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Sample records for drosophila larval development

  1. Immunostaining of the developing embryonic and larval Drosophila brain.

    PubMed

    Diaper, Danielle C; Hirth, Frank

    2014-01-01

    Immunostaining is used to visualize the spatiotemporal expression pattern of developmental control genes that regulate the genesis and specification of the embryonic and larval brain of Drosophila. Immunostaining uses specific antibodies to mark expressed proteins and allows their localization to be traced throughout development. This method reveals insights into gene regulation, cell-type specification, neuron and glial differentiation, and posttranslational protein modifications underlying the patterning and specification of the maturing brain. Depending on the targeted protein, it is possible to visualize a multitude of regions of the Drosophila brain, such as small groups of neurons or glia, defined subcomponents of the brain's axon scaffold, or pre- and postsynaptic structures of neurons. Thus, antibody probes that recognize defined tissues, cells, or subcellular structures like axons or synaptic terminals can be used as markers to identify and analyze phenotypes in mutant embryos and larvae. Several antibodies, combined with different labels, can be used concurrently to examine protein co-localization. This protocol spans over 3-4 days.

  2. Muscle organizers in Drosophila: the role of persistent larval fibers in adult flight muscle development

    NASA Technical Reports Server (NTRS)

    Farrell, E. R.; Fernandes, J.; Keshishian, H.

    1996-01-01

    In many organisms muscle formation depends on specialized cells that prefigure the pattern of the musculature and serve as templates for myoblast organization and fusion. These include muscle pioneers in insects and muscle organizing cells in leech. In Drosophila, muscle founder cells have been proposed to play a similar role in organizing larval muscle development during embryogenesis. During metamorphosis in Drosophila, following histolysis of most of the larval musculature, there is a second round of myogenesis that gives rise to the adult muscles. It is not known whether muscle founder cells organize the development of these muscles. However, in the thorax specific larval muscle fibers do not histolyze at the onset of metamorphosis, but instead serve as templates for the formation of a subset of adult muscles, the dorsal longitudinal flight muscles (DLMs). Because these persistent larval muscle fibers appear to be functioning in many respects like muscle founder cells, we investigated whether they were necessary for DLM development by using a microbeam laser to ablate them singly and in combination. We found that, in the absence of the larval muscle fibers, DLMs nonetheless develop. Our results show that the persistent larval muscle fibers are not required to initiate myoblast fusion, to determine DLM identity, to locate the DLMs in the thorax, or to specify the total DLM fiber volume. However, they are required to regulate the number of DLM fibers generated. Thus, while the persistent larval muscle fibers are not obligatory for DLM fiber formation and differentiation, they are necessary to ensure the development of the correct number of fibers.

  3. Development of the embryonic and larval peripheral nervous system of Drosophila

    PubMed Central

    Singhania, Aditi; Grueber, Wesley B.

    2014-01-01

    The peripheral nervous system (PNS) of embryonic and larval stage Drosophila consists of diverse types of sensory neurons positioned along the body wall. Sensory neurons, and associated end organs, show highly stereotyped locations and morphologies. The many powerful genetic tools for gene manipulation available in Drosophila make the PNS an advantageous system for elucidating basic principles of neural development. Studies of the Drosophila PNS have provided key insights into molecular mechanisms of cell fate specification, asymmetric cell division, and dendritic morphogenesis. A canonical lineage gives rise to sensory neurons and associated organs, and cells within this lineage are diversified through asymmetric cell divisions. Newly specified sensory neurons develop specific dendritic patterns, which are controlled by numerous factors including transcriptional regulators, interactions with neighboring neurons, and intracellular trafficking systems. In addition, sensory axons show modality specific terminations in the central nervous system, which are patterned by secreted ligands and their receptors expressed by sensory axons. Modality-specific axon projections are critical for coordinated larval behaviors. We review the molecular basis for PNS development and address some of the instances in which the mechanisms and molecules identified are conserved in vertebrate development. PMID:24896657

  4. Persistent Activation of the Innate Immune Response in Adult Drosophila Following Radiation Exposure During Larval Development.

    PubMed

    Sudmeier, Lisa J; Samudrala, Sai-Suma; Howard, Steven P; Ganetzky, Barry

    2015-11-01

    Cranial radiation therapy (CRT) is an effective treatment for pediatric central nervous system malignancies, but survivors often suffer from neurological and neurocognitive side effects that occur many years after radiation exposure. Although the biological mechanisms underlying these deleterious side effects are incompletely understood, radiation exposure triggers an acute inflammatory response that may evolve into chronic inflammation, offering one avenue of investigation. Recently, we developed a Drosophila model of the neurotoxic side effects of radiation exposure. Here we use this model to investigate the role of the innate immune system in response to radiation exposure. We show that the innate immune response and NF-ĸB target gene expression is activated in the adult Drosophila brain following radiation exposure during larval development, and that this response is sustained in adult flies weeks after radiation exposure. We also present preliminary data suggesting that innate immunity is radioprotective during Drosophila development. Together our data suggest that activation of the innate immune response may be beneficial initially for survival following radiation exposure but result in long-term deleterious consequences, with chronic inflammation leading to impaired neuronal function and viability at later stages. This work lays the foundation for future studies of how the innate immune response is triggered by radiation exposure and its role in mediating the biological responses to radiation. These studies may facilitate the development of strategies to reduce the deleterious side effects of CRT.

  5. Persistent Activation of the Innate Immune Response in Adult Drosophila Following Radiation Exposure During Larval Development

    PubMed Central

    Sudmeier, Lisa J.; Samudrala, Sai-Suma; Howard, Steven P.; Ganetzky, Barry

    2015-01-01

    Cranial radiation therapy (CRT) is an effective treatment for pediatric central nervous system malignancies, but survivors often suffer from neurological and neurocognitive side effects that occur many years after radiation exposure. Although the biological mechanisms underlying these deleterious side effects are incompletely understood, radiation exposure triggers an acute inflammatory response that may evolve into chronic inflammation, offering one avenue of investigation. Recently, we developed a Drosophila model of the neurotoxic side effects of radiation exposure. Here we use this model to investigate the role of the innate immune system in response to radiation exposure. We show that the innate immune response and NF-ĸB target gene expression is activated in the adult Drosophila brain following radiation exposure during larval development, and that this response is sustained in adult flies weeks after radiation exposure. We also present preliminary data suggesting that innate immunity is radioprotective during Drosophila development. Together our data suggest that activation of the innate immune response may be beneficial initially for survival following radiation exposure but result in long-term deleterious consequences, with chronic inflammation leading to impaired neuronal function and viability at later stages. This work lays the foundation for future studies of how the innate immune response is triggered by radiation exposure and its role in mediating the biological responses to radiation. These studies may facilitate the development of strategies to reduce the deleterious side effects of CRT. PMID:26333838

  6. amontillado, the Drosophila homolog of the prohormone processing protease PC2, is required during embryogenesis and early larval development.

    PubMed Central

    Rayburn, Lowell Y M; Gooding, Holly C; Choksi, Semil P; Maloney, Dhea; Kidd, Ambrose R; Siekhaus, Daria E; Bender, Michael

    2003-01-01

    Biosynthesis of most peptide hormones and neuropeptides requires proteolytic excision of the active peptide from inactive proprotein precursors, an activity carried out by subtilisin-like proprotein convertases (SPCs) in constitutive or regulated secretory pathways. The Drosophila amontillado (amon) gene encodes a homolog of the mammalian PC2 protein, an SPC that functions in the regulated secretory pathway in neuroendocrine tissues. We have identified amon mutants by isolating ethylmethanesulfonate (EMS)-induced lethal and visible mutations that define two complementation groups in the amon interval at 97D1 of the third chromosome. DNA sequencing identified the amon complementation group and the DNA sequence change for each of the nine amon alleles isolated. amon mutants display partial embryonic lethality, are defective in larval growth, and arrest during the first to second instar larval molt. Mutant larvae can be rescued by heat-shock-induced expression of the amon protein. Rescued larvae arrest at the subsequent larval molt, suggesting that amon is also required for the second to third instar larval molt. Our data indicate that the amon proprotein convertase is required during embryogenesis and larval development in Drosophila and support the hypothesis that AMON acts to proteolytically process peptide hormones that regulate hatching, larval growth, and larval ecdysis. PMID:12586710

  7. Sternopleural is a regulatory mutation of wingless with both dominant and recessive effects on larval development of Drosophila melanogaster

    SciTech Connect

    Neumann, C.J.; Cohen, S.M.

    1996-04-01

    The Drosophila wingless (wg) gene encodes a secreted signaling protein that is required for many separate patterning events in both embryonic and larval development. wg functions in the development of the adult structures have been studied using the conditional mutant wg{sup ts} and also using regulatory mutations of wg that reduce larval functions. Here we present evidence that Sternopleural (Sp) is another regulatory allele of wg that affects a subset of larval functions. Sp has both a recessive loss-of-function component and a gain-of-function component. The loss-of-function component reflects a reduction of wg activity in the notum and in the antenna. The gain-of-function component apparently leads to ectopic wg activity in the dorsal first and second leg disc and thereby generates the dominant Sp phenotype. Sp and other wg alleles show a complex pattern of complementation. We present evidence that these genetic properties are due to transvection. These results have implications for the genetic definition of a null allele at loci subject to transvection. 31 refs., 6 figs., 1 tab.

  8. Effects of Three Volatile Oxylipins on Colony Development in Two Species of Fungi and on Drosophila Larval Metamorphosis.

    PubMed

    Yin, Guohua; Padhi, Sally; Lee, Samantha; Hung, Richard; Zhao, Guozhu; Bennett, Joan W

    2015-09-01

    The aim of this study is to investigate the effects of three volatile oxylipins on colony development in two fungi and on Drosophila larval metamorphosis. Using an airborne exposure technique, three common and volatile oxylipins (1-octen-3-ol, (E)-2-hexenal, and 1-hexanol) were compared for their effects on spore germination and colony growth in Aspergillus niger and Penicillium chrysogenum, as well as for their effects on the morphogenesis of larvae of Drosophila melanogaster. Conidia of both A. niger and P. chrysogenum plated in the presence of low concentrations (50 ppm) of these three volatile organic compounds (VOCs) formed fewer colony-forming units (CFUs) and exhibited reduced radial growth of colonies as compared to controls. When A. niger and P. chrysogenum spores were germinated in the presence of the enantiomers of 1-octen-3-ol, (R)-(-)-1-octen-3-ol had the greatest impact on colony morphology (decreased sporulation and colony diameter), while (S)-(+)-1-octen-3-ol and the racemic form yielded similar morphological changes but to a lesser extent. In addition, Drosophila larvae exposed to vapors of these oxylipins exhibited serious delays in metamorphosis and toxic effects on pupae and adult stages. Low concentration of these three VOCs can significantly inhibit the formation of CFUs and the growth of fungi. (R)-(-)-1-octen-3-ol imposed the greatest impact on fungal morphology compared to (S)-(+)-1-octen-3-ol and the racemic form. The three volatile oxylipins could also delay the metamorphosis of Drosophila and impose toxic effects on its pupae and adult stages.

  9. Neuroendocrine Control of Drosophila Larval Light Preference

    PubMed Central

    Yamanaka, Naoki; Romero, Nuria M.; Martin, Francisco A.; Rewitz, Kim F.; Sun, Mu; O’Connor, Michael B.; Léopold, Pierre

    2014-01-01

    Animal development is coupled with innate behaviors that maximize chances of survival. Here we show that the prothoracicotropic hormone (PTTH), a neuropeptide that controls the developmental transition from juvenile stage to sexual maturation, also regulates light avoidance in Drosophila melanogaster larvae. PTTH, through its receptor Torso, acts on two light sensors, the Bolwig’s organ and the peripheral class IV dendritic arborization neurons, to regulate light avoidance. We find that PTTH concomitantly promotes steroidogenesis and light avoidance at the end of larval stage, thereby driving animals towards a darker environment to initiate the immobile maturation phase. Thus, PTTH controls the decisions of when and where animals undergo metamorphosis, optimizing conditions for adult development. PMID:24009394

  10. Transgenerational Effects of Parental Larval Diet on Offspring Development Time, Adult Body Size and Pathogen Resistance in Drosophila melanogaster

    PubMed Central

    Valtonen, Terhi M.; Kangassalo, Katariina; Pölkki, Mari; Rantala, Markus J.

    2012-01-01

    Environmental conditions experienced by parents are increasingly recognized to affect offspring performance. We set out to investigate the effect of parental larval diet on offspring development time, adult body size and adult resistance to the bacterium Serratia marcescens in Drosophila melanogaster. Flies for the parental generation were raised on either poor or standard diet and then mated in the four possible sex-by-parental diet crosses. Females that were raised on poor food produced larger offspring than females that were raised on standard food. Furthermore, male progeny sired by fathers that were raised on poor food were larger than male progeny sired by males raised on standard food. Development times were shortest for offspring whose one parent (mother or the father) was raised on standard and the other parent on poor food and longest for offspring whose parents both were raised on poor food. No evidence for transgenerational effects of parental diet on offspring disease resistance was found. Although paternal effects have been previously demonstrated in D. melanogaster, no earlier studies have investigated male-mediated transgenerational effects of diet in this species. The results highlight the importance of not only considering the relative contribution each parental sex has on progeny performance but also the combined effects that the two sexes may have on offspring performance. PMID:22359607

  11. Gonadosomatic mosaicism for lethal mutations in Drosophila lethal mutations disturbing larval development

    SciTech Connect

    Ivanov, A.I.; Sakharova, N.Yu.

    1988-11-01

    Phenogenetic analysis of autonomous lethal mutations obtained by the method of gonadosomatic mosaicism which manifested during larval stages, established that the nuclei of hypodermal cells, salivary glands suprapharyngeal ganglion, pharynx, esophagus, gizzard, and hindgut are the derivatives of the same nucleus (from the first two nuclei of cleavage) as the nuclei of the cells of the imaginal-somatic tissues.

  12. Live Imaging of Drosophila Larval Neuroblasts

    PubMed Central

    Lerit, Dorothy A.; Plevock, Karen M.; Rusan, Nasser M.

    2014-01-01

    Stem cells divide asymmetrically to generate two progeny cells with unequal fate potential: a self-renewing stem cell and a differentiating cell. Given their relevance to development and disease, understanding the mechanisms that govern asymmetric stem cell division has been a robust area of study. Because they are genetically tractable and undergo successive rounds of cell division about once every hour, the stem cells of the Drosophila central nervous system, or neuroblasts, are indispensable models for the study of stem cell division. About 100 neural stem cells are located near the surface of each of the two larval brain lobes, making this model system particularly useful for live imaging microscopy studies. In this work, we review several approaches widely used to visualize stem cell divisions, and we address the relative advantages and disadvantages of those techniques that employ dissociated versus intact brain tissues. We also detail our simplified protocol used to explant whole brains from third instar larvae for live cell imaging and fixed analysis applications. PMID:25046336

  13. Origin and development of neuropil glia of the Drosophila larval and adult brain: two distinct glial populations derived from separate progenitors

    PubMed Central

    Omoto, Jaison Jiro; Yogi, Puja; Hartenstein, Volker

    2015-01-01

    Glia comprise a conspicuous population of non-neuronal cells in vertebrate and invertebrate nervous systems. Drosophila serves as a favorable model to elucidate basic principles of glial biology in vivo. The Drosophila neuropil glia (NPG), subdivided into astrocyte-like (ALG) and ensheathing glia (EG), extend reticular processes which associate with synapses and sheath-like processes which surround neuropil compartments, respectively. In this paper we characterize the development of NPG throughout fly brain development. We find that differentiated neuropil glia of the larval brain originate as a cluster of precursors derived from embryonic progenitors located in the basal brain. These precursors undergo a characteristic migration to spread over the neuropil surface while specifying/differentiating into primary ALG and EG. Embryonically-derived primary NPG are large cells which are few in number, and occupy relatively stereotyped positions around the larval neuropil surface. During metamorphosis, primary NPG undergo cell death. Neuropil glia of the adult (secondary NPG) are derived from type II lineages during the postembryonic phase of neurogliogenesis. These secondary NPG are much smaller in size but greater in number than primary NPG. Lineage tracing reveals that both NPG subtypes derive from intermediate neural progenitors of multipotent type II lineages. Taken together, this study reveals previously uncharacterized dynamics of NPG development and provides a framework for future studies utilizing Drosophila glia as a model. PMID:25779704

  14. Imaging fictive locomotor patterns in larval Drosophila

    PubMed Central

    Bayley, Timothy G.; Taylor, Adam L.; Berni, Jimena; Bate, Michael; Hedwig, Berthold

    2015-01-01

    We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca2+ indicators. The Ca2+ signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca2+ signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca2+ signals were normally initiated did not eliminate production of Ca2+ waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques. PMID:26311188

  15. Imaging fictive locomotor patterns in larval Drosophila.

    PubMed

    Pulver, Stefan R; Bayley, Timothy G; Taylor, Adam L; Berni, Jimena; Bate, Michael; Hedwig, Berthold

    2015-11-01

    We have established a preparation in larval Drosophila to monitor fictive locomotion simultaneously across abdominal and thoracic segments of the isolated CNS with genetically encoded Ca(2+) indicators. The Ca(2+) signals closely followed spiking activity measured electrophysiologically in nerve roots. Three motor patterns are analyzed. Two comprise waves of Ca(2+) signals that progress along the longitudinal body axis in a posterior-to-anterior or anterior-to-posterior direction. These waves had statistically indistinguishable intersegmental phase delays compared with segmental contractions during forward and backward crawling behavior, despite being ∼10 times slower. During these waves, motor neurons of the dorsal longitudinal and transverse muscles were active in the same order as the muscle groups are recruited during crawling behavior. A third fictive motor pattern exhibits a left-right asymmetry across segments and bears similarities with turning behavior in intact larvae, occurring equally frequently and involving asymmetry in the same segments. Ablation of the segments in which forward and backward waves of Ca(2+) signals were normally initiated did not eliminate production of Ca(2+) waves. When the brain and subesophageal ganglion (SOG) were removed, the remaining ganglia retained the ability to produce both forward and backward waves of motor activity, although the speed and frequency of waves changed. Bilateral asymmetry of activity was reduced when the brain was removed and abolished when the SOG was removed. This work paves the way to studying the neural and genetic underpinnings of segmentally coordinated motor pattern generation in Drosophila with imaging techniques. PMID:26311188

  16. Learning the specific quality of taste reinforcement in larval Drosophila.

    PubMed

    Schleyer, Michael; Miura, Daisuke; Tanimura, Teiichi; Gerber, Bertram

    2015-01-27

    The only property of reinforcement insects are commonly thought to learn about is its value. We show that larval Drosophila not only remember the value of reinforcement (How much?), but also its quality (What?). This is demonstrated both within the appetitive domain by using sugar vs amino acid as different reward qualities, and within the aversive domain by using bitter vs high-concentration salt as different qualities of punishment. From the available literature, such nuanced memories for the quality of reinforcement are unexpected and pose a challenge to present models of how insect memory is organized. Given that animals as simple as larval Drosophila, endowed with but 10,000 neurons, operate with both reinforcement value and quality, we suggest that both are fundamental aspects of mnemonic processing-in any brain.

  17. Learning the specific quality of taste reinforcement in larval Drosophila.

    PubMed

    Schleyer, Michael; Miura, Daisuke; Tanimura, Teiichi; Gerber, Bertram

    2015-01-01

    The only property of reinforcement insects are commonly thought to learn about is its value. We show that larval Drosophila not only remember the value of reinforcement (How much?), but also its quality (What?). This is demonstrated both within the appetitive domain by using sugar vs amino acid as different reward qualities, and within the aversive domain by using bitter vs high-concentration salt as different qualities of punishment. From the available literature, such nuanced memories for the quality of reinforcement are unexpected and pose a challenge to present models of how insect memory is organized. Given that animals as simple as larval Drosophila, endowed with but 10,000 neurons, operate with both reinforcement value and quality, we suggest that both are fundamental aspects of mnemonic processing-in any brain. PMID:25622533

  18. Learning the specific quality of taste reinforcement in larval Drosophila

    PubMed Central

    Schleyer, Michael; Miura, Daisuke; Tanimura, Teiichi; Gerber, Bertram

    2015-01-01

    The only property of reinforcement insects are commonly thought to learn about is its value. We show that larval Drosophila not only remember the value of reinforcement (How much?), but also its quality (What?). This is demonstrated both within the appetitive domain by using sugar vs amino acid as different reward qualities, and within the aversive domain by using bitter vs high-concentration salt as different qualities of punishment. From the available literature, such nuanced memories for the quality of reinforcement are unexpected and pose a challenge to present models of how insect memory is organized. Given that animals as simple as larval Drosophila, endowed with but 10,000 neurons, operate with both reinforcement value and quality, we suggest that both are fundamental aspects of mnemonic processing—in any brain. DOI: http://dx.doi.org/10.7554/eLife.04711.001 PMID:25622533

  19. [Genetic nature of abnormal larval development in the progeny of l(1)ts403(sbr10) females of Drosophila melanogaster].

    PubMed

    Pugacheva, O M; Mamon, L A

    2005-01-01

    In Drosophila melanogaster the small bristles (sbr) gene is vital and evolutionary conservative and controls nuclear export of mRNA. Sbr mutant alleles had a broad pleiotropic effect. High frequency of abnormal larva dying (up to 18 %) at the first instar stage in progeny of heat shock (37 degrees C, 1 h) treated mutant females is one of the most interesting l(l)ts403(sbr10) allele effects. Abnormal larvae display characteristic phenotype that involves the Malpighian tubules defect. Using interphase FISH method (fluorescence in situ hybridization), we showed that abnormal larvae had monosomy on chromosomes 2 and 3. DNA content in neuroblast interphase nuclei of abnormal larvae is 2.1 times less than in normal larvae. We suggest that abnormal larvae could be full or mosaic haploids that appeared as a result of maternal genome loss during fertilization or the mitotic division. Larvae with the same abnormalities appear in a progeny of females with different genotypes mating with males carrying compound chromosomes 2 or 3. FISH analysis showed that such larvae had monosomy only on a chromosome that is compound in paternal strain. Thus, monosomy on large autosomes may cause aspecial phenotype of abnormal larvae in D. melanogaster.

  20. Patterning the dorsal longitudinal flight muscles (DLM) of Drosophila: insights from the ablation of larval scaffolds

    NASA Technical Reports Server (NTRS)

    Fernandes, J. J.; Keshishian, H.

    1996-01-01

    The six Dorsal Longitudinal flight Muscles (DLMs) of Drosophila develop from three larval muscles that persist into metamorphosis and serve as scaffolds for the formation of the adult fibers. We have examined the effect of muscle scaffold ablation on the development of DLMs during metamorphosis. Using markers that are specific to muscle and myoblasts we show that in response to the ablation, myoblasts which would normally fuse with the larval muscle, fuse with each other instead, to generate the adult fibers in the appropriate regions of the thorax. The development of these de novo DLMs is delayed and is reflected in the delayed expression of erect wing, a transcription factor thought to control differentiation events associated with myoblast fusion. The newly arising muscles express the appropriate adult-specific Actin isoform (88F), indicating that they have the correct muscle identity. However, there are frequent errors in the number of muscle fibers generated. Ablation of the larval scaffolds for the DLMs has revealed an underlying potential of the DLM myoblasts to initiate de novo myogenesis in a manner that resembles the mode of formation of the Dorso-Ventral Muscles, DVMs, which are the other group of indirect flight muscles. Therefore, it appears that the use of larval scaffolds is a superimposition on a commonly used mechanism of myogenesis in Drosophila. Our results show that the role of the persistent larval muscles in muscle patterning involves the partitioning of DLM myoblasts, and in doing so, they regulate formation of the correct number of DLM fibers.

  1. Genetic and evolutionary analysis of the Drosophila larval neuromuscular junction

    NASA Astrophysics Data System (ADS)

    Campbell, Megan

    Although evolution of brains and behaviors is of fundamental biological importance, we lack comprehensive understanding of the general principles governing these processes or the specific mechanisms and molecules through which the evolutionary changes are effected. Because synapses are the basic structural and functional units of nervous systems, one way to address these problems is to dissect the genetic and molecular pathways responsible for morphological evolution of a defined synapse. I have undertaken such an analysis by examining morphology of the larval neuromuscular junction (NMJ) in wild caught D. melanogaster as well as in over 20 other species of Drosophila. Whereas variation in NMJ morphology within a species is limited, I discovered a surprisingly extensive variation among different species. Compared with evolution of other morphological traits, NMJ morphology appears to be evolving very rapidly. Moreover, my data indicate that natural selection rather than genetic drift is primarily responsible for evolution of NMJ morphology. To dissect underlying molecular mechanisms that may govern NMJ growth and evolutionary divergence, I focused on a naturally occurring variant in D. melanogaster that causes NMJ overgrowth. I discovered that the variant mapped to Mob2, a gene encoding a kinase adapter protein originally described in yeast as a member of the Mitotic Exit Network (MEN). I have subsequently examined mutations in the Drosophila orthologs of all the core components of the yeast MEN and found that all of them function as part of a common pathway that acts presynaptically to negatively regulate NMJ growth. As in the regulation of yeast cytokinesis, these components of the MEN appear to act ultimately by regulating actin dynamics during the process of bouton growth and division. These studies have thus led to the discovery of an entirely new role for the MEN---regulation of synaptic growth---that is separate from its function in cell division. This work

  2. MicroRNA-dependent roles of Drosha and Pasha in the Drosophila larval ovary morphogenesis.

    PubMed

    Yang, Huiming; Li, Mengjie; Hu, Xiaolong; Xin, Tianchi; Zhang, Shu; Zhao, Gengchun; Xuan, Tao; Li, Mingfa

    2016-08-15

    The Drosophila larval ovary morphogenesis mainly involves coordinated development of somatic and germ cell lineages that is essential for forming a correct number of niche-germline stem cell (GSC) units (ovarioles) in the adult ovary. Ecdysone, Insulin, Activin, Dpp and EGFR signaling pathways form a regulatory network that orchestrates ovarian soma and germ line throughout larval development. Identification and characterization of additional genes or machineries involved in this process will provide more insights into the underlying mechanisms. Here, we show that the core microRNA (miRNA) pathway components Drosha and Pasha are required for coordinated development of somatic and germ cell precursors in the larval ovary. Drosha or pasha mutants display defective proliferation of primordial germ cells (PGCs), the precursors of GSCs prior to late third larval instar (LL3) and promoted PGC differentiation at LL3. In the mean time, loss of Drosha or Pasha function perturbs somatic precursor development, causing defects in formation of terminal filaments (TFs), a major composition of the GSC niche at LL3, as well as in TF precursor accumulation at early larval stages. Comparative analysis of the mutant phenotypes reveals that three other key miRNA pathway components, Dicer-1 (Dcr-1), Loquacious (Loqs) and Argonaute-1 (Ago-1) have similar effects as Drosha and Pasha indicated above, suggesting a role of the canonical miRNA pathway in the ovary development. Furthermore, genome-wide screening and genetic studies identify a set of Drosha-controlled miRNAs including miR-8, miR-14, miR-33, miR-184, miR-317 and let-7-C that function in this gonadogenesis. Taken together, this study provides the first ever demonstration that miRNA-mediated regulation is involved in the Drosophila larval ovary morphogenesis. PMID:27339292

  3. Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli.

    PubMed

    Mishra, Abhishek Kumar; Bargmann, Bastiaan O R; Tsachaki, Maria; Fritsch, Cornelia; Sprecher, Simon G

    2016-02-15

    Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli.

  4. Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli.

    PubMed

    Mishra, Abhishek Kumar; Bargmann, Bastiaan O R; Tsachaki, Maria; Fritsch, Cornelia; Sprecher, Simon G

    2016-02-15

    Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli. PMID:26769100

  5. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

    PubMed

    Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  6. Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

    PubMed

    Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

    2016-09-01

    Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we

  7. A model of the evolution of larval feeding rate in Drosophila driven by conflicting energy demands.

    PubMed

    Mueller, Laurence D; Barter, Thomas T

    2015-02-01

    Energy allocation is believed to drive trade-offs in life history evolution. We develop a physiological and genetic model of energy allocation that drives evolution of feeding rate in a well-studied model system. In a variety of stressful environments Drosophila larvae adapt by altering their rate of feeding. Drosophila larvae adapted to high levels of ammonia, urea, and the presence of parasitoids evolve lower feeding rates. Larvae adapted to crowded conditions evolve higher feeding rates. Feeding rates should affect gross food intake, metabolic rates, and efficiency of food utilization. We develop a model of larval net energy intake as a function of feeding rates. We show that when there are toxic compounds in the larval food that require energy for detoxification, larvae can maximize their energy intake by slowing their feeding rates. While the reduction in feeding rates may increase development time and decrease competitive ability, we show that genotypes with lower feeding rates can be favored by natural selection if they have a sufficiently elevated viability in the toxic environment. This work shows how a simple phenotype, larval feeding rates, may be of central importance in adaptation to a wide variety of stressful environments via its role in energy allocation.

  8. Multilevel control of run orientation in Drosophila larval chemotaxis

    PubMed Central

    Gomez-Marin, Alex; Louis, Matthieu

    2014-01-01

    Chemotaxis is a powerful paradigm to study how orientation behavior is driven by sensory stimulation. Drosophila larvae navigate odor gradients by controlling the duration of their runs and the direction of their turns. Straight runs and wide-amplitude turns represent two extremes of a behavioral continuum. Here we establish that, on average, runs curl toward the direction of higher odor concentrations. We find that the orientation and strength of the local odor gradient perpendicular to the direction of motion modulates the orientation of individual runs in a gradual manner. We discuss how this error-correction mechanism, called weathervaning, contributes to larval chemotaxis. We use larvae with a genetically modified olfactory system to demonstrate that unilateral function restricted to a single olfactory sensory neuron (OSN) is sufficient to direct weathervaning. Our finding that bilateral sensing is not necessary to control weathervaning highlights the role of temporal sampling. A correlational analysis between sensory inputs and behavioral outputs suggests that weathervaning results from low-amplitude head casts implemented without interruption of the run. In addition, we report the involvement of a sensorimotor memory arising from previous reorientation events. Together, our results indicate that larval chemotaxis combines concurrent orientation strategies that involve complex computations on different timescales. PMID:24592220

  9. [Carbohydrate restriction in the larval diet causes oxidative stress in adult insects of Drosophila melanogaster].

    PubMed

    Rovenko, B M; Lushchak, V I; Lushchak, O V

    2013-01-01

    The influence of 20 and 1% glucose and fructose, which were components of larval diet, on the level of oxidized proteins and lipids, low molecular mass antioxidant content as well as activities of antioxidant and associated enzymes in adult fruit fly Drosophila melanogaster were investigated. The restriction of carbohydrates in larval diet leads to oxidative stress in adult insects. It is supported by 40-50% increased content of protein carbonyl groups and by 60-70% decreased level of protein thiol groups as well as by a 4-fold increase of lipid peroxide content in 2-day-old flies of both sexes, developed on the diet with 1% carbohydrates. Oxidative stress, induced by carbohydrate restriction of the larval diet, caused the activation of antioxidant defence, differently exhibited in male and female fruit flies. Caloric restriction increased activity of superoxide dismutase and thioredoxin reductase associating only in males with 2-fold higher activity of NADPH-producing enzymes--glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase. Carbohydrate restriction in the larval diet caused the increase of uric acid content, but the decrease in catalase activity in males. In females the values of these parameters were changed in opposite direction compared with males. The obtained results let us conclude the different involvement of low molecular mass antioxidants, glutathione and uric acid, and antioxidant enzyme catalase in the protection of male and female fruit fly macromolecules against oxidative damages, caused by calorie restriction of larval diet.

  10. Integrin adhesions suppress syncytium formation in the Drosophila larval epidermis

    PubMed Central

    Wang, Yan; Antunes, Marco; Anderson, Aimee E.; Kadrmas, Julie L.; Jacinto, Antonio; Galko, Michael J.

    2015-01-01

    Summary Integrins are critical for barrier epithelial architecture. Integrin loss in vertebrate skin leads to blistering and wound healing defects. However, how Integrins and associated proteins maintain the regular morphology of epithelia is not well understood. We found that targeted knockdown of the integrin focal adhesion (FA) complex components βIntegrin, PINCH, and Integrin-linked kinase (ILK), caused formation of multinucleate epidermal cells within the Drosophila larval epidermis. This phenotype was specific to the Integrin FA complex and not due to secondary effects on polarity or junctional structures. The multinucleate cells resembled the syncytia caused by physical wounding. Live imaging of wound-induced syncytium formation in the pupal epidermis suggested direct membrane breakdown leading to cell-cell fusion and consequent mixing of cytoplasmic contents. Activation of Jun N-terminal kinase (JNK) signaling, which occurs upon wounding, also correlated with syncytium formation induced by PINCH knockdown. Further, ectopic JNK activation directly caused epidermal syncytium formation. No mode of syncytium formation including that induced by wounding, genetic loss-of FA-proteins, or local JNK hyperactivation, involved misregulation of mitosis or apoptosis. Finally, the mechanism of epidermal syncytium formation following JNK hyperactivation and wounding appeared to be direct disassembly of FA complexes. In conclusion, the loss of function phenotype of Integrin FA components in the larval epidermis resembles a wound. Integrin FA loss in mouse and human skin also causes a wound-like appearance. Our results reveal a novel and unexpected role for proper Integrin-based adhesion in suppressing larval epidermal cell-cell fusion– a role that may be conserved in other epithelia. PMID:26255846

  11. Integrin Adhesions Suppress Syncytium Formation in the Drosophila Larval Epidermis.

    PubMed

    Wang, Yan; Antunes, Marco; Anderson, Aimee E; Kadrmas, Julie L; Jacinto, Antonio; Galko, Michael J

    2015-08-31

    Integrins are critical for barrier epithelial architecture. Integrin loss in vertebrate skin leads to blistering and wound healing defects. However, how integrins and associated proteins maintain the regular morphology of epithelia is not well understood. We found that targeted knockdown of the integrin focal adhesion (FA) complex components β-integrin, PINCH, and integrin-linked kinase (ILK) caused formation of multinucleate epidermal cells within the Drosophila larval epidermis. This phenotype was specific to the integrin FA complex and not due to secondary effects on polarity or junctional structures. The multinucleate cells resembled the syncytia caused by physical wounding. Live imaging of wound-induced syncytium formation in the pupal epidermis suggested direct membrane breakdown leading to cell-cell fusion and consequent mixing of cytoplasmic contents. Activation of Jun N-terminal kinase (JNK) signaling, which occurs upon wounding, also correlated with syncytium formation induced by PINCH knockdown. Further, ectopic JNK activation directly caused epidermal syncytium formation. No mode of syncytium formation, including that induced by wounding, genetic loss of FA proteins, or local JNK hyperactivation, involved misregulation of mitosis or apoptosis. Finally, the mechanism of epidermal syncytium formation following JNK hyperactivation and wounding appeared to be direct disassembly of FA complexes. In conclusion, the loss-of-function phenotype of integrin FA components in the larval epidermis resembles a wound. Integrin FA loss in mouse and human skin also causes a wound-like appearance. Our results reveal a novel and unexpected role for proper integrin-based adhesion in suppressing larval epidermal cell-cell fusion--a role that may be conserved in other epithelia.

  12. Sonication-facilitated Immunofluorescence Staining of Late-stage Embryonic and Larval Drosophila Tissues In Situ

    PubMed Central

    Wawersik, Matthew

    2014-01-01

    Studies performed in Drosophila melanogaster embryos and larvae provide crucial insight into developmental processes such as cell fate specification and organogenesis. Immunostaining allows for the visualization of developing tissues and organs. However, a protective cuticle that forms at the end of embryogenesis prevents permeation of antibodies into late-stage embryos and larvae. While dissection prior to immunostaining is regularly used to analyze Drosophila larval tissues, it proves inefficient for some analyses because small tissues may be difficult to locate and isolate. Sonication provides an alternative to dissection in larval Drosophila immunostaining protocols. It allows for quick, simultaneous processing of large numbers of late-stage embryos and larvae and maintains in situ morphology. After fixation in formaldehyde, a sample is sonicated. Sample is then subjected to immunostaining with antigen-specific primary antibodies and fluorescently labeled secondary antibodies to visualize target cell types and specific proteins via fluorescence microscopy. During the process of sonication, proper placement of a sonicating probe above the sample, as well as the duration and intensity of sonication, is critical. Additonal minor modifications to standard immunostaining protocols may be required for high quality stains. For antibodies with low signal to noise ratio, longer incubation times are typically necessary. As a proof of concept for this sonication-facilitated protocol, we show immunostains of three tissue types (testes, ovaries, and neural tissues) at a range of developmental stages. PMID:25146311

  13. Whole-central nervous system functional imaging in larval Drosophila.

    PubMed

    Lemon, William C; Pulver, Stefan R; Höckendorf, Burkhard; McDole, Katie; Branson, Kristin; Freeman, Jeremy; Keller, Philipp J

    2015-08-11

    Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord.

  14. Whole-central nervous system functional imaging in larval Drosophila

    PubMed Central

    Lemon, William C.; Pulver, Stefan R.; Höckendorf, Burkhard; McDole, Katie; Branson, Kristin; Freeman, Jeremy; Keller, Philipp J.

    2015-01-01

    Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord. PMID:26263051

  15. Pharmacological identification of cholinergic receptor subtypes on Drosophila melanogaster larval heart.

    PubMed

    Malloy, Cole A; Ritter, Kyle; Robinson, Jonathan; English, Connor; Cooper, Robin L

    2016-01-01

    The Drosophila melanogaster heart is a popular model in which to study cardiac physiology and development. Progress has been made in understanding the role of endogenous compounds in regulating cardiac function in this model. It is well characterized that common neurotransmitters act on many peripheral and non-neuronal tissues as they flow through the hemolymph of insects. Many of these neuromodulators, including acetylcholine (ACh), have been shown to act directly on the D. melanogaster larval heart. ACh is a primary neurotransmitter in the central nervous system (CNS) of vertebrates and at the neuromuscular junctions on skeletal and cardiac tissue. In insects, ACh is the primary excitatory neurotransmitter of sensory neurons and is also prominent in the CNS. A full understanding regarding the regulation of the Drosophila cardiac physiology by the cholinergic system remains poorly understood. Here we use semi-intact D. melanogaster larvae to study the pharmacological profile of cholinergic receptor subtypes, nicotinic acetylcholine receptors (nAChRs) and muscarinic acetylcholine receptors (mAChRs), in modulating heart rate (HR). Cholinergic receptor agonists, nicotine and muscarine both increase HR, while nAChR agonist clothianidin exhibits no significant effect when exposed to an open preparation at concentrations as low as 100 nM. In addition, both nAChR and mAChR antagonists increase HR as well but also display capabilities of blocking agonist actions. These results provide evidence that both of these receptor subtypes display functional significance in regulating the larval heart's pacemaker activity.

  16. Analysis of synaptic growth and function in Drosophila with an extended larval stage

    PubMed Central

    Miller, Daniel L.; Ballard, Shannon L.; Ganetzky, Barry

    2012-01-01

    The Drosophila larval neuromuscular junction (NMJ) is a powerful system for the genetic and molecular analysis of neuronal excitability, synaptic transmission, and synaptic development. However, its use for studying age-dependent processes, such as maintenance of neuronal viability and synaptic stability, are temporally limited by the onset of pupariation and metamorphosis. Here we characterize larval NMJ growth, growth regulation, structure, and function in a developmental variant with an extended third instar. RNAi-knockdown of the prothoracicotropic hormone receptor, torso, in the ring gland of developing larvae leaves the timing of first and second instar molts largely unchanged, but triples duration of the third instar from 3 to 9.5 days (McBrayer et al., 2007; Rewitz et al., 2009). During this extended third instar (ETI) period, NMJs undergo additional growth (adding over 50 boutons/NMJ), and this growth remains under the control of the canonical regulators Highwire and the TGF-β/BMP pathway. NMJ growth during the ETI period occurs via addition of new branches, satellite boutons and interstitial boutons, and continues even after muscle growth levels off. Throughout the ETI, organization of synapses and active zones remains normal, and synaptic transmission is unchanged. These results establish the ETI larval system as a viable model for studying motor neuron diseases and for investigating time-dependent effects of perturbations that impair mechanisms of neuroprotection, synaptic maintenance, and response to neural injury. PMID:23035089

  17. Analysis of synaptic growth and function in Drosophila with an extended larval stage.

    PubMed

    Miller, Daniel L; Ballard, Shannon L; Ganetzky, Barry

    2012-10-01

    The Drosophila larval neuromuscular junction (NMJ) is a powerful system for the genetic and molecular analysis of neuronal excitability, synaptic transmission, and synaptic development. However, its use for studying age-dependent processes, such as maintenance of neuronal viability and synaptic stability, are temporally limited by the onset of pupariation and metamorphosis. Here we characterize larval NMJ growth, growth regulation, structure, and function in a developmental variant with an extended third instar (ETI). RNAi-knockdown of the prothoracicotropic hormone receptor, torso, in the ring gland of developing larvae leaves the timing of first and second instar molts largely unchanged, but triples duration of the third instar from 3 to 9.5 d (McBrayer et al., 2007; Rewitz et al., 2009). During this ETI period, NMJs undergo additional growth (adding >50 boutons/NMJ), and this growth remains under the control of the canonical regulators Highwire and the TGFβ/BMP pathway. NMJ growth during the ETI period occurs via addition of new branches, satellite boutons, and interstitial boutons, and continues even after muscle growth levels off. Throughout the ETI, organization of synapses and active zones remains normal, and synaptic transmission is unchanged. These results establish the ETI larval system as a viable model for studying motor neuron diseases and for investigating time-dependent effects of perturbations that impair mechanisms of neuroprotection, synaptic maintenance, and response to neural injury. PMID:23035089

  18. Sequential en-face optical coherence tomography imaging and monitoring of Drosophila Melanogaster larval heart

    NASA Astrophysics Data System (ADS)

    Bradu, A.; Ma, Lisha; Bloor, J.; Podoleanu, A. GH.

