1A, encodes functional GTPases whose internal GAP domains catalyze their GTPase activity. To elucidate the biological function of ceng1A in flies, we introduced a deletion in the ceng1A gene by homologous recombination that removes all predicted functional PIKE domains. We found that homozygous ceng1A mutant animals survive to adulthood. In contrast to PIKE -/- mouse mutants, genetic ablation of Drosophila ceng1A does not result in growth defects or weight reduction. Although metabolic pathways such as insulin signaling, sensitivity towards starvation and mobilization of lipids under high fed conditions are not perturbed in ceng1A mutants, homozygous ceng1A mutants show a prolonged development in second instar larval stage, leading to a late onset of pupariation. In line with these results we found that expression of ecdysone inducible genes is reduced in ceng1A mutants. Together, we propose a novel role for Drosophila Ceng1A in regulating ecdysone signaling-dependent second to third instar
Minakuchi, Chieka; Zhou, Xiaofeng; Riddiford, Lynn M
Juvenile hormone (JH) given at pupariation inhibits bristle formation and causes pupal cuticle formation in the abdomen of Drosophila melanogaster due to its prolongation of expression of the transcription factor Broad (BR). In a microarray analysis of JH-induced gene expression in abdominal integument, we found that Krüppel homolog 1 (Kr-h1) was up-regulated during most of adult development. Quantitative real-time PCR analyses showed that Kr-h1 up-regulation began at 10h after puparium formation (APF), and Kr-h1 up-regulation occurred in imaginal epidermal cells, persisting larval muscles, and larval oenocytes. Ectopic expression of Kr-h1 in abdominal epidermis using T155-Gal4 to drive UAS-Kr-h1 resulted in missing or short bristles in the dorsal midline. This phenotype was similar to that seen after a low dose of JH or after misexpression of br between 21 and 30 h APF. Ectopic expression of Kr-h1 prolonged the expression of BR protein in the pleura and the dorsal tergite. No Kr-h1 was seen after misexpression of br. Thus, Kr-h1 mediates some of the JH signaling in the adult abdominal epidermis and is upstream of br in this pathway. We also show for the first time that the JH-mediated maintenance of br expression in this epidermis is patterned and that JH delays the fusion of the imaginal cells and the disappearance of Dpp in the dorsal midline.
Möritz, T; Edström, J E; Pongs, O
The puffing cycle of salivary gland chromosomes of Drosophila larvae, which initiates the developmental path to pupariation, is induced by ecdysteroid hormone. Its action leads to prominent puffs at loci 2B5, 74EF and 75B. Fragments of the 74EF puff of the D. melanogaster 3L chromosome were microdissected from salivary gland squashes. EcoRI-digested DNA of these fragments was cloned into lambda phage. Clones were screened with puff stage-specific cDNA probes. Thirteen out of 650 clones hybridized preferentially with puff stage 4-specific cDNA. The prominent early puffs at 74EF and 75B are most active between puff stage 4 and 6. Therefore, one of the 13 lambda phages was chosen for further analysis. It was used to isolate 24 kb of Drosophila DNA from genomic libraries. The DNA hybridized in situ to locus 74F. The 74F DNA coded for a transcript, which was made in salivary glands, but not in fat body of third instar larvae. It accumulated in K(C) cells in response to ecdysteroid treatment. The polyadenylated transcript size was 2.7 kb as judged by Nothern blot analysis. The transcription start site of the 74F gene has been mapped. Sequences upstream of the transcription site contain several sequence elements common to other eucaryotic genes, including potential Z-DNA forming sequences. Also, there is sequence homology to upstream sequences, which have been involved in the regulation of transcription of the salivary gland glue protein 4 gene.
Anna Lisa Gündner
Full Text Available Phosphoinositide-3-kinase enhancer (PIKE proteins encoded by the PIKE/CENTG1 gene are members of the gamma subgroup of the Centaurin superfamily of small GTPases. They are characterized by their chimeric protein domain architecture consisting of a pleckstrin homology (PH domain, a GTPase-activating (GAP domain, Ankyrin repeats as well as an intrinsic GTPase domain. In mammals, three PIKE isoforms with variations in protein structure and subcellular localization are encoded by the PIKE locus. PIKE inactivation in mice results in a broad range of defects, including neuronal cell death during brain development and misregulation of mammary gland development. PIKE -/- mutant mice are smaller, contain less white adipose tissue, and show insulin resistance due to misregulation of AMP-activated protein kinase (AMPK and insulin receptor/Akt signaling. here, we have studied the role of PIKE proteins in metabolic regulation in the fly. We show that the Drosophila PIKE homolog, ceng1A, encodes functional GTPases whose internal GAP domains catalyze their GTPase activity. To elucidate the biological function of ceng1A in flies, we introduced a deletion in the ceng1A gene by homologous recombination that removes all predicted functional PIKE domains. We found that homozygous ceng1A mutant animals survive to adulthood. In contrast to PIKE -/- mouse mutants, genetic ablation of Drosophila ceng1A does not result in growth defects or weight reduction. Although metabolic pathways such as insulin signaling, sensitivity towards starvation and mobilization of lipids under high fed conditions are not perturbed in ceng1A mutants, homozygous ceng1A mutants show a prolonged development in second instar larval stage, leading to a late onset of pupariation. In line with these results we found that expression of ecdysone inducible genes is reduced in ceng1A mutants. Together, we propose a novel role for Drosophila Ceng1A in regulating ecdysone signaling-dependent second to