    2009-02-01

    This article demonstrates two modalities to acquire information on cardiac function in larval Drosophila Melanogaster: in-vivo imaging and heartbeat monitoring. To achieve these goals a dedicated imaging instrument able to provide simultaneous en-face Optical Coherence Tomography (OCT) and Laser Scanning Confocal Microscopy (LSCM) images has been developed. With this dual imaging system, the heart can easily be located and visualised within the specimen and the change of the heart shape in a cardiac cycle monitored. The system can easily be switched to a stethoscopic regime, simply by interrupting the scanning of the light beam across the sample, after selecting the point of interest in the imaging regime. Here we have used targeted gene expression to knockdown the myospheroid (mys) gene in the larval heart using a specific RNAi construct. By knocking down a β integrin subunit encoded by mys we have recorded an enlarged heart chamber in both diastolic and systolic states. Also, the fraction of reduction of the chamber diameter was smaller in the knockdown heart. These phenotypic differences indicate that impaired cardiac contractility occurs in the heart where the integrin gene express level is reduced. As far as we are aware, this is for the first time when it is shown in Drosophila that integrins have a direct relationship to a dilated heart defect, and conseqThis article demonstrates two modalities to acquire information on cardiac function in larval Drosophila Melanogaster: in-vivo imaging and heartbeat monitoring. To achieve these goals a dedicated imaging instrument able to provide simultaneous en-face Optical Coherence Tomography (OCT) and Laser Scanning Confocal Microscopy (LSCM) images has been developed. With this dual imaging system, the heart can easily be located and visualised within the specimen and the change of the heart shape in a cardiac cycle monitored. The system can easily be switched to a stethoscopic regime, simply by interrupting the

  19. Morphological analysis of Drosophila larval peripheral sensory neuron dendrites and axons using genetic mosaics.

    PubMed

    Karim, M Rezaul; Moore, Adrian W

    2011-11-07

    Nervous system development requires the correct specification of neuron position and identity, followed by accurate neuron class-specific dendritic development and axonal wiring. Recently the dendritic arborization (DA) sensory neurons of the Drosophila larval peripheral nervous system (PNS) have become powerful genetic models in which to elucidate both general and class-specific mechanisms of neuron differentiation. There are four main DA neuron classes (I-IV)(1). They are named in order of increasing dendrite arbor complexity, and have class-specific differences in the genetic control of their differentiation(2-10). The DA sensory system is a practical model to investigate the molecular mechanisms behind the control of dendritic morphology(11-13) because: 1) it can take advantage of the powerful genetic tools available in the fruit fly, 2) the DA neuron dendrite arbor spreads out in only 2 dimensions beneath an optically clear larval cuticle making it easy to visualize with high resolution in vivo, 3) the class-specific diversity in dendritic morphology facilitates a comparative analysis to find key elements controlling the formation of simple vs. highly branched dendritic trees, and 4) dendritic arbor stereotypical shapes of different DA neurons facilitate morphometric statistical analyses. DA neuron activity modifies the output of a larval locomotion central pattern generator(14-16). The different DA neuron classes have distinct sensory modalities, and their activation elicits different behavioral responses(14,16-20). Furthermore different classes send axonal projections stereotypically into the Drosophila larval central nervous system in the ventral nerve cord (VNC)(21). These projections terminate with topographic representations of both DA neuron sensory modality and the position in the body wall of the dendritic field(7,22,23). Hence examination of DA axonal projections can be used to elucidate mechanisms underlying topographic mapping(7,22,23), as well as

  20. Embryonic expression of the divergent Drosophila beta3-tubulin isoform is required for larval behavior.

    PubMed Central

    Dettman, R W; Turner, F R; Hoyle, H D; Raff, E C

    2001-01-01

    We have sought to define the developmental and cellular roles played by differential expression of distinct beta-tubulins. Drosophila beta3-tubulin (beta3) is a structurally divergent isoform transiently expressed during midembryogenesis. Severe beta3 mutations cause larval lethality resulting from failed gut function and consequent starvation. However, mutant larvae also display behavioral abnormalities consistent with defective sensory perception. We identified embryonic beta3 expression in several previously undefined sites, including different types of sensory organs. We conclude that abnormalities in foraging behavior and photoresponsiveness exhibited by prelethal mutant larvae reflect defective beta3 function in the embryo during development of chordotonal and other mechanosensory organs and of Bolwig's organ and nerve. We show that microtubule organization in the cap cells of chordotonal organs is altered in mutant larvae. Thus transient zygotic beta3 expression has permanent consequences for the architecture of the cap cell microtubule cytoskeleton in the larval sensilla, even when beta3 is no longer present. Our data provide a link between the microtubule cytoskeleton in embryogenesis and the behavioral phenotype manifested as defective proprioreception at the larval stage. PMID:11333234

  1. Natural variability in Drosophila larval and pupal NaCl tolerance.

    PubMed

    Riedl, Craig A L; Oster, Sara; Busto, Macarena; Mackay, Trudy F C; Sokolowski, Marla B

    2016-05-01

    The regulation of NaCl is essential for the maintenance of cellular tonicity and functionality, and excessive salt exposure has many adverse effects. The fruit fly, Drosophila melanogaster, is a good osmoregulator and some strains can survive on media with very low or high NaCl content. Previous analyses of mutant alleles have implicated various stress signaling cascades in NaCl sensitivity or tolerance; however, the genes influencing natural variability of NaCl tolerance remain for the most part unknown. Here, we use two approaches to investigate natural variation in D. melanogaster NaCl tolerance. We describe four D. melanogaster lines that were selected for different degrees of NaCl tolerance, and present data on their survival, development, and pupation position when raised on varying NaCl concentrations. After finding evidence for natural variation in salt tolerance, we present the results of Quantitative Trait Loci (QTL) mapping of natural variation in larval and pupal NaCl tolerance, and identify different genomic regions associated with NaCl tolerance during larval and pupal development. PMID:26874056

  2. Functional analysis of the larval feeding circuit in Drosophila.

    PubMed

    Bhatt, Parag K; Neckameyer, Wendi S

    2013-11-19

    The serotonergic feeding circuit in Drosophila melanogaster larvae can be used to investigate neuronal substrates of critical importance during the development of the circuit. Using the functional output of the circuit, feeding, changes in the neuronal architecture of the stomatogastric system can be visualized. Feeding behavior can be recorded by observing the rate of retraction of the mouth hooks, which receive innervation from the brain. Locomotor behavior is used as a physiological control for feeding, since larvae use their mouth hooks to traverse across an agar substrate. Changes in feeding behavior can be correlated with the axonal architecture of the neurites innervating the gut. Using immunohistochemistry it is possible to visualize and quantitate these changes. Improper handling of the larvae during behavior paradigms can alter data as they are very sensitive to manipulations. Proper imaging of the neurite architecture innervating the gut is critical for precise quantitation of number and size of varicosities as well as the extent of branch nodes. Analysis of most circuits allow only for visualization of neurite architecture or behavioral effects; however, this model allows one to correlate the functional output of the circuit with the impairments in neuronal architecture.

  3. Larval Population Density Alters Adult Sleep in Wild-Type Drosophila melanogaster but Not in Amnesiac Mutant Flies.

    PubMed

    Chi, Michael W; Griffith, Leslie C; Vecsey, Christopher G

    2014-08-11

    Sleep has many important biological functions, but how sleep is regulated remains poorly understood. In humans, social isolation and other stressors early in life can disrupt adult sleep. In fruit flies housed at different population densities during early adulthood, social enrichment was shown to increase subsequent sleep, but it is unknown if population density during early development can also influence adult sleep. To answer this question, we maintained Drosophila larvae at a range of population densities throughout larval development, kept them isolated during early adulthood, and then tested their sleep patterns. Our findings reveal that flies that had been isolated as larvae had more fragmented sleep than those that had been raised at higher population densities. This effect was more prominent in females than in males. Larval population density did not affect sleep in female flies that were mutant for amnesiac, which has been shown to be required for normal memory consolidation, adult sleep regulation, and brain development. In contrast, larval population density effects on sleep persisted in female flies lacking the olfactory receptor or83b, suggesting that olfactory signals are not required for the effects of larval population density on adult sleep. These findings show that population density during early development can alter sleep behavior in adulthood, suggesting that genetic and/or structural changes are induced by this developmental manipulation that persist through metamorphosis.

  4. Drosophila Food-Associated Pheromones: Effect of Experience, Genotype and Antibiotics on Larval Behavior

    PubMed Central

    Thibert, Julien; Farine, Jean-Pierre; Cortot, Jérôme; Ferveur, Jean-François

    2016-01-01

    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. PMID:26987117

  5. Altered outward K(+) currents in Drosophila larval neurons of memory mutants rutabaga and amnesiac.

    PubMed

    Yu, D; Feng, C; Guo, A

    1999-08-01

    K(+) currents in cultured Drosophila larval neurons have been classified into four categories according to their inactivation time constants, relative amplitude, and response to K(+) channel blockers 4-AP and tetraethylammonium. The percentage (65%) of neurons displaying K(+) currents which were reduced to 30% in amplitude by 5 mM cyclic adenosine monophosphate (cAMP) analog 8-bromo-cAMP in both Drosophila memory mutants rutabaga (rut) and amnesiac (amn) was significantly larger than that (50%) in wild type. This initial characterization provides evidence for altered K(+) currents in both rut and amn mutants. Arachidonic acid, a specifical inhibitor of Kv4 family (shal) K(+) channels, was found to inhibit K(+) currents in cultured Drosophila neurons, suggesting the presence of shal channels in these neurons. PMID:10413447

  6. Light-avoidance-mediating photoreceptors tile the Drosophila larval body wall.

    PubMed

    Xiang, Yang; Yuan, Quan; Vogt, Nina; Looger, Loren L; Jan, Lily Yeh; Jan, Yuh Nung

    2010-12-16

    Photoreceptors for visual perception, phototaxis or light avoidance are typically clustered in eyes or related structures such as the Bolwig organ of Drosophila larvae. Unexpectedly, we found that the class IV dendritic arborization neurons of Drosophila melanogaster larvae respond to ultraviolet, violet and blue light, and are major mediators of light avoidance, particularly at high intensities. These class IV dendritic arborization neurons, which are present in every body segment, have dendrites tiling the larval body wall nearly completely without redundancy. Dendritic illumination activates class IV dendritic arborization neurons. These novel photoreceptors use phototransduction machinery distinct from other photoreceptors in Drosophila and enable larvae to sense light exposure over their entire bodies and move out of danger.

  7. Larval ethanol exposure alters adult circadian free-running locomotor activity rhythm in Drosophila melanogaster.

    PubMed

    Seggio, Joseph A; Possidente, Bernard; Ahmad, S Tariq

    2012-02-01

    Alcohol consumption causes disruptions in a variety of daily rhythms, including the sleep-wake cycle. Few studies have explored the effect of alcohol exposure only during developmental stages preceding maturation of the adult circadian clock, and none have examined the effects of alcohol on clock function in Drosophila. This study investigates developmental and behavioral correlates between larval ethanol exposure and the adult circadian clock in Drosophila melanogaster, a well-established model for studying circadian rhythms and effects of ethanol exposure. We reared Drosophila larvae on 0%, 10%, or 20% ethanol-supplemented food and assessed effects upon eclosion and the free-running period of the circadian rhythm of locomotor activity. We observed a dose-dependent effect of ethanol on period, with higher doses resulting in shorter periods. We also identified the third larval instar stage as a critical time for the developmental effects of 10% ethanol on circadian period. These results demonstrate that developmental ethanol exposure causes sustainable shortening of the adult free-running period in Drosophila melanogaster, even after adult exposure to ethanol is terminated, and suggests that the third instar is a sensitive time for this effect. PMID:22217104

  8. Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction.

    PubMed

    Sanhueza, Mario; Kubasik-Thayil, Anisha; Pennetta, Giuseppa

    2016-01-01

    Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic pathways. Quantitative descriptions are rarely performed, although genetic manipulations produce a range of phenotypic effects and variations are observed even among individuals within control groups. Emerging evidence shows that morphology, size and location of organelles play a previously underappreciated, yet fundamental role in cell function and survival. Here we provide step-by-step instructions for performing quantitative analyses of phenotypes at the Drosophila larval neuromuscular junction (NMJ). We use several reliable immuno-histochemical markers combined with bio-imaging techniques and morphometric analyses to examine the effects of genetic mutations on specific cellular processes. In particular, we focus on the quantitative analysis of phenotypes affecting morphology, size and position of nuclei within the striated muscles of Drosophila larvae. The Drosophila larval NMJ is a valuable experimental model to investigate the molecular mechanisms underlying the structure and the function of the neuromuscular system, both in health and disease. However, the methodologies we describe here can be extended to other systems as well. PMID:27213489

  9. Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

    PubMed Central

    Pennetta, Giuseppa

    2016-01-01

    Most studies on morphogenesis rely on qualitative descriptions of how anatomical traits are affected by the disruption of specific genes and genetic pathways. Quantitative descriptions are rarely performed, although genetic manipulations produce a range of phenotypic effects and variations are observed even among individuals within control groups. Emerging evidence shows that morphology, size and location of organelles play a previously underappreciated, yet fundamental role in cell function and survival. Here we provide step-by-step instructions for performing quantitative analyses of phenotypes at the Drosophila larval neuromuscular junction (NMJ). We use several reliable immuno-histochemical markers combined with bio-imaging techniques and morphometric analyses to examine the effects of genetic mutations on specific cellular processes. In particular, we focus on the quantitative analysis of phenotypes affecting morphology, size and position of nuclei within the striated muscles of Drosophila larvae. The Drosophila larval NMJ is a valuable experimental model to investigate the molecular mechanisms underlying the structure and the function of the neuromuscular system, both in health and disease. However, the methodologies we describe here can be extended to other systems as well. PMID:27213489

  10. Development of the larval ovary in the moth, Plodia interpunctella.

    PubMed

    Beckemeyer, E F; Shirk, P D

    2004-11-01

    The morphogenesis of ovaries and the organization of germ cells within them were visualized during the larval stages of the moth, Plodia interpunctella. The germ cells were observed by utilizing confocal microscopy coupled with immuno-fluorescent staining for the alpha-crystallin protein 25 (alphaCP25). The alphaCP25 was previously shown to be specific to germ cells of pupae and adults, and this study shows that alphaCP25 is present in larval germ cells as well. A cluster of 28 germ cells that stain for alphaCP25 was found in the gonads of newly hatched first instar larvae. The founding germ cells became segregated into four clusters, most likely by somatic cell intrusion, around the beginning of the second instar. Division of the primary germ cells began by the end of the second instar and the formation of all cystoblasts appeared to be completed within the four ovarioles by the end of the third instar. Within the ovarioles of third instar larvae, the germ cells were organized with a distal cap of seven germ cells which was segregated from the majority of the germ cells. The main body of germ cells was arranged around a central germ cell-free core as a spiral. Divisions of the cystoblasts to form cystocyte clusters were nearly completed during the fourth (last) larval instar. These features suggest that the strategy to produce follicles in moths is fundamentally different from the fruitfly, Drosophila. It appears that during the initial stages of ovary development in P. interpunctella, the primary germ cells undergo stage-complete divisions that are completed prior to the onset of the next set of divisions, which results in a complete complement of follicles available by the time of adult eclosion, while in Drosophila the primary germ cell divisions are initiated in the adult stage, and follicles are produced individually as resources are available.

  11. Failure to Burrow and Tunnel Reveals Roles for jim lovell in the Growth and Endoreplication of the Drosophila Larval Tracheae

    PubMed Central

    Qiang, Karen M.; Beckingham, Kathleen M.

    2016-01-01

    The Drosophila protein Jim Lovell (Lov) is a putative transcription factor of the BTB/POZ (Bric- a-Brac/Tramtrack/Broad/ Pox virus and Zinc finger) domain class that is expressed in many elements of the developing larval nervous system. It has roles in innate behaviors such as larval locomotion and adult courtship. In performing tissue-specific knockdown with the Gal4-UAS system we identified a new behavioral phenotype for lov: larvae failed to burrow into their food during their growth phase and then failed to tunnel into an agarose substratum during their wandering phase. We determined that these phenotypes originate in a previously unrecognized role for lov in the tracheae. By using tracheal-specific Gal4 lines, Lov immunolocalization and a lov enhancer trap line, we established that lov is normally expressed in the tracheae from late in embryogenesis through larval life. Using an assay that monitors food burrowing, substrate tunneling and death we showed that lov tracheal knockdown results in tracheal fluid-filling, producing hypoxia that activates the aberrant behaviors and inhibits development. We investigated the role of lov in the tracheae that initiates this sequence of events. We discovered that when lov levels are reduced, the tracheal cells are smaller, more numerous and show lower levels of endopolyploidization. Together our findings indicate that Lov is necessary for tracheal endoreplicative growth and that its loss in this tissue causes loss of tracheal integrity resulting in chronic hypoxia and abnormal burrowing and tunneling behavior. PMID:27494251

  12. Whole-genome expression analysis in the third instar larval midgut of Drosophila melanogaster.

    PubMed

    Harrop, Thomas W R; Pearce, Stephen L; Daborn, Phillip J; Batterham, Philip

    2014-09-05

    Survival of insects on a substrate containing toxic substances such as plant secondary metabolites or insecticides is dependent on the metabolism or excretion of those xenobiotics. The primary sites of xenobiotic metabolism are the midgut, Malpighian tubules, and fat body. In general, gene expression in these organs is reported for the entire tissue by online databases, but several studies have shown that gene expression within the midgut is compartmentalized. Here, RNA sequencing is used to investigate whole-genome expression in subsections of third instar larval midguts of Drosophila melanogaster. The data support functional diversification in subsections of the midgut. Analysis of the expression of gene families that are implicated in the metabolism of xenobiotics suggests that metabolism may not be uniform along the midgut. These data provide a starting point for investigating gene expression and xenobiotic metabolism and other functions of the larval midgut.

  13. Whole-Genome Expression Analysis in the Third Instar Larval Midgut of Drosophila melanogaster

    PubMed Central

    Harrop, Thomas W. R.; Pearce, Stephen L.; Daborn, Phillip J.; Batterham, Philip

    2014-01-01

    Survival of insects on a substrate containing toxic substances such as plant secondary metabolites or insecticides is dependent on the metabolism or excretion of those xenobiotics. The primary sites of xenobiotic metabolism are the midgut, Malpighian tubules, and fat body. In general, gene expression in these organs is reported for the entire tissue by online databases, but several studies have shown that gene expression within the midgut is compartmentalized. Here, RNA sequencing is used to investigate whole-genome expression in subsections of third instar larval midguts of Drosophila melanogaster. The data support functional diversification in subsections of the midgut. Analysis of the expression of gene families that are implicated in the metabolism of xenobiotics suggests that metabolism may not be uniform along the midgut. These data provide a starting point for investigating gene expression and xenobiotic metabolism and other functions of the larval midgut. PMID:25193493

  14. Temperature and parasitism by Asobara tabida (Hymenoptera: Braconidae) influence larval pupation behaviour in two Drosophila species

    NASA Astrophysics Data System (ADS)

    Josso, Céline; Moiroux, Joffrey; Vernon, Philippe; van Baaren, Joan; van Alphen, Jacques J. M.

    2011-08-01

    In holometabolous insects, pupation site selection behaviour has large consequences for survival. Here, we investigated the combined effects of temperature and parasitism by the parasitoid Asobara tabida on larval pupation behaviour in two of its main Drosophila sp. hosts differing in their climate origin. We found that larvae of Drosophila melanogaster—a species with a (sub)tropical origin—placed at 25°C pupated higher in rearing jars than those placed at 15°C. The opposite pattern was observed for Drosophila subobscura larvae—a species from temperate regions—which pupated lower, i.e. on or near the substrate at 25°C, than those placed at 15°C. When placed at 25°C, parasitized larvae of both species pupated closer to the substrate than unparasitized ones. Moreover, the Drosophila larvae that had been exposed and probably stung by A. tabida, but were not parasitized, pupated lower than the control unparasitized larvae. These results provide new insights of host behaviour manipulation by A. tabida larvae.

  15. Identification of Mob2, a novel regulator of larval neuromuscular junction morphology, in natural populations of Drosophila melanogaster.

    PubMed

    Campbell, Megan; Ganetzky, Barry

    2013-11-01

    Although evolutionary changes must take place in neural connectivity and synaptic architecture as nervous systems become more complex, we lack understanding of the general principles and specific mechanisms by which these changes occur. Previously, we found that morphology of the larval neuromuscular junction (NMJ) varies extensively among different species of Drosophila but is relatively conserved within a species. To identify specific genes as candidates that might underlie phenotypic differences in NMJ morphology among Drosophila species, we performed a genetic analysis on one of two phenotypic variants we found among 20 natural isolates of Drosophila melanogaster. We discovered genetic polymorphisms for both positive and negative regulators of NMJ growth segregating within the variant line. Focusing on one subline, that displayed NMJ overgrowth, we mapped the phenotype to Mob2 [Monopolar spindle (Mps) one binding protein 2)], a gene encoding a Nuclear Dbf2 (Dumbbell formation 2)-Related (NDR) kinase activator. We confirmed this identification by transformation rescue experiments and showed that presynaptic expression of Mob2 is necessary and sufficient to regulate NMJ growth. Mob2 interacts in a dominant, dose-dependent manner with tricornered but not with warts, to cause NMJ overgrowth, suggesting that Mob2 specifically functions in combination with the former NDR kinase to regulate NMJ development. These results demonstrate the feasibility and utility of identifying genetic variants affecting NMJ morphology in natural populations of Drosophila. These variants can lead to discovery of new genes and molecular mechanisms that regulate NMJ development while also providing new information that can advance our understanding of mechanisms that underlie nervous system evolution. PMID:23979583

  16. Regulation of larval hematopoiesis in Drosophila melanogaster: a role for the multi sex combs gene.

    PubMed Central

    Remillieux-Leschelle, Nathalie; Santamaria, Pedro; Randsholt, Neel B

    2002-01-01

    Drosophila larval hematopoietic organs produce circulating hemocytes that ensure the cellular host defense by recognizing and neutralizing non-self or noxious objects through phagocytosis or encapsulation and melanization. Hematopoietic lineage specification as well as blood cell proliferation and differentiation are tightly controlled. Mutations in genes that regulate lymph gland cell proliferation and hemocyte numbers in the body cavity cause hematopoietic organ overgrowth and hemocyte overproliferation. Occasionally, mutant hemocytes invade self-tissues, behaving like neoplastic malignant cells. Two alleles of the Polycomb group (PcG) gene multi sex combs (mxc) were previously isolated as such lethal malignant blood neoplasm mutations. PcG genes regulate Hox gene expression in vertebrates and invertebrates and participate in mammalian hematopoiesis control. Hence we investigated the need for mxc in Drosophila hematopoietic organs and circulating hemocytes. We show that mxc-induced hematopoietic hyperplasia is cell autonomous and that mxc mainly controls plasmatocyte lineage proliferation and differentiation in lymph glands and circulating hemocytes. Loss of the Toll pathway, which plays a similar role in hematopoiesis, counteracted mxc hemocyte proliferation but not mxc hemocyte differentiation. Several PcG genes tested in trans had no effects on mxc hematopoietic phenotypes, whereas the trithorax group gene brahma is important for normal and mutant hematopoiesis control. We propose that mxc provides one of the regulatory inputs in larval hematopoiesis that control normal rates of plasmatocyte and crystal lineage proliferation as well as normal rates and timing of hemocyte differentiation. PMID:12454071

  17. The Relationship between Dipeptidase Activity Variation and Larval Viability in Drosophila melanogaster

    PubMed Central

    Hiraizumi, Kazuo; Laurie, Cathy C.

    1987-01-01

    The enzyme dipeptidase-A (DIP-A) in Drosophila melanogaster is coded by a second chromosome locus that is polymorphic for three allozymes in natural populations. DIP-A appears to be the only enzyme in D. melanogaster capable of hydrolyzing the dipeptide glycyl-l-isoleucine, since flies homozygous for null alleles at this locus have no detectable glycyl- l-isoleucine-ase activity. DIP-A activity occurs in many tissues and throughout development, but is particularly high in the larval midgut, suggesting an important role in protein digestion. These observations suggested an experimental design for investigating the adaptive significance of genetic variation in DIP-A activity. Fitness components of DIP-A variants could be estimated and compared under two environmental conditions (defined diets under axenic conditions). In the restrictive environment, the essential amino acid l-isoleucine is provided only in the form of glycyl-l-isoleucine, whereas in the permissive environment, l-isoleucine is provided in free form. We predicted that DIP-A activity would be essential in the restrictive, but not in the permissive environment. The results reported here clearly contradict this prediction. Two stocks homozygous for DIP-A null alleles from different geographic locations are each viable on the restrictive diet. Furthermore, relative viability experiments in which null allele larvae compete with larvae having DIP-A activity provide no evidence for even a partial reduction in egg to adult survival on the restrictive diet. Apparently, the null allele larvae have some alternative mechanism for obtaining l-isoleucine from the dipeptide, even though no glycyl-l-isoleucine-ase activity can be detected in vitro. These results, along with the viability of null alleles for many other enzymes, support the idea that eukaryotes have an intricate network of alternative biochemical pathways through which the same necessary function may be achieved. Such "buffering capacity" makes it very

  18. Motor nerve terminals on abdominal muscles in larval flesh flies, Sarcophaga bullata: comparisons with Drosophila.

    PubMed

    Feeney, C J; Karunanithi, S; Pearce, J; Govind, C K; Atwood, H L

    1998-12-14

    Motor nerve terminals on abdominal body-wall muscles 6A and 7A in larval flesh flies were investigated to establish their general structural features with confocal microscopy, transmission electron microscopy, and freeze-fracture procedures. As in Drosophila and other dipterans, two motor axons supply these muscles, and two morphologically different terminals were discerned with confocal microscopy: thin terminals with relatively small varicosities (Type Is), and thicker terminals with larger varicosities (Type Ib). In serial electron micrographs, Type Ib terminals were distinguished from Type Is terminals by their larger cross-sectional area, more extensive subsynaptic reticulum, more mitochondrial profiles, and more clear synaptic vesicles. Type Ib terminals possessed larger synapses and more synaptic contact area per unit terminal length. Although presynaptic dense bars of active zones were similar in mean length for the two terminal types, there were almost twice as many dense bars per synapse for Type Ib terminals. Freeze-fractures through the presynaptic membrane showed particle-free areas indicative of synapses on the P-face, within which were localized aggregations of large intramembranous particles indicative of active zones. These particles were similar in number to those found at active zones of several other arthropod neuromuscular junctions. In general, synaptic structural parameters strongly paralleled those of the anatomically homologous muscles in Drosophila melanogaster. In live preparations, simultaneous focal recording from identified varicosities and intracellular recording indicated that the two terminals produced excitatory junction potentials of similar amplitude in a physiological solution similar to that used for Drosophila.

  19. Maintenance and regulation of extracellular volume and the ion environment in Drosophila larval nerves

    PubMed Central

    Leiserson, William M.; Keshishian, Haig

    2010-01-01

    In mammals and insects, paracellular blood barriers isolate the nervous system from the rest of the animal. Glia and accessory cells of the nervous system use pumps, channels, cotransporters, and exchangers collectively to maintain the extracellular ion environment and osmotic balance in the nervous system. At present the molecular mechanisms that regulate this process remain unclear. In humans, loss of extracellular ion and volume regulation in the nervous system poses serious health threats. Drosophila is a model genetic organism with a proven track record for uncovering molecular mechanisms relevant to human health and disease. Here, we review what is known about extracellular ion and volume regulation in larval abdominal nerves, present some new data about the impact of neural activity on the extracellular environment, and relate the findings to mammalian systems. Homologies have been found at the level of morphology, physiology, molecular mechanisms, and mutant phenotypes. The Fray-Ncc69 module regulates extracellular volume in larval nerves. Genetic rescue experiments with the mammalian orthologs prove this module has a direct correlate in humans. This and other molecular homologies, together with the similar physiological needs, suggest that uncovering the molecular mechanisms of ion and volume regulation in larval nerves will likely provide significant insights into this process in mammalian systems. PMID:21305613

  20. Drosulfakinin activates CCKLR-17D1 and promotes larval locomotion and escape response in Drosophila

    PubMed Central

    Chen, Xu; Peterson, Jonathan; Nachman, Ronald J.; Ganetzky, Barry

    2012-01-01

    Neuropeptides are ubiquitous in both mammals and invertebrates and play essential roles in regulation and modulation of many developmental and physiological processes through activation of G-protein-coupled-receptors (GPCRs). However, the mechanisms by which many of the neuropeptides regulate specific neural function and behaviors remain undefined. Here we investigate the functions of Drosulfakinin (DSK), the Drosophila homolog of vertebrate neuropeptide cholecystokinin (CCK), which is the most abundant neuropeptide in the central nervous system. We provide biochemical evidence that sulfated DSK-1 and DSK-2 activate the CCKLR-17D1 receptor in a cell culture assay. We further examine the role of DSK and CCKLR-17D1 in the regulation of larval locomotion, both in a semi-intact larval preparation and in intact larvae under intense light exposure. Our results suggest that DSK/CCKLR-17D1 signaling promote larval body wall muscle contraction and is necessary for mediating locomotor behavior in stress-induced escape response. PMID:22885328

  1. Identification of excitatory premotor interneurons which regulate local muscle contraction during Drosophila larval locomotion

    PubMed Central

    Hasegawa, Eri; Truman, James W.; Nose, Akinao

    2016-01-01

    We use Drosophila larval locomotion as a model to elucidate the working principles of motor circuits. Larval locomotion is generated by rhythmic and sequential contractions of body-wall muscles from the posterior to anterior segments, which in turn are regulated by motor neurons present in the corresponding neuromeres. Motor neurons are known to receive both excitatory and inhibitory inputs, combined action of which likely regulates patterned motor activity during locomotion. Although recent studies identified candidate inhibitory premotor interneurons, the identity of premotor interneurons that provide excitatory drive to motor neurons during locomotion remains unknown. In this study, we searched for and identified two putative excitatory premotor interneurons in this system, termed CLI1 and CLI2 (cholinergic lateral interneuron 1 and 2). These neurons were segmentally arrayed and activated sequentially from the posterior to anterior segments during peristalsis. Consistent with their being excitatory premotor interneurons, the CLIs formed GRASP- and ChAT-positive putative synapses with motoneurons and were active just prior to motoneuronal firing in each segment. Moreover, local activation of CLI1s induced contraction of muscles in the corresponding body segments. Taken together, our results suggest that the CLIs directly activate motoneurons sequentially along the segments during larval locomotion. PMID:27470675

  2. Analysis of Drosophila larval feeding response to quinine-adulterated food.

    PubMed

    Shen, Ping

    2012-08-01

    The food responses of Drosophila larvae offer an excellent opportunity to study the genetic and neural regulation of feeding behavior. Compared with fed larvae, hungry larvae are more likely to display aggressive foraging, rapid food intake, compensatory feeding, and stress-resistant food procurement. Omnivores, including humans, tend to avoid noxious or unfamiliar food. Fly larvae avoid bitter substances such as quinine. As an increasing amount of quinine is added to an otherwise palatable liquid medium containing sugar and inactivated yeast, larvae become less likely to consume the tainted food. Larval feeding activity is assayed by scoring the percentage of larvae containing dyed food in a large portion of the midgut. Defensive foraging behavior can be modulated by physiological need and food deprivation significantly increases larval tolerance to quinine. Therefore, the larval response to quinine food and its regulation by hunger provides a useful paradigm for elucidating the genetic and neural regulation of food choice that favors short-term survival. The test described here is designed for quantitative assessment of the motivation of individual larvae to ingest quinine-adulterated food under different energy states. The test is applicable to routine functional testing and larger-scale screening of genetic mutations and biologics that might affect food consumption.

  3. Drosophila 4EHP is essential for the larval-pupal transition and required in the prothoracic gland for ecdysone biosynthesis.

    PubMed

    Valzania, Luca; Ono, Hajime; Ignesti, Marilena; Cavaliere, Valeria; Bernardi, Fabio; Gamberi, Chiara; Lasko, Paul; Gargiulo, Giuseppe

    2016-02-01

    Maternal expression of the translational regulator 4EHP (eIF4E-Homologous Protein) has an established role in generating protein gradients essential for specifying the Drosophila embryonic pattern. We generated a null mutation of 4EHP, which revealed for the first time that it is essential for viability and for completion of development. In fact, 4EHP null larvae, and larvae ubiquitously expressing RNAi targeting 4EHP, are developmentally delayed, fail to grow and eventually die. In addition, we found that expressing RNAi that targets 4EHP specifically in the prothoracic gland disrupted ecdysone biosynthesis, causing a block of the transition from the larval to pupal stages. This phenotype can be rescued by dietary administration of ecdysone. Consistent with this, 4EHP is highly expressed in the prothoracic gland and it is required for wild type expression levels of steroidogenic enzymes. Taken together, these results uncover a novel essential function for 4EHP in regulating ecdysone biosynthesis.

  4. Drosophila 4EHP is essential for the larval-pupal transition and required in the prothoracic gland for ecdysone biosynthesis.

    PubMed

    Valzania, Luca; Ono, Hajime; Ignesti, Marilena; Cavaliere, Valeria; Bernardi, Fabio; Gamberi, Chiara; Lasko, Paul; Gargiulo, Giuseppe

    2016-02-01

    Maternal expression of the translational regulator 4EHP (eIF4E-Homologous Protein) has an established role in generating protein gradients essential for specifying the Drosophila embryonic pattern. We generated a null mutation of 4EHP, which revealed for the first time that it is essential for viability and for completion of development. In fact, 4EHP null larvae, and larvae ubiquitously expressing RNAi targeting 4EHP, are developmentally delayed, fail to grow and eventually die. In addition, we found that expressing RNAi that targets 4EHP specifically in the prothoracic gland disrupted ecdysone biosynthesis, causing a block of the transition from the larval to pupal stages. This phenotype can be rescued by dietary administration of ecdysone. Consistent with this, 4EHP is highly expressed in the prothoracic gland and it is required for wild type expression levels of steroidogenic enzymes. Taken together, these results uncover a novel essential function for 4EHP in regulating ecdysone biosynthesis. PMID:26721418

  5. Food selection in larval fruit flies: dynamics and effects on larval development

    NASA Astrophysics Data System (ADS)

    Schwarz, Sebastian; Durisko, Zachary; Dukas, Reuven

    2014-01-01

    Selecting food items and attaining a nutritionally balanced diet is an important challenge for all animals including humans. We aimed to establish fruit fly larvae ( Drosophila melanogaster) as a simple yet powerful model system for examining the mechanisms of specific hunger and diet selection. In two lab experiments with artificial diets, we found that larvae deprived of either sucrose or protein later selectively fed on a diet providing the missing nutrient. When allowed to freely move between two adjacent food patches, larvae surprisingly preferred to settle on one patch containing yeast and ignored the patch providing sucrose. Moreover, when allowed to move freely between three patches, which provided either yeast only, sucrose only or a balanced mixture of yeast and sucrose, the majority of larvae settled on the yeast-plus-sucrose patch and about one third chose to feed on the yeast only food. While protein (yeast) is essential for development, we also quantified larval success on diets with or without sucrose and show that larvae develop faster on diets containing sucrose. Our data suggest that fruit fly larvae can quickly assess major nutrients in food and seek a diet providing a missing nutrient. The larvae, however, probably prefer to quickly dig into a single food substrate for enhanced protection over achieving an optimal diet.

  6. Functional Genetic Screen to Identify Interneurons Governing Behaviorally Distinct Aspects of Drosophila Larval Motor Programs

    PubMed Central

    Clark, Matt Q.; McCumsey, Stephanie J.; Lopez-Darwin, Sereno; Heckscher, Ellie S.; Doe, Chris Q.

    2016-01-01

    Drosophila larval crawling is an attractive system to study rhythmic motor output at the level of animal behavior. Larval crawling consists of waves of muscle contractions generating forward or reverse locomotion. In addition, larvae undergo additional behaviors, including head casts, turning, and feeding. It is likely that some neurons (e.g., motor neurons) are used in all these behaviors, but the identity (or even existence) of neurons dedicated to specific aspects of behavior is unclear. To identify neurons that regulate specific aspects of larval locomotion, we performed a genetic screen to identify neurons that, when activated, could elicit distinct motor programs. We used 165 Janelia CRM-Gal4 lines—chosen for sparse neuronal expression—to ectopically express the warmth-inducible neuronal activator TrpA1, and screened for locomotor defects. The primary screen measured forward locomotion velocity, and we identified 63 lines that had locomotion velocities significantly slower than controls following TrpA1 activation (28°). A secondary screen was performed on these lines, revealing multiple discrete behavioral phenotypes, including slow forward locomotion, excessive reverse locomotion, excessive turning, excessive feeding, immobile, rigid paralysis, and delayed paralysis. While many of the Gal4 lines had motor, sensory, or muscle expression that may account for some or all of the phenotype, some lines showed specific expression in a sparse pattern of interneurons. Our results show that distinct motor programs utilize distinct subsets of interneurons, and provide an entry point for characterizing interneurons governing different elements of the larval motor program. PMID:27172197

  7. ROS-mediated activation of Drosophila larval nociceptor neurons by UVC irradiation

    PubMed Central

    2014-01-01

    Background The complex Drosophila larval peripheral nervous system, capable of monitoring sensory input from the external environment, includes a family of multiple dendritic (md) neurons with extensive dendritic arbors tiling the inner surface of the larval body wall. The class IV multiple dendritic (mdIV) neurons are the most complex with dendritic nerve endings forming direct intimate contacts with epithelial cells of the larval body wall. Functioning as polymodal mechanonociceptors with the ability to respond to both noxious mechanical stimulation and noxious heat, the mdIV neurons are also activated by nanomolar levels of the endogenous reactive oxygen species (ROS), H2O2. Although often associated with tissue damage related to oxidative stress, endogenous ROS have also been shown to function as signaling molecules at lower concentrations. The overall role of ROS in sensory signaling is poorly understood but the acutely sensitive response of mdIV neurons to ROS-mediated activation is consistent with a routine role in the regulation of mdIV neuronal activity. Larvae respond to short wavelength ultraviolet (UVC) light with an immediate and visual system-independent writhing and twisting of the body previously described as a nociceptive response. Molecular and cellular mechanisms mediating this response and potential relationships with ROS generation are not well understood. We have used the UVC-induced writhing response as a model for investigation of the proposed link between endogenous ROS production and mdIV neuron function in the larval body wall. Results Transgenic inactivation of mdIV neurons caused a strong suppression of UVC-induced writhing behavior consistent with a key role for the mdIV neurons as mediators of the behavioral response. Direct imaging of ROS-activated fluorescence showed that UVC irradiation caused a significant increase in endogenous ROS levels in the larval body wall and transgenic overexpression of antioxidant enzymes strongly

  8. Dystroglycan and Protein O-Mannosyltransferases 1 and 2 Are Required to Maintain Integrity of Drosophila Larval Muscles

    PubMed Central

    Seabrooke, Sara; Stewart, Bryan A.

    2007-01-01

    In vertebrates, mutations in Protein O-mannosyltransferase1 (POMT1) or POMT2 are associated with muscular dystrophy due to a requirement for O-linked mannose glycans on the Dystroglycan (Dg) protein. In this study we examine larval body wall muscles of Drosophila mutant for Dg, or RNA interference knockdown for Dg and find defects in muscle attachment, altered muscle contraction, and a change in muscle membrane resistance. To determine if POMTs are required for Dg function in Drosophila, we examine larvae mutant for genes encoding POMT1 or POMT2. Larvae mutant for either POMT, or doubly mutant for both, show muscle attachment and muscle contraction phenotypes identical to those associated with reduced Dg function, consistent with a requirement for O-linked mannose on Drosophila Dg. Together these data establish a central role for Dg in maintaining integrity in Drosophila larval muscles and demonstrate the importance of glycosylation to Dg function in Drosophila. This study opens the possibility of using Drosophila to investigate muscular dystrophy. PMID:17881734

  9. UPRT, a suicide-gene therapy candidate in higher eukaryotes, is required for Drosophila larval growth and normal adult lifespan

    PubMed Central

    Ghosh, Arpan C.; Shimell, MaryJane; Leof, Emma R.; Haley, Macy J.; O’Connor, Michael B.

    2015-01-01

    Uracil phosphoribosyltransferase (UPRT) is a pyrimidine salvage pathway enzyme that catalyzes the conversion of uracil to uridine monophosphate (UMP). The enzyme is highly conserved from prokaryotes to humans and yet phylogenetic evidence suggests that UPRT homologues from higher-eukaryotes, including Drosophila, are incapable of binding uracil. Purified human UPRT also do not show any enzymatic activity in vitro, making microbial UPRT an attractive candidate for anti-microbial drug development, suicide-gene therapy, and cell-specific mRNA labeling techniques. Nevertheless, the enzymatic site of UPRT remains conserved across the animal kingdom indicating an in vivo role for the enzyme. We find that the Drosophila UPRT homologue, krishah (kri), codes for an enzyme that is required for larval growth, pre-pupal/pupal viability and long-term adult lifespan. Our findings suggest that UPRT from all higher eukaryotes is likely enzymatically active in vivo and challenges the previous notion that the enzyme is non-essential in higher eukaryotes and cautions against targeting the enzyme for therapeutic purposes. Our findings also suggest that expression of the endogenous UPRT gene will likely cause background incorporation when using microbial UPRT as a cell-specific mRNA labeling reagent in higher eukaryotes. PMID:26271729

  10. Lineage-associated tracts defining the anatomy of the Drosophila first instar larval brain.

    PubMed

    Hartenstein, Volker; Younossi-Hartenstein, Amelia; Lovick, Jennifer K; Kong, Angel; Omoto, Jaison J; Ngo, Kathy T; Viktorin, Gudrun

    2015-10-01

    Fixed lineages derived from unique, genetically specified neuroblasts form the anatomical building blocks of the Drosophila brain. Neurons belonging to the same lineage project their axons in a common tract, which is labeled by neuronal markers. In this paper, we present a detailed atlas of the lineage-associated tracts forming the brain of the early Drosophila larva, based on the use of global markers (anti-Neuroglian, anti-Neurotactin, inscuteable-Gal4>UAS-chRFP-Tub) and lineage-specific reporters. We describe 68 discrete fiber bundles that contain axons of one lineage or pairs/small sets of adjacent lineages. Bundles enter the neuropil at invariant locations, the lineage tract entry portals. Within the neuropil, these fiber bundles form larger fascicles that can be classified, by their main orientation, into longitudinal, transverse, and vertical (ascending/descending) fascicles. We present 3D digital models of lineage tract entry portals and neuropil fascicles, set into relationship to commonly used, easily recognizable reference structures such as the mushroom body, the antennal lobe, the optic lobe, and the Fasciclin II-positive fiber bundles that connect the brain and ventral nerve cord. Correspondences and differences between early larval tract anatomy and the previously described late larval and adult lineage patterns are highlighted. Our L1 neuro-anatomical atlas of lineages constitutes an essential step towards following morphologically defined lineages to the neuroblasts of the early embryo, which will ultimately make it possible to link the structure and connectivity of a lineage to the expression of genes in the particular neuroblast that gives rise to that lineage. Furthermore, the L1 atlas will be important for a host of ongoing work that attempts to reconstruct neuronal connectivity at the level of resolution of single neurons and their synapses.

  11. Four Individually Identified Paired Dopamine Neurons Signal Reward in Larval Drosophila.

    PubMed

    Rohwedder, Astrid; Wenz, Nana L; Stehle, Bernhard; Huser, Annina; Yamagata, Nobuhiro; Zlatic, Marta; Truman, James W; Tanimoto, Hiromu; Saumweber, Timo; Gerber, Bertram; Thum, Andreas S

    2016-03-01

    Dopaminergic neurons serve multiple functions, including reinforcement processing during associative learning [1-12]. It is thus warranted to understand which dopaminergic neurons mediate which function. We study larval Drosophila, in which only approximately 120 of a total of 10,000 neurons are dopaminergic, as judged by the expression of tyrosine hydroxylase (TH), the rate-limiting enzyme of dopamine biosynthesis [5, 13]. Dopaminergic neurons mediating reinforcement in insect olfactory learning target the mushroom bodies, a higher-order "cortical" brain region [1-5, 11, 12, 14, 15]. We discover four previously undescribed paired neurons, the primary protocerebral anterior medial (pPAM) neurons. These neurons are TH positive and subdivide the medial lobe of the mushroom body into four distinct subunits. These pPAM neurons are acutely necessary for odor-sugar reward learning and require intact TH function in this process. However, they are dispensable for aversive learning and innate behavior toward the odors and sugars employed. Optogenetical activation of pPAM neurons is sufficient as a reward. Thus, the pPAM neurons convey a likely dopaminergic reward signal. In contrast, DL1 cluster neurons convey a corresponding punishment signal [5], suggesting a cellular division of labor to convey dopaminergic reward and punishment signals. On the level of individually identified neurons, this uncovers an organizational principle shared with adult Drosophila and mammals [1-4, 7, 9, 10] (but see [6]). The numerical simplicity and connectomic tractability of the larval nervous system [16-19] now offers a prospect for studying circuit principles of dopamine function at unprecedented resolution. PMID:26877086

  12. Distinct visual pathways mediate Drosophila larval light avoidance and circadian clock entrainment.

    PubMed

    Keene, Alex C; Mazzoni, Esteban O; Zhen, Jamie; Younger, Meg A; Yamaguchi, Satoko; Blau, Justin; Desplan, Claude; Sprecher, Simon G

    2011-04-27

    Visual organs perceive environmental stimuli required for rapid initiation of behaviors and can also entrain the circadian clock. The larval eye of Drosophila is capable of both functions. Each eye contains only 12 photoreceptors (PRs), which can be subdivided into two subtypes. Four PRs express blue-sensitive rhodopsin5 (rh5) and eight express green-sensitive rhodopsin6 (rh6). We found that either PR-subtype is sufficient to entrain the molecular clock by light, while only the Rh5-PR subtype is essential for light avoidance. Acetylcholine released from PRs confers both functions. Both subtypes of larval PRs innervate the main circadian pacemaker neurons of the larva, the neuropeptide PDF (pigment-dispersing factor)-expressing lateral neurons (LNs), providing sensory input to control circadian rhythms. However, we show that PDF-expressing LNs are dispensable for light avoidance, and a distinct set of three clock neurons is required. Thus we have identified distinct sensory and central circuitry regulating light avoidance behavior and clock entrainment. Our findings provide insights into the coding of sensory information for distinct behavioral functions and the underlying molecular and neuronal circuitry. PMID:21525293

  13. Divergence of larval resource acquisition for water conservation and starvation resistance in Drosophila melanogaster.

    PubMed

    Parkash, Ravi; Aggarwal, Dau Dayal; Ranga, Poonam; Singh, Divya

    2012-07-01

    Laboratory selection experiments have evidenced storage of energy metabolites in adult flies of desiccation and starvation resistant strains of D. melanogaster but resource acquisition during larval stages has received lesser attention. For wild populations of D. melanogaster, it is not clear whether larvae acquire similar or different energy metabolites for desiccation and starvation resistance. We tested the hypothesis whether larval acquisition of energy metabolites is consistent with divergence of desiccation and starvation resistance in darker and lighter isofemale lines of D. melanogaster. Our results are interesting in several respects. First, we found contrasting patterns of larval resource acquisition, i.e., accumulation of higher carbohydrates during 3rd instar larval stage of darker flies versus higher levels of triglycerides in 1st and 2nd larval instars of lighter flies. Second, 3rd instar larvae of darker flies showed ~40 h longer duration of development at 21°C; and greater accumulation of carbohydrates (trehalose and glycogen) in fed larvae as compared with larvae non-fed after 150 h of egg laying. Third, darker isofemale lines have shown significant increase in total water content (18%); hemolymph (86%) and dehydration tolerance (11%) as compared to lighter isofemale lines. Loss of hemolymph water under desiccation stress until death was significantly higher in darker as compared to lighter isofemale lines but tissue water loss was similar. Fourth, for larvae of darker flies, about 65% energy content is contributed by carbohydrates for conferring greater desiccation resistance while the larvae of lighter flies acquire 2/3 energy from lipids for sustaining starvation resistance; and such energy differences persist in the newly eclosed flies. Thus, larval stages of wild-caught darker and lighter flies have evolved independent physiological processes for the accumulation of energy metabolites to cope with desiccation or starvation stress.

  14. Acquisition of high-quality digital video of Drosophila larval and adult behaviors from a lateral perspective.

    PubMed

    Zenger, Beatrix; Wetzel, Sabine; Duncan, Jason

    2014-01-01

    Drosophila melanogaster is a powerful experimental model system for studying the function of the nervous system. Gene mutations that cause dysfunction of the nervous system often produce viable larvae and adults that have locomotion defective phenotypes that are difficult to adequately describe with text or completely represent with a single photographic image. Current modes of scientific publishing, however, support the submission of digital video media as supplemental material to accompany a manuscript. Here we describe a simple and widely accessible microscopy technique for acquiring high-quality digital video of both Drosophila larval and adult phenotypes from a lateral perspective. Video of larval and adult locomotion from a side-view is advantageous because it allows the observation and analysis of subtle distinctions and variations in aberrant locomotive behaviors. We have successfully used the technique to visualize and quantify aberrant crawling behaviors in third instar larvae, in addition to adult mutant phenotypes and behaviors including grooming. PMID:25350294

  15. Acquisition of High-Quality Digital Video of Drosophila Larval and Adult Behaviors from a Lateral Perspective

    PubMed Central

    Zenger, Beatrix; Wetzel, Sabine; Duncan, Jason

    2014-01-01

    Drosophila melanogaster is a powerful experimental model system for studying the function of the nervous system. Gene mutations that cause dysfunction of the nervous system often produce viable larvae and adults that have locomotion defective phenotypes that are difficult to adequately describe with text or completely represent with a single photographic image. Current modes of scientific publishing, however, support the submission of digital video media as supplemental material to accompany a manuscript. Here we describe a simple and widely accessible microscopy technique for acquiring high-quality digital video of both Drosophila larval and adult phenotypes from a lateral perspective. Video of larval and adult locomotion from a side-view is advantageous because it allows the observation and analysis of subtle distinctions and variations in aberrant locomotive behaviors. We have successfully used the technique to visualize and quantify aberrant crawling behaviors in third instar larvae, in addition to adult mutant phenotypes and behaviors including grooming. PMID:25350294

  16. Synaptic excitation is regulated by the postsynaptic dSK channel at the Drosophila larval NMJ

    PubMed Central

    Gertner, Daniel M.; Desai, Sunil

    2014-01-01

    In the mammalian central nervous system, the postsynaptic small-conductance Ca2+-dependent K+ (SK) channel has been shown to reduce postsynaptic depolarization and limit Ca2+ influx through N-methyl-d-aspartate receptors. To examine further the role of the postsynaptic SK channel in synaptic transmission, we studied its action at the Drosophila larval neuromuscular junction (NMJ). Repetitive synaptic stimulation produced an increase in postsynaptic membrane conductance leading to depression of excitatory postsynaptic potential amplitude and hyperpolarization of the resting membrane potential (RMP). This reduction in synaptic excitation was due to the postsynaptic Drosophila SK (dSK) channel; synaptic depression, increased membrane conductance and RMP hyperpolarization were reduced in dSK mutants or after expressing a Ca2+ buffer in the muscle. Ca2+ entering at the postsynaptic membrane was sufficient to activate dSK channels based upon studies in which the muscle membrane was voltage clamped to prevent opening voltage-dependent Ca2+ channels. Increasing external Ca2+ produced an increase in resting membrane conductance and RMP that was not seen in dSK mutants or after adding the glutamate-receptor blocker philanthotoxin. Thus it appeared that dSK channels were also activated by spontaneous transmitter release and played a role in setting membrane conductance and RMP. In mammals, dephosphorylation by protein phosphatase 2A (PP2A) increased the Ca2+ sensitivity of the SK channel; PP2A appeared to increase the sensitivity of the dSK channel since PP2A inhibitors reduced activation of the dSK channel by evoked synaptic activity or increased external Ca2+. It is proposed that spontaneous and evoked transmitter release activate the postsynaptic dSK channel to limit synaptic excitation and stabilize synapses. PMID:24671529

  17. Using Drosophila Larval Imaginal Discs to Study Low-Dose Radiation-Induced Cell Cycle Arrest

    PubMed Central

    Yan, Shian-Jang; Li, Willis X.

    2012-01-01

    Under genotoxic stress, activation of cell cycle checkpoint responses leads to cell cycle arrest, which allows cells to repair DNA damage before continuing to cycle. Drosophila larval epithelial sacs, called imaginal discs, are an excellent in vivo model system for studying radiation-induced cell cycle arrest. Larval imaginal discs go into cell cycle arrest after being subjected to low-dose irradiation, are subject to easy genetic manipulation, are not crucial for survival of the organism, and can be dissected easily for further molecular or cellular analysis. In this chapter, we describe methods for assessing low-dose irradiation-induced cell cycle arrest. Mitotic cells are identified by immunofluorescence staining for the mitotic marker phosphorylated histone H3 (phospho-histone H3 or pH3). When wandering third-instar control larvae, without transgene expression, are exposed to 500 rads of X-ray or γ-ray irradiation, the number of pH3-positive cells in wing imaginal discs is reduced from hundreds before irradiation to approximately 30 after irradiation, with an equal distribution between the anterior and posterior compartments (Yan et al., 2011, FASEB J). Using the GAL4/UAS system, RNAi, cDNA, or microRNA sponge transgenes can be expressed in the posterior compartment of the wing disc using drivers such as engrailed (en)-Gal4, while the anterior compartment serves as an internal control. This approach makes it possible to do genome-wide genetic screening for molecules involved in radiation-induced cell cycle arrest. PMID:21870287

  18. Redundant cis-acting elements control expression of the Drosophila affinidisjuncta Adh gene in the larval fat body.

    PubMed Central

    McKenzie, R W; Hu, J; Brennan, M D

    1994-01-01

    The alcohol dehydrogenase (Adh) gene in the Hawaiian species of fruit fly, Drosophila affinidisjuncta, like the Adh genes from all Drosophila species analyzed, is expressed at high levels in the larval fat body via a larval-specific promoter. To identify the cis-acting elements involved in this highly conserved aspect of Adh gene expression, deleted D. affinidisjuncta genes were introduced into D. melanogaster by somatic transformation. Unlike previously described methods, this transformation system allows analysis of Adh gene expression specifically in the larval fat body. The arrangement of sequences influencing expression of the proximal promoter of this gene in the larval fat body differs markedly from that described for the Adh gene from the distant relative, D. melanogaster. Multiple redundant elements dispersed 5' and 3' to the gene, only some of which map to regions carrying evolutionarily conserved sequences, affect expression in the fat body. D. affinidisjuncta employs a novel mode of Adh gene regulation in which the proximal promoter is influenced by sequences having roles in expression of the distal promoter. This gene is also unique in that far upstream sequences can compensate for loss of sequences within 200 bp of the proximal RNA start site. Furthermore, expression is influenced in an unusual, context-dependent manner by a naturally-occurring 3' duplication of the proximal promoter--a feature found only in Hawaiian species. Images PMID:8165141

  19. Lineage mapping identifies molecular and architectural similarities between the larval and adult Drosophila central nervous system

    PubMed Central

    Lacin, Haluk; Truman, James W

    2016-01-01

    Neurogenesis in Drosophila occurs in two phases, embryonic and post-embryonic, in which the same set of neuroblasts give rise to the distinct larval and adult nervous systems, respectively. Here, we identified the embryonic neuroblast origin of the adult neuronal lineages in the ventral nervous system via lineage-specific GAL4 lines and molecular markers. Our lineage mapping revealed that neurons born late in the embryonic phase show axonal morphology and transcription factor profiles that are similar to the neurons born post-embryonically from the same neuroblast. Moreover, we identified three thorax-specific neuroblasts not previously characterized and show that HOX genes confine them to the thoracic segments. Two of these, NB2-3 and NB3-4, generate leg motor neurons. The other neuroblast is novel and appears to have arisen recently during insect evolution. Our findings provide a comprehensive view of neurogenesis and show how proliferation of individual neuroblasts is dictated by temporal and spatial cues. DOI: http://dx.doi.org/10.7554/eLife.13399.001 PMID:26975248

  20. Drosophila Immunity: Analysis of Larval Hemocytes by P-Element-Mediated Enhancer Trap

    PubMed Central

    Braun, A.; Lemaitre, B.; Lanot, R.; Zachary, D.; Meister, M.

    1997-01-01

    Our aim was to identify new genes involved in the cellular aspects of defense mechanisms of Drosophila, as well as in melanotic tumor formation processes that are linked to blood cell disregulation. We have screened 1341 enhancer detector fly lines for expression of the lacZ reporter gene in larval hemocytes at the end of the third instar. We have selected 21 lines in which we observed a reproducible lacZ expression in blood cells. These lines were classified according to the subsets of hemocytes in which lacZ was expressed, and we identified five lines that can be used as lamellocyte markers. Three lines were selected for further analysis. The first exhibited strong lacZ expression in all lamellocytes. The second expressed lacZ in plasmatocytes and lamellocytes, and exhibited a melanotic tumor phenotype in larvae homozygous for the insertion. A third line showed a striking insertion-linked phenotype of melanized lymph glands (the hematopoietic organ), which resulted in the total absence of circulating hemocytes in the mutant larvae. We anticipate that this mutation, which we named domino, will prove a useful tool in the analysis of the role of hemocytes during the various aspects of immune response and melanotic tumor formation. PMID:9335599

  1. Gemin3 Is an Essential Gene Required for Larval Motor Function and Pupation in Drosophila

    PubMed Central

    Shpargel, Karl B.; Praveen, Kavita; Rajendra, T. K.

    2009-01-01

    The assembly of metazoan Sm-class small nuclear ribonucleoproteins (snRNPs) is an elaborate, step-wise process that takes place in multiple subcellular compartments. The initial steps, including formation of the core RNP, are mediated by the survival motor neuron (SMN) protein complex. Loss-of-function mutations in human SMN1 result in a neuromuscular disease called spinal muscular atrophy. The SMN complex is comprised of SMN and a number of tightly associated proteins, collectively called Gemins. In this report, we identify and characterize the fruitfly ortholog of the DEAD box protein, Gemin3. Drosophila Gemin3 (dGem3) colocalizes and interacts with dSMN in vitro and in vivo. RNA interference for dGem3 codepletes dSMN and inhibits efficient Sm core assembly in vitro. Transposon insertion mutations in Gemin3 are larval lethals and also codeplete dSMN. Transgenic overexpression of dGem3 rescues lethality, but overexpression of dSMN does not, indicating that loss of dSMN is not the primary cause of death. Gemin3 mutant larvae exhibit motor defects similar to previously characterized Smn alleles. Remarkably, appreciable numbers of Gemin3 mutants (along with one previously undescribed Smn allele) survive as larvae for several weeks without pupating. Our results demonstrate the conservation of Gemin3 protein function in metazoan snRNP assembly and reveal that loss of either Smn or Gemin3 can contribute to neuromuscular dysfunction. PMID:18923150

  2. Pox neuro control of cell lineages that give rise to larval poly-innervated external sensory organs in Drosophila.

    PubMed

    Jiang, Yanrui; Boll, Werner; Noll, Markus

    2015-01-15

    The Pox neuro (Poxn) gene of Drosophila plays a crucial role in the development of poly-innervated external sensory (p-es) organs. However, how Poxn exerts this role has remained elusive. In this study, we have analyzed the cell lineages of all larval p-es organs, namely of the kölbchen, papilla 6, and hair 3. Surprisingly, these lineages are distinct from any previously reported cell lineages of sensory organs. Unlike the well-established lineage of mono-innervated external sensory (m-es) organs and a previously proposed model of the p-es lineage, we demonstrate that all wild-type p-es lineages exhibit the following features: the secondary precursor, pIIa, gives rise to all three support cells-socket, shaft, and sheath, whereas the other secondary precursor, pIIb, is neuronal and gives rise to all neurons. We further show that in one of the p-es lineages, that of papilla 6, one cell undergoes apoptosis. By contrast in Poxn null mutants, all p-es lineages have a reduced number of cells and their pattern of cell divisions is changed to that of an m-es organ, with the exception of a lineage in a minority of mutant kölbchen that retains a second bipolar neuron. Indeed, the role of Poxn in p-es lineages is consistent with the specification of the developmental potential of secondary precursors and the regulation of cell division but not apoptosis.

  3. Piezo Is Essential for Amiloride-Sensitive Stretch-Activated Mechanotransduction in Larval Drosophila Dorsal Bipolar Dendritic Sensory Neurons.

    PubMed

    Suslak, Thomas J; Watson, Sonia; Thompson, Karen J; Shenton, Fiona C; Bewick, Guy S; Armstrong, J Douglas; Jarman, Andrew P

    2015-01-01

    Stretch-activated afferent neurons, such as those of mammalian muscle spindles, are essential for proprioception and motor co-ordination, but the underlying mechanisms of mechanotransduction are poorly understood. The dorsal bipolar dendritic (dbd) sensory neurons are putative stretch receptors in the Drosophila larval body wall. We have developed an in vivo protocol to obtain receptor potential recordings from intact dbd neurons in response to stretch. Receptor potential changes in dbd neurons in response to stretch showed a complex, dynamic profile with similar characteristics to those previously observed for mammalian muscle spindles. These profiles were reproduced by a general in silico model of stretch-activated neurons. This in silico model predicts an essential role for a mechanosensory cation channel (MSC) in all aspects of receptor potential generation. Using pharmacological and genetic techniques, we identified the mechanosensory channel, DmPiezo, in this functional role in dbd neurons, with TRPA1 playing a subsidiary role. We also show that rat muscle spindles exhibit a ruthenium red-sensitive current, but found no expression evidence to suggest that this corresponds to Piezo activity. In summary, we show that the dbd neuron is a stretch receptor and demonstrate that this neuron is a tractable model for investigating mechanisms of mechanotransduction.

  4. A single GABAergic neuron mediates feedback of odor-evoked signals in the mushroom body of larval Drosophila

    PubMed Central

    Masuda-Nakagawa, Liria M.; Ito, Kei; Awasaki, Takeshi; O'Kane, Cahir J.

    2014-01-01

    Inhibition has a central role in defining the selectivity of the responses of higher order neurons to sensory stimuli. However, the circuit mechanisms of regulation of these responses by inhibitory neurons are still unclear. In Drosophila, the mushroom bodies (MBs) are necessary for olfactory memory, and by implication for the selectivity of learned responses to specific odors. To understand the circuitry of inhibition in the calyx (the input dendritic region) of the MBs, and its relationship with MB excitatory activity, we used the simple anatomy of the Drosophila larval olfactory system to identify any inhibitory inputs that could contribute to the selectivity of MB odor responses. We found that a single neuron accounts for all detectable GABA innervation in the calyx of the MBs, and that this neuron has pre-synaptic terminals in the calyx and post-synaptic branches in the MB lobes (output axonal area). We call this neuron the larval anterior paired lateral (APL) neuron, because of its similarity to the previously described adult APL neuron. Reconstitution of GFP partners (GRASP) suggests that the larval APL makes extensive contacts with the MB intrinsic neurons, Kenyon Cells (KCs), but few contacts with incoming projection neurons (PNs). Using calcium imaging of neuronal activity in live larvae, we show that the larval APL responds to odors, in a mannner that requires output from KCs. Our data suggest that the larval APL is the sole GABAergic neuron that innervates the MB input region and carries inhibitory feedback from the MB output region, consistent with a role in modulating the olfactory selectivity of MB neurons. PMID:24782716

  5. The ecdysteroidome of Drosophila: influence of diet and development.

    PubMed

    Lavrynenko, Oksana; Rodenfels, Jonathan; Carvalho, Maria; Dye, Natalie A; Lafont, Rene; Eaton, Suzanne; Shevchenko, Andrej

    2015-11-01

    Ecdysteroids are the hormones regulating development, physiology and fertility in arthropods, which synthesize them exclusively from dietary sterols. But how dietary sterol diversity influences the ecdysteroid profile, how animals ensure the production of desired hormones and whether there are functional differences between different ecdysteroids produced in vivo remains unknown. This is because currently there is no analytical technology for unbiased, comprehensive and quantitative assessment of the full complement of endogenous ecdysteroids. We developed a new LC-MS/MS method to screen the entire chemical space of ecdysteroid-related structures and to quantify known and newly discovered hormones and their catabolites. We quantified the ecdysteroidome in Drosophila melanogaster and investigated how the ecdysteroid profile varies with diet and development. We show that Drosophila can produce four different classes of ecdysteroids, which are obligatorily derived from four types of dietary sterol precursors. Drosophila makes makisterone A from plant sterols and epi-makisterone A from ergosterol, the major yeast sterol. However, they prefer to selectively utilize scarce ergosterol precursors to make a novel hormone 24,28-dehydromakisterone A and trace cholesterol to synthesize 20-hydroxyecdysone. Interestingly, epi-makisterone A supports only larval development, whereas all other ecdysteroids allow full adult development. We suggest that evolutionary pressure against producing epi-C-24 ecdysteroids might explain selective utilization of ergosterol precursors and the puzzling preference for cholesterol.

  6. Comparison of dopamine kinetics in the larval Drosophila ventral nerve cord and protocerebrum with improved optogenetic stimulation.

    PubMed

    Privman, Eve; Venton, B Jill

    2015-11-01

    Dopamine release and uptake have been studied in the Drosophila larval ventral nerve cord (VNC) using optogenetics to stimulate endogenous release. However, other areas of the central nervous system remain uncharacterized. Here, we compare dopamine release in the VNC and protocerebrum of larval Drosophila. Stimulations were performed with CsChrimson, a new, improved, red light-activated channelrhodopsin. In both regions, dopamine release was observed after only a single, 4 ms duration light pulse. Michaelis-Menten modeling was used to understand release and uptake parameters for dopamine. The amount of dopamine released ([DA]p ) on the first stimulation pulse is higher than the average [DA]p released from subsequent pulses. The initial and average amount of dopamine released per stimulation pulse is smaller in the protocerebrum than in the VNC. The average Vmax of 0.08 μM/s in the protocerebrum was significantly higher than the Vmax of 0.05 μM/s in the VNC. The average Km of 0.11 μM in the protocerebrum was not significantly different from the Km of 0.10 μM in the VNC. When the competitive dopamine transporter (DAT) inhibitor nisoxetine was applied, the Km increased significantly in both regions while Vmax stayed the same. This work demonstrates regional differences in dopamine release and uptake kinetics, indicating important variation in the amount of dopamine available for neurotransmission and neuromodulation. We use a new optogenetic tool, red light activated CsChrimson, to stimulate the release of dopamine in the ventral nerve cord and medial protocerebrum of the larval Drosophila central nervous system. We monitored extracellular dopamine by fast scan cyclic voltammetry and used Michaelis-Menten modeling to probe the regulation of extracellular dopamine, discovering important similarities and differences in these two regions.

  7. Gene Regulation Networks for Modeling Drosophila Development

    NASA Technical Reports Server (NTRS)

    Mjolsness, E.

    1999-01-01

    This chapter will very briefly introduce and review some computational experiments in using trainable gene regulation network models to simulate and understand selected episodes in the development of the fruit fly, Drosophila Melanogaster.

  8. Searching for motifs in the behaviour of larval Drosophila melanogaster and Caenorhabditis elegans reveals continuity between behavioural states.

    PubMed

    Szigeti, Balázs; Deogade, Ajinkya; Webb, Barbara

    2015-12-01

    We present a novel method for the unsupervised discovery of behavioural motifs in larval Drosophila melanogaster and Caenorhabditis elegans. A motif is defined as a particular sequence of postures that recurs frequently. The animal's changing posture is represented by an eigenshape time series, and we look for motifs in this time series. To find motifs, the eigenshape time series is segmented, and the segments clustered using spline regression. Unlike previous approaches, our method can classify sequences of unequal duration as the same motif. The behavioural motifs are used as the basis of a probabilistic behavioural annotator, the eigenshape annotator (ESA). Probabilistic annotation avoids rigid threshold values and allows classification uncertainty to be quantified. We apply eigenshape annotation to both larval Drosophila and C. elegans and produce a good match to hand annotation of behavioural states. However, we find many behavioural events cannot be unambiguously classified. By comparing the results with ESA of an artificial agent's behaviour, we argue that the ambiguity is due to greater continuity between behavioural states than is generally assumed for these organisms.

  9. Searching for motifs in the behaviour of larval Drosophila melanogaster and Caenorhabditis elegans reveals continuity between behavioural states

    PubMed Central

    Szigeti, Balázs; Webb, Barbara

    2015-01-01

    We present a novel method for the unsupervised discovery of behavioural motifs in larval Drosophila melanogaster and Caenorhabditis elegans. A motif is defined as a particular sequence of postures that recurs frequently. The animal's changing posture is represented by an eigenshape time series, and we look for motifs in this time series. To find motifs, the eigenshape time series is segmented, and the segments clustered using spline regression. Unlike previous approaches, our method can classify sequences of unequal duration as the same motif. The behavioural motifs are used as the basis of a probabilistic behavioural annotator, the eigenshape annotator (ESA). Probabilistic annotation avoids rigid threshold values and allows classification uncertainty to be quantified. We apply eigenshape annotation to both larval Drosophila and C. elegans and produce a good match to hand annotation of behavioural states. However, we find many behavioural events cannot be unambiguously classified. By comparing the results with ESA of an artificial agent's behaviour, we argue that the ambiguity is due to greater continuity between behavioural states than is generally assumed for these organisms. PMID:26609067

  10. Characterization of null and hypomorphic alleles of the Drosophila l(2)dtl/cdt2 gene: Larval lethality and male fertility.

    PubMed

    Sloan, Roketa S; Swanson, Christina I; Gavilano, Lily; Smith, Kristen N; Malek, Pamela Y; Snow-Smith, Mayronne; Duronio, Robert J; Key, S Catherine Silver

    2012-01-01

    The Drosophila lethal(2)denticleless (l(2)dtl) gene was originally reported as essential for embryogenesis and formation of the rows of tiny hairs on the larval ventral cuticle known as denticle belts. It is now well-established that l(2)dtl (also called cdt2) encodes a subunit of a Cullin 4-based E3 ubiquitin ligase complex that targets a number of key cell cycle regulatory proteins, including p21, Cdt1, E2F1 and Set8, to prevent replication defects and maintain cell cycle control. To investigate the role of l(2)dtl/cdt2 during development, we characterized existing l(2)dtl/cdt2 mutants and generated new deletion alleles, using P-element excision mutagenesis. Surprisingly, homozygous l(2)dtl/cdt2 mutant embryos developed beyond embryogenesis, had intact denticle belts, and lacked an observable embryonic replication defect. These mutants died during larval stages, affirming that loss of l(2)dtl/cdt2 function is lethal. Our data show that L(2)dtl/Cdt2 is maternally deposited, remains nuclear throughout the cell cycle, and has a previously unreported, elevated expression in the developing gonads. We also find that E2f1 regulates l(2)dtl/cdt2 expression during embryogenesis, possibly via several highly conserved putative E2f1 binding sites near the l(2)dtl/cdt2 promoter. Finally, hypomorphic allele combinations of the l(2)dtl/cdt2 gene result in a novel phenotype: viable, low-fertility males. We conclude that "denticleless" is a misnomer, but that l(2)dtl/cdt2 is an essential gene for Drosophila development.

  11. TIF-IA-dependent regulation of ribosome synthesis in drosophila muscle is required to maintain systemic insulin signaling and larval growth.

    PubMed

    Ghosh, Abhishek; Rideout, Elizabeth J; Grewal, Savraj S

    2014-10-01

    The conserved TOR kinase signaling network links nutrient availability to cell, tissue and body growth in animals. One important growth-regulatory target of TOR signaling is ribosome biogenesis. Studies in yeast and mammalian cell culture have described how TOR controls rRNA synthesis-a limiting step in ribosome biogenesis-via the RNA Polymerase I transcription factor TIF-IA. However, the contribution of TOR-dependent ribosome synthesis to tissue and body growth in animals is less clear. Here we show in Drosophila larvae that ribosome synthesis in muscle is required non-autonomously to maintain normal body growth and development. We find that amino acid starvation and TOR inhibition lead to reduced levels of TIF-IA, and decreased rRNA synthesis in larval muscle. When we mimic this decrease in muscle ribosome synthesis using RNAi-mediated knockdown of TIF-IA, we observe delayed larval development and reduced body growth. This reduction in growth is caused by lowered systemic insulin signaling via two endocrine responses: reduced expression of Drosophila insulin-like peptides (dILPs) from the brain and increased expression of Imp-L2-a secreted factor that binds and inhibits dILP activity-from muscle. We also observed that maintaining TIF-IA levels in muscle could partially reverse the starvation-mediated suppression of systemic insulin signaling. Finally, we show that activation of TOR specifically in muscle can increase overall body size and this effect requires TIF-IA function. These data suggest that muscle ribosome synthesis functions as a nutrient-dependent checkpoint for overall body growth: in nutrient rich conditions, TOR is required to maintain levels of TIF-IA and ribosome synthesis to promote high levels of systemic insulin, but under conditions of starvation stress, reduced muscle ribosome synthesis triggers an endocrine response that limits systemic insulin signaling to restrict growth and maintain homeostasis.

  12. Orthodenticle is necessary for survival of a cluster of clonally related dopaminergic neurons in the Drosophila larval and adult brain

    PubMed Central

    2011-01-01

    Background The dopaminergic (DA) neurons present in the central brain of the Drosophila larva are spatially arranged in stereotyped groups that define clusters of bilaterally symmetrical neurons. These clusters have been classified according to anatomical criteria (position of the cell bodies within the cortex and/or projection pattern of the axonal tracts). However, information pertaining to the developmental biology, such as lineage relationship of clustered DA neurons and differential cell subtype-specific molecular markers and mechanisms of differentiation and/or survival, is currently not available. Results Using MARCM and twin-spot MARCM techniques together with anti-tyrosine hydroxylase immunoreactivity, we have analyzed the larval central brain DA neurons from a developmental point of view and determined their time of birth, their maturation into a DA neurotransmitter phenotype as well as their lineage relationships. In addition, we have found that the homeodomain containing transcription factor Orthodenticle (Otd) is present in a cluster of clonally related DA neurons in both the larval and adult brain. Taking advantage of the otd hypomorphic mutation ocelliless (oc) and the oc2-Gal4 reporter line, we have studied the involvement of orthodenticle (otd) in the survival and/or cell fate specification of these post-mitotic neurons. Conclusions Our findings provide evidence of the presence of seven neuroblast lineages responsible for the generation of the larval central brain DA neurons during embryogenesis. otd is expressed in a defined group of clonally related DA neurons from first instar larvae to adulthood, making it possible to establish an identity relationship between the larval DL2a and the adult PPL2 DA clusters. This poses otd as a lineage-specific and differential marker of a subset of clonally related DA neurons. Finally, we show that otd is required in those DA neurons for their survival. PMID:21999236

  13. Nerve-muscle interactions during flight muscle development in Drosophila

    NASA Technical Reports Server (NTRS)

    Fernandes, J. J.; Keshishian, H.

    1998-01-01

    During Drosophila pupal metamorphosis, the motoneurons and muscles differentiate synchronously, providing an opportunity for extensive intercellular regulation during synapse formation. We examined the existence of such interactions by developmentally delaying or permanently eliminating synaptic partners during the formation of indirect flight muscles. When we experimentally delayed muscle development, we found that although adult-specific primary motoneuron branching still occurred, the higher order (synaptic) branching was suspended until the delayed muscle fibers reached a favourable developmental state. In reciprocal experiments we found that denervation caused a decrease in the myoblast pool. Furthermore, the formation of certain muscle fibers (dorsoventral muscles) was specifically blocked. Exceptions were the adult muscles that use larval muscle fibers as myoblast fusion targets (dorsal longitudinal muscles). However, when these muscles were experimentally compelled to develop without their larval precursors, they showed an absolute dependence on the motoneurons for their formation. These data show that the size of the myoblast pool and early events in fiber formation depend on the presence of the nerve, and that, conversely, peripheral arbor development and synaptogenesis is closely synchronized with the developmental state of the muscle.

  14. Long Term Ex Vivo Culture and Live Imaging of Drosophila Larval Imaginal Discs

    PubMed Central

    Lee, Yuan-Ming; Huang, Yu-Fen

    2016-01-01

    Continuous imaging of live tissues provides clear temporal sequence of biological events. The Drosophila imaginal discs have been popular experimental subjects for the study of a wide variety of biological phenomena, but long term culture that allows normal development has not been satisfactory. Here we report a culture method that can sustain normal development for 18 hours and allows live imaging. The method is validated in multiple discs and for cell proliferation, differentiation and migration. However, it does not support disc growth and cannot support cell proliferation for more than 7 to 12 hr. We monitored the cellular behavior of retinal basal glia in the developing eye disc and found that distinct glia type has distinct properties of proliferation and migration. The live imaging provided direct proof that wrapping glia differentiated from existing glia after migrating to the anterior front, and unexpectedly found that they undergo endoreplication before wrapping axons, and their nuclei migrate up and down along the axons. UV-induced specific labeling of a single carpet glia also showed that the two carpet glia membrane do not overlap and suggests a tiling or repulsion mechanism between the two cells. These findings demonstrated the usefulness of an ex vivo culture method and live imaging. PMID:27685172

  15. Expression of anterior Hox genes during larval development of the gastropod Haliotis asinina.

    PubMed

    Hinman, Veronica F; O'Brien, Elizabeth K; Richards, Gemma S; Degnan, Bernard M

    2003-01-01

    We report the spatial expression patterns of five anterior Hox genes during larval development of the gastropod mollusc Haliotis asinina, an unsegmented spiralian lophotrochozoan. Molecular alignments and phylogenetic analysis indicate that these genes are homologues of Drosophila HOM-C genes labial, proboscipedia, zen, Deformed, and Sex combs reduced; the abalone genes are named Has-Hox1, -Hox2, -Hox3, -Hox4, and -Hox5. Has-Hox transcripts are first detected in the free-swimming trochophore larval stage and restricted to the posttrochal ectoderm. Has-Hox2, -Hox3, and -Hox4 are expressed in bilaterally symmetrical and overlapping patterns in presumptive neuroectodermal cells on the ventral side of the trochophore. Has-Hox1 expression is restricted to a ring of cells on the dorsoposterior surface, corresponding to the outer mantle edge where new larval shell is being synthesized. There appears to be little change in the expression domains of these Has-Hox genes in pre- and posttorsional veliger larvae, with expression maintained in ectodermal and neuroectodermal tissues. Has-Hox2, -Hox3, -Hox4, and-Hox5 appear to be expressed in a colinear manner in the ganglia and connectives in the twisted nervous system. This pattern is not evident in older larvae. Has-Hox1 and-Hox4 are expressed in the margin of the mantle in the posttorsional veliger, suggesting that Hox genes play a role in gastropod shell formation.

  16. Differences in larval nutritional requirements and female oviposition preference reflect the order of fruit colonization of Zaprionus indianus and Drosophila simulans.

    PubMed

    Matavelli, Cristiane; Carvalho, Maria João A; Martins, Nelson E; Mirth, Christen K

    2015-11-01

    Species coexist using the same nutritional resource by partitioning it either in space or time, but few studies explore how species-specific nutritional requirements allow partitioning. Zaprionus indianus and Drosophila simulans co-exist in figs by invading the fruit at different stages; Z. indianus colonizes ripe figs, whereas D. simulans oviposits in decaying fruit. Larvae feed on yeast growing on the fruit, which serves as their primary protein source. Because yeast populations increase as fruit decays, we find that ripe fruit has lower protein content than rotting fruit. Therefore, we hypothesized that Z. indianus and D. simulans larvae differ in their dietary requirements for protein. We used nutritional geometry to assess the effects of protein and carbohydrate concentration in the larval diet on life history characters in both species. Survival, development time, and ovariole number respond differently to the composition of the larval diet, with Z. indianus generally performing better across a wider range of protein concentrations. Correspondingly, we found that Z. indianus females preferred to lay eggs on low protein foods, while D. simulans females chose higher protein foods for oviposition when competing with Z. indianus. We propose the different nutritional requirements and oviposition preference of these two species allows them to temporally partition their habitat.

  17. Differences in larval nutritional requirements and female oviposition preference reflect the order of fruit colonization of Zaprionus indianus and Drosophila simulans.

    PubMed

    Matavelli, Cristiane; Carvalho, Maria João A; Martins, Nelson E; Mirth, Christen K

    2015-11-01

    Species coexist using the same nutritional resource by partitioning it either in space or time, but few studies explore how species-specific nutritional requirements allow partitioning. Zaprionus indianus and Drosophila simulans co-exist in figs by invading the fruit at different stages; Z. indianus colonizes ripe figs, whereas D. simulans oviposits in decaying fruit. Larvae feed on yeast growing on the fruit, which serves as their primary protein source. Because yeast populations increase as fruit decays, we find that ripe fruit has lower protein content than rotting fruit. Therefore, we hypothesized that Z. indianus and D. simulans larvae differ in their dietary requirements for protein. We used nutritional geometry to assess the effects of protein and carbohydrate concentration in the larval diet on life history characters in both species. Survival, development time, and ovariole number respond differently to the composition of the larval diet, with Z. indianus generally performing better across a wider range of protein concentrations. Correspondingly, we found that Z. indianus females preferred to lay eggs on low protein foods, while D. simulans females chose higher protein foods for oviposition when competing with Z. indianus. We propose the different nutritional requirements and oviposition preference of these two species allows them to temporally partition their habitat. PMID:26358399

  18. NIP/DuoxA is essential for Drosophila embryonic development and regulates oxidative stress response

    PubMed Central

    Xie, Xiaojun; Hu, Jack; Liu, Xiping; Qin, Hanjuan; Percival-Smith, Anthony; Rao, Yong; Li, Shawn S.C.

    2010-01-01

    NIP/DuoxA, originally cloned as a protein capable of binding to the cell fate determinant Numb in Drosophila, was recently identified as a modulator of reactive oxygen species (ROS) production in mammalian systems. Despite biochemical and cellular studies that link NIP/DuoxA to the generation of ROS through the dual oxidase (Duox) enzyme, the in vivo function of NIP/DuoxA has not been characterized to date. Here we report a genetic and functional characterization of nip in Drosophila melanogaster. We show that nip is essential for Drosophila development as nip null mutants die at the 1st larval instar. Expression of UAS-nip, but not UAS-Duox, rescued the lethality. To understand the function of nip beyond the early larval stage, we generated GAL4 inducible UAS-RNAi transgenes. daG32-GAL4 driven, ubiquitous RNAi-mediated silencing of nip led to profound abnormality in pre-adult development, crinkled wing and markedly reduced lifespan at 29°C. Compared to wild type flies, da-GAL4 induced nip-RNAi transgenic flies exhibited significantly reduced ability to survive under oxidative stress and displayed impaired mitochondrial aconitase function. Our work provides in vivo evidence for a critical role for nip in the development and oxidative stress response in Drosophila. PMID:20567495

  19. Development of Connectivity in a Motoneuronal Network in Drosophila Larvae

    PubMed Central

    Couton, Louise; Mauss, Alex S.; Yunusov, Temur; Diegelmann, Soeren; Evers, Jan Felix; Landgraf, Matthias

    2015-01-01

    Summary Background Much of our understanding of how neural networks develop is based on studies of sensory systems, revealing often highly stereotyped patterns of connections, particularly as these diverge from the presynaptic terminals of sensory neurons. We know considerably less about the wiring strategies of motor networks, where connections converge onto the dendrites of motoneurons. Here, we investigated patterns of synaptic connections between identified motoneurons with sensory neurons and interneurons in the motor network of the Drosophila larva and how these change as it develops. Results We find that as animals grow, motoneurons increase the number of synapses with existing presynaptic partners. Different motoneurons form characteristic cell-type-specific patterns of connections. At the same time, there is considerable variability in the number of synapses formed on motoneuron dendrites, which contrasts with the stereotypy reported for presynaptic terminals of sensory neurons. Where two motoneurons of the same cell type contact a common interneuron partner, each postsynaptic cell can arrive at a different connectivity outcome. Experimentally changing the positioning of motoneuron dendrites shows that the geography of dendritic arbors in relation to presynaptic partner terminals is an important determinant in shaping patterns of connectivity. Conclusions In the Drosophila larval motor network, the sets of connections that form between identified neurons manifest an unexpected level of variability. Synapse number and the likelihood of forming connections appear to be regulated on a cell-by-cell basis, determined primarily by the postsynaptic dendrites of motoneuron terminals. PMID:25702582

  20. Receptor Tyrosine Kinases in Drosophila Development

    PubMed Central

    Sopko, Richelle; Perrimon, Norbert

    2013-01-01

    Tyrosine phosphorylation plays a significant role in a wide range of cellular processes. The Drosophila genome encodes more than 20 receptor tyrosine kinases and extensive studies in the past 20 years have illustrated their diverse roles and complex signaling mechanisms. Although some receptor tyrosine kinases have highly specific functions, others strikingly are used in rather ubiquitous manners. Receptor tyrosine kinases regulate a broad expanse of processes, ranging from cell survival and proliferation to differentiation and patterning. Remarkably, different receptor tyrosine kinases share many of the same effectors and their hierarchical organization is retained in disparate biological contexts. In this comprehensive review, we summarize what is known regarding each receptor tyrosine kinase during Drosophila development. Astonishingly, very little is known for approximately half of all Drosophila receptor tyrosine kinases. PMID:23732470

  1. The essential role of bursicon during Drosophila development

    PubMed Central

    2010-01-01

    Background The protective external cuticle of insects does not accommodate growth during development. To compensate for this, the insect life cycle is punctuated by a series of molts. During the molt, a new and larger cuticle is produced underneath the old cuticle. Replacement of the smaller, old cuticle culminates with ecdysis, a stereotyped sequence of shedding behaviors. Following each ecdysis, the new cuticle must expand and harden. Studies from a variety of insect species indicate that this cuticle hardening is regulated by the neuropeptide bursicon. However, genetic evidence from Drosophila melanogaster only supports such a role for bursicon after the final ecdysis, when the adult fly emerges. The research presented here investigates the role that bursicon has at stages of Drosophila development which precede adult ecdysis. Results We addressed the mechanism and timing of hormonal release from bursicon-positive motor neurons at the larval neuromuscular junction. Our findings indicate that vesicle membrane proteins which are required for classical neurotransmitter release are also expressed at these peptidergic motor neuron terminals; and that these terminals secrete hormones including bursicon at the neuromuscular junction, coinciding with larval ecdysis. This release surprisingly occurs in two waves, indicating bursicon secretion preceding and following the ecdysis sequence. Next, we addressed the functional significance of bursicon signaling during development, by disrupting the expression of its receptor, rickets, in different target tissues. We determined that rickets is developmentally required in the epidermis and imaginal discs for proper formation of the prepupa. It is also required to harden the pharate adult cuticle before eclosion. Significantly, we have also found that the available rickets mutants are not genetic nulls as previously believed, which necessitated the use of targeted RNA interference to disrupt rickets expression. Conclusions Our

  2. An Allele of Sequoia Dominantly Enhances a Trio Mutant Phenotype to Influence Drosophila Larval Behavior

    PubMed Central

    Liebl, Eric C.

    2013-01-01

    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. PMID:24376789

  3. Quantitative trait loci for life span in Drosophila melanogaster: interactions with genetic background and larval density.

    PubMed Central

    Leips, J; Mackay, T F

    2000-01-01

    The genetic architecture of variation in adult life span was examined for a population of recombinant inbred lines, each of which had been crossed to both inbred parental strains from which the lines were derived, after emergence from both high and low larval density. QTL affecting life span were mapped within each sex and larval density treatment by linkage to highly polymorphic roo-transposable element markers, using a composite interval mapping method. We detected a total of six QTL affecting life span; the additive effects and degrees of dominance for all were highly sex- and larval environment-specific. There were significant epistatic interactions between five of the life span QTL, the effects of which also differed according to genetic background, sex, and larval density. Five additional QTL were identified that contributed to differences among lines in their sensitivity to variation in larval density. Further fine-scale mapping is necessary to determine whether candidate genes within the regions to which the QTL map are actually responsible for the observed variation in life span. PMID:10924473

  4. Planar cell polarity: the Dachsous/Fat system contributes differently to the embryonic and larval stages of Drosophila

    PubMed Central

    Saavedra, Pedro; Brittle, Amy; Palacios, Isabel M.; Strutt, David; Casal, José; Lawrence, Peter A.

    2016-01-01

    ABSTRACT The epidermal patterns of all three larval instars (L1–L3) of Drosophila are made by one unchanging set of cells. The seven rows of cuticular denticles of all larval stages are consistently planar polarised, some pointing forwards, others backwards. In L1 all the predenticles originate at the back of the cells but, in L2 and L3, they form at the front or the back of the cell depending on the polarity of the forthcoming denticles. We find that, to polarise all rows, the Dachsous/Fat system is differentially utilised; in L1 it is active in the placement of the actin-based predenticles but is not crucial for the final orientation of the cuticular denticles, in L2 and L3 it is needed for placement and polarity. We find Four-jointed to be strongly expressed in the tendon cells and show how this might explain the orientation of all seven rows. Unexpectedly, we find that L3 that lack Dachsous differ from larvae lacking Fat and we present evidence that this is due to differently mislocalised Dachs. We make some progress in understanding how Dachs contributes to phenotypes of wildtype and mutant larvae and adults. PMID:26935392

  5. [Larval development of Hypsophrys nicaraguensis (Pisces: Cichlidae) under laboratory conditions].