王吉锐; 穆丽霞; 杜予州; 徐志宏
Aleurocanthus inceratus Silvestri, a newly recorded species of whitefly infesting tea plants, was morphologically described and illustrated. It has 11 pairs of spines along submarginal area, among which 5 pairs are on cephalothorax. Moreover, there are 9 pairs of spines on cephalothorax of the median dorsum, 14 pairs of spines on the median of venter, with 3 rows. Vasiform orifice and operculum are rounded.and cordate respectively., While caudal furrow is indistinct. Nine species of whitefly infesting tea plants in China were counted, namely, Aleurotrachelus camelliae (Kuwana), Parabamisia myricae (Kuwana), Aleurocanthus spiniferus (Quaintance), Aleuroclava guyavae (Takahashi), Aleurolobus rhododendri Takahashi, Dialeurodes citri (Ashmead), Aleurocanthus inceratus Silvestri. An identification key to identify these species based on the puparial characters was provided.%记述了茶树上一新记录粉虱——粉背刺粉虱 Aleurocanthus inceratus Silvestri，该种亚缘区有11对长度一致的刺毛，其中头胸部5对；在背面中区头胸部有刺毛9对；腹部背面中区有14对，纵向分列3排；管状孔近圆形，盖瓣心形，尾沟不明显。统计了茶树上的9种粉虱即山茶褶粉虱 Aleurotrachelus camelliae (Kuwana)、杨梅类伯粉虱 Parabamisia myricae (Kuwana)、黑刺粉虱 Aleurocanthus spiniferus (Quaintance)、番石榴白棒粉虱 Aleuroclava psidii Singh、流苏子瘤粉虱 Aleuroclava thysanospermi (Takahashi)、归亚瘤棒粉虱Aleuroclava guyavae (Takahashi)、杜鹃穴粉虱 Aleurolobus rhododendri Takahashi、柑橘裸粉虱 Dialeurodes citri (Ashmead)和粉背刺粉虱 Aleurocanthus inceratus Silvestri，根据其伪蛹特征编制了茶树上粉虱分类检索表。
牛长缨; 姜勇; 雷朝亮; 胡萃
The objective of this study was to elucidate the effects of cadmium on housefly, Musca domestica. It is suggested that of cadmium in low concentrations of had little influence on growth and development of housefly. Cadmium was mainly distributed in the digestive tracts of housefly larvae, where the cadmium content was higher than that of other parts. During the metamorphosis of housefly the change trend of the cadmium content was very apparent. The cadmium content increased gradually in larval period, whereas it decreased significantly after pupariation. Until the sixth day after emergence, only negligible cadmium was left in adult housefly. All these results demonstrated that the response of housefly to cadmium is an evolution adaptation in natural selection.%研究重金属镉对家蝇生长发育的影响,以及镉在家蝇变态过程中的代谢.结果表明:低浓度的Cd2+对家蝇的生长发育几乎没有什么影响,而高浓度的Cd2+则影响家蝇卵孵化率、幼虫相对存活率、化蛹率、羽化率、百头幼虫重和百头蛹重.进入家蝇幼虫体内的Cd2+主要分布在消化道,其次是体壁,脂肪体和血淋巴中含量很少.在家蝇变态过程中,Cd2+的含量变化趋势十分明显:幼虫期Cd2+逐渐累积,化蛹后Cd2+含量大幅度下降,羽化后的第6天,成虫体内只剩下极微量的Cd2+.这些结果表明家蝇对环境中重金属镉的反应是一种在自然选择过程中形成的高度的进化适应.
Bélai, Iván; Fekete, Gábor
In order to improve the larvicidal activity of the azole analogues of metyrapone, previously found to have a strong inhibitory activity on ecdysone 20-monooxygenase (E-20-M) from the fleshfly Neobellieria bullata Parker, soft-alkylated compounds (3-(1,1-dimethyl-2-oxo-2-phenylethyl)-1-dodecanoyloxymethyl-1H-imidazolium chloride, sPIM) and (1-(1,1-dimethyl-2-oxo-2-phenylethyl)-4-dodecanoyloxymethyl-1H-1,2,4-triazolium chloride, sPTM), derivatives of phenyl-imidazolyl-metyrapone (PIM) and phenyl-1,2,4-triazolyl-metyrapone (PTM), respectively, were synthesized. Both sPIM and sPTM, designed as propesticides, inhibited E-20-M in vitro at 10(-4) M concentration, which was unexpected since they had been expected to be inactive in vitro and to gain activity only within the organism. sPTM significantly delayed the pupariation of N. bullata larvae and this effect could be reversed by the simultaneous application of 20-hydroxyecdysone (20E), supporting the hypothesis that sPTM can act by interfering with the moulting hormone system. Due to this in vitro activity, sPTM and sPIM cannot be considered to be simple drug precursors, and their structure should contain structural elements (pharmacophores) responsible for the observed biological effects. In order to examine this hypothesis, derivatives of sPTM and sPIM were synthesised in which the hydrolytically labile N(+)-CH2O(CO)- moiety was changed to the more stable N(+)-CH2CH2(CO)-group. In three new stable derivatives, a dodecylamino or a phenyl group, respectively, is attached to the carbonyl group to obtain PTM and PIM derivatives quaternised with a 2-dodecylcarbamoylethyl or a 3-oxo-3-phenylpropyl group. In one derivative, the 2-oxo-2-phenylethyl quaternising group has one fewer carbon atom. In addition to their moderate activity (LC50 = 10(-6)-10(-5) M) against the red cotton bug Dysdercus cingulatus F, they delayed development and caused developmental abnormalities, including mortality in the pharate phase, mortality