    PubMed

    Molina Arias, Alex

    2011-12-01

    The cichlid Hypsophrys nicaraguensis is a popular fish known as butterfly, and despite its widespread use as pets, little is known about its reproductive biology. In order to contribute to this knowledge, the study describes the relevant larval development characteristics, from adult and larval cultures in captivity. Every 12h, samples of larvae were collected and observed under the microscope for larval stage development, and every 24h morphometric measurements were taken. Observations showed that at 120h, some larvae had swimming activity and the pectoral fins development was visible; at 144h, the dorsal fin appear and all larvae started food intake; at 168h, the formation of anal fins begins, small rudiments of pelvic fins emerge, the separation of caudal fin from anal and dorsal fins starts, and the yolk sac is reabsorbed almost completely; at 288h, the pelvic fins starts to form; at 432h, the rays and spines of dorsal and anal fins can be distinguished, both the anal and the dorsal fins have the same number of spines and rays as in adults. After 480h larvae have the first scales, ending the larval stages and starting the transformation to fingerlings. Larvae were successfully fed with commercial diet.

  6. [Larval development of Hypsophrys nicaraguensis (Pisces: Cichlidae) under laboratory conditions].

    PubMed

    Molina Arias, Alex

    2011-12-01

    The cichlid Hypsophrys nicaraguensis is a popular fish known as butterfly, and despite its widespread use as pets, little is known about its reproductive biology. In order to contribute to this knowledge, the study describes the relevant larval development characteristics, from adult and larval cultures in captivity. Every 12h, samples of larvae were collected and observed under the microscope for larval stage development, and every 24h morphometric measurements were taken. Observations showed that at 120h, some larvae had swimming activity and the pectoral fins development was visible; at 144h, the dorsal fin appear and all larvae started food intake; at 168h, the formation of anal fins begins, small rudiments of pelvic fins emerge, the separation of caudal fin from anal and dorsal fins starts, and the yolk sac is reabsorbed almost completely; at 288h, the pelvic fins starts to form; at 432h, the rays and spines of dorsal and anal fins can be distinguished, both the anal and the dorsal fins have the same number of spines and rays as in adults. After 480h larvae have the first scales, ending the larval stages and starting the transformation to fingerlings. Larvae were successfully fed with commercial diet. PMID:22208084

  7. The Impact of Odor--Reward Memory on Chemotaxis in Larval "Drosophila"

    ERIC Educational Resources Information Center

    Schleyer, Michael; Reid, Samuel F.; Pamir, Evren; Saumweber, Timo; Paisios, Emmanouil; Davies, Alexander; Gerber, Bertram; Louis, Matthieu

    2015-01-01

    How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the "Drosophila" larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii)…

  8. A Behavior-Based Circuit Model of How Outcome Expectations Organize Learned Behavior in Larval "Drosophila"

    ERIC Educational Resources Information Center

    Schleyer, Michael; Saumweber, Timo; Nahrendorf, Wiebke; Fischer, Benjamin; von Alpen, Desiree; Pauls, Dennis; Thum, Andreas; Gerber, Bertram

    2011-01-01

    Drosophila larvae combine a numerically simple brain, a correspondingly moderate behavioral complexity, and the availability of a rich toolbox for transgenic manipulation. This makes them attractive as a study case when trying to achieve a circuit-level understanding of behavior organization. From a series of behavioral experiments, we suggest a…

  9. Chemical mutagenesis testing in Drosophila. VII. Results of 22 coded compounds tested in larval feeding experiments

    SciTech Connect

    Zimmering, S.; Mason, J.M.; Valencia, R. )

    1989-01-01

    Twenty-two chemicals were tested for mutagenicity in the sex-linked recessive lethal (SLRL) mutation assay after being fed to Drosophila melanogaster larvae. One compound, maleic hydrazide, was found to be mutagenic. It was tested for the ability to produce reciprocal translocations (RTs) and was positive in that assay as well.

  10. Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

    NASA Technical Reports Server (NTRS)

    Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

    1994-01-01

    Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by introduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spa ceflight, and show that extensive degrees of development can take place in this microgravity environment.

  11. Embryogenesis, hatching and larval development of Artemia during orbital spaceflight

    NASA Astrophysics Data System (ADS)

    Spooner, B. S.; Debell, L.; Armbrust, L.; Guikema, J. A.; Metcalf, J.; Paulsen, A.

    1994-08-01

    Developmental biology studies, using gastrula-arrested cysts of the brine shrimp Artemia franciscana, were conducted during two flights of the space shuttle Atlantis (missions STS-37 and STS-43) in 1991. Dehydrated cysts were activated, on orbit, by addition of salt water to the cysts, and then development was terminated by the addition of fixative. Development took place in 5 ml syringes, connected by tubing to activation syringes, containing salt water, and termination syringes, containing fixative. Comparison of space results with simultaneous ground control experiments showed that equivalent percentages of naupliar larvae hatched in the syringes (40%). Thus, reactivation of development, completion of embryogenesis, emergence and hatching took place, during spaceflight, without recognizable alteration in numbers of larvae produced. Post-hatching larval development was studied in experiments where development was terminated, by intrduction of fixative, 2 days, 4 days, and 8 days after reinitiation of development. During spaceflight, successive larval instars or stages, interrupted by molts, occurred, generating brine shrimp at appropriate larval instars. Naupliar larvae possessed the single naupliar eye, and development of the lateral pair of adult eyes also took place in space. Transmission electron microscopy revealed extensive differentiation, including skeletal muscle and gut endoderm, as well as the eye tissues. These studies demonstrate the potential value of Artemia for developmental biology studies during spaceflight, and show that extensive degress of development can take place in this microgravity environment.

  12. Drosophila nociceptors mediate larval aversion to dry surface environments utilizing both the painless TRP channel and the DEG/ENaC subunit, PPK1.

    PubMed

    Johnson, Wayne A; Carder, Justin W

    2012-01-01

    A subset of sensory neurons embedded within the Drosophila larval body wall have been characterized as high-threshold polymodal nociceptors capable of responding to noxious heat and noxious mechanical stimulation. They are also sensitized by UV-induced tissue damage leading to both thermal hyperalgesia and allodynia very similar to that observed in vertebrate nociceptors. We show that the class IV multiple-dendritic(mdIV) nociceptors are also required for a normal larval aversion to locomotion on to a dry surface environment. Drosophila melanogaster larvae are acutely susceptible to desiccation displaying a strong aversion to locomotion on dry surfaces severely limiting the distance of movement away from a moist food source. Transgenic inactivation of mdIV nociceptor neurons resulted in larvae moving inappropriately into regions of low humidity at the top of the vial reflected as an increased overall pupation height and larval desiccation. This larval lethal desiccation phenotype was not observed in wild-type controls and was completely suppressed by growth in conditions of high humidity. Transgenic hyperactivation of mdIV nociceptors caused a reciprocal hypersensitivity to dry surfaces resulting in drastically decreased pupation height but did not induce the writhing nocifensive response previously associated with mdIV nociceptor activation by noxious heat or harsh mechanical stimuli. Larvae carrying mutations in either the Drosophila TRP channel, Painless, or the degenerin/epithelial sodium channel subunit Pickpocket1(PPK1), both expressed in mdIV nociceptors, showed the same inappropriate increased pupation height and lethal desiccation observed with mdIV nociceptor inactivation. Larval aversion to dry surfaces appears to utilize the same or overlapping sensory transduction pathways activated by noxious heat and harsh mechanical stimulation but with strikingly different sensitivities and disparate physiological responses. PMID:22403719

  13. Drosophila Nociceptors Mediate Larval Aversion to Dry Surface Environments Utilizing Both the Painless TRP Channel and the DEG/ENaC Subunit, PPK1

    PubMed Central

    Johnson, Wayne A.; Carder, Justin W.

    2012-01-01

    A subset of sensory neurons embedded within the Drosophila larval body wall have been characterized as high-threshold polymodal nociceptors capable of responding to noxious heat and noxious mechanical stimulation. They are also sensitized by UV-induced tissue damage leading to both thermal hyperalgesia and allodynia very similar to that observed in vertebrate nociceptors. We show that the class IV multiple-dendritic(mdIV) nociceptors are also required for a normal larval aversion to locomotion on to a dry surface environment. Drosophila melanogaster larvae are acutely susceptible to desiccation displaying a strong aversion to locomotion on dry surfaces severely limiting the distance of movement away from a moist food source. Transgenic inactivation of mdIV nociceptor neurons resulted in larvae moving inappropriately into regions of low humidity at the top of the vial reflected as an increased overall pupation height and larval desiccation. This larval lethal desiccation phenotype was not observed in wild-type controls and was completely suppressed by growth in conditions of high humidity. Transgenic hyperactivation of mdIV nociceptors caused a reciprocal hypersensitivity to dry surfaces resulting in drastically decreased pupation height but did not induce the writhing nocifensive response previously associated with mdIV nociceptor activation by noxious heat or harsh mechanical stimuli. Larvae carrying mutations in either the Drosophila TRP channel, Painless, or the degenerin/epithelial sodium channel subunit Pickpocket1(PPK1), both expressed in mdIV nociceptors, showed the same inappropriate increased pupation height and lethal desiccation observed with mdIV nociceptor inactivation. Larval aversion to dry surfaces appears to utilize the same or overlapping sensory transduction pathways activated by noxious heat and harsh mechanical stimulation but with strikingly different sensitivities and disparate physiological responses. PMID:22403719

  14. Social coercion of larval development in an ant species

    NASA Astrophysics Data System (ADS)

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

  15. Social coercion of larval development in an ant species.

    PubMed

    Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

    2016-04-01

    Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults. PMID:26874941

  16. Hydroxyurea-mediated neuroblast ablation establishes birth dates of secondary lineages and addresses neuronal interactions in the developing Drosophila brain.

    PubMed

    Lovick, Jennifer K; Hartenstein, Volker

    2015-06-01

    The Drosophila brain is comprised of neurons formed by approximately 100 lineages, each of which is derived from a stereotyped, asymmetrically dividing neuroblast. Lineages serve as structural and developmental units of Drosophila brain anatomy and reconstruction of lineage projection patterns represents a suitable map of Drosophila brain circuitry at the level of neuron populations ("macro-circuitry"). Two phases of neuroblast proliferation, the first in the embryo and the second during the larval phase (following a period of mitotic quiescence), produce primary and secondary lineages, respectively. Using temporally controlled pulses of hydroxyurea (HU) to ablate neuroblasts and their corresponding secondary lineages during the larval phase, we analyzed the effect on development of primary and secondary lineages in the late larval and adult brain. Our findings indicate that timing of neuroblast re-activation is highly stereotyped, allowing us to establish "birth dates" for all secondary lineages. Furthermore, our results demonstrate that, whereas the trajectory and projection pattern of primary and secondary lineages is established in a largely independent manner, the final branching pattern of secondary neurons is dependent upon the presence of appropriate neuronal targets. Taken together, our data provide new insights into the degree of neuronal plasticity during Drosophila brain development.

  17. Changes in protein expression during honey bee larval development

    PubMed Central

    Chan, Queenie WT; Foster, Leonard J

    2008-01-01

    Background The honey bee (Apis mellifera), besides its role in pollination and honey production, serves as a model for studying the biochemistry of development, metabolism, and immunity in a social organism. Here we use mass spectrometry-based quantitative proteomics to quantify nearly 800 proteins during the 5- to 6-day larval developmental stage, tracking their expression profiles. Results We report that honey bee larval growth is marked by an age-correlated increase of protein transporters and receptors, as well as protein nutrient stores, while opposite trends in protein translation activity and turnover were observed. Levels of the immunity factors prophenoloxidase and apismin are positively correlated with development, while others surprisingly were not significantly age-regulated, suggesting a molecular explanation for why bees are susceptible to major age-associated bee bacterial infections such as American Foulbrood or fungal diseases such as chalkbrood. Previously unreported findings include the reduction of antioxidant and G proteins in aging larvae. Conclusion These data have allowed us to integrate disparate findings in previous studies to build a model of metabolism and maturity of the immune system during larval development. This publicly accessible resource for protein expression trends will help generate new hypotheses in the increasingly important field of honey bee research. PMID:18959778

  18. Tcmof regulates larval/pupal development and female fecundity in red flour beetle, Tribolium castaneum.

    PubMed

    Wang, Yanyun; Li, Chengjun; Sang, Ming; Li, Bin

    2015-02-01

    Males absent on the first (MOF) was originally identified as an essential component of the X chromosome dosage compensation system in Drosophila melanogaster, and is also a member of the MYST family of histone acetyltransferases. MOF has been extensively studied in D. melanogaster and mammals. However, whether MOF is involved in dosage compensation and/or other vital functions for newly emerging model insects such as Tribolium castaneum, is unclear. We cloned the mof from T. castaneum, named Tcmof. Phylogenetic analysis revealed that mof is highly conserved in eukaryotes but lost in birds. qPCR showed that Tcmof was most highly expressed in the early embryo stage and equally expressed in males and females. Treating larvae with ds-Tcmof led 79.1% of the insects to arrest during its eclosion; the remaining insects died either in the larval stage or immediately following eclosion. Treating pupae with the same construct eliminated the fertility of T. castaneum. This effect was rescued by reciprocal crosses with wild-type females, but not males. We infer that the mof gene is essential for larval/pupal development and female fertility in T. castaneum.

  19. Serotonin receptors expressed in Drosophila mushroom bodies differentially modulate larval locomotion.

    PubMed

    Silva, Bryon; Goles, Nicolás I; Varas, Rodrigo; Campusano, Jorge M

    2014-01-01

    Drosophila melanogaster has been successfully used as a simple model to study the cellular and molecular mechanisms underlying behaviors, including the generation of motor programs. Thus, it has been shown that, as in vertebrates, CNS biogenic amines (BA) including serotonin (5HT) participate in motor control in Drosophila. Several evidence show that BA systems innervate an important association area in the insect brain previously associated to the planning and/or execution of motor programs, the Mushroom Bodies (MB). The main objective of this work is to evaluate the contribution of 5HT and its receptors expressed in MB to motor behavior in fly larva. Locomotion was evaluated using an automated tracking system, in Drosophila larvae (3(rd)-instar) exposed to drugs that affect the serotonergic neuronal transmission: alpha-methyl-L-dopa, MDMA and fluoxetine. In addition, animals expressing mutations in the 5HT biosynthetic enzymes or in any of the previously identified receptors for this amine (5HT1AR, 5HT1BR, 5HT2R and 5HT7R) were evaluated in their locomotion. Finally, RNAi directed to the Drosophila 5HT receptor transcripts were expressed in MB and the effect of this manipulation on motor behavior was assessed. Data obtained in the mutants and in animals exposed to the serotonergic drugs, suggest that 5HT systems are important regulators of motor programs in fly larvae. Studies carried out in animals pan-neuronally expressing the RNAi for each of the serotonergic receptors, support this idea and further suggest that CNS 5HT pathways play a role in motor control. Moreover, animals expressing an RNAi for 5HT1BR, 5HT2R and 5HT7R in MB show increased motor behavior, while no effect is observed when the RNAi for 5HT1AR is expressed in this region. Thus, our data suggest that CNS 5HT systems are involved in motor control, and that 5HT receptors expressed in MB differentially modulate motor programs in fly larvae.

  20. Serotonin Receptors Expressed in Drosophila Mushroom Bodies Differentially Modulate Larval Locomotion

    PubMed Central

    Silva, Bryon; Goles, Nicolás I.; Varas, Rodrigo; Campusano, Jorge M.

    2014-01-01

    Drosophila melanogaster has been successfully used as a simple model to study the cellular and molecular mechanisms underlying behaviors, including the generation of motor programs. Thus, it has been shown that, as in vertebrates, CNS biogenic amines (BA) including serotonin (5HT) participate in motor control in Drosophila. Several evidence show that BA systems innervate an important association area in the insect brain previously associated to the planning and/or execution of motor programs, the Mushroom Bodies (MB). The main objective of this work is to evaluate the contribution of 5HT and its receptors expressed in MB to motor behavior in fly larva. Locomotion was evaluated using an automated tracking system, in Drosophila larvae (3rd-instar) exposed to drugs that affect the serotonergic neuronal transmission: alpha-methyl-L-dopa, MDMA and fluoxetine. In addition, animals expressing mutations in the 5HT biosynthetic enzymes or in any of the previously identified receptors for this amine (5HT1AR, 5HT1BR, 5HT2R and 5HT7R) were evaluated in their locomotion. Finally, RNAi directed to the Drosophila 5HT receptor transcripts were expressed in MB and the effect of this manipulation on motor behavior was assessed. Data obtained in the mutants and in animals exposed to the serotonergic drugs, suggest that 5HT systems are important regulators of motor programs in fly larvae. Studies carried out in animals pan-neuronally expressing the RNAi for each of the serotonergic receptors, support this idea and further suggest that CNS 5HT pathways play a role in motor control. Moreover, animals expressing an RNAi for 5HT1BR, 5HT2R and 5HT7R in MB show increased motor behavior, while no effect is observed when the RNAi for 5HT1AR is expressed in this region. Thus, our data suggest that CNS 5HT systems are involved in motor control, and that 5HT receptors expressed in MB differentially modulate motor programs in fly larvae. PMID:24586928

  1. A development-based compartmentalization of the Drosophila central brain

    PubMed Central

    Pereanu, Wayne; Kumar, Abilasha; Jennett, Arnim; Reichert, Heinrich; Hartenstein, Volker

    2010-01-01

    The neuropile of the Drosophila brain is subdivided into anatomically discrete compartments. Compartments are rich in terminal neurite branching and synapses; they are the neuropile domains in which signal processing takes place. Compartment boundaries are defined by more or less dense layers of glial cells, as well as long neurite fascicles. These fascicles are formed during the larval period when the approximately 100 neuronal lineages that constitute the Drosophila central brain differentiate. Each lineage forms an axon tract with a characteristic trajectory in the neuropile; groups of spatially related tracts congregate into the brain fascicles that can be followed from the larva throughout metamorphosis into the adult stage. In this paper we provide a map of the adult brain compartments and the relevant fascicles defining compartmental boundaries. We have identified the neuronal lineages contributing to each fascicle, which allowed us to directly compare compartments of the larval and adult brain. Most adult compartments can be recognized already in the early larval brain where they form a “protomap” of the later adult compartments. Our analysis highlights the morphogenetic changes shaping the Drosophila brain; the data will be important for studies that link early acting genetic mechanisms to the adult neuronal structures and circuits controlled by these mechanisms. PMID:20533357

  2. New Components of Drosophila Leg Development Identified through Genome Wide Association Studies

    PubMed Central

    Su, Xin; Petrisko, Tiffany; Rosario, Juan B.; Mahaffey, James W.

    2013-01-01

    The adult Drosophila melanogaster body develops from imaginal discs, groups of cells set-aside during embryogenesis and expanded in number during larval stages. Specification and development of Drosophila imaginal discs have been studied for many years as models of morphogenesis. These studies are often based on mutations with large developmental effects, mutations that are often lethal in embryos when homozygous. Such forward genetic screens can be limited by factors such as early lethality and genetic redundancy. To identify additional genes and genetic pathways involved in leg imaginal disc development, we employed a Genome Wide Association Study utilizing the natural genetic variation in leg proportionality found in the Drosophila Genetic Reference Panel fly lines. In addition to identifying genes already known to be involved in leg development, we identified several genes involved in pathways that had not previously been linked with leg development. Several of the genes appear to be involved in signaling activities, while others have no known roles at this time. Many of these uncharacterized genes are conserved in mammals, so we can now begin to place these genes into developmental contexts. Interestingly, we identified five genes which, when their function is reduced by RNAi, cause an antenna-to-leg transformation. Our results demonstrate the utility of this approach, integrating the tools of quantitative and molecular genetics to study developmental processes, and provide new insights into the pathways and networks involved in Drosophila leg development. PMID:23560084

  3. Rapid feedback regulation of synaptic efficacy during high-frequency activity at the Drosophila larval neuromuscular junction

    PubMed Central

    Kauwe, Grant; Isacoff, Ehud Y.

    2013-01-01

    High-frequency firing of neurons depresses transmitter release at many synapses. At the glutamatergic synapse of the Drosophila larval neuromuscular junction, we find that presynaptic depression is modulated by postsynaptic ionotropic glutamate receptor (iGluR) activity. Although basal release at low frequency was insensitive to postsynaptic iGluR activity, recovery from depression elicited by high-frequency presynaptic trains decreased with partial block of native iGluRs. Moreover, recovery from depression increased with optical activation of the light-gated mammalian iGluR6 (LiGluR) expressed postsynaptically. The enhancement of recovery from depression occurred within 2 min of optical activation of LiGluR and persisted for minutes after optical deactivation. This effect depended on cAMP-dependent presynaptic recruitment of vesicles from the reserve pool. Our findings reveal a unique dimension to postsynaptic iGluR activity: fast retrograde signaling that preserves transmission efficacy during high-frequency presynaptic firing. PMID:23674684

  4. Decapentaplegic and growth control in the developing Drosophila wing.

    PubMed

    Akiyama, Takuya; Gibson, Matthew C

    2015-11-19

    As a central model for morphogen action during animal development, the bone morphogenetic protein 2/4 (BMP2/4)-like ligand Decapentaplegic (Dpp) is proposed to form a long-range signalling gradient that directs both growth and pattern formation during Drosophila wing disc development. While the patterning role of Dpp secreted from a stripe of cells along the anterior-posterior compartmental boundary is well established, the mechanism by which a Dpp gradient directs uniform cell proliferation remains controversial and poorly understood. Here, to determine the precise spatiotemporal requirements for Dpp during wing disc development, we use CRISPR-Cas9-mediated genome editing to generate a flippase recognition target (FRT)-dependent conditional null allele. By genetically removing Dpp from its endogenous stripe domain, we confirm the requirement of Dpp for the activation of a downstream phospho-Mothers against dpp (p-Mad) gradient and the regulation of the patterning targets spalt (sal), optomotor blind (omb; also known as bifid) and brinker (brk). Surprisingly, however, third-instar wing blade primordia devoid of compartmental dpp expression maintain relatively normal rates of cell proliferation and exhibit only mild defects in growth. These results indicate that during the latter half of larval development, the Dpp morphogen gradient emanating from the anterior-posterior compartment boundary is not directly required for wing disc growth. PMID:26550824

  5. Decapentaplegic and growth control in the developing Drosophila wing.

    PubMed

    Akiyama, Takuya; Gibson, Matthew C

    2015-11-19

    As a central model for morphogen action during animal development, the bone morphogenetic protein 2/4 (BMP2/4)-like ligand Decapentaplegic (Dpp) is proposed to form a long-range signalling gradient that directs both growth and pattern formation during Drosophila wing disc development. While the patterning role of Dpp secreted from a stripe of cells along the anterior-posterior compartmental boundary is well established, the mechanism by which a Dpp gradient directs uniform cell proliferation remains controversial and poorly understood. Here, to determine the precise spatiotemporal requirements for Dpp during wing disc development, we use CRISPR-Cas9-mediated genome editing to generate a flippase recognition target (FRT)-dependent conditional null allele. By genetically removing Dpp from its endogenous stripe domain, we confirm the requirement of Dpp for the activation of a downstream phospho-Mothers against dpp (p-Mad) gradient and the regulation of the patterning targets spalt (sal), optomotor blind (omb; also known as bifid) and brinker (brk). Surprisingly, however, third-instar wing blade primordia devoid of compartmental dpp expression maintain relatively normal rates of cell proliferation and exhibit only mild defects in growth. These results indicate that during the latter half of larval development, the Dpp morphogen gradient emanating from the anterior-posterior compartment boundary is not directly required for wing disc growth.

  6. Effects of diet and development on the Drosophila lipidome

    PubMed Central

    Carvalho, Maria; Sampaio, Julio L; Palm, Wilhelm; Brankatschk, Marko; Eaton, Suzanne; Shevchenko, Andrej

    2012-01-01

    Cells produce tens of thousands of different lipid species, but the importance of this complexity in vivo is unclear. Analysis of individual tissues and cell types has revealed differences in abundance of individual lipid species, but there has been no comprehensive study comparing tissue lipidomes within a single developing organism. Here, we used quantitative shotgun profiling by high-resolution mass spectrometry to determine the absolute (molar) content of 250 species of 14 major lipid classes in 6 tissues of animals at 27 developmental stages raised on 4 different diets. Comparing these lipidomes revealed unexpected insights into lipid metabolism. Surprisingly, the fatty acids present in dietary lipids directly influence tissue phospholipid composition throughout the animal. Furthermore, Drosophila differentially regulates uptake, mobilization and tissue accumulation of specific sterols, and undergoes unsuspected shifts in fat metabolism during larval and pupal development. Finally, we observed striking differences between tissue lipidomes that are conserved between phyla. This study provides a comprehensive, quantitative and expandable resource for further pharmacological and genetic studies of metabolic disorders and molecular mechanisms underlying dietary response. PMID:22864382

  7. Immediate and punitive impact of mechanosensory disturbance on olfactory behaviour of larval Drosophila

    PubMed Central

    Saumweber, Timo; Cano, Carmen; Klessen, Juliane; Eichler, Katharina; Fendt, Markus; Gerber, Bertram

    2014-01-01

    ABSTRACT The ability to respond to and to learn about mechanosensory disturbance is widespread among animals. Using Drosophila larvae, we describe how the frequency of mechanosensory disturbance (‘buzz’) affects three aspects of behaviour: free locomotion, innate olfactory preference, and potency as a punishment. We report that (i) during 2–3 seconds after buzz onset the larvae slowed down and then turned, arguably to escape this situation; this was seen for buzz frequencies of 10, 100, and 1000 Hz, (ii) innate olfactory preference was reduced when tested in the presence of the buzz; this effect was strongest for the 100 Hz frequency, (iii) after odour-buzz associative training, we observed escape from the buzz-associated odour; this effect was apparent for 10 and 100, but not for 1000 Hz. We discuss the multiple behavioural effects of mechanosensation and stress that the immediate effects on locomotion and the impact as punishment differ in their frequency-dependence. Similar dissociations between immediate, reflexive behavioural effects and reinforcement potency were previously reported for sweet, salty and bitter tastants. It should be interesting to see how these features map onto the organization of sensory, ascending pathways. PMID:25260919

  8. Survival of heat stress with and without heat hardening in Drosophila melanogaster: interactions with larval density.

    PubMed

    Arias, Leticia N; Sambucetti, Pablo; Scannapieco, Alejandra C; Loeschcke, Volker; Norry, Fabian M

    2012-07-01

    Survival of a potentially lethal high temperature stress is a genetically variable thermal adaptation trait in many organisms. Organisms cope with heat stress by basal or induced thermoresistance. Here, we tested quantitative trait loci (QTL) for heat stress survival (HSS) in Drosophila melanogaster, with and without a cyclic heat-hardening pre-treatment, for flies that were reared at low (LD) or high (HD) density. Mapping populations were two panels of recombinant inbred lines (RIL), which were previously constructed from heat stress-selected stocks: RIL-D48 and RIL-SH2, derived from backcrosses to stocks of low and high heat resistance, respectively. HSS increased with heat hardening in both LD and HD flies. In addition, HSS increased consistently with density in non-hardened flies. There was a significant interaction between heat hardening and density effects in RIL-D48. Several QTL were significant for both density and hardening treatments. Many QTL overlapped with thermotolerance QTL identified for other traits in previous studies based on LD cultures only. However, three new QTL were found in HD only (cytological ranges: 12E-16F6; 30A3-34C2; 49C-50C). Previously found thermotolerance QTL were also significant for flies from HD cultures.

  9. Analysis of Sequences Regulating Larval Expression of the Adh Gene of Drosophila Melanogaster

    PubMed Central

    Shen, NLL.; Hotaling, E. C.; Subrahmanyam, G.; Martin, P. F.; Sofer, W.

    1991-01-01

    The effects of a series of eight, 50 base pair internal deletions in the 5' region upstream of the proximal transcription start site of the Adh gene of Drosophila melanogaster were examined in a quantitative assay. Mixtures of two plasmids, one bearing a deleted gene, the other with an intact reference gene, were injected into alcohol dehydrogenase-negative embryos. Third instar larvae of the injected generation were assayed for relative alcohol dehydrogenase enzyme activity. Quantitative analysis of the eight deletions indicated that two regions were required for any detectable enzyme activity and one region was required for appropriate tissue specificity. The remaining five deletions significantly decreased, but did not eliminate activity. When the deleted genes were placed on a plasmid with an intact reference gene, activities of all but one deletion were restored to levels equivalent to that of the intact reference gene (regardless of orientation). This restoration of activity did not occur when the regulatory region of the intact gene was replaced with the Hsp70 heat shock promoter nor when the 50-base pair deletion encompassed the region that includes the TATA sequence. The fact that seven of the eight deleted genes express activity in the presence of a reference gene on the same plasmid suggests that the deleted gene is controlled by regulatory elements in the reference gene. Further, these regulatory elements exhibit no preference for their own, more proximate, promoter. PMID:1752419

  10. Identification of Inhibitory Premotor Interneurons Activated at a Late Phase in a Motor Cycle during Drosophila Larval Locomotion

    PubMed Central

    Itakura, Yuki; Kohsaka, Hiroshi; Ohyama, Tomoko; Zlatic, Marta

    2015-01-01

    Rhythmic motor patterns underlying many types of locomotion are thought to be produced by central pattern generators (CPGs). Our knowledge of how CPG networks generate motor patterns in complex nervous systems remains incomplete, despite decades of work in a variety of model organisms. Substrate borne locomotion in Drosophila larvae is driven by waves of muscular contraction that propagate through multiple body segments. We use the motor circuitry underlying crawling in larval Drosophila as a model to try to understand how segmentally coordinated rhythmic motor patterns are generated. Whereas muscles, motoneurons and sensory neurons have been well investigated in this system, far less is known about the identities and function of interneurons. Our recent study identified a class of glutamatergic premotor interneurons, PMSIs (period-positive median segmental interneurons), that regulate the speed of locomotion. Here, we report on the identification of a distinct class of glutamatergic premotor interneurons called Glutamatergic Ventro-Lateral Interneurons (GVLIs). We used calcium imaging to search for interneurons that show rhythmic activity and identified GVLIs as interneurons showing wave-like activity during peristalsis. Paired GVLIs were present in each abdominal segment A1-A7 and locally extended an axon towards a dorsal neuropile region, where they formed GRASP-positive putative synaptic contacts with motoneurons. The interneurons expressed vesicular glutamate transporter (vGluT) and thus likely secrete glutamate, a neurotransmitter known to inhibit motoneurons. These anatomical results suggest that GVLIs are premotor interneurons that locally inhibit motoneurons in the same segment. Consistent with this, optogenetic activation of GVLIs with the red-shifted channelrhodopsin, CsChrimson ceased ongoing peristalsis in crawling larvae. Simultaneous calcium imaging of the activity of GVLIs and motoneurons showed that GVLIs’ wave-like activity lagged behind that of

  11. Neuronal development in larval chiton Ischnochiton hakodadensis (Mollusca: Polyplacophora).

    PubMed

    Voronezhskaya, Elena E; Tyurin, Sergei A; Nezlin, Leonid P

    2002-02-25

    Chitons are the most primitive molluscs and, thus, a matter of considerable interest for understanding both basic principles of molluscan neurogenesis and phylogeny. The development of the nervous system in trochophores of the chiton Ischnochiton hakodadensis from hatching to metamorphosis is described in detail by using confocal laser scanning microscopy and antibodies raised against serotonin, FMRFamide, and acetylated alpha tubulin. The earliest nervous elements detected were peripheral neurons located in the frontal hemisphere of posthatching trochophores and projecting into the apical organ. Among them, two pairs of unique large lateral cells appear to pioneer the pathways of developing adult nervous system. Chitons possess an apical organ that contains the largest number of neurons among all molluscan larvae investigated so far. Besides, many pretrochal neurons are situated outside the apical organ. The prototroch is not innervated by larval neurons. The first neurons of the developing adult central nervous system (CNS) appear later in the cerebral ganglion and pedal cords. None of the neurons of the larval nervous system are retained in the adult CNS. They cease to express their transmitter content and disintegrate after settlement. Although the adult CNS of chitons resembles that of polychaetes, their general scenario of neuronal development resembles that of advanced molluscs and differs from annelids. Thus, our data demonstrate the conservative pattern of molluscan neurogenesis and suggest independent origin of molluscan and annelid trochophores.

  12. Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development.

    PubMed

    Rowbottom, Raylea; Carver, Scott; Barmuta, Leon A; Weinstein, Philip; Foo, Dahlia; Allen, Geoff R

    2015-01-01

    Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level). To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission. PMID:26558896

  13. Resource Limitation, Controphic Ostracod Density and Larval Mosquito Development

    PubMed Central

    Rowbottom, Raylea; Carver, Scott; Barmuta, Leon A.; Weinstein, Philip; Foo, Dahlia; Allen, Geoff R.

    2015-01-01

    Aquatic environments can be restricted with the amount of available food resources especially with changes to both abiotic and biotic conditions. Mosquito larvae, in particular, are sensitive to changes in food resources. Resource limitation through inter-, and intra-specific competition among mosquitoes are known to affect both their development and survival. However, much less is understood about the effects of non-culicid controphic competitors (species that share the same trophic level). To address this knowledge gap, we investigated and compared mosquito larval development, survival and adult size in two experiments, one with different densities of non-culicid controphic conditions and the other with altered resource conditions. We used Aedes camptorhynchus, a salt marsh breeding mosquito and a prominent vector for Ross River virus in Australia. Aedes camptorhynchus usually has few competitors due to its halo-tolerance and distribution in salt marshes. However, sympatric ostracod micro-crustaceans often co-occur within these salt marshes and can be found in dense populations, with field evidence suggesting exploitative competition for resources. Our experiments demonstrate resource limiting conditions caused significant increases in mosquito developmental times, decreased adult survival and decreased adult size. Overall, non-culicid exploitation experiments showed little effect on larval development and survival, but similar effects on adult size. We suggest that the alterations of adult traits owing to non-culicid controphic competition has potential to extend to vector-borne disease transmission. PMID:26558896

  14. The impact of odor–reward memory on chemotaxis in larval Drosophila

    PubMed Central

    Schleyer, Michael; Reid, Samuel F.; Pamir, Evren; Saumweber, Timo; Paisios, Emmanouil; Davies, Alexander

    2015-01-01

    How do animals adaptively integrate innate with learned behavioral tendencies? We tackle this question using chemotaxis as a paradigm. Chemotaxis in the Drosophila larva largely results from a sequence of runs and oriented turns. Thus, the larvae minimally need to determine (i) how fast to run, (ii) when to initiate a turn, and (iii) where to direct a turn. We first report how odor-source intensities modulate these decisions to bring about higher levels of chemotactic performance for higher odor-source intensities during innate chemotaxis. We then examine whether the same modulations are responsible for alterations of chemotactic performance by learned odor “valence” (understood throughout as level of attractiveness). We find that run speed (i) is neither modulated by the innate nor by the learned valence of an odor. Turn rate (ii), however, is modulated by both: the higher the innate or learned valence of the odor, the less often larvae turn whenever heading toward the odor source, and the more often they turn when heading away. Likewise, turning direction (iii) is modulated concordantly by innate and learned valence: turning is biased more strongly toward the odor source when either innate or learned valence is high. Using numerical simulations, we show that a modulation of both turn rate and of turning direction is sufficient to account for the empirically found differences in preference scores across experimental conditions. Our results suggest that innate and learned valence organize adaptive olfactory search behavior by their summed effects on turn rate and turning direction, but not on run speed. This work should aid studies into the neural mechanisms by which memory impacts specific aspects of behavior. PMID:25887280

  15. Proteomic analysis through larval development of Solea senegalensis flatfish.

    PubMed

    Chicano-Gálvez, Eduardo; Asensio, Esther; Cañavate, José Pedro; Alhama, José; López-Barea, Juan

    2015-12-01

    The post-embryonic development of the Senegalese sole, Solea senegalensis, a flatfish of growing interest in fisheries and aquaculture, is associated with drastic morpho-physiological changes during metamorphosis. Although in the last two decades knowledge on sole culture has notably increased, especially in Southern Europe, its progress was restricted due to lack of methods to control reproduction, improve larval quality and increase juvenile disease resistance. A limited knowledge of the physiological, molecular and genetic mechanisms involved is at the base of such limitation. A proteomic study was carried out to explore the molecular events that occur during S. senegalensis ontogenesis. Protein expression changes were monitored in larvae from 5 to 21 dph by combining 2DE and protein identification with de novo MS/MS sequencing. An average of 6177 ± 282 spots was resolved in 2DE gels. Hierarchical cluster analysis of the 705 selected spots grouped them in eight patterns. Thirty-four proteins were identified and assigned biological functions including structure, metabolism highlighting energy metabolism, transport, protein folding, stress response, chromatin organization and regulation of gene expression. These changes provide a sequential description of the molecular events associated with the biochemical and biological transformations that occur during sole larval development.

  16. Torso, a Drosophila receptor tyrosine kinase, plays a novel role in the larval fat body in regulating insulin signaling and body growth.

    PubMed

    Jun, Jong Woo; Han, Gangsik; Yun, Hyun Myoung; Lee, Gang Jun; Hyun, Seogang

    2016-08-01

    Torso is a receptor tyrosine kinase whose localized activation at the termini of the Drosophila embryo is mediated by its ligand, Trunk. Recent studies have unveiled a second function of Torso in the larval prothoracic gland (PG) as the receptor for the prothoracicotropic hormone, which triggers pupariation. As such, inhibition of Torso in the PG prolongs the larval growth period, thereby increasing the final pupa size. Here, we report that Torso also acts in the larval fat body, regulating body size in a manner opposite from that of Torso in PG. We confirmed the expression of torso mRNA in the larval fat body and its reduction by RNA interference (RNAi). Fat body-specific knockdown of torso, by either of the two independent RNAi transgenes, significantly decreased the final pupal size. We found that torso knockdown suppresses insulin/target of rapamycin (TOR) signaling in the fat body, as confirmed by repression of Akt and S6K. Notably, the decrease in insulin/TOR signaling and decrease of pupal size induced by the knockdown of torso were rescued by the expression of a constitutively active form of the insulin receptor or by the knockdown of FOXO. Our study revealed a novel role for Torso in the fat body with respect to regulation of insulin/TOR signaling and body size. This finding exemplifies the contrasting effects of the same gene expressed in two different organs on organismal physiology. PMID:27126913

  17. Hypomorphic mutations in the larval photokinesis A (lphA) gene have stage-specific effects on visual system function in Drosophila melanogaster

    SciTech Connect

    Gordesky-Gold, B.; Warrick, J.M.; Bixler, A.

    1995-04-01

    Of the many genes that are expressed in the visual system of Drosophila melanogaster adults, some affect larval vision. However, with the exception of one X-linked mutation, no genes that have larval-specific effects on visual system structure or function have previously been reported. We describe the isolation and characterization of two mutant alleles that define the larval photokinesis A (lphA) gene, one allele of which is associated with a P-element insertion at cytogenetic locus 8E1-10. Larvae that express lphA mutations are, like normal animals, negatively photokinetic, but they are less responsive to white light than lphA+ controls. Larvae that are heterozygous in trans for a mutant allele and a deficiency that uncovers the lphA locus are blind, which indicates that the mutant allele is hypomorphic. lphA larvae respond normally to odorants and taste stimuli. Moreover, the lphA mutations do not affect adult flies` fast phototaxis or visually driven aspects of male sexual behavior, and electroretinograms recorded from the compound eyes of lphA/deficiency heterozygotes and lphA{sup 1}/lphA{sup 2} females are normal. These observations suggest that the lphA gene affects a larval-specific aspect of visual system function. 27 refs., 2 figs., 4 tabs.

  18. Duration of larval development of Simulium yahense (Diptera: Simuliidae) under natural conditions.

    PubMed

    Davis, J R; Barbiero, V K; Trpis, M

    1992-01-01

    The duration of Simulium yahense Vajime & Dunbar larval development on a dam spillway in Harbel, Liberia, was observed to make accurate decisions regarding the frequency of larvicide treatments against this onchocerciasis vector. Larval development required a minimum of 10-12 d from eclosion to first pupation. Initial larvicidal treatment for S. yahense control would require a treatment cycle of 7 d. Once suppression of adult and larval populations is achieved, a 9-12-9-12 day treatment cycle could be adopted.

  19. Transcription factor broad suppresses precocious development of adult structures during larval-pupal metamorphosis in the red flour beetle, Tribolium castaneum.

    PubMed

    Parthasarathy, R; Tan, A; Bai, H; Palli, Subba R

    2008-01-01

    Broad (br), a transcription factor containing the Broad-Tramtrack-Bric-a-brac (BTB) and zinc finger domains was shown to mediate 20-hydroxyecdysone (20E) action and pupal development in Drosophila melanogaster and Manduca sexta. We determined the key roles of br during larval-pupal metamorphosis using RNA interference (RNAi) in a coleopteran insect, Tribolium castaneum. Two major peaks of T. castaneum broad (Tcbr) mRNA, one peak at the end of feeding stage prior to the larvae entering the quiescent stage and another peak during the quiescent stage were detected in the whole body and midgut tissue dissected from staged insects. Expression of br during the final instar larval stage is essential for successful larval-pupal metamorphosis, because, RNAi-mediated knock-down of Tcbr during this stage derailed larval-pupal metamorphosis and produced insects that showed larval, pupal and adult structures. Tcbr dsRNA injected into the final instar larvae caused reduction in the mRNA levels of genes known to be involved in 20E action (EcRA, E74 and E75B). Tcbr dsRNA injected into the final instar larvae also caused an increase in the mRNA levels of JH-response genes (JHE and Kr-h1b). Knock-down of Tcbr expression also affected 20E-mediated remodeling of midgut during larval-pupal metamorphosis. These data suggest that the expression of Tcbr during the final instar larval stage promotes pupal program while suppressing the larval and adult programs ensuring a transitory pupal stage in holometabolous insects. PMID:18083350

  20. Genetic control of Drosophila nerve cord development

    NASA Technical Reports Server (NTRS)

    Skeath, James B.; Thor, Stefan

    2003-01-01

    The Drosophila ventral nerve cord has been a central model system for studying the molecular genetic mechanisms that control CNS development. Studies show that the generation of neural diversity is a multistep process initiated by the patterning and segmentation of the neuroectoderm. These events act together with the process of lateral inhibition to generate precursor cells (neuroblasts) with specific identities, distinguished by the expression of unique combinations of regulatory genes. The expression of these genes in a given neuroblast restricts the fate of its progeny, by activating specific combinations of downstream genes. These genes in turn specify the identity of any given postmitotic cell, which is evident by its cellular morphology and choice of neurotransmitter.

  1. Embryonic and larval development of Brycon amazonicus (SPIX & AGASSIZ, 1829).

    PubMed

    Nakauth, A C S Sampaio; Villacorta-Correa, M A; Figueiredo, M R; Bernardino, G; França, J M

    2016-02-01

    The objective of this study was to describe the embryonic and larval development of Brycon amazonicus, featuring the main events up to 50 hours after fertilization (AF). The material was provided by the Aquaculture Training, Technology and Production Center, Presidente Figueiredo (AM). The characterization was based on stereomicroscopic examination of the morphology of eggs, embryos and larvae and comparison with the literature. Matrinxã eggs are free, transparent, and spherical, with a perivitelline space of 0.56 ± 0.3 mm. The successive divisions give rise to cells with 64 blastomeres during the first hour AF. The gastrula stage, beginning 02 h 40 min AF, was characterized by progressive regression cells and the formation of the embryonic axis, leading to differentiation of the head and tail 05 h 30 min AF. From 06 to 09 h AF the somites, notochord, otic and optic vesicles and otoliths were observed, in addition to heart rate and the release of the tail. The larvae hatched at 10 h 30 min AF (29.9 °C), with a total length of 3.56 ± 0.46 mm. Between 19 and 30 h AF, we observed 1) pigmentation and gut formation, 2) branchial arches, 3) pectoral fins, 4) a mouth opening and 5) teeth. Cannibalism was initiated earlier (34 h AF) which was associated with rapid yolk absorption (more than 90% until 50 h AF), signaling the need for an exogenous nutritional source. The environmental conditions (especially temperature) influenced the time course of some events throughout the embryonic and larval development, suggesting the need for further studies on this subject.

  2. Embryonic and larval development of Brycon amazonicus (SPIX & AGASSIZ, 1829).

    PubMed

    Nakauth, A C S Sampaio; Villacorta-Correa, M A; Figueiredo, M R; Bernardino, G; França, J M

    2016-02-01

    The objective of this study was to describe the embryonic and larval development of Brycon amazonicus, featuring the main events up to 50 hours after fertilization (AF). The material was provided by the Aquaculture Training, Technology and Production Center, Presidente Figueiredo (AM). The characterization was based on stereomicroscopic examination of the morphology of eggs, embryos and larvae and comparison with the literature. Matrinxã eggs are free, transparent, and spherical, with a perivitelline space of 0.56 ± 0.3 mm. The successive divisions give rise to cells with 64 blastomeres during the first hour AF. The gastrula stage, beginning 02 h 40 min AF, was characterized by progressive regression cells and the formation of the embryonic axis, leading to differentiation of the head and tail 05 h 30 min AF. From 06 to 09 h AF the somites, notochord, otic and optic vesicles and otoliths were observed, in addition to heart rate and the release of the tail. The larvae hatched at 10 h 30 min AF (29.9 °C), with a total length of 3.56 ± 0.46 mm. Between 19 and 30 h AF, we observed 1) pigmentation and gut formation, 2) branchial arches, 3) pectoral fins, 4) a mouth opening and 5) teeth. Cannibalism was initiated earlier (34 h AF) which was associated with rapid yolk absorption (more than 90% until 50 h AF), signaling the need for an exogenous nutritional source. The environmental conditions (especially temperature) influenced the time course of some events throughout the embryonic and larval development, suggesting the need for further studies on this subject. PMID:26909629

  3. The black-pearl gene of Drosophila defines a novel conserved protein family and is required for larval growth and survival.

    PubMed

    Becker, S; Gehrsitz, A; Bork, P; Buchner, S; Buchner, E

    2001-01-10

    Using a transposon insertion line of the Drosophila Genome Project we have cloned the black-pearl gene (blp), analyzed cDNA clones, generated various mutants, and characterized their phenotypes. The blp gene codes for a protein of 15.7 kDa calculated molecular weight that has been conserved from yeast to plants and mammals with high homology. A domain of these new proteins shows distant similarity to DnaJ domains indicating a functionally relevant interaction with other proteins. The P element insertion in line P1539 lies within the 5' untranslated leader of the black-pearl gene. Flies homozygous for this insertion are semi-lethal, escapers produce very few offspring and show melanotic inclusions in the hemocoel ('black pearls') similar to various melanotic 'tumor' mutants. Two small deletions confined to the blp gene and two EMS-induced mutations are homozygous lethal. These null mutants appear normal up to a prolonged first instar larval stage but fail to grow and die. Thus in Drosophila the blp gene is specifically required for larval growth. The evolutionary conservation in both unicellular and multicellular organisms suggests for the new protein family described here a fundamental role in cell growth.

  4. Drosophila Growth and Development in the Absence of dMyc and dMnt

    PubMed Central

    Pierce, Sarah B.; Yost, Cynthia; Anderson, Sarah A. R.; Flynn, Erin M.; Delrow, Jeffrey; Eisenman, Robert N.

    2008-01-01

    Myc oncoproteins are essential regulators of the growth and proliferation of mammalian cells. In Drosophila the single ortholog of Myc (dMyc), encoded by the dm gene, influences organismal size and the growth of both mitotic and endoreplicating cells. A null mutation in dm results in attenuated endoreplication and growth arrest early in larval development. Drosophila also contains a single ortholog of the mammalian Mad/Mnt transcriptional repressor proteins (dMnt), which is thought to antagonize dMyc function. Here we show that animals lacking both dMyc and dMnt display increased viability and grow significantly larger and develop further than dMyc single mutants. We observe increased endoreplication and growth of larval tissues in these double mutants and disproportionate growth of the imaginal discs. Gene expression analysis indicates that loss of dMyc leads to decreased expression of genes required for ribosome biogenesis and protein synthesis. The additional loss of dMnt partially rescues expression of a small number of dMyc and dMnt genes that are primarily involved in rRNA synthesis and processing. Our results indicate that dMnt repression is normally overridden by dMyc activation during larval development. Therefore the severity of the dm null phenotype is likely due to unopposed repression by dMnt on a subset of genes critical for cell and organismal growth. Surprisingly, considerable growth and development can occur in the absence of both dMyc and dMnt. PMID:18241851

  5. Effects of Spaceflight on Drosophila Neural Development

    NASA Technical Reports Server (NTRS)

    Keshishian, Haig S.

    1997-01-01

    The major goal from the animal side, however, has been achieved, namely to develop Drosophila lines where we can assay individual neuromuscular endings directly without dissection. This was achieved by means of using the GAL4-UAS system, where we have succeeded in establishing stocks of flies where the key neuromuscular connections can be assayed directly in undissected larvae by means of the expression of endogenously fluorescent reporters in the specific motor endings. The green fluorescent protein (GFP) as a reporter allows scoring of neural anatomy en-masse in whole mount using fluorescent microscopy without the need for either dissection or specific labeling. Two stocks have been developed. The first, which we developed first, uses the S65T mutant form, which has a dramatically brighter expression than the native protein. This animal will use GAL4 drivers with expression under the control of the elav gene, and which will ensure expression in all neurons of the embryo and larva. The second transgenic animal we have developed is of a novel kind, and makes use of dicistronic design, so that two copies of the protein will be expressed per insert. We have also developed a tricistronic form, but this has not yet been transformed into flies, and we do not imagine that this third line will be ready in time for the flight.

  6. Visual attraction in Drosophila larvae develops during a critical period and is modulated by crowding conditions.

    PubMed

    Slepian, Zoe; Sundby, Kelsey; Glier, Sarah; McDaniels, Jennifer; Nystrom, Taylor; Mukherjee, Suvadip; Acton, Scott T; Condron, Barry

    2015-10-01

    The development of social behavior is poorly understood. Many animals adjust their behavior to environmental conditions based on a social context. Despite having relatively simple visual systems, Drosophila larvae are capable of identifying and are attracted to the movements of other larvae. Here, we show that Drosophila larval visual recognition is encoded by the movements of nearby larvae, experienced during a specific developmental critical period. Exposure to moving larvae, only during a specific period, is sufficient for later visual recognition of movement. Larvae exposed to wild-type body movements, during the critical period, are not attracted to the movements of tubby mutants, which have altered morphology. However, exposure to tubby, during the critical period, results in tubby recognition at the expense of wild-type recognition indicating that this is true learning. Visual recognition is not learned in excessively crowded conditions, and this is emulated by exposure, during the critical period, to food previously used by crowded larvae. We propose that Drosophila larvae have a distinct critical period, during which they assess both social and resource conditions, and that this irreversibly determines later visually guided social behavior. This model provides a platform towards understanding the regulation and development of social behavior. PMID:26265464

  7. Collective synchronization of divisions in Drosophila development

    NASA Astrophysics Data System (ADS)

    Vergassola, Massimo

    Mitoses in the early development of most metazoans are rapid and synchronized across the entire embryo. While diffusion is too slow, in vitro experiments have shown that waves of the cell-cycle regulator Cdk1 can transfer information rapidly across hundreds of microns. However, the signaling dynamics and the physical properties of chemical waves during embryonic development remain unclear. We develop FRET biosensors for the activity of Cdk1 and the checkpoint kinase Chk1 in Drosophila embryos and exploit them to measure waves in vivo. We demonstrate that Cdk1 chemical waves control mitotic waves and that their speed is regulated by the activity of Cdk1 during the S-phase (and not mitosis). We quantify the progressive slowdown of the waves with developmental cycles and identify its underlying control mechanism by the DNA replication checkpoint through the Chk1/Wee1 pathway. The global dynamics of the mitotic signaling network illustrates a novel control principle: the S-phase activity of Cdk1 regulates the speed of the mitotic wave, while the Cdk1 positive feedback ensures an invariantly rapid onset of mitosis. Mathematical modeling captures the speed of the waves and predicts a fundamental distinction between the S-phase Cdk1 trigger waves and the mitotic phase waves, which is illustrated by embryonic ablation experiments. In collaboration with Victoria Deneke1, Anna Melbinger2, and Stefano Di Talia1 1 Department of Cell Biology, Duke University Medical Center 2 Department of Physics, University of California San Diego.

  8. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    PubMed

    Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

    2014-01-01

    Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods

  9. Correlated evolution between mode of larval development and habitat in muricid gastropods.

    PubMed

    Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

    2014-01-01

    Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods.

  10. Correlated Evolution between Mode of Larval Development and Habitat in Muricid Gastropods

    PubMed Central

    Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

    2014-01-01

    Abstract Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids

  11. Effects of Disinfectants on Larval Development of Ascaris suum Eggs

    PubMed Central

    Oh, Ki-Seok; Kim, Geon-Tae; Ahn, Kyu-Sung; Shin, Sung-Shik

    2016-01-01

    The objective of this study was to evaluate the effects of several different commercial disinfectants on the embryogenic development of Ascaris suum eggs. A 1-ml aliquot of each disinfectant was mixed with approximately 40,000 decorticated or intact A. suum eggs in sterile tubes. After each treatment time (at 0.5, 1, 5, 10, 30, and 60 min), disinfectants were washed away, and egg suspensions were incubated at 25˚C in distilled water for development of larvae inside. At 3 weeks of incubation after exposure, ethanol, methanol, and chlorohexidin treatments did not affect the larval development of A. suum eggs, regardless of their concentration and treatment time. Among disinfectants tested in this study, 3% cresol, 0.2% sodium hypochlorite and 0.02% sodium hypochlorite delayed but not inactivated the embryonation of decorticated eggs at 3 weeks of incubation, because at 6 weeks of incubation, undeveloped eggs completed embryonation regardless of exposure time, except for 10% povidone iodine. When the albumin layer of A. suum eggs remained intact, however, even the 10% povidone iodine solution took at least 5 min to reasonably inactivate most eggs, but never completely kill them with even 60 min of exposure. This study demonstrated that the treatment of A. suum eggs with many commercially available disinfectants does not affect the embryonation. Although some disinfectants may delay or stop the embryonation of A. suum eggs, they can hardly kill them completely. PMID:26951988

  12. Genetic control of cuticle formation during embryonic development of Drosophila melanogaster.

    PubMed Central

    Ostrowski, Stephen; Dierick, Herman A; Bejsovec, Amy

    2002-01-01

    The embryonic cuticle of Drosophila melanogaster is deposited by the epidermal epithelium during stage 16 of development. This tough, waterproof layer is essential for maintaining the structural integrity of the larval body. We have characterized mutations in a set of genes required for proper deposition and/or morphogenesis of the cuticle. Zygotic disruption of any one of these genes results in embryonic lethality. Mutant embryos are hyperactive within the eggshell, resulting in a high proportion reversed within the eggshell (the "retroactive" phenotype), and all show poor cuticle integrity when embryos are mechanically devitellinized. This last property results in embryonic cuticle preparations that appear grossly inflated compared to wild-type cuticles (the "blimp" phenotype). We find that one of these genes, krotzkopf verkehrt (kkv), encodes the Drosophila chitin synthase enzyme and that a closely linked gene, knickkopf (knk), encodes a novel protein that shows genetic interaction with the Drosophila E-cadherin, shotgun. We also demonstrate that two other known mutants, grainy head (grh) and retroactive (rtv), show the blimp phenotype when devitellinized, and we describe a new mutation, called zeppelin (zep), that shows the blimp phenotype but does not produce defects in the head cuticle as the other mutations do. PMID:12019232

  13. Regulation of synaptic development and function by the Drosophila PDZ protein Dyschronic.

    PubMed

    Jepson, James E C; Shahidullah, Mohammed; Liu, Die; le Marchand, Sylvain J; Liu, Sha; Wu, Mark N; Levitan, Irwin B; Dalva, Matthew B; Koh, Kyunghee

    2014-12-01

    Synaptic scaffold proteins control the localization of ion channels and receptors, and facilitate molecular associations between signaling components that modulate synaptic transmission and plasticity. Here, we define novel roles for a recently described scaffold protein, Dsychronic (DYSC), at the Drosophila larval neuromuscular junction. DYSC is the Drosophila homolog of whirlin/DFNB31, a PDZ domain protein linked to Usher syndrome, the most common form of human deaf-blindness. We show that DYSC is expressed presynaptically and is often localized adjacent to the active zone, the site of neurotransmitter release. Loss of DYSC results in marked alterations in synaptic morphology and cytoskeletal organization. Moreover, active zones are frequently enlarged and misshapen in dysc mutants. Electrophysiological analyses further demonstrate that dysc mutants exhibit substantial increases in both evoked and spontaneous synaptic transmission. We have previously shown that DYSC binds to and regulates the expression of the Slowpoke (SLO) BK potassium channel. Consistent with this, slo mutant larvae exhibit similar alterations in synapse morphology, active zone size and neurotransmission, and simultaneous loss of dysc and slo does not enhance these phenotypes, suggesting that dysc and slo act in a common genetic pathway to modulate synaptic development and output. Our data expand our understanding of the neuronal functions of DYSC and uncover non-canonical roles for the SLO potassium channel at Drosophila synapses.

  14. Elevated major ion concentrations inhibit larval mayfly growth and development.

    PubMed

    Johnson, Brent R; Weaver, Paul C; Nietch, Christopher T; Lazorchak, James M; Struewing, Katherine A; Funk, David H

    2015-01-01

    Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species.

  15. Elevated major ion concentrations inhibit larval mayfly growth and development.

    PubMed

    Johnson, Brent R; Weaver, Paul C; Nietch, Christopher T; Lazorchak, James M; Struewing, Katherine A; Funk, David H

    2015-01-01

    Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species. PMID:25307284

  16. The proprotein convertase amontillado (amon) is required during Drosophila pupal development.

    PubMed

    Rayburn, Lowell Y M; Rhea, Jeanne; Jocoy, Steven R; Bender, Michael

    2009-09-01

    Peptide hormones governing many developmental processes are generated via endoproteolysis of inactive precursor molecules by a family of subtilisin-like proprotein convertases (SPCs). We previously identified mutations in the Drosophila amontillado (amon) gene, a homolog of the vertebrate neuroendocrine-specific Prohormone Convertase 2 (PC2) gene, and showed that amon is required during embryogenesis, early larval development, and larval molting. Here, we define amon requirements during later developmental stages using a conditional rescue system and find that amon is required during pupal development for head eversion, leg and wing disc extension, and abdominal differentiation. Immuno-localization experiments show that amon protein is expressed in a subset of central nervous system cells but does not co-localize with peptide hormones known to elicit molting behavior, suggesting the involvement of novel regulatory peptides in this process. The amon protein is expressed in neuronal cells that innervate the corpus allatum and corpora cardiaca of the ring gland, an endocrine organ which is the release site for many key hormonal signals. Expression of amon in a subset of these cell types using the GAL4/UAS system in an amon mutant background partially rescues larval molting and growth. Our results show that amon is required for pupal development and identify a subset of neuronal cell types in which amon function is sufficient to rescue developmental progression and growth defects shown by amon mutants. The results are consistent with a model that the amon protein acts to proteolytically process a diverse suite of peptide hormones that coordinate larval and pupal growth and development. PMID:19559693

  17. The proprotein convertase amontillado (amon) is required during Drosophila pupal development

    PubMed Central

    Rayburn, Lowell Y.M.; Rhea, Jeanne; Jocoy, Steven R.; Bender, Michael

    2009-01-01

    Peptide hormones governing many developmental processes are generated via endoproteolysis of inactive precursor molecules by a family of subtilisin-like proprotein convertases (SPCs). We previously identified mutations in the Drosophila amontillado (amon) gene, a homolog of the vertebrate neuroendocrine-specific Prohormone Convertase 2 (PC2) gene, and showed that amon is required during embryogenesis, early larval development, and larval molting. Here, we define amon requirements during later developmental stages using a conditional rescue system and find that amon is required during pupal development for head eversion, leg and wing disc extension, and abdominal differentiation. Immuno-localization experiments show that amon protein is expressed in a subset of central nervous system cells but does not co-localize with peptide hormones known to elicit molting behavior, suggesting the involvement of novel regulatory peptides in this process. The amon protein is expressed in neuronal cells that innervate the corpus allatum and corpora cardiaca of the ring gland, an endocrine organ which is the release site for many key hormonal signals. Expression of amon in a subset of these cell types using the GAL4/UAS system in an amon mutant background partially rescues larval molting and growth. Our results show that amon is required for pupal development and identify a subset of neuronal cell types in which amon function is sufficient to rescue developmental progression and growth defects shown by amon mutants. The results are consistent with a model that the amon protein acts to proteolytically process a diverse suite of peptide hormones that coordinate larval and pupal growth and development. PMID:19559693

  18. Effects of Synthetic Diets Enriched in Specific Nutrients on Drosophila Development, Body Fat, and Lifespan

    PubMed Central

    Reis, Tânia

    2016-01-01

    Gene-diet interactions play a crucial but poorly understood role in susceptibility to obesity. Accordingly, the development of genetically tractable model systems to study the influence of diets in obesity-prone genetic backgrounds is a focus of current research. Here I present a modified synthetic Drosophila diet optimized for timely larval development, a stage dedicated to energy storage. Specifically increasing the levels of individual macronutrients–carbohydrate, lipid, or protein–resulted in markedly different organismal effects. A high-carbohydrate diet adversely affected the timing of development, size, early lifespan and body fat. Strikingly, quadrupling the amount of dietary lipids had none of these effects. Diets rich in protein appeared to be the most beneficial, as larvae developed faster, with no change in size, into long-lived adults. I believe this synthetic diet will significantly facilitate the study of gene-diet interactions in organismal energy balance. PMID:26741692

  19. Larval development of Culex quinquefasciatus in water with low to moderate.

    PubMed

    Noori, Navideh; Lockaby, B Graeme; Kalin, Latif

    2015-12-01

    Population growth and urbanization have increased the potential habitats, and consequently the abundance of Culex quinquefasciatus, the southern house mosquito, a vector of West Nile Virus in urban areas. Water quality is critical in larval habitat distribution and in providing microbial food resources for larvae. A mesocosm experiment was designed to demonstrate which specific components of water chemistry are conducive to larval Culex mosquitoes. Dose-response relationships between larval development and NO3 , NH4 , and PO4 concentrations in stream water were developed through this experiment to describe the isolated effects of each nutrient on pre-adult development. The emergence pattern of Culex mosquitoes was found to be strongly related to certain nutrients, and results showed that breeding sites with higher PO4 or NO3 concentrations had higher larval survival rates. High NO3 concentrations favor the development of male mosquitoes and suppress the development of female mosquitoes, but those adult females that do emerge develop faster in containers with high NO3 levels compared to the reference group. The addition of PO4 in the absence of nitrogen sources to the larval habitat slowed larval development, however, it took fewer days for larvae to reach the pupal stage in containers with combinations of NO3 and PO4 or NH4 and PO4 nutrients. Results from this study may bolster efforts to control WNV in urban landscapes by exploring water quality conditions of Culex larval habitats that produce adult mosquitoes. PMID:26611953

  20. Effect of ace inhibitors and TMOF on growth, development, and trypsin activity of larval Spodoptera littoralis.

    PubMed

    Lemeire, Els; Borovsky, Dov; Van Camp, John; Smagghe, Guy

    2008-12-01

    Angiotensin converting enzyme (ACE) is a zinc metallopeptidase capable of cleaving dipeptide or dipeptideamide moieties at the C-terminal end of peptides. ACE is present in the hemolymph and reproductive tissues of insects. The presence of ACE in the hemolymph and its broad substrate specificity suggests an important role in processing of bioactive peptides. This study reports the effects of ACE inhibitors on larval growth in the cotton leafworm Spodoptera littoralis. Feeding ACE inhibitors ad lib decreased the growth rate, inhibited ACE activity in the larval hemolymph, and down-regulated trypsin activity in the larval gut. These results indicate that S. littoralis ACE may influence trypsin biosynthesis in the larval gut by interacting with a trypsin-modulating oostatic factor (TMOF). Injecting third instar larvae with a combination of Aea-TMOF and the ACE inhibitor captopril, down-regulated trypsin biosynthesis in the larval gut indicating that an Aea-TMOF gut receptor analogue could be present. Injecting captopril and enalapril into newly molted fifth instar larvae stopped larval feeding and decreased weight gain. Together, these results indicate that ACE inhibitors are efficacious in stunting larval growth and ACE plays an important role in larval growth and development. PMID:18949805

  1. Drosophila larval to pupal switch under nutrient stress requires IP3R/Ca2+ signalling in glutamatergic interneurons

    PubMed Central

    Jayakumar, Siddharth; Richhariya, Shlesha; Reddy, O Venkateswara; Texada, Michael J; Hasan, Gaiti

    2016-01-01

    Neuronal circuits are known to integrate nutritional information, but the identity of the circuit components is not completely understood. Amino acids are a class of nutrients that are vital for the growth and function of an organism. Here, we report a neuronal circuit that allows Drosophila larvae to overcome amino acid deprivation and pupariate. We find that nutrient stress is sensed by the class IV multidendritic cholinergic neurons. Through live calcium imaging experiments, we show that these cholinergic stimuli are conveyed to glutamatergic neurons in the ventral ganglion through mAChR. We further show that IP3R-dependent calcium transients in the glutamatergic neurons convey this signal to downstream medial neurosecretory cells (mNSCs). The circuit ultimately converges at the ring gland and regulates expression of ecdysteroid biosynthetic genes. Activity in this circuit is thus likely to be an adaptation that provides a layer of regulation to help surpass nutritional stress during development. DOI: http://dx.doi.org/10.7554/eLife.17495.001 PMID:27494275

  2. An amphioxus netrin gene is expressed in midline structures during embryonic and larval development.

    PubMed

    Shimeld, S

    2000-07-01

    Members of the netrin gene family have been identified in vertebrates, Drosophila and Caenorhabditis elegans and found to encode secreted molecules involved in axon guidance. Here I use the conserved function of netrins in triploblasts, coupled with the phylogenetic position of amphioxus (the closest living relative of the vertebrates), to investigate the evolution of an axon guidance cue in chordates. A single amphioxus netrin gene was isolated by PCR and cDNA library screening and named AmphiNetrin. The predicted AmphiNetrin protein showed high identity to other netrin family members but differed in that the third of three EGF repeats found in other netrins was absent. Molecular phylogene-tic analysis showed that despite the absent EGF repeat AmphiNetrin is most closely related to the vertebrate netrins. AmphiNetrin expression was identified in embryonic notochord and floor plate, a pattern similar to that of vertebrate netrin-1 expression. AmphiNetrin expression was also identified more widely in the posterior larval brain, and in the anterior extension of the notochord that underlies the anterior of the amphioxus brain. All of these areas of expression are correlated with developing axon trajectories: The floor plate with ventrally projecting somatic motor neurons and Rohde cell projections, the posterior brain with the ventral commissure and primary motor centre and the anterior extension of the notochord with ventrally projecting neurons associated with the median eye. Amphioxus is naturally cyclopaedic and also lacks the ventral brain cells that the induction of which results in the splitting of the vertebrate eye field and, when missing, result in cyclopaedia. These cells normally express netrins required for developing axon tracts in the brain, and the expression of AmphiNetrin in the anterior extension of the notochord underlying the brain may explain how amphioxus is able to maintain ventral guidance cues while lacking these cells.

  3. Experimentally Increased Codon Bias in the Drosophila Adh Gene Leads to an Increase in Larval, But Not Adult, Alcohol Dehydrogenase Activity

    PubMed Central

    Hense, Winfried; Anderson, Nathan; Hutter, Stephan; Stephan, Wolfgang; Parsch, John; Carlini, David B.

    2010-01-01

    Although most amino acids can be encoded by more than one codon, the synonymous codons are not used with equal frequency. This phenomenon is known as codon bias and appears to be a universal feature of genomes. The translational selection hypothesis posits that the use of optimal codons, which match the most abundant species of isoaccepting tRNAs, results in increased translational efficiency and accuracy. Previous work demonstrated that the experimental reduction of codon bias in the Drosophila alcohol dehydrogenase (Adh) gene led to a significant decrease in ADH protein expression. In this study we performed the converse experiment: we replaced seven suboptimal leucine codons that occur naturally in the Drosophila melanogaster Adh gene with the optimal codon. We then compared the in vivo ADH activities imparted by the wild-type and mutant alleles. The introduction of optimal leucine codons led to an increase in ADH activity in third-instar larvae. In adult flies, however, the introduction of optimal codons led to a decrease in ADH activity. There is no evidence that other selectively constrained features of the Adh gene, or its rate of transcription, were altered by the synonymous replacements. These results are consistent with translational selection for codon bias being stronger in the larval stage and suggest that there may be a selective conflict over optimal codon usage between different developmental stages. PMID:19966063

  4. Experimentally increased codon bias in the Drosophila Adh gene leads to an increase in larval, but not adult, alcohol dehydrogenase activity.

    PubMed

    Hense, Winfried; Anderson, Nathan; Hutter, Stephan; Stephan, Wolfgang; Parsch, John; Carlini, David B

    2010-02-01

    Although most amino acids can be encoded by more than one codon, the synonymous codons are not used with equal frequency. This phenomenon is known as codon bias and appears to be a universal feature of genomes. The translational selection hypothesis posits that the use of optimal codons, which match the most abundant species of isoaccepting tRNAs, results in increased translational efficiency and accuracy. Previous work demonstrated that the experimental reduction of codon bias in the Drosophila alcohol dehydrogenase (Adh) gene led to a significant decrease in ADH protein expression. In this study we performed the converse experiment: we replaced seven suboptimal leucine codons that occur naturally in the Drosophila melanogaster Adh gene with the optimal codon. We then compared the in vivo ADH activities imparted by the wild-type and mutant alleles. The introduction of optimal leucine codons led to an increase in ADH activity in third-instar larvae. In adult flies, however, the introduction of optimal codons led to a decrease in ADH activity. There is no evidence that other selectively constrained features of the Adh gene, or its rate of transcription, were altered by the synonymous replacements. These results are consistent with translational selection for codon bias being stronger in the larval stage and suggest that there may be a selective conflict over optimal codon usage between different developmental stages.

  5. A Flippase-Mediated GAL80/GAL4 Intersectional Resource for Dissecting Appendage Development in Drosophila.

    PubMed

    Smith, Brittany N; Ghazanfari, Arash M; Bohm, Rudolf A; Welch, William P; Zhang, Bing; Masly, John P

    2015-08-13

    Drosophila imaginal discs provide an ideal model to study processes important for cell signaling and cell specification, tissue differentiation, and cell competition during development. One challenge to understanding genetic control of cellular processes and cell interactions is the difficulty in effectively targeting a defined subset of cells in developing tissues in gene manipulation experiments. A recently developed Flippase-induced intersectional GAL80/GAL4 repression method incorporates several gene manipulation technologies in Drosophila to enable such fine-scale dissection in neural tissues. In particular, this approach brings together existing GAL4 transgenes, newly developed enhancer-trap flippase transgenes, and GAL80 transgenes flanked by Flippase recognition target sites. The combination of these tools enables gene activation/repression in particular subsets of cells within a GAL4 expression pattern. Here, we expand the utility of a large collection of these enhancer-trap flippase transgenic insertion lines by characterizing their expression patterns in third larval instar imaginal discs. We screened 521 different enhancer-trap flippase lines and identified 28 that are expressed in imaginal tissues, including two transgenes that show sex-specific expression patterns. Using a line that expresses Flippase in the wing imaginal disc, we demonstrate the utility of this intersectional approach for studying development by knocking down gene expression of a key member of the planar cell polarity pathway. The results of our experiments show that these enhancer-trap flippase lines enable fine-scale manipulation in imaginal discs.

  6. The Drosophila histone demethylase dKDM5/LID regulates hematopoietic development.

    PubMed

    Morán, Tomás; Bernués, Jordi; Azorín, Fernando

    2015-09-15

    dKDM5/LID regulates transcription of essential developmental genes and, thus, is required for different developmental processes. Here, we report the essential contribution of dKDM5/LID to hematopoiesis in Drosophila. Our results show that dKDM5/LID is abundant in hemocytes and that its depletion induces over-proliferation and differentiation defects of larval hemocytes and disrupts organization of the actin cytoskeleton. We also show that dKDM5/LID regulates expression of key factors of hematopoietic development. In particular, dKDM5/LID depletion up-regulates expression of several transcription factors involved in hemocytes proliferation and differentiation as well as of several small-GTPases that link signaling effectors to actin cytoskeleton formation and dynamics.

  7. Larval development of the subantarctic king crabs Lithodes santolla and Paralomis granulosa reared in the laboratory

    NASA Astrophysics Data System (ADS)

    Calcagno, J. A.; Anger, K.; Lovrich, G. A.; Thatje, S.; Kaffenberger, A.

    2004-02-01

    The larval development and survival in the two subantarctic lithodid crabs Lithodes santolla (Jaquinot) and Paralomis granulosa (Molina) from the Argentine Beagle Channel were studied in laboratory cultures. In L. santolla, larval development lasted about 70 days, passing through three zoeal stages and the megalopa stage, with a duration of approximately 4, 7, 11 and 48 days, respectively. The larval development in P. granulosa is more abbreviated, comprising only two zoeal stages and the megalopa stage, with 6, 11 and 43 days' duration, respectively. In both species, we tested for effects of presence versus absence of food (Artemia nauplii) on larval development duration and survival rate. In P. granulosa, we also studied effects of different rearing conditions, such as individual versus mass cultures, as well as aerated versus unaerated cultures. No differences in larval development duration and survival were observed between animals subjected to those different rearing conditions. The lack of response to the presence or absence of potential food confirms, in both species, a complete lecithotrophic mode of larval development. Since lithodid crabs are of high economic importance in the artisanal fishery in the southernmost parts of South America, the knowledge of optimal rearing conditions for lithodid larvae is essential for future attempts at repopulating the collapsing natural stocks off Tierra del Fuego.

  8. Larval and metamorphic development of the foregut and proboscis in the caenogastropod Marsenina (Lamellaria) stearnsii.

    PubMed

    Page, L R

    2002-05-01

    The specialized, postmetamorphic feeding structures of predatory caenogastropods evolved by changes to an ancestral caenogastropod developmental program that generated a planktotrophic larval stage followed by a herbivorous postmetamorphic stage. As part of a program of comparative studies aimed at reconstructing these developmental changes, I studied the development of the postmetamorphic feeding system of Marsenina stearnsii using histological sections for light microscopy and scanning and transmission electron microscopy. The feeding system of this species has two very different designs during ontogeny. The larval system uses ciliary effectors to capture and ingest microalgae, whereas the juvenile/adult system includes a proboscis, jaws, and radular apparatus for predation on ascidian zooids. The postmetamorphic foregut begins to develop during the early larval phase, but the anlagen does not interfere with larval feeding because it develops as an increasingly elaborate outpocketing from the ventral wall of the larval esophagus. At metamorphosis, an opening is created in the anterior tip of the prospective, postmetamorphic buccal cavity and the margins of this opening anneal with the metamorphically remodeled lips of the larval mouth. This process exposes the jaws, which differentiate within the buccal cavity prior to metamorphosis. As a working hypothesis, I suggest that rupture of the buccal cavity to the outside at metamorphosis was selected as a mechanism to allow precocious development of jaws in species where jaws enhanced feeding performance by young juveniles. The larval esophagus of M. stearnsii appears to be completely destroyed at metamorphosis. Larval esophageal cells have distinctive apical characteristics (cilia, blebbed microvilli, stacks of lamellae within the glycocalyx) and no cells having this signature persist through metamorphosis. Development of the proboscis and proboscis sac, which begins prior to metamorphosis, conforms to previous

  9. Regulation of apoptosis of rbf mutant cells during Drosophila development

    PubMed Central

    Tanaka-Matakatsu, Miho; Xu, Jinhua; Cheng, Leping; Du, Wei

    2008-01-01

    Inactivation of the retinoblastoma gene Rb leads to defects in cell proliferation, differentiation, or apoptosis, depending on specific cell or tissue types. To gain insights into the genes that can modulate the consequences of Rb inactivation, we carried out a genetic screen in Drosophila to identify mutations that affected apoptosis induced by inactivation of the Retinoblastoma-family protein (rbf) and identified a mutation that blocked apoptosis induced by rbf. We found this mutation to be a new allele of head involution defective (hid) and showed that hid expression is deregulated in rbf mutant cells in larval imaginal discs. We identified an enhancer that regulates hid expression in response to developmental cues as well as to radiation and demonstrated that this hid enhancer is directly repressed by RBF through an E2F binding site. These observations indicate that apoptosis of rbf mutant cells is mediated by an upregulation of hid. Finally, we showed that bantam, a miRNA that regulates hid translation, is expressed in the interommatidial cells in the larval eye discs and modulates the survival of rbf mutant cells. PMID:19100727

  10. The vav oncogene antagonises EGFR signalling and regulates adherens junction dynamics during Drosophila eye development.

    PubMed

    Martín-Bermudo, Maria-Dolores; Bardet, Pierre-Luc; Bellaïche, Yohanns; Malartre, Marianne

    2015-04-15

    Organ shaping and patterning depends on the coordinated regulation of multiple processes. The Drosophila compound eye provides an excellent model to study the coordination of cell fate and cell positioning during morphogenesis. Here, we find that loss of vav oncogene function during eye development is associated with a disorganised retina characterised by the presence of additional cells of all types. We demonstrate that these defects result from two distinct roles of Vav. First, and in contrast to its well-established role as a positive effector of the EGF receptor (EGFR), we show that readouts of the EGFR pathway are upregulated in vav mutant larval eye disc and pupal retina, indicating that Vav antagonises EGFR signalling during eye development. Accordingly, decreasing EGFR signalling in vav mutant eyes restores retinal organisation and rescues most vav mutant phenotypes. Second, using live imaging in the pupal retina, we observe that vav mutant cells do not form stable adherens junctions, causing various defects, such as recruitment of extra primary pigment cells. In agreement with this role in junction dynamics, we observe that these phenotypes can be exacerbated by lowering DE-Cadherin or Cindr levels. Taken together, our findings establish that Vav acts at multiple times during eye development to prevent excessive cell recruitment by limiting EGFR signalling and by regulating junction dynamics to ensure the correct patterning and morphogenesis of the Drosophila eye.

  11. ATM is required for telomere maintenance and chromosome stability during Drosophila development.

    PubMed

    Silva, Elizabeth; Tiong, Stanley; Pedersen, Michael; Homola, Ellen; Royou, Anne; Fasulo, Barbara; Siriaco, Giorgia; Campbell, Shelagh D

    2004-08-10

    ATM is a large, multifunctional protein kinase that regulates responses required for surviving DNA damage: including DNA repair, apoptosis, and cell cycle checkpoints. Here, we show that Drosophila ATM function is essential for normal adult development. Extensive, inappropriate apoptosis occurs in proliferating atm mutant tissues, and in clonally derived atm mutant embryos, frequent mitotic defects were seen. At a cellular level, spontaneous telomere fusions and other chromosomal abnormalities are common in atm larval neuroblasts, suggesting a conserved and essential role for dATM in the maintenance of normal telomeres and chromosome stability. Evidence from other systems supports the idea that DNA double-strand break (DSB) repair functions of ATM kinases promote telomere maintenance by inhibition of illegitimate recombination or fusion events between the legitimate ends of chromosomes and spontaneous DSBs. Drosophila will be an excellent model system for investigating how these ATM-dependent chromosome structural maintenance functions are deployed during development. Because neurons appear to be particularly sensitive to loss of ATM in both flies and humans, this system should be particularly useful for identifying cell-specific factors that influence sensitivity to loss of dATM and are relevant for understanding the human disease, ataxia-telangiectasia.

  12. Methods to assess Drosophila heart development, function and aging

    PubMed Central

    Ocorr, Karen; Vogler, Georg; Bodmer, Rolf

    2014-01-01

    In recent years the Drosophila heart has become an established model of many different aspects of human cardiac disease. This model has allowed identification of disease-causing mechanisms underlying congenital heart disease and cardiomyopathies and has permitted the study underlying genetic, metabolic and age-related contributions to heart function. In this review we discuss methods currently employed in the analysis of the Drosophila heart structure and function, such as optical methods to infer heart function and performance, electrophysiological and mechanical approaches to characterize cardiac tissue properties, and conclude with histological techniques used in the study of heart development and adult structure. PMID:24727147

  13. Exploration of the "larval pool": development and ground-truthing of a larval transport model off leeward Hawai'i.

    PubMed

    Wren, Johanna L K; Kobayashi, Donald R

    2016-01-01

    Most adult reef fish show site fidelity thus dispersal is limited to the mobile larval stage of the fish, and effective management of such species requires an understanding of the patterns of larval dispersal. In this study, we assess larval reef fish distributions in the waters west of the Big Island of Hawai'i using both in situ and model data. Catches from Cobb midwater trawls off west Hawai'i show that reef fish larvae are most numerous in offshore waters deeper than 3,000 m and consist largely of pre-settlement Pomacanthids, Acanthurids and Chaetodontids. Utilizing a Lagrangian larval dispersal model, we were able to replicate the observed shore fish distributions from the trawl data and we identified the 100 m depth strata as the most likely depth of occupancy. Additionally, our model showed that for larval shore fish with a pelagic larval duration longer than 40 days there was no significant change in settlement success in our model. By creating a general additive model (GAM) incorporating lunar phase and angle we were able to explain 67.5% of the variance between modeled and in situ Acanthurid abundances. We took steps towards creating a predictive larval distribution model that will greatly aid in understanding the spatiotemporal nature of the larval pool in west Hawai'i, and the dispersal of larvae throughout the Hawaiian archipelago.

  14. MAP kinase subcellular localization controls both pattern and proliferation in the developing Drosophila wing

    PubMed Central

    Marenda, Daniel R.; Vrailas, Alysia D.; Rodrigues, Aloma B.; Cook, Summer; Powers, Maureen A.; Lorenzen, James A.; Perkins, Lizabeth A.; Moses, Kevin

    2007-01-01

    Mitogen-activated protein kinases (MAPKs) phosphorylate target proteins in both the cytoplasm and nucleus, and a strong correlation exists between the subcellular localization of MAPK and resulting cellular responses. It was thought that MAPK phosphorylation was always followed by rapid nuclear translocation. However, we and others have found that MAPK phosphorylation is not always sufficient for nuclear translocation in vivo. In the developing Drosophila wing, MAPK-mediated signaling is required both for patterning and for cell proliferation, although the mechanism of this differential control is not fully understood. Here, we show that phosphorylated MAPK (pMAPK) is held in the cytoplasm in differentiating larval and pupal wing vein cells, and we show that this cytoplasmic hold is required for vein cell fate. At the same time, we show that MAPK does move into the nucleus of other wing cells where it promotes cell proliferation. We propose a novel Ras pathway bifurcation in Drosophila and our results suggest a mechanism by which MAPK phosphorylation can signal two different cellular outcomes (differentiation versus proliferation) based on the subcellular localization of MAPK. PMID:16308331

  15. Transgenic inhibitors identify two roles for protein kinase A in Drosophila development.

    PubMed Central

    Kiger, J A; Eklund, J L; Younger, S H; O'Kane, C J

    1999-01-01

    We have initiated an analysis of protein kinase A (PKA) in Drosophila using transgenic techniques to modulate PKA activity in specific tissues during development. We have constructed GAL4/UAS-regulated transgenes in active and mutant forms that encode PKAc, the catalytic subunit of PKA, and PKI(1-31), a competitive inhibitor of PKAc. We present evidence that the wild-type transgenes are active and summarize the phenotypes produced by a number of GAL4 enhancer-detector strains. We compare the effects of transgenes encoding PKI(1-31) with those encoding PKAr*, a mutant regulatory subunit that constitutively inhibits PKAc because of its inability to bind cyclic AMP. Both inhibitors block larval growth, but only PKAr* alters pattern formation by activating the Hedgehog signaling pathway. Therefore, transgenic PKI(1-31) should provide a tool to investigate the role of PKAc in larval growth regulation without concomitant changes in pattern formation. The different effects of PKI(1-31) and PKAr* suggest two distinct roles, cytoplasmic and nuclear, for PKAc in Hedgehog signal transduction. Alternatively, PKAr* may target proteins other than PKAc, suggesting a role for free PKAr in signal transduction, a role inhibited by PKAc in reversal of the classical relationship of these subunits. PMID:10224260

  16. Genetic architecture of olfactory behavior in Drosophila melanogaster: differences and similarities across development

    PubMed Central

    Lavagnino, N.J.; Arya, G.H.; Korovaichuk, A.; Fanara, J.J.

    2013-01-01

    In the holometabolous insect Drosophila melanogaster, genetic, physiological and anatomical aspects of olfaction are well known in the adult stage, while larval stages olfactory behavior has received some attention it has been less studied than its adult counterpart. Most of these studies focus on olfactory receptors (Or) genes that produce peripheral odor recognition. In this paper, through a loss-of-function screen using P-element inserted lines and also by means of expression analyses of larval olfaction candidate genes, we extended the uncovering of the genetic underpinnings of D. melanogaster larval olfactory behavior by demonstrating that larval olfactory behavior is, in addition to Or genes, orchestrated by numerous genes with diverse functions. Also, our results points out that the genetic architecture of olfactory behavior in D. melanogaster presents a dynamic and changing organization across environments and ontogeny. PMID:23563598

  17. dTAF10- and dTAF10b-Containing Complexes Are Required for Ecdysone-Driven Larval-Pupal Morphogenesis in Drosophila melanogaster

    PubMed Central

    Pahi, Zoltan; Kiss, Zsuzsanna; Komonyi, Orbán; Borsos, Barbara N.; Tora, Laszlo; Boros, Imre M.; Pankotai, Tibor

    2015-01-01

    In eukaryotes the TFIID complex is required for preinitiation complex assembly which positions RNA polymerase II around transcription start sites. On the other hand, histone acetyltransferase complexes including SAGA and ATAC, modulate transcription at several steps through modification of specific core histone residues. In this study we investigated the function of Drosophila melanogaster proteins TAF10 and TAF10b, which are subunits of dTFIID and dSAGA, respectively. We generated a mutation which eliminated the production of both Drosophila TAF10 orthologues. The simultaneous deletion of both dTaf10 genes impaired the recruitment of the dTFIID subunit dTAF5 to polytene chromosomes, while binding of other TFIID subunits, dTAF1 and RNAPII was not affected. The lack of both dTAF10 proteins resulted in failures in the larval-pupal transition during metamorphosis and in transcriptional reprogramming at this developmental stage. Surprisingly, unlike dSAGA mutations, dATAC subunit mutations resulted in very similar changes in the steady state mRNA levels of approximately 5000 genes as did ablation of both dTaf10 genes, indicating that dTAF10- and/or dTAF10b-containing complexes and dATAC affect similar pathways. Importantly, the phenotype resulting from dTaf10+dTaf10b mutation could be rescued by ectopically added ecdysone, suggesting that dTAF10- and/or dTAF10b-containing complexes are involved in the expression of ecdysone biosynthetic genes. Indeed, in dTaf10+dTaf10b mutants, cytochrome genes, which regulate ecdysone synthesis in the ring gland, were underrepresented. Therefore our data support the idea that the presence of dTAF10 proteins in dTFIID and/or dSAGA is required only at specific developmental steps. We propose that distinct forms of dTFIID and/or dSAGA exist during Drosophila metamorphosis, wherein different TAF compositions serve to target RNAPII at different developmental stages and tissues. PMID:26556600

  18. Clonal development and organization of the adult Drosophila central brain

    PubMed Central

    Yu, Hung-Hsiang; Awasaki, Takeshi; Schroeder, Mark David; Long, Fuhui; Yang, Jacob S.; He, Yisheng; Ding, Peng; Kao, Jui-Chun; Wu, Gloria Yueh-Yi; Peng, Hanchuan; Myers, Gene; Lee, Tzumin

    2013-01-01

    Summary Background The insect brain can be divided into neuropils that are formed by neurites of both local and remote origin. The complexity of the interconnections obscures how these neuropils are established and interconnected through development. The Drosophila central brain develops from a fixed number of neuroblasts (NBs) that deposit neurons in regional clusters. Results By determining individual NB clones and pursuing their projections into specific neuropils we unravel the regional development of the brain neural network. Exhaustive clonal analysis revealed 95 stereotyped neuronal lineages with characteristic cell body locations and neurite trajectories. Most clones show complex projection patterns, but despite the complexity, neighboring clones often co-innervate the same local neuropil(s) and further target a restricted set of distant neuropils. Conclusions These observations argue for regional clonal development of both neuropils and neuropil connectivity throughout the Drosophila central brain. PMID:23541733

  19. Modeling larval connectivity of the Atlantic surfclams within the Middle Atlantic Bight: Model development, larval dispersal and metapopulation connectivity

    NASA Astrophysics Data System (ADS)

    Zhang, Xinzhong; Haidvogel, Dale; Munroe, Daphne; Powell, Eric N.; Klinck, John; Mann, Roger; Castruccio, Frederic S.

    2015-02-01

    To study the primary larval transport pathways and inter-population connectivity patterns of the Atlantic surfclam, Spisula solidissima, a coupled modeling system combining a physical circulation model of the Middle Atlantic Bight (MAB), Georges Bank (GBK) and the Gulf of Maine (GoM), and an individual-based surfclam larval model was implemented, validated and applied. Model validation shows that the model can reproduce the observed physical circulation patterns and surface and bottom water temperature, and recreates the observed distributions of surfclam larvae during upwelling and downwelling events. The model results show a typical along-shore connectivity pattern from the northeast to the southwest among the surfclam populations distributed from Georges Bank west and south along the MAB shelf. Continuous surfclam larval input into regions off Delmarva (DMV) and New Jersey (NJ) suggests that insufficient larval supply is unlikely to be the factor causing the failure of the population to recover after the observed decline of the surfclam populations in DMV and NJ from 1997 to 2005. The GBK surfclam population is relatively more isolated than populations to the west and south in the MAB; model results suggest substantial inter-population connectivity from southern New England to the Delmarva region. Simulated surfclam larvae generally drift for over one hundred kilometers along the shelf, but the distance traveled is highly variable in space and over time. Surfclam larval growth and transport are strongly impacted by the physical environment. This suggests the need to further examine how the interaction between environment, behavior, and physiology affects inter-population connectivity. Larval vertical swimming and sinking behaviors have a significant net effect of increasing larval drifting distances when compared with a purely passive model, confirming the need to include larval behavior.

  20. It takes two to tango, a dance between the cells of origin and cancer stem cells in the Drosophila larval brain.

    PubMed

    Janssens, Derek H; Lee, Cheng-Yu

    2014-04-01

    During malignant transformation the cells of origin give rise to cancer stem cells which possess the capacity to undergo limitless rounds of self-renewing division, regenerating themselves while producing more tumor cells. Within normal tissues, a limitless self-renewal capacity is unique to the stem cells, which divide asymmetrically to produce more restricted progenitors. Accumulating evidence suggests that misregulation of the self-renewal machinery in stem cell progeny can lead to tumorigenesis, but how it influences the properties of the resulting tumors remains unclear. Studies of the type II neural stem cell (neuroblast) lineages in the Drosophila larval brain have identified a regulatory cascade that promotes commitment to a progenitor cell identity by restricting their response to the self-renewal machinery. Brain tumor (Brat) and Numb initiate this cascade by asymmetrically extinguishing the activity of the self-renewal factors. Subsequently, Earmuff (Erm) and the SWI/SNF complex stably restrict the competence of the progenitor cell to respond to reactivation of self-renewal mechanisms. Together, this cascade programs the progenitor cell to undergo limited rounds of division, generating exclusive differentiated progeny. Here we review how defects in this cascade lead to tumor initiation and how inhibiting the self-renewal mechanisms may be an effective strategy to block CSC expansion.

  1. Circulation constrains the evolution of larval development modes and life histories in the coastal ocean.

    PubMed

    Pringle, James M; Byers, James E; Pappalardo, Paula; Wares, John P; Marshall, Dustin

    2014-04-01

    The evolutionary pressures that drive long larval planktonic durations in some coastal marine organisms, while allowing direct development in others, have been vigorously debated. We introduce into the argument the asymmetric dispersal of larvae by coastal currents and find that the strength of the currents helps determine which dispersal strategies are evolutionarily stable. In a spatially and temporally uniform coastal ocean of finite extent, direct development is always evolutionarily stable. For passively drifting larvae, long planktonic durations are stable when the ratio of mean to fluctuating currents is small and the rate at which larvae increase in size in the plankton is greater than the mortality rate (both in units of per time). However, larval behavior that reduces downstream larval dispersal for a given time in plankton will be selected for, consistent with widespread observations of behaviors that reduce dispersal of marine larvae. Larvae with long planktonic durations are shown to be favored not for the additional dispersal they allow, but for the additional fecundity that larval feeding in the plankton enables. We analyzed the spatial distribution of larval life histories in a large database of coastal marine benthic invertebrates and documented a link between ocean circulation and the frequency of planktotrophy in the coastal ocean. The spatial variation in the frequency of species with planktotrophic larvae is largely consistent with our theory; increases in mean currents lead to a decrease in the fraction of species with planktotrophic larvae over a broad range of temperatures.

  2. Efficiency of three diets for larval development in mass rearing Aedes albopictus (Diptera: Culicidae).

    PubMed

    Puggioli, Arianna; Balestrino, F; Damiens, D; Lees, R S; Soliban, S M; Madakacherry, O; Dindo, M L; Bellini, R; Gilles, J R L

    2013-07-01

    A fundamental step in establishing a mass production system is the development of a larval diet that promotes high adult performance at a reasonable cost. To identify a suitable larval diet for Aedes albopictus (Skuse), three diets were compared: a standard laboratory diet used at the Centro Agricoltura Ambiente, Italy (CAA) and two diets developed specifically for mosquito mass rearing at the FAO/IAEA Laboratory, Austria. The two IAEA diets, without affecting survival to the pupal stage, resulted in a shorter time to pupation and to emergence when compared with the CAA diet. At 24 h from pupation onset, 50 and 90% of the male pupae produced on the CAA and IAEA diets, respectively, had formed and could be collected. The diet received during the larval stage affected the longevity of adult males with access to water only, with best results observed when using the CAA larval diet. However, similar longevity among diet treatments was observed when males were supplied with sucrose solution. No differences were observed in the effects of larval diet on adult male size or female fecundity and fertility. Considering these results, along with the relative costs of the three diets, the IAEA 2 diet is found to be the preferred choice for mass rearing of Aedes albopictus, particularly if a sugar meal can be given to adult males before release, to ensure their teneral reserves are sufficient for survival, dispersal, and mating in the field.

  3. Comparison of two versions of larval development test to detect anthelmintic resistance in Haemonchus contortus.

    PubMed

    Várady, Marián; Corba, Július; Letková, Valéria; Kovác, Gabriel

    2009-03-23

    Larval development (LDT) and micro-agar larval development tests (MALDT) were used to compare the reliability and sensitivity of two methods for detecting anthelmintic resistance in Haemonchus contortus. The tests were conducted using three resistant and four susceptible isolates of H. contortus. Both versions of the tests provided comparable results with regard to the characterization of benzimidazole and levamisole susceptibility but neither test was sufficiently sensitive to discrimination between an ivermectin (IVM) susceptible and an IVM resistant isolate. Each test has its own merits with the LDT having the advantage of being less time-consuming.

  4. Roles of hesC and gcm in echinoid larval mesenchyme cell development.

    PubMed

    Yamazaki, Atsuko; Minokawa, Takuya

    2016-04-01

    To understand the roles of hesC and gcm during larval mesenchyme specification and differentiation in echinoids, we performed perturbation experiments for these genes in two distantly related euechinoids, Hemicentrotus pulcherrimus and Scaphechinus mirabilis. The number of larval mesenchyme cells increased when the translation of hesC was inhibited, thereby suggesting that hesC has a general role in larval mesenchyme development. We confirmed previous results by demonstrating that gcm is involved in pigment cell differentiation. Simultaneous inhibition of the translation of hesC and gcm induced a significant increase in the number of skeletogenic cells, which suggests that gcm functions in skeletogenic fate repression. Based on these observations, we suggest that: (i) hesC participates in some general aspects of mesenchymal cell development; and (ii) gcm is involved in the mechanism responsible for the binary specification of skeletogenic and pigment cell fates. PMID:27046223

  5. Worker honey bee ovary development: seasonal variation and the influence of larval and adult nutrition.

    PubMed

    Hoover, Shelley E R; Higo, Heather A; Winston, Mark L

    2006-01-01

    We examined the effect of larval and adult nutrition on worker honey bee (Apis mellifera L.) ovary development. Workers were fed high or low-pollen diets as larvae, and high or low-protein diets as adults. Workers fed low-protein diets at both life stages had the lowest levels of ovary development, followed by those fed high-protein diets as larvae and low- quality diets as adults, and then those fed diets poor in protein as larvae but high as adults. Workers fed high-protein diets at both life stages had the highest levels of ovary development. The increases in ovary development due to improved dietary protein in the larval and adult life stages were additive. Adult diet also had an effect on body mass. The results demonstrate that both carry-over of larval reserves and nutrients acquired in the adult life stage are important to ovary development in worker honey bees. Carry-over from larval development, however, appears to be less important to adult fecundity than is adult nutrition. Seasonal trends in worker ovary development and mass were examined throughout the brood rearing season. Worker ovary development was lowest in spring, highest in mid-summer, and intermediate in fall.

  6. Exploring Larval Development and Applications in Marine Fish Aquaculture Using Pink Snapper Embryos

    ERIC Educational Resources Information Center

    Tamaru, Clyde; Haverkort-Yeh, Roxanne D.; Gorospe, Kelvin D.; Rivera, Malia Ana J.

    2014-01-01

    This biology investigation on "Pristipomoides filamentosus" larval development, survival, and aquaculture research was developed with three educational objectives: to provide high school students with (1) a scientific background on the biology and science of fisheries as well as overfishing, its consequences, and possible mitigations;…

  7. [BIO-INSECTICIDAL ACTIVITY OF ALPINIA GALANGA (L.) ON LARVAL DEVELOPMENT OF SPODOPTERA LITURA (LEPIDOPTERA: NOCTUIDAE).

    PubMed

    Pumchan, A; Puangsomchit, A; Temyarasilp, P; Pluempanupat, W; Bullangpoti, V

    2015-01-01

    The aim of the study was to assess the bio-efficacy of four Alpinia galanga rhizome crude extracts against the second and third instars of Spodoptera litura, an important field pest. The growth of younger larvae was significantly affected while that of the older larval stage was less influenced. In both stages, the methanol crude extract showed the greatest efficiency which caused the highest number of abnormal adults to occur and produced a large LD₅₀ value (12.816 µg/ larvae) pupicidal percentage after treatment, whereas, hexane extract caused the highest mortality during the larval-pupal stage after treatment with an LD₅₀ value of 6.354 µg/ larvae. However, the larval development was not significantly different among all treated larvae compared to the control. This study suggests that secondary larval instars of S. litura are more susceptible to the larval growth inhibitory action of Alpinia galanga extracts and these extracts could also be applied for use in the management of pests.

  8. Building from the ground up: basement membranes in Drosophila development

    PubMed Central

    Isabella, Adam J.; Horne-Badovinac, Sally

    2016-01-01

    Basement Membranes (BMs) are sheet-like extracellular matrices found at the basal surfaces of epithelial tissues. The structural and functional diversity of these matrices within the body endows them with the ability to affect multiple aspects of cell behavior and communication; for this reason, BMs are integral to many developmental processes. The power of Drosophila genetics, as applied to the BM, has yielded substantial insight into how these matrices influence development. Here, we explore three facets of BM biology to which Drosophila research has made particularly important contributions. First we discuss how newly synthesized BM proteins are secreted to and assembled exclusively on basal epithelial surfaces. Next, we examine how regulation of the structural properties of the BM mechanically supports and guides tissue morphogenesis. Finally, we explore how BMs influence development through the modulation of several major signaling pathways. PMID:26610918

  9. Genome-Wide Approaches to Drosophila Heart Development

    PubMed Central

    Frasch, Manfred

    2016-01-01

    The development of the dorsal vessel in Drosophila is one of the first systems in which key mechanisms regulating cardiogenesis have been defined in great detail at the genetic and molecular level. Due to evolutionary conservation, these findings have also provided major inputs into studies of cardiogenesis in vertebrates. Many of the major components that control Drosophila cardiogenesis were discovered based on candidate gene approaches and their functions were defined by employing the outstanding genetic tools and molecular techniques available in this system. More recently, approaches have been taken that aim to interrogate the entire genome in order to identify novel components and describe genomic features that are pertinent to the regulation of heart development. Apart from classical forward genetic screens, the availability of the thoroughly annotated Drosophila genome sequence made new genome-wide approaches possible, which include the generation of massive numbers of RNA interference (RNAi) reagents that were used in forward genetic screens, as well as studies of the transcriptomes and proteomes of the developing heart under normal and experimentally manipulated conditions. Moreover, genome-wide chromatin immunoprecipitation experiments have been performed with the aim to define the full set of genomic binding sites of the major cardiogenic transcription factors, their relevant target genes, and a more complete picture of the regulatory network that drives cardiogenesis. This review will give an overview on these genome-wide approaches to Drosophila heart development and on computational analyses of the obtained information that ultimately aim to provide a description of this process at the systems level. PMID:27294102

  10. A description of the larval development of Megabalanus azoricus (Pilsbry, 1916) reared in the laboratory

    NASA Astrophysics Data System (ADS)

    Dionísio, Maria; Rodrigues, Armindo; Costa, Ana

    2014-03-01

    This study provides the first description of the larval development of the commercially exploited barnacle Megabalanus azoricus. It describes the changes in larval size and shape as well as the general morphology and duration of each larval stage. Embryos were obtained from gravid specimens collected at São Miguel Island and reared through six naupliar stages to the cypris stage in laboratory conditions. The planktotrophic nauplii reached the cypris stage after 14 days of hatching in individual cultures at 20 °C under natural illumination and fed with phytoplankton ( Chaetoceros gracilis, Isochrysis sp., and Tetraselmis sp.). The nauplius of M. azoricus has a normal size compared with nauplii of other congeneric species, ranging between the 261 μm (nauplius I) and 912 μm (nauplius VI). This work provides the first description of larvae of the genus Megabalanus for the Portuguese oceanic islands and provides comparisons with congeneric species in other parts of the world.

  11. Transcriptomic Response of Drosophila Melanogaster Pupae Developed in Hypergravity

    NASA Technical Reports Server (NTRS)

    Hosamani, Ravikumar; Hateley, Shannon; Bhardwaj, Shilpa R.; Pachter, Lior; Bhattacharya, Sharmila

    2016-01-01

    The metamorphosis of Drosophila is evolutionarily adapted to Earth's gravity, and is a tightly regulated process. Deviation from 1g to microgravity or hypergravity can influence metamorphosis, and alter associated gene expression. Understanding the relationship between an altered gravity environment and developmental processes is important for NASA's space travel goals. In the present study, 20 female and 20 male synchronized (Canton S, 2 to 3day old) flies were allowed to lay eggs while being maintained in a hypergravity environment (3g). Centrifugation was briefly stopped to discard the parent flies after 24hrs of egg laying, and then immediately continued until the eggs developed into P6-staged pupae (25 - 43 hours after pupation initiation). Post hypergravity exposure, P6-staged pupae were collected, total RNA was extracted using Qiagen RNeasy mini kits. We used RNA-Seq and qRT-PCR techniques to profile global transcriptomic changes in early pupae exposed to chronic hypergravity. During the pupal stage, Drosophila relies upon gravitational cues for proper development. Assessing gene expression changes in the pupa under altered gravity conditions helps highlight gravity dependent genetic pathways. A robust transcriptional response was observed in hypergravity-exposed pupae compared to controls, with 1,513 genes showing a significant (q < 0.05) difference in gene expression. Five major biological processes were affected: ion transport, redox homeostasis, immune response, proteolysis, and cuticle development. This outlines the underlying molecular changes occurring in Drosophila pupae in response to hypergravity.

  12. Distinct Biochemical Activities of Eyes absent During Drosophila Eye Development.

    PubMed

    Jin, Meng; Mardon, Graeme

    2016-01-01

    Eyes absent (Eya) is a highly conserved transcriptional coactivator and protein phosphatase that plays vital roles in multiple developmental processes from Drosophila to humans. Eya proteins contain a PST (Proline-Serine-Threonine)-rich transactivation domain, a threonine phosphatase motif (TPM), and a tyrosine protein phosphatase domain. Using a genomic rescue system, we find that the PST domain is essential for Eya activity and Dac expression, and the TPM is required for full Eya function. We also find that the threonine phosphatase activity plays only a minor role during Drosophila eye development and the primary function of the PST and TPM domains is transactivation that can be largely substituted by the heterologous activation domain VP16. Along with our previous results that the tyrosine phosphatase activity of Eya is dispensable for normal Eya function in eye formation, we demonstrate that a primary function of Eya during Drosophila eye development is as a transcriptional coactivator. Moreover, the PST/TPM and the threonine phosphatase activity are not required for in vitro interaction between retinal determination factors. Finally, this work is the first report of an Eya-Ey physical interaction. These findings are particularly important because they highlight the need for an in vivo approach that accurately dissects protein function. PMID:26980695

  13. Development of a larval diet for the South American fruit fly Anastrepha fraterculus (Diptera:Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mass-rearing protocols must be developed. In particular, a cost-effective larval diet, to implement the sterile insect technique against Anastrepha fratercculus (Wiedemann). The key elements of this diet are the optimal nutrients and their concentrations, diet supports or bulking agents, and the pH ...

  14. Inhibition of larval development of the marine copepod Acartia tonsa by four synthetic musk substances.

    PubMed

    Wollenberger, Leah; Breitholtz, Magnus; Ole Kusk, Kresten; Bengtsson, Bengt Erik

    2003-04-15

    A nitro musk (musk ketone) and three polycyclic musks (Tonalide, Galaxolide and Celestolide) were tested for acute and subchronic effects on a marine crustacean, the calanoid copepod Acartia tonsa. Sublethal effects on A. tonsa larvae were investigated with a rapid and cost effective bioassay, which is based on the easily detectable morphological change from the last nauplius to the first copepodite stage during copepod larval development. The inhibition of larval development after 5 days exposure was a very sensitive endpoint, with 5-d-EC(50)-values as low as 0.026 mg/l (Tonalide), 0.059 mg/l (Galaxolide), 0.066 mg/l (musk ketone) and 0.160 mg/l (Celestolide), respectively. These values were generally more than one order of magnitude below the 48-h-LC(50)-values found for adults, which were 0.47 mg/l (Galaxolide), 0.71 mg/l (Celestolide), 1.32 mg/l (musk ketone) and 2.5 mg/l (Tonalide). Since the synthetic musks strongly inhibited larval development in A. tonsa at low nominal concentrations, they should be considered as very toxic. The larval development test with A. tonsa is able to provide important aquatic toxicity data for the evaluation of synthetic musks, for which there is little published ecotoxicological information available regarding Crustacea. It is suggested that subchronic and chronic copepod toxicity tests should be used more frequently for risk assessment of environmental pollutants.

  15. Evolution and development of gastropod larval shell morphology: experimental evidence for mechanical defense and repair.

    PubMed

    Hickman, C S

    2001-01-01

    The structural diversity of gastropod veliger larvae offers an instructive counterpoint to the view of larval forms as conservative archetypes. Larval structure, function, and development are fine-tuned for survival in the plankton. Accordingly, the study of larval adaptation provides an important perspective for evolutionary-developmental biology as an integrated science. Patterns of breakage and repair in the field, as well as patterns of breakage in arranged encounters with zooplankton under laboratory conditions, are two powerful sources of data on the adaptive significance of morphological and microsculptural features of the gastropod larval shell. Shells of the planktonic veliger larvae of the caenogastropod Nassarius paupertus [GOULD] preserve multiple repaired breaks, attributed to unsuccessful zooplankton predators. In culture, larvae isolated from concentrated zooplankton samples rapidly repaired broken apertural margins and restored the "ideal" apertural form, in which an elaborate projection or "beak" covers the head of the swimming veliger. When individuals with repaired apertures were reintroduced to a concentrated mixture of potential zooplankton predators, the repaired margins were rapidly chipped and broken back. The projecting beak of the larval shell is the first line of mechanical defense, covering the larval head and mouth and potentially the most vulnerable part of the shell to breakage. Patterns of mechanical failure show that spiral ridges do reinforce the beak and retard breakage. The capacity for rapid shell repair and regeneration, and the evolution of features that resist or retard mechanical damage, may play a more prominent role than previously thought in enhancing the ability of larvae to survive in the plankton.

  16. Genetic variation in locomotor activity rhythm among populations of Leptopilina heterotoma (Hymenoptera: Eucoilidae), a larval parasitoid of Drosophila species.

    PubMed

    Fleury, F; Allemand, R; Fouillet, P; Boulétreau, M

    1995-01-01

    The locomotor activity rhythm of Leptopilina heterotoma, a parasitoid insect of Drosophila larvae, was investigated under laboratory conditions. Under LD 12:12, the locomotor activity of females shows a clear rhythm which persists under continuous darkness (circadian rhythm). However, comparative study of five populations indicates that both the rate of activity and the profile of the rhythm vary according to the origin of females. The Mediterranean populations (Tunisia and Antibes) show two peaks of activity, at the beginning and at the end of the photophase, whereas more northern populations (Lyon and the Netherlands) are mostly active during the afternoon. Females originating from the area of Lyon have a very low level of activity. Reciprocal crosses (F1 hybrids and backcrosses) between the French and the Tunisian strains demonstrated the genetic basis of these variations and the biparental inheritance of the trait. This genetic variability is interpreted as a consequence of selective pressures and suggests a local adaptation of natural populations in host foraging behavior. The selective factors which could act on the daily organization of parasitoid behaviors are discussed. PMID:7755522

  17. Vacuole dynamics in the salivary glands of Drosophila melanogaster during prepupal development.

    PubMed

    Farkaš, Robert; Beňová-Liszeková, Denisa; Mentelová, Lucia; Mahmood, Silvia; Ďatková, Zuzana; Beňo, Milan; Pečeňová, Ludmila; Raška, Otakar; Šmigová, Jana; Chase, Bruce A; Raška, Ivan; Mechler, Bernard M

    2015-01-01

    A central function of the Drosophila salivary glands (SGs), historically known for their polytene chromosomes, is to produce and then release during pupariation the secretory glue used to affix a newly formed puparium to a substrate. This essential event in the life history of Drosophila is regulated by the steroid hormone ecdysone in the late-larval period. Ecdysone triggers a cascade of sequential gene activation that leads to glue secretion and initiates the developmentally-regulated programmed cell death (PCD) of the larval salivary glands, which culminates 16 h after puparium formation (APF). We demonstrate here that, even after the larval salivary glands have completed what is perceived to be one of their major biological functions--glue secretion during pupariation--they remain dynamic and physiologically active up until the execution phase of PCD. We have used specific metabolic inhibitors and genetic tools, including mutations or transgenes for shi, Rab5, Rab11, vha55, vha68-2, vha36-1, syx1A, syx4, and Vps35 to characterize the dramatic series of cellular changes occurring in the SG cells between pupariation and 7-8 h APF. Early in the prepupal period, they are remarkably active in endocytosis, forming acidic vacuoles. Midway through the prepupal period, there is abundant late endosomal trafficking and vacuole growth, which is followed later by vacuole neutralization and disappearance via membrane consolidation. This work provides new insights into the function of Drosophila SGs during the early- to mid-prepupal period.

  18. Mef2 Interacts with the Notch Pathway during Adult Muscle Development in Drosophila melanogaster

    PubMed Central

    Caine, Charlotte; Kasherov, Petar; Silber, Joël; Lalouette, Alexis

    2014-01-01

    Myogenesis of indirect flight muscles (IFMs) in Drosophila melanogaster follows a well-defined cellular developmental scheme. During embryogenesis, a set of cells, the Adult Muscle Precursors (AMPs), are specified. These cells will become proliferating myoblasts during the larval stages which will then give rise to the adult IFMs. Although the cellular aspect of this developmental process is well studied, the molecular biology behind the different stages is still under investigation. In particular, the interactions required during the transition from proliferating myoblasts to differentiated myoblasts ready to fuse to the muscle fiber. It has been previously shown that the Notch pathway is active in proliferating myoblasts, and that this pathway is inhibited in developing muscle fibers. Furthermore, the Myocyte Enhancing Factor 2 (Mef2), Vestigial (Vg) and Scalloped (Sd) transcription factors are necessary for IFM development and that Vg is required for Notch pathway repression in differentiating fibers. Here we examine the interactions between Notch and Mef2 and mechanisms by which the Notch pathway is inhibited during differentiation. We show that Mef2 is capable of inhibiting the Notch pathway in non myogenic cells. A previous screen for Mef2 potential targets identified Delta a component of the Notch pathway. Dl is expressed in Mef2 and Sd-positive developing fibers. Our results show that Mef2 and possibly Sd regulate a Dl enhancer specifically expressed in the developing IFMs and that Mef2 is required for Dl expression in developing IFMs. PMID:25247309

  19. The Temporal Requirements for Insulin Signaling During Development in Drosophila

    PubMed Central

    2005-01-01

    Recent studies have indicated that the insulin-signaling pathway controls body and organ size in Drosophila, and most metazoans, by signaling nutritional conditions to the growing organs. The temporal requirements for insulin signaling during development are, however, unknown. Using a temperature-sensitive insulin receptor (Inr) mutation in Drosophila, we show that the developmental requirements for Inr activity are organ specific and vary in time. Early in development, before larvae reach the “critical size” (the size at which they commit to metamorphosis and can complete development without further feeding), Inr activity influences total development time but not final body and organ size. After critical size, Inr activity no longer affects total development time but does influence final body and organ size. Final body size is affected by Inr activity from critical size until pupariation, whereas final organ size is sensitive to Inr activity from critical size until early pupal development. In addition, different organs show different sensitivities to changes in Inr activity for different periods of development, implicating the insulin pathway in the control of organ allometry. The reduction in Inr activity is accompanied by a two-fold increase in free-sugar levels, similar to the effect of reduced insulin signaling in mammals. Finally, we find that varying the magnitude of Inr activity has different effects on cell size and cell number in the fly wing, providing a potential linkage between the mode of action of insulin signaling and the distinct downstream controls of cell size and number. We present a model that incorporates the effects of the insulin-signaling pathway into the Drosophila life cycle. We hypothesize that the insulin-signaling pathway controls such diverse effects as total developmental time, total body size and organ size through its effects on the rate of cell growth, and proliferation in different organs. PMID:16086608

  20. Cell position during larval development affects postdiapause development in Megachile rotundata (Hymenoptera: Megachilidae).

    PubMed

    Yocum, George D; Rinehart, Joseph P; Kemp, William P

    2014-08-01

    Megachile rotundata (F.) (Hymenoptera: Megachilidae) is the primary pollinator of alfalfa in the northwestern United States and western Canada and provides pollination services for onion, carrot, hybrid canola, various legumes, and other specialty crops. M. rotundata females are gregarious, nest in cavities either naturally occurring or in artificial nesting blocks, where they construct a linear series of brood cells. Because of the physical layout of the nest, the age of the larvae within the nest and the microenvironment the individual larvae experience will vary. These interacting factors along with other maternal inputs affect the resulting phenotypes of the nest mates. To further our understanding of in-nest physiology, gender and developmental rates were examined in relationship to cell position within the nest. Eighty-two percent of the females were located within the first three cells, those furthest from the nest entrance. For those individuals developing in cells located in the deepest half of the nest, the sex of the previous bee had a significant effect on the female decision of the gender of the following nest mate. Removing the prepupae from the nest and rearing them under identical conditions demonstrated that position within the nest during larval development had a significant effect on the postdiapause developmental rates, with males whose larval development occurred deeper in the nest developing more slowly than those toward the entrance. No positional effect on postdiapause developmental rates was noted for the females. The cell position effect on male postdiapause developmental rate demonstrates that postdiapause development is not a rigid physiological mechanism uniform in all individuals, but is a dynamic plastic process shaped by past environmental conditions. PMID:24914676

  1. Development of the Acoustically Evoked Behavioral Response in Larval Plainfin Midshipman Fish, Porichthys notatus

    PubMed Central

    Alderks, Peter W.; Sisneros, Joseph A.

    2013-01-01

    The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r2 = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or −15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140–150 dB re 1 µPa or −33 to −23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9–2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages. PMID:24340003

  2. Positive effects of cyanogenic glycosides in food plants on larval development of the common blue butterfly.

    PubMed

    Goverde, Marcel; Bazin, Alain; Kéry, Marc; Shykoff, Jacqui A; Erhardt, Andreas

    2008-09-01

    Cyanogenesis is a widespread chemical defence mechanism in plants against herbivory. However, some specialised herbivores overcome this protection by different behavioural or metabolic mechanisms. In the present study, we investigated the effect of presence or absence of cyanogenic glycosides in birdsfoot trefoil (Lotus corniculatus, Fabaceae) on oviposition behaviour, larval preference, larval development, adult weight and nectar preference of the common blue butterfly (Polyommatus icarus, Lycaenidae). For oviposition behaviour there was a female-specific reaction to cyanogenic glycoside content; i.e. some females preferred to oviposit on cyanogenic over acyanogenic plants, while other females behaved in the opposite way. Freshly hatched larvae did not discriminate between the two plant morphs. Since the two plant morphs differed not only in their content of cyanogenic glycoside, but also in N and water content, we expected these differences to affect larval growth. Contrary to our expectations, larvae feeding on cyanogenic plants showed a faster development and stronger weight gain than larvae feeding on acyanogenic plants. Furthermore, female genotype affected development time, larval and pupal weight of the common blue butterfly. However, most effects detected in the larval phase disappeared for adult weight, indicating compensatory feeding of larvae. Adult butterflies reared on the two cyanogenic glycoside plant morphs did not differ in their nectar preference. But a gender-specific effect was found, where females preferred amino acid-rich nectar while males did not discriminate between the two nectar mimics. The presented results indicate that larvae of the common blue butterfly can metabolise the surplus of N in cyanogenic plants for growth. Additionally, the female-specific behaviour to oviposit preferably on cyanogenic or acyanogenic plant morphs and the female-genotype-specific responses in life history traits indicate the genetic flexibility of this

  3. Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda: Anomura: Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius

    NASA Astrophysics Data System (ADS)

    Bartilotti, Cátia; Calado, Ricardo; Dos Santos, Antonina

    2008-06-01

    The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5-11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.

  4. The effect of silencing arginine kinase by RNAi on the larval development of Helicoverpa armigera.

    PubMed

    Qi, X-L; Su, X-F; Lu, G-Q; Liu, C-X; Liang, G-M; Cheng, H-M

    2015-10-01

    Arginine kinase (AK) is an important regulation factor of energy metabolism in invertebrate. An arginine kinase gene, named HaAK, was identified to be differentially expressed between Cry1Ac-susceptible (96S) and Cry1Ac-resistant (Bt-R) Helicoverpa armigera larvae using cDNA-amplification fragment length polymorphism analysis. The full-length open reading frame sequence of HaAK gene with 1068 bp was isolated from H. armigera. Quantitative reverse transcription polymerase chain reaction assay revealed that HaAK gene is specifically expressed in multiple tissues and at larval developmental stages. The peak expression level of HaAK was detected in the midgut of the fifth-instar larvae. Moreover, the expression of HaAK was obviously down-regulated in Bt-R larvae. We further constructed a dsRNA vector directly targeting HaAK and employed RNAi technology to control the larvae. The feeding bioassays showed that minute quantities of dsRNA could greatly increase the larval mortality and delay the larval pupation. Silencing of HaAK significantly retarded the larval development, indicating that HaAK is a potential target for RNA interference-based pest management. PMID:26138927

  5. Faster development does not lead to correlated evolution of greater pre-adult competitive ability in Drosophila melanogaster.

    PubMed

    Shakarad, Mallikarjun; Prasad, N G; Gokhale, Kaustubh; Gadagkar, Vikram; Rajamani, M; Joshi, Amitabh

    2005-03-22

    In comparisons across Drosophila species, faster pre-adult development is phenotypically correlated with increased pre-adult competitive ability, suggesting that these two traits may also be evolutionary correlates of one another. However, correlations between traits within- and among- species can differ, and in most cases it is the within-species genetic correlations that are likely to act as constraints on adaptive evolution. Moreover, laboratory studies on Drosophila melanogaster have shown that the suite of traits that evolves in populations subjected to selection for faster development is the opposite of the traits that evolve in populations selected for increased pre-adult competitive ability. This observation led us to propose that, despite having a higher carrying capacity and a reduced minimum food requirement for completing development than controls, D. melanogaster populations subjected to selection for faster development should have lower competitive ability than controls owing to their reduced larval feeding rates and urea tolerance. Here, we describe results from pre-adult competition experiments that clearly show that the faster developing populations are substantially poorer competitors than controls when reared at high density in competition with a marked mutant strain. We briefly discuss these results in the context of different formulations of density-dependent selection theory.

  6. DAAM is required for thin filament formation and Sarcomerogenesis during muscle development in Drosophila.

    PubMed

    Molnár, Imre; Migh, Ede; Szikora, Szilárd; Kalmár, Tibor; Végh, Attila G; Deák, Ferenc; Barkó, Szilvia; Bugyi, Beáta; Orfanos, Zacharias; Kovács, János; Juhász, Gábor; Váró, György; Nyitrai, Miklós; Sparrow, John; Mihály, József

    2014-02-01

    During muscle development, myosin and actin containing filaments assemble into the highly organized sarcomeric structure critical for muscle function. Although sarcomerogenesis clearly involves the de novo formation of actin filaments, this process remained poorly understood. Here we show that mouse and Drosophila members of the DAAM formin family are sarcomere-associated actin assembly factors enriched at the Z-disc and M-band. Analysis of dDAAM mutants revealed a pivotal role in myofibrillogenesis of larval somatic muscles, indirect flight muscles and the heart. We found that loss of dDAAM function results in multiple defects in sarcomere development including thin and thick filament disorganization, Z-disc and M-band formation, and a near complete absence of the myofibrillar lattice. Collectively, our data suggest that dDAAM is required for the initial assembly of thin filaments, and subsequently it promotes filament elongation by assembling short actin polymers that anneal to the pointed end of the growing filaments, and by antagonizing the capping protein Tropomodulin.

  7. Development of a two photon microscope for tracking Drosophila larvae

    NASA Astrophysics Data System (ADS)

    Karagyozov, Doycho; Mihovilovic Skanata, Mirna; Gershow, Marc

    Current in vivo methods for measuring neural activity in Drosophila larva require immobilization of the animal. Although we can record neural signals while stimulating the sensory organs, we cannot read the behavioral output because we have prevented the animal from moving. Many research questions cannot be answered without observation of neural activity in behaving (freely-moving) animals. Our project aims to develop a tracking microscope that maintains the neurons of interest in the field of view and in focus during the rapid three dimensional motion of a free larva.

  8. Mutations Modulating Raf Signaling in Drosophila Eye Development

    PubMed Central

    Dickson, B. J.; van-der-Straten, A.; Dominguez, M.; Hafen, E.

    1996-01-01

    The R7 fate is specified during Drosophila eye development by an inductive signal transduced intracellularly via the Raf kinase. We have performed a genetic screen for dominant mutations that alter the efficiency with which cells respond to a constitutively activated Raf kinase. Such mutations may affect genes involved in signal transduction downstream of Raf. We have isolated 44 mutations that define eight genes. One of these encodes a mitogen-activated protein kinase homologue; another is a putative target gene of this signaling pathway. We present the results of this screen in detail, as well as a preliminary genetic analysis of the six loci still to be characterized molecularly. PMID:8770593

  9. Influence of resources on Hermetia illucens (Diptera: Stratiomyidae) larval development.

    PubMed

    Nguyen, Trinh T X; Tomberlin, Jeffery K; Vanlaerhoven, Sherah

    2013-07-01

    Arthropod development can be used to determine the time of colonization of human remains to infer a minimum postmortem interval. The black soldier fly, Hermetia illucens L. (Diptera. Stratiomyidae) is native to North America and is unique in that its larvae can consume a wide range of decomposing organic material, including carrion. Larvae development was observed on six resources: control poultry feed, liver, manure, kitchen waste, fruits and vegetables, and fish rendering. Larvae fed manure were shorter, weighed less, and took longer to develop. Kitchen waste produced longer and heavier larvae, whereas larvae fed fish had almost 100% mortality. Black soldier flies can colonize human remains, which in many instances can coincide with food and organic wastes. Therefore, it is necessary to understand black soldier fly development on different food resources other than carrion tissue to properly estimate their age when recovered from human remains. PMID:23926790

  10. Influence of resources on Hermetia illucens (Diptera: Stratiomyidae) larval development.

    PubMed

    Nguyen, Trinh T X; Tomberlin, Jeffery K; Vanlaerhoven, Sherah

    2013-07-01

    Arthropod development can be used to determine the time of colonization of human remains to infer a minimum postmortem interval. The black soldier fly, Hermetia illucens L. (Diptera. Stratiomyidae) is native to North America and is unique in that its larvae can consume a wide range of decomposing organic material, including carrion. Larvae development was observed on six resources: control poultry feed, liver, manure, kitchen waste, fruits and vegetables, and fish rendering. Larvae fed manure were shorter, weighed less, and took longer to develop. Kitchen waste produced longer and heavier larvae, whereas larvae fed fish had almost 100% mortality. Black soldier flies can colonize human remains, which in many instances can coincide with food and organic wastes. Therefore, it is necessary to understand black soldier fly development on different food resources other than carrion tissue to properly estimate their age when recovered from human remains.

  11. Warmer winters reduce frog fecundity and shift breeding phenology, which consequently alters larval development and metamorphic timing.

    PubMed

    Benard, Michael F

    2015-03-01

    One widely documented phenological response to climate change is the earlier occurrence of spring-breeding events. While such climate change-driven shifts in phenology are common, their consequences for individuals and populations have rarely been investigated. I addressed this gap in our knowledge by using a multi-year observational study of six wood frog (Rana sylvatica) populations near the southern edge of their range. I tested first if winter temperature or precipitation affected the date of breeding and female fecundity, and second if timing of breeding affected subsequent larval development rate, mass at metamorphosis, date of metamorphosis, and survival. Warmer winters were associated with earlier breeding but reduced female fecundity. Winter precipitation did not affect breeding date, but was positively associated with female fecundity. There was no association between earlier breeding and larval survival or mass at metamorphosis, but earlier breeding was associated with delayed larval development. The delay in larval development was explained through a counterintuitive correlation between breeding date and temperature during larval development. Warmer winters led to earlier breeding, which in turn was associated with cooler post-breeding temperatures that slowed larval development. The delay in larval development did not fully compensate for the earlier breeding, such that for every 2 days earlier that breeding took place, the average date of metamorphosis was 1 day earlier. Other studies have found that earlier metamorphosis is associated with increased postmetamorphic growth and survival, suggesting that earlier breeding has beneficial effects on wood frog populations.

  12. Engrailed is expressed in larval development and in the radial nervous system of Patiriella sea stars.

    PubMed

    Byrne, Maria; Cisternas, Paula; Elia, Laura; Relf, Bronwyn

    2005-12-01

    We documented expression of the pan-metazoan neurogenic gene engrailed in larval and juvenile Patiriella sea stars to determine if this gene patterns bilateral and radial echinoderm nervous systems. Engrailed homologues, containing conserved En protein domains, were cloned from the radial nerve cord. During development, engrailed was expressed in ectodermal (nervous system) and mesodermal (coeloms) derivatives. In larvae, engrailed was expressed in cells lining the larval and future adult coeloms. Engrailed was not expressed in the larval nervous system. As adult-specific developmental programs were switched on during metamorphosis, engrailed was expressed in the central nervous system and peripheral nervous system (PNS), paralleling the pattern of neuropeptide immunolocalisation. Engrailed was first seen in the developing nerve ring and appeared to be up-regulated as the nervous system developed. Expression of engrailed in the nerve plexus of the tube feet, the lobes of the hydrocoel along the adult arm axis, is similar to the reiterated pattern of expression seen in other animals. Engrailed expression in developing nervous tissue reflects its conserved role in neurogenesis, but its broad expression in the adult nervous system of Patiriella differs from the localised expression seen in other bilaterians. The role of engrailed in patterning repeated PNS structures indicates that it may be important in patterning the fivefold organisation of the ambulacrae, a defining feature of the Echinodermata.

  13. The role of TORC1 in muscle development in Drosophila.

    PubMed

    Hatfield, Isabelle; Harvey, Innocence; Yates, Erika R; Redd, JeAnna R; Reiter, Lawrence T; Bridges, Dave

    2015-01-01

    Myogenesis is an important process during both development and muscle repair. Previous studies suggest that mTORC1 plays a role in the formation of mature muscle from immature muscle precursor cells. Here we show that gene expression for several myogenic transcription factors including Myf5, Myog and Mef2c but not MyoD and myosin heavy chain isoforms decrease when C2C12 cells are treated with rapamycin, supporting a role for mTORC1 pathway during muscle development. To investigate the possibility that mTORC1 can regulate muscle in vivo we ablated the essential dTORC1 subunit Raptor in Drosophila melanogaster and found that muscle-specific knockdown of Raptor causes flies to be too weak to emerge from their pupal cases during eclosion. Using a series of GAL4 drivers we also show that muscle-specific Raptor knockdown also causes shortened lifespan, even when eclosure is unaffected. Together these results highlight an important role for TORC1 in muscle development, integrity and function in both Drosophila and mammalian cells.

  14. Matricellular proteins in development: perspectives from the Drosophila heart.

    PubMed

    Volk, T; Wang, S; Rotstein, B; Paululat, A

    2014-07-01

    The Drosophila model represents an attractive system in which to study the functional contribution of specific genes to organ development. Within the embryo, the heart tube serves as an informative developmental paradigm to analyze functional aspects of matricellular proteins. Here, we describe two essential extracellular matricellular proteins, Multiplexin (Mp) and Lonely heart (Loh). Each of these proteins contributes to the development and morphogenesis of the heart tube by regulating the activity/localization of essential extracellular proteins. Mp, which is secreted by heart cardioblasts and is specifically distributed in the lumen of the heart tube, binds to the signaling protein Slit, and facilitates its local signaling at the heart's luminal domain. Loh is an ADAMTS-like protein, which serves as an adapter protein to Pericardin (a collagen-like protein), promoting its specific localization at the abluminal domain of the heart tube. We also introduce the Drosophila orthologues of matricellular proteins present in mammals, including Thrombospondin, and SPARC, and discuss a possible role for Teneurins (Ten-A and Ten-M) in the heart. Understanding the role of these proteins provides a novel developmental perspective into the functional contribution of matricellular proteins to organ development.

  15. Complete larval development of the Monkey River Prawn Macrobrachium lar (Palaemonidae) using a novel greenwater technique.

    PubMed

    Lal, Monal M; Seeto, Johnson; Pickering, Timothy D

    2014-01-01

    This study documents the complete larval development of the Monkey River Prawn Macrobrachium lar using a new greenwater rearing technique. Approximately 6,000 larvae were reared for 110 days at an initial stocking density of 1 ind./6 L. Salinity at hatch was 10 ± 2 ppt and progressively increased to 30 ± 2 ppt until decapodids had metamorphosed. Temperature was maintained at 28 ± 0.5°C, pH at 7.8 ± 0.2, DO2 > 6.5 mg/L and NH(4+) and NH3 ≤ 1.5 and ≤0.1 ppm respectively throughout the culture period. Larval development was extended and occurred through 13 zoeal stages, with the first decapodid measuring 6.2 ± 0.63 mm in total length observed after 77 days. 5 decapodids in total were produced, and overall survival to this stage was 0.08%. Overall, the pattern of larval growth shares similarities with those of other Macrobrachium spp. that have a prolonged/normal type of development, and it is likely that larvae underwent mark time moulting which contributed to the lengthened development duration. While this study represents a significant breakthrough in efforts to domesticate M. lar, improvement of larval survival rates and decreased time till metamorphosis are required before it can become fully viable for commercial scale aquaculture.

  16. Complete larval development of the Monkey River Prawn Macrobrachium lar (Palaemonidae) using a novel greenwater technique.

    PubMed

    Lal, Monal M; Seeto, Johnson; Pickering, Timothy D

    2014-01-01

    This study documents the complete larval development of the Monkey River Prawn Macrobrachium lar using a new greenwater rearing technique. Approximately 6,000 larvae were reared for 110 days at an initial stocking density of 1 ind./6 L. Salinity at hatch was 10 ± 2 ppt and progressively increased to 30 ± 2 ppt until decapodids had metamorphosed. Temperature was maintained at 28 ± 0.5°C, pH at 7.8 ± 0.2, DO2 > 6.5 mg/L and NH(4+) and NH3 ≤ 1.5 and ≤0.1 ppm respectively throughout the culture period. Larval development was extended and occurred through 13 zoeal stages, with the first decapodid measuring 6.2 ± 0.63 mm in total length observed after 77 days. 5 decapodids in total were produced, and overall survival to this stage was 0.08%. Overall, the pattern of larval growth shares similarities with those of other Macrobrachium spp. that have a prolonged/normal type of development, and it is likely that larvae underwent mark time moulting which contributed to the lengthened development duration. While this study represents a significant breakthrough in efforts to domesticate M. lar, improvement of larval survival rates and decreased time till metamorphosis are required before it can become fully viable for commercial scale aquaculture. PMID:25332868

  17. Larval Development of Two N. E. Pacific Pilidiophoran Nemerteans (Heteronemertea; Lineidae).

    PubMed

    Hiebert, Terra C; Maslakova, Svetlana A

    2015-12-01

    Unique to the phylum Nemertea, the pilidium is an unmistakable planktonic larva found in one group of nemerteans, the Pilidiophora. Inside the pilidium, the juvenile develops from a series of epidermal invaginations in the larval body, called imaginal discs. The discs grow and fuse around the larval gut over the course of weeks to months in the plankton. Once complete, the juvenile breaks free from the larval body in a catastrophic metamorphosis, and often devours the larva as its first meal. One third of nemertean species are expected to produce a pilidium, but the larvae are known for very few species; development from fertilization to metamorphosis has been described in only one species, Micrura alaskensis. Known pilidia include both planktotrophic and lecithotrophic forms, and otherwise exhibit great morphological diversity. Here, we describe the complete development in two lineiform species that are common to the northeast Pacific coast, Micrura wilsoni and Lineus sp. "red." Both species possess typical, cap-shaped planktotrophic pilidia, and the order of emergence of imaginal discs is similar to that which is described in M. alaskensis. The pilidium of Lineus sp. "red" resembles pilidia of several other species, such as Lineus flavescens, and potentially characterizes a pilidiophoran clade. M. wilsoni has relatively transparent oocytes and a pilidium with what appears to be a unique pattern of pigmentation. The adults of both species are more commonly observed in intertidal zones than their larvae are in the plankton.

  18. Ferritin Is Required in Multiple Tissues during Drosophila melanogaster Development

    PubMed Central

    Blowes, Liisa M.; Missirlis, Fanis; Riesgo-Escovar, Juan R.

    2015-01-01

    In Drosophila melanogaster, iron is stored in the cellular endomembrane system inside a protein cage formed by 24 ferritin subunits of two types (Fer1HCH and Fer2LCH) in a 1:1 stoichiometry. In larvae, ferritin accumulates in the midgut, hemolymph, garland, pericardial cells and in the nervous system. Here we present analyses of embryonic phenotypes for mutations in Fer1HCH, Fer2LCH and in both genes simultaneously. Mutations in either gene or deletion of both genes results in a similar set of cuticular embryonic phenotypes, ranging from non-deposition of cuticle to defects associated with germ band retraction, dorsal closure and head involution. A fraction of ferritin mutants have embryonic nervous systems with ventral nerve cord disruptions, misguided axonal projections and brain malformations. Ferritin mutants die with ectopic apoptotic events. Furthermore, we show that ferritin maternal contribution, which varies reflecting the mother’s iron stores, is used in early development. We also evaluated phenotypes arising from the blockage of COPII transport from the endoplasmic reticulum to the Golgi apparatus, feeding the secretory pathway, plus analysis of ectopically expressed and fluorescently marked Fer1HCH and Fer2LCH. Overall, our results are consistent with insect ferritin combining three functions: iron storage, intercellular iron transport, and protection from iron-induced oxidative stress. These functions are required in multiple tissues during Drosophila embryonic development. PMID:26192321

  19. The functional diversity of Drosophila Ino80 in development.

    PubMed

    Ghasemi, Mohsen; Pawar, Hema; Mishra, Rakesh K; Brahmachari, Vani

    2015-11-01

    Ino80 is well known as a chromatin remodeling protein with the catalytic function of DNA dependent ATPase and is highly conserved across phyla. Ino80 in human and Drosophila is known to form the Ino80 complex in association with the DNA binding protein Ying-Yang 1 (YY1)/Pleiohomeotic (Pho) the Drosophila homologue. We have earlier reported that Ino80 sub-family of proteins has two functional domains, namely, the DNA dependent ATPase and the DNA binding domain. In the background of the essential role of dIno80 in development, we provide evidence of Pho independent function of dIno80 in development and analyze the dual role of dIno80 in activation as well as repression in the context of the homeotic gene Scr (sex combs reduced) in imaginal discs. This differential effect of dIno80 in different imaginal discs suggests the contextual function of dIno80 as an Enhancer of Trithorax and Polycomb (ETP). We speculate on the role of dIno80 as a chromatin remodeler on one hand and a potential recruiter of epigenetic regulatory complexes on the other.

  20. The silkworm glutathione S-transferase gene noppera-bo is required for ecdysteroid biosynthesis and larval development.

    PubMed

    Enya, Sora; Daimon, Takaaki; Igarashi, Fumihiko; Kataoka, Hiroshi; Uchibori, Miwa; Sezutsu, Hideki; Shinoda, Tetsuro; Niwa, Ryusuke

    2015-06-01

    Insect molting and metamorphosis are tightly controlled by ecdysteroids, which are important steroid hormones that are synthesized from dietary sterols in the prothoracic gland. One of the ecdysteroidogenic genes in the fruit fly Drosophila melanogaster is noppera-bo (nobo), also known as GSTe14, which encodes a member of the epsilon class of glutathione S-transferases. In D. melanogaster, nobo plays a crucial role in utilizing cholesterol via regulating its transport and/or metabolism in the prothoracic gland. However, it is still not known whether the orthologs of nobo from other insects are also involved in ecdysteroid biosynthesis via cholesterol transport and/or metabolism in the prothoracic gland. Here we report genetic evidence showing that the silkworm Bombyx mori ortholog of nobo (nobo-Bm; GSTe7) is essential for silkworm development. nobo-Bm is predominantly expressed in the prothoracic gland. To assess the functional importance of nobo-Bm, we generated a B. mori genetic mutant of nobo-Bm using TALEN-mediated genome editing. We show that loss of nobo-Bm function causes larval arrest and a glossy cuticle phenotype, which are rescued by the application of 20-hydroxyecdysone. Moreover, the prothoracic gland cells isolated from the nobo-Bm mutant exhibit an abnormal accumulation of 7-dehydrocholesterol, a cholesterol metabolite. These results suggest that the nobo family of glutathione S-transferases is essential for development and for the regulation of sterol utilization in the prothoracic gland in not only the Diptera but also the Lepidoptera. On the other hand, loss of nobo function mutants of D. melanogaster and B. mori abnormally accumulates different sterols, implying that the sterol utilization in the PG is somewhat different between these two insect species. PMID:25881968

  1. Effect of purified condensed tannins from pine bark on larval motility, egg hatching and larval development of Teladorsagia circumcincta and Trichostrongylus colubriformis (Nematoda: Trichostrongylidae).

    PubMed

    Molan, Abdul-Lateef

    2014-08-01

    The effects of condensed tannins (CTs) extracted from pine bark on egg hatching, larval development and the viability of infective L3 larvae of Trichostrongylus colubriformis (Giles, 1892) and Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. Significant inhibitory effects of CTs were obtained on the viability of the infective larvae, egg hatching and larval development of both nematodes. In all bioassays, the larval stages of Te. circumcincta were significantly (P < 0.05) more susceptible to the inhibitory effects of CT than those of Tr. colubriformis. At 1 000 microg/ml, CTs from pine bark inhibited 48% and 69% of the infective larvae of Tr. colubriformis and Te. circumcincta, respectively, from passing through the sieve relative to the control incubations (no CT added; P < 0.0001). At the same concentration, CTs were able to inhibit 36% and 47% of the eggs of the two parasites, respectively, from hatching relative to the control incubations without CTs. Moreover, at 150 microg/ml, the CTs were able to inhibit 88% and 95% (P < 0.0001 relative to control incubation) of L1 larvae of the two nematodes, respectively, from attaining the full development to L3 larvae in comparison with the control incubations without CTs. At 200 microg/ml, CTs were able to inhibit completely the larval development in both nematodes. Addition of 2 microg polyethylene glycol (PEG; tannin inhibitor) per microg CT eliminated up to 87% of the CT activity (P < 0.0001) compared to incubations without PEG. In conclusion, this study shows that CTs are able to disrupt the life cycle of nematodes and their effects varied according to the parasite species and stage.

  2. The complete larval development of the mud shrimp Upogebia vasquezi (Gebiidea: Upogebiidae) reared in the laboratory.

    PubMed

    De Oliveira, Danielly Brito; Martinelli-Lemos, Jussara Moretto; Abrunhosa, Fernando Araújo

    2014-01-01

    The larval development of Upogebia vasquezi consists of four zoeal stages and a megalopa. In the present study, each larval stage was described and illustrated in detail. The first two stages are re-described in order to provide a detailed comparison with the data available for this species recorded in a previous study. The morphological features of all the stages are compared with those of the larvae of other Upogebia species reported previously in the literature. Broad morphological similarities and distinctions were found among most Upogebia species. The main interspecific variations in the morphology of the zoeal stages are the segmentation pattern of the antennular endopod and number of aesthetascs, the number of setae on the scaphognathite and the presence or absence of a mandibular palp. PMID:24990062

  3. UV wavelengths experienced during development affect larval newt visual sensitivity and predation efficiency.

    PubMed

    Martin, Mélissa; Théry, Marc; Rodgers, Gwendolen; Goven, Delphine; Sourice, Stéphane; Mège, Pascal; Secondi, Jean

    2016-02-01

    We experimentally investigated the influence of developmental plasticity of ultraviolet (UV) visual sensitivity on predation efficiency of the larval smooth newt, Lissotriton vulgaris. We quantified expression of SWS1 opsin gene (UV-sensitive protein of photoreceptor cells) in the retinas of individuals who had developed in the presence (UV+) or absence (UV-) of UV light (developmental treatments), and tested their predation efficiency under UV+ and UV- light (testing treatments). We found that both SWS1 opsin expression and predation efficiency were significantly reduced in the UV- developmental group. Larvae in the UV- testing environment displayed consistently lower predation efficiency regardless of their developmental treatment. These results prove for the first time, we believe, functional UV vision and developmental plasticity of UV sensitivity in an amphibian at the larval stage. They also demonstrate that UV wavelengths enhance predation efficiency and suggest that the magnitude of the behavioural response depends on retinal properties induced by the developmental lighting environment.

  4. Major digestive carbohydrase during larval development of meal moth, Plodia interpunctella (Lepidoptera: pyralidae).

    PubMed

    de Sales, M P; Alcazar, Alonso; Lima, L M; Amorim, Ticiana M L; Pitanga, J C M; Pereira, R A; Macedo, L L P; Macedo, F P; Oliveira, A S; Uchôa, Adriana F

    2008-01-01

    The digestive system of P. interpunctella was characterized during its larval development to determination of carbohydrases using disaccharides (sucrose and maltose) and polysaccharides (starch and inulin) as substrate. At 6(th) instar larval, Invertase>alpha-amylase> maltase activities peaks were observed. Invertase was fractionated with acetone and isolated. The Invertase was 485.5 fold purified by Sephacryl S-200 and DEAE-Sephadex. Its kinetic parameters were K(m) of 6.6 mM, V(max) of 0.48, pH optimum of 5.5 and temperature optimum of 30 degrees C. This enzyme was activated by CaCl(2) and inhibited by EDTA. When analyzed by SDS-PAGE it showed one band of M(r) 34 kDa. The understanding of the digestive system of P. interpunctella could be a key step in the design of bioinsecticides.

  5. UV wavelengths experienced during development affect larval newt visual sensitivity and predation efficiency.

    PubMed

    Martin, Mélissa; Théry, Marc; Rodgers, Gwendolen; Goven, Delphine; Sourice, Stéphane; Mège, Pascal; Secondi, Jean

    2016-02-01

    We experimentally investigated the influence of developmental plasticity of ultraviolet (UV) visual sensitivity on predation efficiency of the larval smooth newt, Lissotriton vulgaris. We quantified expression of SWS1 opsin gene (UV-sensitive protein of photoreceptor cells) in the retinas of individuals who had developed in the presence (UV+) or absence (UV-) of UV light (developmental treatments), and tested their predation efficiency under UV+ and UV- light (testing treatments). We found that both SWS1 opsin expression and predation efficiency were significantly reduced in the UV- developmental group. Larvae in the UV- testing environment displayed consistently lower predation efficiency regardless of their developmental treatment. These results prove for the first time, we believe, functional UV vision and developmental plasticity of UV sensitivity in an amphibian at the larval stage. They also demonstrate that UV wavelengths enhance predation efficiency and suggest that the magnitude of the behavioural response depends on retinal properties induced by the developmental lighting environment. PMID:26843556

  6. Postembryonic lineages of the Drosophila brain: I. Development of the lineage-associated fiber tracts

    PubMed Central

    Lovick, Jennifer K.; Ngo, Kathy T.; Omoto, Jaison J.; Wong, Darren C.; Nguyen, Joseph D.; Hartenstein, Volker

    2013-01-01

    Neurons of the Drosophila central brain fall into approximately 100 paired groups, termed lineages. Each lineage is derived from a single asymmetrically-dividing neuroblast. Embryonic neuroblasts produce 1,500 primary neurons (per hemisphere) that make up the larval CNS followed by a second mitotic period in the larva that generates approximately 10,000 secondary, adult-specific neurons. Clonal analyses based on previous works using lineage-specific Gal4 drivers have established that such lineages form highly invariant morphological units. All neurons of a lineage project as one or a few axon tracts (secondary axon tracts, SATs) with characteristic trajectories, thereby representing unique hallmarks. In the neuropil, SATs assemble into larger fiber bundles (fascicles) which interconnect different neuropil compartments. We have analyzed the SATs and fascicles formed by lineages during larval, pupal, and adult stages using antibodies against membrane molecules (Neurotactin/Neuroglian) and synaptic proteins (Bruchpilot/N-Cadherin). The use of these markers allows one to identify fiber bundles of the adult brain and associate them with SATs and fascicles of the larval brain. This work lays the foundation for assigning the lineage identity of GFP-labeled MARCM clones on the basis of their close association with specific SATs and neuropil fascicles, as described in the accompanying paper (Wong et al., 2013. Postembryonic lineages of the Drosophila brain: II. Identification of lineage projection patterns based on MARCM clones. Submitted.). PMID:23880429

  7. Spawning, fertilization, and larval development of Potamocorbula amurensis (Mollusca: Bivalvia) from San Francisco Bay, California

    USGS Publications Warehouse

    Nicolini, M.H.; Penry, D.L.

    2000-01-01

    In Potamocorbula amurensis time for development to the straight-hinge larval stage is 48 hr at 15??C. Potamocorbula amurensis settles at a shell length of approximately 135 ??m 17 to 19 days after fertilization. Our observations of timing of larval devdlopment in P. amurensis support the hypothesis of earlier workers that its route of initial introduction to San Francisco Bay was as veliger larvae transported in ballast water by trans-Pacific cargo ships. The length of the larval period of P. amurensis relative to water mass residence times in San Francisco Bay suggests that it is sufficient to allow substantial dispersal from North Bay to South Bay populations in concordance with previous observations that genetic differentiation among populations of P. amurensis in San Francisco Bay is low. Potamocorbula amurensis is markedly euryhaline at all stages of development. Spawning and fertilization can occur at salinities from 5 to 25 psu, and eggs and sperms can each tolerance at least a 10-psu step increase or decrease in salinity. Embryos that are 2 hr old can tolerate the same range of salinities from (10 to 30 psu), and by the time they are 24 hr old they can tolerate the same range of salinities (2 to 30 psu) that adult clams can. The ability of P. amurensis larvae to tolerate substantial step changes in salinity suggests a strong potential to survive incomplete oceanic exchanges of ballast water and subsequent discharge into receiving waters across a broad range of salinities.

  8. Cancer Drug Development Using Drosophila as an in vivo Tool: From Bedside to Bench and Back.

    PubMed

    Yadav, Amarish Kumar; Srikrishna, Saripella; Gupta, Subash Chandra

    2016-09-01

    The fruit fly Drosophila melanogaster has been used for modeling cancer and as an in vivo tool for the validation and/or development of cancer therapeutics. The impetus for the use of Drosophila in cancer research stems from the high conservation of its signaling pathways, lower genetic redundancy, short life cycle, genetic amenability, and ease of maintenance. Several cell signaling pathways in Drosophila have been used for cancer drug development. The efficacy of combination therapy and uptake/bioavailability of drugs have also been studied. Drosophila has been validated using several FDA-approved drugs, suggesting a potential application of this model in drug repurposing. The model is emerging as a powerful tool for high-throughput screening and should significantly reduce the cost and time associated with drug development. In this review we discuss the applications of Drosophila in cancer drug development. The advantages and limitations of the model are discussed. PMID:27298020

  9. Reproductive behavior, embryonic and early larval development of the red head goby, Elacatinus puncticulatus.

    PubMed

    Pedrazzani, Ana Silvia; Pham, Nancy Kim; Lin, Junda; Neto, Antonio Ostrensky

    2014-02-01

    The goals of this study are to provide a technical foundation for the production of the red head goby Elacatinus puncticulatus by evaluating its reproductive behavior and its embryonic and early larval development. Five pairs were kept under controlled conditions for thirty days. Courtship behavior, spawning period and the number of eggs produced were recorded. For the evaluation of embryo development, eggs were sampled at 12, 18, 24, 48, 72, 96, 120, 144 and 168h post-fertilization(HPF). To test the influence of the incubation period on larval total length and height, eggs with six days (6D) of incubation and with seven days of incubation (7D) were subjected to flashlight illumination for 30min to induce larval hatching. Another experiment evaluated the difference in larval survival with three different diets: Euplotes sp. (EU); rotifers Brachionus rotundiformis and Brachionus plicatilis and Paramecium sp. (BP); plankton collected from the wild (WP). The males displayed a gray head and pale yellow and black body coloration. Females exhibited strong red and black colors until three days before spawning, which occurred at intervals of 7 to 10 days. The hatching rate was 98-99%. The larvae total mean lengths and heights were 3.05 and 2.95mm (p>0.05) and 0.37 and 0.48mm (p<0.05) for treatments 6D and 7D, respectively. However, both groups exhibited high mortality at 5 days post-hatch (DPH). No larvae from the EU group survived after 5 DPH. At 8 DPH, 4% survivorship was found in treatment BP and 2% in treatment WP.

  10. Reproductive behavior, embryonic and early larval development of the red head goby, Elacatinus puncticulatus.

    PubMed

    Pedrazzani, Ana Silvia; Pham, Nancy Kim; Lin, Junda; Neto, Antonio Ostrensky

    2014-02-01

    The goals of this study are to provide a technical foundation for the production of the red head goby Elacatinus puncticulatus by evaluating its reproductive behavior and its embryonic and early larval development. Five pairs were kept under controlled conditions for thirty days. Courtship behavior, spawning period and the number of eggs produced were recorded. For the evaluation of embryo development, eggs were sampled at 12, 18, 24, 48, 72, 96, 120, 144 and 168h post-fertilization(HPF). To test the influence of the incubation period on larval total length and height, eggs with six days (6D) of incubation and with seven days of incubation (7D) were subjected to flashlight illumination for 30min to induce larval hatching. Another experiment evaluated the difference in larval survival with three different diets: Euplotes sp. (EU); rotifers Brachionus rotundiformis and Brachionus plicatilis and Paramecium sp. (BP); plankton collected from the wild (WP). The males displayed a gray head and pale yellow and black body coloration. Females exhibited strong red and black colors until three days before spawning, which occurred at intervals of 7 to 10 days. The hatching rate was 98-99%. The larvae total mean lengths and heights were 3.05 and 2.95mm (p>0.05) and 0.37 and 0.48mm (p<0.05) for treatments 6D and 7D, respectively. However, both groups exhibited high mortality at 5 days post-hatch (DPH). No larvae from the EU group survived after 5 DPH. At 8 DPH, 4% survivorship was found in treatment BP and 2% in treatment WP. PMID:24440435

  11. Drosophila Shep and C. elegans SUP-26 are RNA-binding proteins that play diverse roles in nervous system development.

    PubMed

    Schachtner, Logan T; Sola, Ismail E; Forand, Daniel; Antonacci, Simona; Postovit, Adam J; Mortimer, Nathan T; Killian, Darrell J; Olesnicky, Eugenia C

    2015-11-01

    The Caenorhabditis elegans gene sup-26 encodes a well-conserved RNA-recognition motif-containing RNA-binding protein (RBP) that functions in dendrite morphogenesis of the PVD sensory neuron. The Drosophila ortholog of sup-26, alan shepard (shep), is expressed throughout the nervous system and has been shown to regulate neuronal remodeling during metamorphosis. Here, we extend these studies to show that sup-26 and shep are required for the development of diverse cell types within the nematode and fly nervous systems during embryonic and larval stages. We ascribe roles for sup-26 in regulating dendrite number and the expression of genes involved in mechanosensation within the nematode peripheral nervous system. We also find that in Drosophila, shep regulates dendrite length and branch order of nociceptive neurons, regulates the organization of neuronal clusters of the peripheral nervous system and the organization of axons within the ventral nerve cord. Taken together, our results suggest that shep/sup-26 orthologs play diverse roles in neural development across animal species. Moreover, we discuss potential roles for shep/sup-26 orthologs in the human nervous system.

  12. Small Molecule Suppressors of Drosophila Kinesin Deficiency Rescue Motor Axon Development in a Zebrafish Model of Spinal Muscular Atrophy

    PubMed Central

    Gassman, Andrew; Hao, Le T.; Bhoite, Leena; Bradford, Chad L.; Chien, Chi-Bin; Beattie, Christine E.; Manfredi, John P.

    2013-01-01

    Proximal spinal muscular atrophy (SMA) is the most common inherited motor neuropathy and the leading hereditary cause of infant mortality. Currently there is no effective treatment for the disease, reflecting a need for pharmacologic interventions that restore performance of dysfunctional motor neurons or suppress the consequences of their dysfunction. In a series of assays relevant to motor neuron biology, we explored the activities of a collection of tetrahydroindoles that were reported to alter the metabolism of amyloid precursor protein (APP). In Drosophila larvae the compounds suppressed aberrant larval locomotion due to mutations in the Khc and Klc genes, which respectively encode the heavy and light chains of kinesin-1. A representative compound of this class also suppressed the appearance of axonal swellings (alternatively termed axonal spheroids or neuritic beads) in the segmental nerves of the kinesin-deficient Drosophila larvae. Given the importance of kinesin-dependent transport for extension and maintenance of axons and their growth cones, three members of the class were tested for neurotrophic effects on isolated rat spinal motor neurons. Each compound stimulated neurite outgrowth. In addition, consistent with SMA being an axonopathy of motor neurons, the three axonotrophic compounds rescued motor axon development in a zebrafish model of SMA. The results introduce a collection of small molecules as pharmacologic suppressors of SMA-associated phenotypes and nominate specific members of the collection for development as candidate SMA therapeutics. More generally, the results reinforce the perception of SMA as an axonopathy and suggest novel approaches to treating the disease. PMID:24023935

  13. Drosophila Shep and C. elegans SUP-26 are RNA-binding proteins that play diverse roles in nervous system development.

    PubMed

    Schachtner, Logan T; Sola, Ismail E; Forand, Daniel; Antonacci, Simona; Postovit, Adam J; Mortimer, Nathan T; Killian, Darrell J; Olesnicky, Eugenia C

    2015-11-01

    The Caenorhabditis elegans gene sup-26 encodes a well-conserved RNA-recognition motif-containing RNA-binding protein (RBP) that functions in dendrite morphogenesis of the PVD sensory neuron. The Drosophila ortholog of sup-26, alan shepard (shep), is expressed throughout the nervous system and has been shown to regulate neuronal remodeling during metamorphosis. Here, we extend these studies to show that sup-26 and shep are required for the development of diverse cell types within the nematode and fly nervous systems during embryonic and larval stages. We ascribe roles for sup-26 in regulating dendrite number and the expression of genes involved in mechanosensation within the nematode peripheral nervous system. We also find that in Drosophila, shep regulates dendrite length and branch order of nociceptive neurons, regulates the organization of neuronal clusters of the peripheral nervous system and the organization of axons within the ventral nerve cord. Taken together, our results suggest that shep/sup-26 orthologs play diverse roles in neural development across animal species. Moreover, we discuss potential roles for shep/sup-26 orthologs in the human nervous system. PMID:26271810

  14. Regulation of twin of eyeless during Drosophila development.

    PubMed

    Skottheim Honn, John; Johansson, Linn; Rasmuson Lestander, Åsa

    2016-03-01

    The Pax-6 protein is vital for eye development in all seeing animals, from sea urchins to humans. Either of the Pax6 genes in Drosophila (twin of eyeless and eyeless) can induce a gene cascade leading to formation of entire eyes when expressed ectopically. The twin of eyeless (toy) gene in Drosophila is expressed in the anterior region of the early fly embryo. At later stages it is expressed in the brain, ventral nerve cord and (eventually) the visual primordium that gives rise to the eye-antennal imaginal discs of the larvae. These discs subsequently form the major part of the adult head, including compound eyes. We have searched for genes that are required for normal toy expression in the early embryo to elucidate initiating events of eye organogenesis. Candidate genes identified by mutation analyses were subjected to further knock-out and miss-expression tests to investigate their interactions with toy. Our results indicate that the head-specific gap gene empty spiracles can act as a repressor of Toy, while ocelliless (oc) and spalt major (salm) appear to act as positive regulators of toy gene expression. PMID:26976323

  15. Drosophila provides rapid modeling of renal development, function, and disease.

    PubMed

    Dow, Julian A T; Romero, Michael F

    2010-12-01

    The evolution of specialized excretory cells is a cornerstone of the metazoan radiation, and the basic tasks performed by Drosophila and human renal systems are similar. The development of the Drosophila renal (Malpighian) tubule is a classic example of branched tubular morphogenesis, allowing study of mesenchymal-to-epithelial transitions, stem cell-mediated regeneration, and the evolution of a glomerular kidney. Tubule function employs conserved transport proteins, such as the Na(+), K(+)-ATPase and V-ATPase, aquaporins, inward rectifier K(+) channels, and organic solute transporters, regulated by cAMP, cGMP, nitric oxide, and calcium. In addition to generation and selective reabsorption of primary urine, the tubule plays roles in metabolism and excretion of xenobiotics, and in innate immunity. The gene expression resource FlyAtlas.org shows that the tubule is an ideal tissue for the modeling of renal diseases, such as nephrolithiasis and Bartter syndrome, or for inborn errors of metabolism. Studies are assisted by uniquely powerful genetic and transgenic resources, the widespread availability of mutant stocks, and low-cost, rapid deployment of new transgenics to allow manipulation of renal function in an organotypic context.

  16. Laminin A chain: expression during Drosophila development and genomic sequence.

    PubMed Central

    Kusche-Gullberg, M; Garrison, K; MacKrell, A J; Fessler, L I; Fessler, J H

    1992-01-01

    A Drosophila laminin A chain gene was characterized as a 14 kb genomic nucleotide sequence which encodes an open reading frame of 3712 amino acids in 15 exons. Overall, this A chain is similar to its vertebrate counterparts, especially in its N- and C-terminal globular domains, but the sequence that forms the laminin A short arm is quite different and larger. Laminin messages appear in newly formed mesoderm and are later prominently expressed in hemocytes, which also synthesize basement membrane collagen IV. The composition of Drosophila basement membranes changes with development. A novel method of tandemly fused RNA probes showed that developmental increases of laminin mRNAs were primarily associated with periods of morphogenesis, and preceded those of collagen IV, a protein strongly expressed during growth. The ratio of A:B1:B2 mRNAs varied little during embryogenesis, with less mRNA for A than B chains. Staining of embryos with antibodies confirmed and extended the information provided by in situ hybridization. Homologs of the G-subdomains of this A chain, which occur in interacting regions of agrin, perlecan, laminin and sex steroid binding protein, may be involved in protein associations. Images PMID:1425586

  17. Biotic and abiotic factors impacting development, behavior, phenology, and reproductive biology of Drosophila suzukii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spotted wing drosophila, Drosophila suzukii, quickly emerged as a devastating invasive pest of small and stone fruits in the Americas and Europe. To better understand the population dynamics of D. suzukii, we reviewed recent work on juvenile development, adult reproduction, and seasonal variation in...

  18. Proteasomal activities in the claw muscle tissue of European lobster, Homarus gammarus, during larval development.

    PubMed

    Götze, Sandra; Saborowski, Reinhard

    2011-10-01

    Decapod crustaceans grow discontinuously and gain size through complex molt processes. The molt comprises the loss of the old cuticle and, moreover, substantial reduction and re-organization of muscles and connective tissues. In adult lobsters, the muscle tissue of the massive claws undergoes significant atrophy of 40-75% before ecdysis. The degradation of this tissue is facilitated by calcium-dependent proteases and by the proteasome, an intra-cellular proteolytic multi-enzyme complex. In contrast to the adults, the involvement of the proteasome during the larval development is yet not validated. Therefore, we developed micro-methods to measure the 20S and the 26S proteasomal activities within mg- and sub-mg-quantities of the larval claw tissue of the European lobster, Homarus gammarus. Within the three larval stages (Z1-3) we distinguished between sub-stages of freshly molted/hatched (post-molt), inter-molt, and ready to molt (pre-molt) larvae. Juveniles were analyzed in the post-molt and in the inter-molt stage. The trypsin-like, the chymotrypsin-like, and the peptidyl-glutamyl peptide hydrolase activity (PGPH) of the 20S proteasome increased distinctly from freshly hatched larvae to pre-molt Z1. During the Z2 stage, the activities were highest in the post-molt animals, decreased in the inter-molt animals and increased again in the pre-molt animals. A similar but less distinct trend was evident in the Z3 stages. In the juveniles, the proteasomal activities decreased toward the lowest values. A similar pattern was present for the chymotrypsin-like activity of the 26S proteasome. The results show that the proteasome plays a significant role during the larval development of lobsters. This is not only reflected by the elevated activities, but also by the continuous change of the trypsin/chymotrypsin-ratio which may indicate a shift in the subunit composition of the proteasome and, thus, a biochemical adjustment to better cope with elevated protein turnover rates

  19. CCDC-55 is required for larval development and distal tip cell migration in Caenorhabditis elegans.

    PubMed

    Kovacevic, Ismar; Ho, Richard; Cram, Erin J

    2012-01-01

    The Caenorhabditis elegans distal tip cells (DTCs) are an in vivo model for the study of developmentally regulated cell migration. In this study, we characterize a novel role for CCDC-55, a conserved coiled-coil domain containing protein, in DTC migration and larval development in C. elegans. Although animals homozygous for a probable null allele, ccdc-55(ok2851), display an early larval arrest, RNAi depletion experiments allow the analysis of later phenotypes and suggest that CCDC-55 is needed within the DTC for migration to cease at the end of larval morphogenesis. The ccdc-55 gene is found in an operon with rnf-121 and rnf-5, E3 ubiquitin ligases that target cell migration genes such as the β-integrin PAT-3. Genetic interaction studies using RNAi depletion and the deletion alleles rnf-121(ok848) and rnf-5(tm794) indicate that CCDC-55 and the RNF genes act at least partially in parallel to promote termination of cell migration in the adult DTC.

  20. Artificial substrates for oviposition and larval development of the pepper weevil (Coleoptera: Curculionidae).

    PubMed

    Addesso, K M; McAuslane, H J; Stansly, P A; Slansky, F; Schuster, D J

    2009-02-01

    The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of cultivated peppers (Capsicum spp.) and other cultivated and wild species within the family Solanaceae. Laboratory study of this insect, as well as its biological control agents, will be greatly facilitated by an artificial rearing system that does not rely on pepper fruit. An egg collection method and amendments to a standard larval diet were investigated for use in the rearing of this weevil. Spherical sachets made of Parafilm or netting enclosing leaves of pepper, American black nightshade, eggplant, tomato, potato, and jasmine tobacco induced oviposition. Tomato, potato, and jasmine tobacco leaves were accepted despite the fact that these are not oviposition hosts for pepper weevils in the wild. A standard larval diet formula was modified in an attempt to improve egg hatch, larval survival, developmental time, and adult mass. The diet formula was modified with the addition of freeze-dried jalapeño pepper powder, an additional lipid source, alternate protein sources, and the removal of methyl paraben. None of the aforementioned treatments resulted in a significant improvement over the standard diet. Egg hatch was greater when eggs were incubated on moist paper towels rather than in diet; thus, placement of neonates rather than eggs into diet improved production of adults. Suggestions for more efficient rearing of weevils on the currently available diet and future directions for the development of an artificial rearing system for pepper weevil are discussed. PMID:19253644

  1. Development of inexpensive and globally available larval diet for rearing Anopheles stephensi (Diptera: Culicidae) mosquitoes

    PubMed Central

    2013-01-01

    Background Success of sterile insect technique (SIT) is dependent upon the mass rearing and release of quality insects, the production of which is directly related to the suitability of the diet ingredients used. Commercial diets used for small-scale culture of mosquitoes are expensive and thus not feasible for mass production. Methods A series of low cost globally available diet ingredients including, wheat, rice, corn, chickpeas, and beans along with liver, were provided to 4 h larvae (L1) of Anopheles stephensi (Liston) to see their effect on fitness parameters including larval duration, percent emergence, survival, adult wing size and female fecundity. Different quantities of the candidate diet ingredients were then mixed together to work out a combination diet with a balanced nutritive value that can be used for efficient rearing of the mosquito larvae at relatively lower costs. Results Fastest larval and pupal development and highest survival rates were recorded using a combination diet of bean, corn, wheat, chickpea, rice, and bovine liver at 5 mg/day. The diet is easy to prepare, and much cheaper than the diets reported earlier. The estimated cost of the reported diet is 14.7 US$/ 1.3 kg for rearing one million larvae. Conclusions A combination diet with ingredients from cereals and legumes mixed with liver is a low cost balanced larval diet with the potential for use in both small scale laboratory rearing and mass production of Anopheles in SIT control programs. PMID:23570246

  2. CCDC-55 is required for larval development and distal tip cell migration in Caenorhabditis elegans.

    PubMed

    Kovacevic, Ismar; Ho, Richard; Cram, Erin J

    2012-01-01

    The Caenorhabditis elegans distal tip cells (DTCs) are an in vivo model for the study of developmentally regulated cell migration. In this study, we characterize a novel role for CCDC-55, a conserved coiled-coil domain containing protein, in DTC migration and larval development in C. elegans. Although animals homozygous for a probable null allele, ccdc-55(ok2851), display an early larval arrest, RNAi depletion experiments allow the analysis of later phenotypes and suggest that CCDC-55 is needed within the DTC for migration to cease at the end of larval morphogenesis. The ccdc-55 gene is found in an operon with rnf-121 and rnf-5, E3 ubiquitin ligases that target cell migration genes such as the β-integrin PAT-3. Genetic interaction studies using RNAi depletion and the deletion alleles rnf-121(ok848) and rnf-5(tm794) indicate that CCDC-55 and the RNF genes act at least partially in parallel to promote termination of cell migration in the adult DTC. PMID:22285439

  3. Artificial substrates for oviposition and larval development of the pepper weevil (Coleoptera: Curculionidae).

    PubMed

    Addesso, K M; McAuslane, H J; Stansly, P A; Slansky, F; Schuster, D J

    2009-02-01

    The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is a major pest of cultivated peppers (Capsicum spp.) and other cultivated and wild species within the family Solanaceae. Laboratory study of this insect, as well as its biological control agents, will be greatly facilitated by an artificial rearing system that does not rely on pepper fruit. An egg collection method and amendments to a standard larval diet were investigated for use in the rearing of this weevil. Spherical sachets made of Parafilm or netting enclosing leaves of pepper, American black nightshade, eggplant, tomato, potato, and jasmine tobacco induced oviposition. Tomato, potato, and jasmine tobacco leaves were accepted despite the fact that these are not oviposition hosts for pepper weevils in the wild. A standard larval diet formula was modified in an attempt to improve egg hatch, larval survival, developmental time, and adult mass. The diet formula was modified with the addition of freeze-dried jalapeño pepper powder, an additional lipid source, alternate protein sources, and the removal of methyl paraben. None of the aforementioned treatments resulted in a significant improvement over the standard diet. Egg hatch was greater when eggs were incubated on moist paper towels rather than in diet; thus, placement of neonates rather than eggs into diet improved production of adults. Suggestions for more efficient rearing of weevils on the currently available diet and future directions for the development of an artificial rearing system for pepper weevil are discussed.

  4. Drosophila neural stem cells in brain development and tumor formation.

    PubMed

    Jiang, Yanrui; Reichert, Heinrich

    2014-01-01

    Neuroblasts, the neural stem cells in Drosophila, generate the complex neural structure of the central nervous system. Significant progress has been made in understanding the mechanisms regulating the self-renewal, proliferation, and differentiation in Drosophila neuroblast lineages. Deregulation of these mechanisms can lead to severe developmental defects and the formation of malignant brain tumors. Here, the authors review the molecular genetics of Drosophila neuroblasts and discuss some recent advances in stem cell and cancer biology using this model system.

  5. Temperature- and sex-related effects of serine protease alleles on larval development in the Glanville fritillary butterfly.

    PubMed

    Ahola, V; Koskinen, P; Wong, S C; Kvist, J; Paulin, L; Auvinen, P; Saastamoinen, M; Frilander, M J; Lehtonen, R; Hanski, I

    2015-12-01

    The body reserves of adult Lepidoptera are accumulated during larval development. In the Glanville fritillary butterfly, larger body size increases female fecundity, but in males fast larval development and early eclosion, rather than large body size, increase mating success and hence fitness. Larval growth rate is highly heritable, but genetic variation associated with larval development is largely unknown. By comparing the Glanville fritillary population living in the Åland Islands in northern Europe with a population in Nantaizi in China, within the source of the post-glacial range expansion, we identified candidate genes with reduced variation in Åland, potentially affected by selection under cooler climatic conditions than in Nantaizi. We conducted an association study of larval growth traits by genotyping the extremes of phenotypic trait distributions for 23 SNPs in 10 genes. Three genes in clip-domain serine protease family were associated with larval growth rate, development time and pupal weight. Additive effects of two SNPs in the prophenoloxidase-activating proteinase-3 (ProPO3) gene, related to melanization, showed elevated growth rate in high temperature but reduced growth rate in moderate temperature. The allelic effects of the vitellin-degrading protease precursor gene on development time were opposite in the two sexes, one genotype being associated with long development time and heavy larvae in females but short development time in males. Sexually antagonistic selection is here evident in spite of sexual size dimorphism.

  6. Regulatory mechanisms of EGFR signalling during Drosophila eye development.

    PubMed

    Malartre, Marianne

    2016-05-01

    EGFR signalling is a well-conserved signalling pathway playing major roles during development and cancers. This review explores what studying the EGFR pathway during Drosophila eye development has taught us in terms of the diversity of its regulatory mechanisms. This model system has allowed the identification of numerous positive and negative regulators acting at specific time and place, thus participating to the tight control of signalling. EGFR signalling regulation is achieved by a variety of mechanisms, including the control of ligand processing, the availability of the receptor itself and the transduction of the cascade in the cytoplasm. Ultimately, the transcriptional responses contribute to the establishment of positive and negative feedback loops. The combination of these multiple mechanisms employed to regulate the EGFR pathway leads to specific cellular outcomes involved in functions as diverse as the acquisition of cell fate, proliferation, survival, adherens junction remodelling and morphogenesis. PMID:26935860

  7. Regulatory mechanisms of EGFR signalling during Drosophila eye development.

    PubMed

    Malartre, Marianne

    2016-05-01

    EGFR signalling is a well-conserved signalling pathway playing major roles during development and cancers. This review explores what studying the EGFR pathway during Drosophila eye development has taught us in terms of the diversity of its regulatory mechanisms. This model system has allowed the identification of numerous positive and negative regulators acting at specific time and place, thus participating to the tight control of signalling. EGFR signalling regulation is achieved by a variety of mechanisms, including the control of ligand processing, the availability of the receptor itself and the transduction of the cascade in the cytoplasm. Ultimately, the transcriptional responses contribute to the establishment of positive and negative feedback loops. The combination of these multiple mechanisms employed to regulate the EGFR pathway leads to specific cellular outcomes involved in functions as diverse as the acquisition of cell fate, proliferation, survival, adherens junction remodelling and morphogenesis.

  8. [Genetic control of macrochaetae development in Drosophila melanogaster].

    PubMed

    Furman, D P; Bukharina, T A

    2008-01-01

    The Drosophila head and body have a regular species-specific pattern of strictly defined number of external sensory organs--macrochaetae (large bristles). The pattern constancy and relatively simple organization of each bristle organ composed of only four specialized cells makes macrochaetae a convenient model to study the developmental patterns of spatial structures with a fixed number of elements in specific positions as well as the mechanisms of cell differentiation. The experimental data on the major genes and their products controlling three stages of macrochaetae development--the emergence of proneural clusters in the imaginal disc ectoderm, the precursor cell determination in the proneural clusters, and the specialization of cells of the definitive sensory organ--were reviewed. The role of the achaeta-scute gene complex, EGFR and Notch signaling, and selector genes in these processes was considered. Analysis of published data allowed us to propose an integrated diagram of the system controlling macrochaetae development in D. melanogaster.

  9. Development of Johnston’s organ in Drosophila

    PubMed Central

    EBERL, DANIEL F.; BOEKHOFF-FALK, GRACE

    2012-01-01

    Hearing is a specialized mechanosensory modality that is refined during evolution to meet the particular requirements of different organisms. In the fruitfly, Drosophila, hearing is mediated by Johnston’s organ, a large chordotonal organ in the antenna that is exquisitely sensitive to the near-field acoustic signal of courtship songs generated by male wing vibration. We summarize recent progress in understanding the molecular genetic determinants of Johnston’s organ development and discuss surprising differences from other chordotonal organs that likely facilitate hearing. We outline novel discoveries of active processes that generate motion of the antenna for acute sensitivity to the stimulus. Finally, we discuss further research directions that would probe remaining questions in understanding Johnston’s organ development, function and evolution. PMID:17891726

  10. A choice behavior for morphine reveals experience-dependent drug preference and underlying neural substrates in developing larval zebrafish.

    PubMed

    Bretaud, S; Li, Q; Lockwood, B L; Kobayashi, K; Lin, E; Guo, S

    2007-05-25

    Transparent larval zebrafish offer the opportunity to unravel genetic and neuronal networks underlying behavior in a developing system. In this study, we developed a choice chamber paradigm to measure reward-associated behavior in larval zebrafish. In the chamber where larval zebrafish have a choice of spending their time in either a water- or morphine-containing compartment, larvae that have previously experienced morphine spend significantly more time in the compartment containing morphine. This behavior can be attentuated by pre-treatment with antagonists of the opioid receptor or the dopamine receptor, and furthermore, is impaired in the too few mutant, which has a genetic deficiency in the production of specific groups of dopaminergic and serotonergic neurons in the ventral forebrain. These results uncover a choice behavior for an addictive substance in larval zebrafish that is mediated through central opioid and monoaminergic neurotransmitter systems.

  11. Reproduction, larval growth, and reproductive development in African clawed frogs (Xenopus laevis) exposed to atrazine.

    PubMed

    Du Preez, Louis H; Kunene, Nisile; Everson, Gideon J; Carr, James A; Giesy, John P; Gross, Timothy S; Hosmer, Alan J; Kendall, Ronald J; Smith, Ernest E; Solomon, Keith R; Van Der Kraak, Glen J

    2008-03-01

    Reproductive success and development of F2 offspring from F1 adult African clawed frogs (Xenopus laevis) exposed to atrazine throughout larval development and as sexually mature adults was examined. Larval X. laevis were exposed to one of four nominal concentrations of atrazine (0, 1, 10, 25 microg atrazine/l) beginning 96 hr after fertilization and continuing through two years post-metamorphosis. Clutch size and survival of offspring were used as measurement endpoints to gauge reproductive success of the F1 frogs. Larval survivorship and time to metamorphosis were used to gauge developmental success of the F2 offspring from atrazine-exposed frogs. Testes in F1 and F2 frogs were examined for incidence of anomalies, such as testicular ovarian follicles, and sex ratios in F2 offspring were investigated to determine if exposure to atrazine caused trans-generational effects (effects on F2 individuals due to exposure of F1 individuals). There were no effects of any of the studied concentrations of atrazine on clutch size of F1 frogs. There were also no effects on hatching success or time to metamorphosis. Sex ratios did not differ between F2 offspring among treatments. There was no evidence to suggest a transgenerational effect of atrazine on spawning success or reproductive development of X. laevis. This is consistent with the presence of robust populations of X. laevis in areas where they are exposed to atrazine that has been used for several decades for weed control in production of corn. Our observations also are consistent with the results of most other studies of frogs where no effects were found to be associated with exposure to atrazine. Our data do not support the hypothesis that atrazine significantly affects reproductive fitness and development of frogs.

  12. Suitability of monotypic and mixed diets for Anopheles hermsi larval development.

    PubMed

    Beasley, Donald A; Walton, William E

    2016-06-01

    The developmental time and survival to eclosion of Anopheles hermsi Barr & Guptavanij fed monotypic and mixed diets of ten food types were examined in laboratory studies. Larvae fed monotypic diets containing animal detritus (freeze-dried rotifers, freeze-dried Daphnia pulicaria, and TetraMin® fish food flakes) and the mixotrophic protistan Cryptomonas ovata developed faster and survived better than larvae that were fed other monotypic diets. Survival to adulthood of larvae fed several concentrations of the diatom Planothidium (=Achnanthes) lanceolatum was poor (<13%) and larval development time was approximately twice that of larvae fed TetraMin® fish food flakes, the standard laboratory diet. Larvae fed monotypic diets containing prokaryotes (bacteria [Bacillus cereus] and cyanobacteria [Oscillatoria prolifera]) and brewer's yeast (Saccharomyces cerevisiae) failed to survive beyond the 1(st) and 2(nd) instar, respectively. Larvae fed only chlorophytes, single-celled Chlamydomonas reinhardtii and filamentous Spirogyra communis, failed to complete larval development, regardless of the concentration tested. Cohorts fed a combination of food types (mixed diets) usually developed better than cohorts fed monotypic diets. Food types that failed to support complete development when fed alone often facilitated development to adulthood when fed in combination with food types containing >1% C20 polyunsaturated fatty acids as total fat, but regardless of essential fatty acid content, algae that produced mucilage and filaments that sank out of the feeding zone were poor quality diets.

  13. Suitability of monotypic and mixed diets for Anopheles hermsi larval development.

    PubMed

    Beasley, Donald A; Walton, William E

    2016-06-01

    The developmental time and survival to eclosion of Anopheles hermsi Barr & Guptavanij fed monotypic and mixed diets of ten food types were examined in laboratory studies. Larvae fed monotypic diets containing animal detritus (freeze-dried rotifers, freeze-dried Daphnia pulicaria, and TetraMin® fish food flakes) and the mixotrophic protistan Cryptomonas ovata developed faster and survived better than larvae that were fed other monotypic diets. Survival to adulthood of larvae fed several concentrations of the diatom Planothidium (=Achnanthes) lanceolatum was poor (<13%) and larval development time was approximately twice that of larvae fed TetraMin® fish food flakes, the standard laboratory diet. Larvae fed monotypic diets containing prokaryotes (bacteria [Bacillus cereus] and cyanobacteria [Oscillatoria prolifera]) and brewer's yeast (Saccharomyces cerevisiae) failed to survive beyond the 1(st) and 2(nd) instar, respectively. Larvae fed only chlorophytes, single-celled Chlamydomonas reinhardtii and filamentous Spirogyra communis, failed to complete larval development, regardless of the concentration tested. Cohorts fed a combination of food types (mixed diets) usually developed better than cohorts fed monotypic diets. Food types that failed to support complete development when fed alone often facilitated development to adulthood when fed in combination with food types containing >1% C20 polyunsaturated fatty acids as total fat, but regardless of essential fatty acid content, algae that produced mucilage and filaments that sank out of the feeding zone were poor quality diets. PMID:27232128

  14. Expression and light-triggered movement of rhodopsins in the larval visual system of mosquitoes

    PubMed Central

    Rocha, Manuel; Kimler, Kyle J.; Leming, Matthew T.; Hu, Xiaobang; Whaley, Michelle A.; O'Tousa, Joseph E.

    2015-01-01

    ABSTRACT During the larval stages, the visual system of the mosquito Aedes aegypti contains five stemmata, often referred to as larval ocelli, positioned laterally on each side of the larval head. Here we show that stemmata contain two photoreceptor types, distinguished by the expression of different rhodopsins. The rhodopsin Aaop3 (GPROP3) is expressed in the majority of the larval photoreceptors. There are two small clusters of photoreceptors located within the satellite and central stemmata that express the rhodopsin Aaop7 (GPROP7) instead of Aaop3. Electroretinogram analysis of transgenic Aaop7 Drosophila indicates that Aaop3 and Aaop7, both classified as long-wavelength rhodopsins, possess similar but not identical spectral properties. Light triggers an extensive translocation of Aaop3 from the photosensitive rhabdoms to the cytoplasmic compartment, whereas light-driven translocation of Aaop7 is limited. The results suggest that these photoreceptor cell types play distinct roles in larval vision. An additional component of the larval visual system is the adult compound eye, which starts to develop at the anterior face of the larval stemmata during the 1st instar stage. The photoreceptors of the developing compound eye show rhodopsin expression during the 4th larval instar stage, consistent with indications from previous reports that the adult compound eye contributes to larval and pupal visual capabilities. PMID:25750414

  15. Does atrazine influence larval development and sexual differentiation in Xenopus laevis?

    PubMed

    Kloas, Werner; Lutz, Ilka; Springer, Timothy; Krueger, Henry; Wolf, Jeff; Holden, Larry; Hosmer, Alan

    2009-02-01

    Debate and controversy exists concerning the potential for the herbicide atrazine to cause gonadal malformations in developing Xenopus laevis. Following review of the existing literature the U.S. Environmental Protection Agency required a rigorous investigation conducted under standardized procedures. X. laevis tadpoles were exposed to atrazine at concentrations of 0.01, 0.1, 1, 25, or 100 microg/l from day 8 postfertilization (dpf) until completion of metamorphosis or dpf 83, whichever came first. Nearly identical experiments were performed in two independent laboratories: experiment 1 at Wildlife International, Ltd. and experiment 2 at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB). Both experiments employed optimized animal husbandry procedures and environmental conditions in validated flow-through exposure systems. The two experiments demonstrated consistent survival, growth, and development of X. laevis tadpoles, and all measured parameters were within the expected ranges and were comparable in negative control and atrazine-treated groups. Atrazine, at concentrations up to 100 microg/l, had no effect in either experiment on the percentage of males or the incidence of mixed sex as determined by histological evaluation. In contrast, exposure of larval X. laevis to 0.2 microg 17beta-estradiol/l as the positive control resulted in gonadal feminization. Instead of an even distribution of male and female phenotypes, percentages of males:females:mixed sex were 19:75:6 and 22:60:18 in experiments 1 and 2, respectively. These studies demonstrate that long-term exposure of larval X. laevis to atrazine at concentrations ranging from 0.01 to 100 microg/l does not affect growth, larval development, or sexual differentiation.

  16. Hox gene expression in larval development of the polychaetes Nereis virens and Platynereis dumerilii (Annelida, Lophotrochozoa).

    PubMed

    Kulakova, Milana; Bakalenko, Nadezhda; Novikova, Elena; Cook, Charles E; Eliseeva, Elena; Steinmetz, Patrick R H; Kostyuchenko, Roman P; Dondua, Archil; Arendt, Detlev; Akam, Michael; Andreeva, Tatiana

    2007-01-01

    The bilaterian animals are divided into three great branches: the Deuterostomia, Ecdysozoa, and Lophotrochozoa. The evolution of developmental mechanisms is less studied in the Lophotrochozoa than in the other two clades. We have studied the expression of Hox genes during larval development of two lophotrochozoans, the polychaete annelids Nereis virens and Platynereis dumerilii. As reported previously, the Hox cluster of N. virens consists of at least 11 genes (de Rosa R, Grenier JK, Andreeva T, Cook CE, Adoutte A, Akam M, Carroll SB, Balavoine G, Nature, 399:772-776, 1999; Andreeva TF, Cook C, Korchagina NM, Akam M, Dondua AK, Ontogenez 32:225-233, 2001); we have also cloned nine Hox genes of P. dumerilii. Hox genes are mainly expressed in the descendants of the 2d blastomere, which form the integument of segments, ventral neural ganglia, pre-pygidial growth zone, and the pygidial lobe. Patterns of expression are similar for orthologous genes of both nereids. In Nereis, Hox2, and Hox3 are activated before the blastopore closure, while Hox1 and Hox4 are activated just after this. Hox5 and Post2 are first active during the metatrochophore stage, and Hox7, Lox4, and Lox2 at the late nectochaete stage only. During larval stages, Hox genes are expressed in staggered domains in the developing segments and pygidial lobe. The pattern of expression of Hox cluster genes suggests their involvement in the vectorial regionalization of the larval body along the antero-posterior axis. Hox gene expression in nereids conforms to the canonical patterns postulated for the two other evolutionary branches of the Bilateria, the Ecdysozoa and the Deuterostomia, thus supporting the evolutionary conservatism of the function of Hox genes in development.

  17. [Effects of salinity on spawning and larval development of Exopalaemon carinicauda].

    PubMed

    Liang, Jun-Ping; Li, Jian; Li, Ji-Tao; Liu, Ping; Zhao, Fa-Zhen; Nie, Guo-Xing; Li, Xue-Jun; Kong, Xiang-Hui

    2014-07-01

    Female Exopalaemon carinicauda at ovarian maturation stage II rearing by artificial propagation in the laboratory were chosen as test material. The shrimps were gradually acclimated to the experimental salinity levels of 2, 5, 10, 15, 20, 25 and 30 to determine the effects of salinity on spawning, embryonic development and larval growth of E. carinicauda. The results showed that the ovaries of female E. carinicauda could mature at all test salinity levels. However, it failed to spawn at salinity 2. Salinity levels from 10 to 20 were the most favorable for female E. carinicauda spawning. Although larval development was most successful in eggs incubated at salinity levels of 5 to 30, embryonic development were significantly affected by salinity, and the egg incubation period was shorter at salinities of 15, 20 and 25 than at the other salinities. There were no significant effects of salinity on the rates of larval metamorphosis and survival, but the dry mass of individuals was significantly affected by salinity. The dry mass of shrimps reared at salinities of 15 and 20 were significantly higher than at the other salinities. The growth of 20-day old shrimps was significantly affected by salinity. The specific growth rate increased with the increasing salinity level from 5 to 20, and then decreased at the salinity above 20. The mRNA level of gill Na(+)-K(+)-ATPase was high at high and low salinities, and the lowest at the theoretical salinity 17.5, which might be equal to the hemolymph osmotic pressure of E. carinicauda. It was implied that female parent E. carinicauda could reproduce in a wide range of salinities, while 20-day old shrimps presented higher growth rates at salinities near its theoretical isosmotic point.

  18. Larval spicules, cilia, and symmetry as remnants of indirect development in the direct developing sea urchin Heliocidaris erythrogramma.

    PubMed

    Emlet, R B

    1995-02-01

    Nonfeeding larvae of the echinoid Heliocidaris erythrogramma were raised in culture and examined for expression of a larval skeleton and for the arrangement of the ciliated band. Opaque larvae were fixed, cleared, and examined under polarized light for evidence of calcification. By 35 hr after fertilization (at 22 degrees C), a pair of triradiate spicules was present at the posterior end of the larvae. Each member of this pair formed a fenestrated spicule as it grew laterally. This pair and another pair which formed subsequently, were arranged across a plane of bilateral symmetry orthagonal to the juvenile oral aboral axis. These paired larval spicules can be identified as reduced expressions of postoral and posterodorsal rods found in plutei, and their expression indicates that the juvenile rudiment of H. erythrogramma forms on the left side and that larval body axes are conserved in this modified larva. By 44 hr the ciliated band formed as an incomplete transverse loop of three segments at the posterior end and on the dorsal surface of the ovoid larva. Cilia in these segments grew to lengths of 45-50 microns, longer than other swimming and feeding cilia reported for echinoderm larvae. Band segments are interpreted as expressions of epaulettes (specialized swimming bands) rather than the feeding ciliated band of the pluteus. The ciliated band segments and the larval spicules are both bilaterally symmetrical with respect to the same plane and indicate conserved larval bilateral symmetry despite the major asymmetry of the fates of cells on either side of this plane in their contribution to juvenile development.

  19. Morphological development of larval cobia Rachycentron canadum and the influence of dietary taurine supplementation.

    PubMed

    Salze, G; Craig, S R; Smith, B H; Smith, E P; McLean, E

    2011-05-01

    The morphological development of larval cobia Rachycentron canadum from 3 days post hatch (dph) until weaning (27 dph) was examined using S.E.M. Two groups of fish were studied: a control group (CF), reared under standard feeding protocol, and a group in which prey items were enriched with supplemental taurine (4 g l(-1) day(-1) ; TF). TF fish grew faster (P < 0·001), attained greater size (mean ±s.e. 55·1 ± 1·5 v. 33·9 ± 1·0 mm total length) and had better survival (mean ±s.e. 29·3 ± 0·4 v. 7·1 ± 1·2 %) than CF fish. Canonical variance analysis confirmed findings with respect to differences in growth between the treatment groups with separation being explained by two cranial measurements. S.E.M. revealed that 3 dph larvae of R. canadum (in both groups) possess preopercular spines, superficial neuromasts on the head and body, taste buds in the mouth, an olfactory epithelium which takes the form of simple concave depressions, and primordial gill arches. Gill filaments start to form as early as 6 dph and lamellae buds are visible at 8 dph in both groups. In CF fish, the cephalic lateral line system continues its development at 12-14 dph with invagination of both supra- and infraorbital canals. At the same time, a thorn-like or acanthoid crest forms above the eye. At 14 dph, invaginations of the mandibular and preopercular canals are visible and around 22 dph enclosure of all cranial canals nears completion. In CF larvae, however, completely enclosed cranial canals were not observed within the course of the trial, i.e. 27 dph. In TF larvae, grooves of the cephalic lateral line system form 4 days earlier than observed in CF larvae of R. canadum (i.e. at 8 dph), with enclosure commencing at 16 dph, and completed by 27 dph. Along the flanks of 6 dph larvae of either treatment, four to five equally spaced neuromasts delineate the future position of the trunk lateral line. As myomeres are added to the growing larvae, new neuromasts appear such that at 16 dph

  20. Protein evolution in the context of Drosophila development.

    PubMed

    Davis, Jerel C; Brandman, Onn; Petrov, Dmitri A

    2005-06-01

    The tempo at which a protein evolves depends not only on the rate at which mutations arise but also on the selective effects that those mutations have at the organismal level. It is intuitive that proteins functioning during different stages of development may be predisposed to having mutations of different selective effects. For example, it has been hypothesized that changes to proteins expressed during early development should have larger phenotypic consequences because later stages depend on them. Conversely, changes to proteins expressed much later in development should have smaller consequences at the organismal level. Here we assess whether proteins expressed at different times during Drosophila development vary systematically in their rates of evolution. We find that proteins expressed early in development and particularly during mid-late embryonic development evolve unusually slowly. In addition, proteins expressed in adult males show an elevated evolutionary rate. These two trends are independent of each other and cannot be explained by peculiar rates of mutation or levels of codon bias. Moreover, the observed patterns appear to hold across several functional classes of genes, although the exact developmental time of the slowest protein evolution differs among each class. We discuss our results in connection with data on the evolution of development.

  1. Urbanization Increases Aedes albopictus Larval Habitats and Accelerates Mosquito Development and Survivorship

    PubMed Central

    Li, Yiji; Kamara, Fatmata; Zhou, Guofa; Puthiyakunnon, Santhosh; Li, Chunyuan; Liu, Yanxia; Zhou, Yanhe; Yao, Lijie; Yan, Guiyun; Chen, Xiao-Guang

    2014-01-01

    Introduction Aedes albopictus is a very invasive and aggressive insect vector that causes outbreaks of dengue fever, chikungunya disease, and yellow fever in many countries. Vector ecology and disease epidemiology are strongly affected by environmental changes. Urbanization is a worldwide trend and is one of the most ecologically modifying phenomena. The purpose of this study is to determine how environmental changes due to urbanization affect the ecology of Aedes albopictus. Methods Aquatic habitats and Aedes albopictus larval population surveys were conducted from May to November 2013 in three areas representing rural, suburban, and urban settings in Guangzhou, China. Ae. albopictus adults were collected monthly using BG-Sentinel traps. Ae. albopictus larva and adult life-table experiments were conducted with 20 replicates in each of the three study areas. Results The urban area had the highest and the rural area had the lowest number of aquatic habitats that tested positive for Ae. albopictus larvae. Densities in the larval stages varied among the areas, but the urban area had almost two-fold higher densities in pupae and three-fold higher in adult populations compared with the suburban and rural areas. Larvae developed faster and the adult emergence rate was higher in the urban area than in suburban and rural areas. The survival time of adult mosquitoes was also longer in the urban area than it was in suburban and rural areas. Study regions, surface area, water depth, water clearance, surface type, and canopy coverage were important factors associated with the presence of Ae. albopictus larvae. Conclusions Urbanization substantially increased the density, larval development rate, and adult survival time of Ae. albopictus, which in turn potentially increased the vector capacity, and therefore, disease transmissibility. Mosquito ecology and its correlation with dengue virus transmission should be compared in different environmental settings. PMID:25393814

  2. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

    Günther, Maximilian N; Nettesheim, Guilherme; Shubeita, George T

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly's power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer's disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  3. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  4. Expression of Drosophila forkhead transcription factors during kidney development.

    PubMed

    Baek, Jeong-In; Choi, Soo Young; Chacon-Heszele, Maria F; Zuo, Xiaofeng; Lipschutz, Joshua H

    2014-03-28

    The Drosophila forkhead (Dfkh) family of transcription factors has over 40 family members. One Dfkh family member, BF2 (aka FoxD1), has been shown, by targeted disruption, to be essential for kidney development. In order to determine if other Dfkh family members were involved in kidney development and to search for new members of this family, reverse transcriptase polymerase chain reaction (RT-PCR) was performed using degenerate primers of the consensus sequence of the DNA binding domain of this family and developing rat kidney RNA. The RT-PCR product was used to probe RNA from a developing rat kidney (neonatal), from a 20-day old kidney, and from an adult kidney. The RT-PCR product hybridized only to a developing kidney RNA transcript of ∼2.3 kb (the size of BF2). A lambda gt10 mouse neonatal kidney library was then screened, using the above-described RT-PCR product as a probe. Three lambda phage clones were isolated that strongly hybridized to the RT-PCR probe. Sequencing of the RT-PCR product and the lambda phage clones isolated from the developing kidney library revealed Dfkh BF2. In summary, only Dfkh family member BF2, which has already been shown to be essential for nephrogenesis, was identified in our screen and no other candidate Dfkh family members were identified.

  5. Expression of Drosophila Forkhead Transcription Factors During Kidney Development

    PubMed Central

    Baek, Jeong-In; Choi, Soo Young; Chacon-Heszele, Maria F.; Zuo, Xiaofeng; Lipschutz, Joshua H.

    2014-01-01

    The Drosophila forkhead (Dfkh) family of transcription factors has over 40 family members. One Dfkh family member, BF2 (aka FoxD1), has been shown, by targeted disruption, to be essential for kidney development. In order to determine if other Dfkh family members were involved in kidney development and to search for new members of this family, reverse transcriptase polymerase chain reaction (RT-PCR) was performed using degenerate primers of the consensus sequence of the DNA binding domain of this family and developing rat kidney RNA. The RT-PCR product was used to probe RNA from a developing rat kidney (neonatal), from a 20-day old kidney, and from an adult kidney. The RT-PCR product hybridized only to a developing kidney RNA transcript of ~2.3 kb (the size of BF2). A lambda gt10 mouse neonatal kidney library was then screened, using the above-described RT-PCR product as a probe. Three lambda phage clones were isolated that strongly hybridized to the RT-PCR probe. Sequencing of the RT-PCR product and the lambda phage clones isolated from the developing kidney library revealed Dfkh BF2. In summary, only Dfkh family member BF2, which has already been shown to be essential for nephrogenesis, was identified in our screen and no other candidate Dfkh family members were identified. PMID:24491558

  6. Effects of Oral Morphine on the Larvae, Pupae and Imago Development in Drosophila Melanogaster

    PubMed Central

    Tekieh, Elaheh; Kazemi, Masoomeh; Dehghani, Leila; Bahramyian, Sina; Sadogi, Mehrangiz; Zardooz, Homeira; Fakhanik-Babaei, Javad; Sahraei, Hedayat

    2011-01-01

    Objective: Previous studies, focusing on the effects of abused drugs, have used mice or rats as the main animal models; the present study tries to introduce a simple animal model. For this propose, we investigated the effects of oral morphine consumption by parents on the development of larvae, pupae and imago in Drosophila Melanogaster (D. Melanogaster). Materials and Methods: In this experimental study, twenty male and 20 female D. Melanogaster pupae were housed in test tubes with banana (5 pupae /tube).). Male and female groups each were divided into three experimental group and one control group, which were maintained at 25℃. Morphine (0.2, 0.02, 0.002 mg/ml) was added into the test tubes of the experimental groups. The control group maintained at morphine-free test tube. The male and female groups with the same treatment were coupled and then female fertilization, egg deposit, larval, pupae and imago stages were studied macro and microscopically. The SPSS software (version 9.01) was used for statistical evaluations. Results: In the experimental groups, in the larvae stage, both increase and decrease of length and surface area in the pupae stage were observed. The number of larvae pupae, and imago was reduced in the experimental groups. Conclusion: The study showed that oral morphine consumption by parents may affect the development of larvae, pupation and imago stages in D. Melanogaster. The results also showed that D. Melanogaster may be a reliable animal model to study on the concerns about abused drugs especially those with opioids. PMID:23508520

  7. Growth and development of larval green frogs (Rana clamitans) exposed to multiple doses of an insecticide

    USGS Publications Warehouse

    Boone, M.D.; Bridges, C.M.; Rothermel, B.B.

    2001-01-01

    Our objective was to determine how green frogs (Rana clamitans) are affected by multiple exposures to a sublethal level of the carbamate insecticide, carbaryl, in outdoor ponds. Tadpoles were added to 1,000-1 ponds at a low or high density which were exposed to carbaryl 0, 1, 2, or 3 times. Length of the larval period, mass, developmental stage, tadpole survival, and proportion metamorphosed were used to determine treatment effects. The frequency of dosing affected the proportion of green frogs that reached metamorphosis and the developmental stage of tadpoles. Generally, exposure to carbaryl increased rates of metamorphosis and development. The effect of the frequency of carbaryl exposure on development varied with the density treatment; the majority of metamorphs and the most developed tadpoles came from high-density ponds exposed to carbaryl 3 times. This interaction suggests that exposure to carbaryl later in the larval period stimulated metamorphosis, directly or indirectly, under high-density conditions. Our study indicates that exposure to a contaminant can lead to early initiation of metamorphosis and that natural biotic factors can mediate the effects of a contaminant in the environment.

  8. Larval development of the feline lungworm Aelurostrongylus abstrusus in Helix aspersa.

    PubMed

    Di Cesare, Angela; Crisi, Paolo Emidio; Di Giulio, Emanuela; Veronesi, Fabrizia; Frangipane di Regalbono, Antonio; Talone, Tonino; Traversa, Donato

    2013-09-01

    The cat lungworm Aelurostrongylus abstrusus affects the domestic cat and other felids all over the world. Feline aelurostrongylosis is of importance in clinical feline medicine and is gaining more and more attention for the present expansion in the geographical range of A. abstrusus. Global warming and changes in phenology of snail intermediate hosts have been incriminated in this spreading. Helix aspersa, a potential vector of A. abstrusus, is endemic in most regions of the world, where it has become recently a pest outside its native Mediterranean range. The present work evaluated key features of larval development of A. abstrusus in H. aspersa at two different temperature conditions. The results showed that A. abstrusus may reach the infective stage in muscular foot and viscera of H. aspersa and that environmental temperatures may influence the biological cycle of the cat lungworm. In particular, the higher the average temperature, the higher the rate of larval development, i.e., about 50% of larvae of A. abstrusus reached the infective stage between temperatures of 18.8-29.5 °C, while only 17.8% of larvae completed their development at temperatures of 6.7-22 °C. Biological and epidemiological implications are discussed.

  9. Effect of Two Oil Dispersants on Larval Grass Shrimp (Palaemonetes pugio) Development.

    NASA Astrophysics Data System (ADS)

    Betancourt, P.; Key, P. B.; Chung, K. W.; DeLorenzo, M. E.

    2015-12-01

    The study focused on the effects that two oil dispersants, Corexit® EC9500A and Finasol® OSR52, have on the development of larval grass shrimp, (Palaemonetes pugio). The hypothesis was that Finasol would have a greater effect on larval grass shrimp development than Corexit. The experiment was conducted using 300 grass shrimp larvae that were 24 hours old. Each larva was exposed individually. In total, five sub-lethal concentrations were tested for each dispersant (control, 1.25, 2.50, 5.0,10.0 mg/L). The larvae were exposed for five days then transferred to clean seawater until metamorphosis into the juvenile stage. Key data measurements recorded included number of days to become juveniles, number of instars, length, dry weight, and mortality. Data from exposed shrimp was compared to the results of the control for each dispersant concentration. Corexit and Finasol exposure treatments of 5 mg/L and 10 mg/L showed significantly higher values for number of days and number of instars to reach juvenile status than values obtained from unexposed, control shrimp. Overall, mortality was higher in the Finasol treatments but the two dispersants did not respond significantly different from one another. Future studies are needed to determine the long term effects of dispersant exposure on all grass shrimp life stages and how any dispersant exposure impacts grass shrimp populations. Grass shrimp serve as excellent toxicity indicators of estuaries, and further studies will help to develop better oil spill mitigation techniques.

  10. Mapping organism expression levels at cellular resolution in developing Drosophila

    NASA Astrophysics Data System (ADS)

    Knowles, David W.; Keranen, Soile; Biggin, Mark D.; Sudar, Damir

    2002-05-01

    The development of an animal embryo is orchestrated by a network of genetically determined, temporal and spatial gene expression patterns that determine the animals final form. To understand such networks, we are developing novel quantitative optical imaging techniques to map gene expression levels at cellular and sub-cellular resolution within pregastrula Drosophila. Embryos at different stages of development are labeled for total DNA and specific gene products using different fluorophors and imaged in 3D with confocal microscopy. Innovative steps have been made which allow the DNA-image to be automatically segmented to produce a morphological mask of the individual nuclear boundaries. For each stage of development an average morphology is chosen to which images from different embryo are compared. The morphological mask is then used to quantify gene-product on a per nuclei basis. What results is an atlas of the relative amount of the specific gene product expressed within the nucleus of every cell in the embryo at the various stages of development. We are creating a quantitative database of transcription factor and target gene expression patterns in wild-type and factor mutant embryos with single cell resolution. Our goal is to uncover the rules determining how patterns of gene expression are generated.

  11. Spatial expression of transcription factors in Drosophila embryonic organ development

    PubMed Central

    2013-01-01

    Background Site-specific transcription factors (TFs) bind DNA regulatory elements to control expression of target genes, forming the core of gene regulatory networks. Despite decades of research, most studies focus on only a small number of TFs and the roles of many remain unknown. Results We present a systematic characterization of spatiotemporal gene expression patterns for all known or predicted Drosophila TFs throughout embryogenesis, the first such comprehensive study for any metazoan animal. We generated RNA expression patterns for all 708 TFs by in situ hybridization, annotated the patterns using an anatomical controlled vocabulary, and analyzed TF expression in the context of organ system development. Nearly all TFs are expressed during embryogenesis and more than half are specifically expressed in the central nervous system. Compared to other genes, TFs are enriched early in the development of most organ systems, and throughout the development of the nervous system. Of the 535 TFs with spatially restricted expression, 79% are dynamically expressed in multiple organ systems while 21% show single-organ specificity. Of those expressed in multiple organ systems, 77 TFs are restricted to a single organ system either early or late in development. Expression patterns for 354 TFs are characterized for the first time in this study. Conclusions We produced a reference TF dataset for the investigation of gene regulatory networks in embryogenesis, and gained insight into the expression dynamics of the full complement of TFs controlling the development of each organ system. PMID:24359758

  12. Aspects of Embryonic and Larval Development in Bighead Carp Hypophthalmichthys nobilis and Silver Carp Hypophthalmichthys molitrix

    PubMed Central

    George, Amy E.; Chapman, Duane C.

    2013-01-01

    As bighead carp Hypophthalmichthysnobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region’s economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within the Great Lakes basin. In laboratory experiments, the embryonic and larval developmental rates, size, and behaviors of bigheaded carp were tracked at two temperature treatments, one “cold” and one “warm”. Developmental rates were computed using previously described stages of development and the cumulative thermal unit method. Both species have similar thermal requirements, with a minimum developmental temperature for embryonic stages of 12.1° C for silver carp and 12.9° C for bighead carp, and 13.3° C for silver carp larval stages and 13.4° C for bighead carp larval stages. Egg size differed among species and temperature treatments, as egg size was larger in bighead carp, and “warm" temperature treatments. The larvae started robust upwards vertical swimming immediately after hatching, interspersed with intervals of sinking. Vertical swimming tubes were used to measure water column distribution, and ascent and descent rates of vertically swimming fish. Water column distribution and ascent and descent rates changed with ontogeny. Water column distribution also showed some diel periodicity. Developmental rates, size, and behaviors contribute to the drift distance needed to fulfill the early life history requirements of bigheaded carps and can be used in conjunction with transport information to assess invasibility of a river. PMID:23967350

  13. Aspects of embryonic and larval development in bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix

    USGS Publications Warehouse

    George, Amy E.; Chapman, Duane C.

    2013-01-01

    As bighead carp Hypophthalmichthys nobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region’s economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within the Great Lakes basin. In laboratory experiments, the embryonic and larval developmental rates, size, and behaviors of bigheaded carp were tracked at two temperature treatments, one “cold” and one “warm”. Developmental rates were computed using previously described stages of development and the cumulative thermal unit method. Both species have similar thermal requirements, with a minimum developmental temperature for embryonic stages of 12.1° C for silver carp and 12.9° C for bighead carp, and 13.3° C for silver carp larval stages and 13.4° C for bighead carp larval stages. Egg size differed among species and temperature treatments, as egg size was larger in bighead carp, and “warm" temperature treatments. The larvae started robust upwards vertical swimming immediately after hatching, interspersed with intervals of sinking. Vertical swimming tubes were used to measure water column distribution, and ascent and descent rates of vertically swimming fish. Water column distribution and ascent and descent rates changed with ontogeny. Water column distribution also showed some diel periodicity. Developmental rates, size, and behaviors contribute to the drift distance needed to fulfill the early life history requirements of bigheaded carps and can be used in conjunction with transport information to assess invasibility of a river.

  14. Aspects of embryonic and larval development in bighead carp Hypophthalmichthys nobilis and silver carp Hypophthalmichthys molitrix.

    PubMed

    George, Amy E; Chapman, Duane C

    2013-01-01

    As bighead carp Hypophthalmichthysnobilis and silver carp H. molitrix (the bigheaded carps) are poised to enter the Laurentian Great Lakes and potentially damage the region's economically important fishery, information on developmental rates and behaviors of carps is critical to assessing their ability to establish sustainable populations within the Great Lakes basin. In laboratory experiments, the embryonic and larval developmental rates, size, and behaviors of bigheaded carp were tracked at two temperature treatments, one "cold" and one "warm". Developmental rates were computed using previously described stages of development and the cumulative thermal unit method. Both species have similar thermal requirements, with a minimum developmental temperature for embryonic stages of 12.1° C for silver carp and 12.9° C for bighead carp, and 13.3° C for silver carp larval stages and 13.4° C for bighead carp larval stages. Egg size differed among species and temperature treatments, as egg size was larger in bighead carp, and "warm" temperature treatments. The larvae started robust upwards vertical swimming immediately after hatching, interspersed with intervals of sinking. Vertical swimming tubes were used to measure water column distribution, and ascent and descent rates of vertically swimming fish. Water column distribution and ascent and descent rates changed with ontogeny. Water column distribution also showed some diel periodicity. Developmental rates, size, and behaviors contribute to the drift distance needed to fulfill the early life history requirements of bigheaded carps and can be used in conjunction with transport information to assess invasibility of a river. PMID:23967350

  15. Ire1 supports normal ER differentiation in developing Drosophila photoreceptors

    PubMed Central

    Xu, Zuyuan; Chikka, Madhusudana Rao; Xia, Hongai; Ready, Donald F.

    2016-01-01

    ABSTRACT The endoplasmic reticulum (ER) serves virtually all aspects of cell physiology and, by pathways that are incompletely understood, is dynamically remodeled to meet changing cell needs. Inositol-requiring enzyme 1 (Ire1), a conserved core protein of the unfolded protein response (UPR), participates in ER remodeling and is particularly required during the differentiation of cells devoted to intense secretory activity, so-called ‘professional’ secretory cells. Here, we characterize the role of Ire1 in ER differentiation in the developing Drosophila compound eye photoreceptors (R cells). As part of normal development, R cells take a turn as professional secretory cells with a massive secretory effort that builds the photosensitive membrane organelle, the rhabdomere. We find rough ER sheets proliferate as rhabdomere biogenesis culminates, and Ire1 is required for normal ER differentiation. Ire1 is active early in R cell development and is required in anticipation of peak biosynthesis. Without Ire1, the amount of rough ER sheets is strongly reduced and the extensive cortical ER network at the rhabdomere base, the subrhabdomere cisterna (SRC), fails. Instead, ER proliferates in persistent and ribosome-poor tubular tangles. A phase of Ire1 activity early in R cell development thus shapes dynamic ER. PMID:26787744

  16. Rearing Tenebrio molitor in BLSS: Dietary fiber affects larval growth, development, and respiration characteristics

    NASA Astrophysics Data System (ADS)

    Li, Leyuan; Stasiak, Michael; Li, Liang; Xie, Beizhen; Fu, Yuming; Gidzinski, Danuta; Dixon, Mike; Liu, Hong

    2016-01-01

    Rearing of yellow mealworm (Tenebrio molitor L.) will provide good animal nutrition for astronauts in a bioregenerative life support system. In this study, growth and biomass conversion data of T. molitor larvae were tested for calculating the stoichiometric equation of its growth. Result of a respiratory quotient test proved the validity of the equation. Fiber had the most reduction in mass during T. molitor‧s consumption, and thus it is speculated that fiber is an important factor affecting larval growth of T. molitor. In order to further confirm this hypothesis and find out a proper feed fiber content, T. molitor larvae were fed on diets with 4 levels of fiber. Larval growth, development and respiration in each group were compared and analyzed. Results showed that crude-fiber content of 5% had a significant promoting effect on larvae in early instars, and is beneficial for pupa eclosion. When fed on feed of 5-10% crude-fiber, larvae in later instars reached optimal levels in growth, development and respiration. Therefore, we suggest that crude fiber content in feed can be controlled within 5-10%, and with the consideration of food palatability, a crude fiber of 5% is advisable.

  17. Embryonic and larval development of the host sea anemones Entacmaea quadricolor and Heteractis crispa.

    PubMed

    Scott, Anna; Harrison, Peter L

    2007-10-01

    Little information is available on the sexual reproductive biology of anemones that provide essential habitat for anemonefish. Here we provide the first information on the surface ultrastructural and morphological changes during development of the embryos and planula larvae of Entacmaea quadricolor and Heteractis crispa, using light and scanning electron microscopy. Newly spawned eggs of E. quadricolor and H. crispa averaged 794 microm and 589 microm diameter, respectively, and were covered by many spires of microvilli that were evenly distributed over the egg surface, except for a single bare patch. Eggs of both species contained abundant zooxanthellae when spawned, indicating vertical transmission of symbionts. Fertilization was external, and the resulting embryos displayed superficial cleavage. As development continued, individual blastomeres became readily distinguishable and a round-to-ovoid blastula was formed, which flattened with further divisions. The edges of the blastula thickened, creating a concave-convex dish-shaped gastrula. The outer margins of the gastrula appeared to roll inward, leading to the formation of an oral pore and a ciliated planula larva. Larval motility and directional movement were first observed 36 h after spawning. E. quadricolor larval survival remained high during the first 4 d after spawning, then decreased rapidly. PMID:17928518

  18. Transcriptome Profiling Identifies Multiplexin as a Target of SAGA Deubiquitinase Activity in Glia Required for Precise Axon Guidance During Drosophila Visual Development

    PubMed Central

    Ma, Jingqun; Brennan, Kaelan J.; D’Aloia, Mitch R.; Pascuzzi, Pete E.; Weake, Vikki M.

    2016-01-01

    The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex is a transcriptional coactivator with histone acetylase and deubiquitinase activities that plays an important role in visual development and function. In Drosophila melanogaster, four SAGA subunits are required for the deubiquitination of monoubiquitinated histone H2B (ubH2B): Nonstop, Sgf11, E(y)2, and Ataxin 7. Mutations that disrupt SAGA deubiquitinase activity cause defects in neuronal connectivity in the developing Drosophila visual system. In addition, mutations in SAGA result in the human progressive visual disorder spinocerebellar ataxia type 7 (SCA7). Glial cells play a crucial role in both the neuronal connectivity defect in nonstop and sgf11 flies, and in the retinal degeneration observed in SCA7 patients. Thus, we sought to identify the gene targets of SAGA deubiquitinase activity in glia in the Drosophila larval central nervous system. To do this, we enriched glia from wild-type, nonstop, and sgf11 larval optic lobes using affinity-purification of KASH-GFP tagged nuclei, and then examined each transcriptome using RNA-seq. Our analysis showed that SAGA deubiquitinase activity is required for proper expression of 16% of actively transcribed genes in glia, especially genes involved in proteasome function, protein folding and axon guidance. We further show that the SAGA deubiquitinase-activated gene Multiplexin (Mp) is required in glia for proper photoreceptor axon targeting. Mutations in the human ortholog of Mp, COL18A1, have been identified in a family with a SCA7-like progressive visual disorder, suggesting that defects in the expression of this gene in SCA7 patients could play a role in the retinal degeneration that is unique to this ataxia. PMID:27261002

  19. Transcriptome Profiling Identifies Multiplexin as a Target of SAGA Deubiquitinase Activity in Glia Required for Precise Axon Guidance During Drosophila Visual Development.

    PubMed

    Ma, Jingqun; Brennan, Kaelan J; D'Aloia, Mitch R; Pascuzzi, Pete E; Weake, Vikki M

    2016-01-01

    The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex is a transcriptional coactivator with histone acetylase and deubiquitinase activities that plays an important role in visual development and function. In Drosophila melanogaster, four SAGA subunits are required for the deubiquitination of monoubiquitinated histone H2B (ubH2B): Nonstop, Sgf11, E(y)2, and Ataxin 7. Mutations that disrupt SAGA deubiquitinase activity cause defects in neuronal connectivity in the developing Drosophila visual system. In addition, mutations in SAGA result in the human progressive visual disorder spinocerebellar ataxia type 7 (SCA7). Glial cells play a crucial role in both the neuronal connectivity defect in nonstop and sgf11 flies, and in the retinal degeneration observed in SCA7 patients. Thus, we sought to identify the gene targets of SAGA deubiquitinase activity in glia in the Drosophila larval central nervous system. To do this, we enriched glia from wild-type, nonstop, and sgf11 larval optic lobes using affinity-purification of KASH-GFP tagged nuclei, and then examined each transcriptome using RNA-seq. Our analysis showed that SAGA deubiquitinase activity is required for proper expression of 16% of actively transcribed genes in glia, especially genes involved in proteasome function, protein folding and axon guidance. We further show that the SAGA deubiquitinase-activated gene Multiplexin (Mp) is required in glia for proper photoreceptor axon targeting. Mutations in the human ortholog of Mp, COL18A1, have been identified in a family with a SCA7-like progressive visual disorder, suggesting that defects in the expression of this gene in SCA7 patients could play a role in the retinal degeneration that is unique to this ataxia. PMID:27261002

  20. Chromosomal Distribution of PcG Proteins during Drosophila Development

    PubMed Central

    Nègre, Nicolas; Hennetin, Jérôme; Sun, Ling V; Lavrov, Sergey; Bellis, Michel; White, Kevin P

    2006-01-01

    Polycomb group (PcG) proteins are able to maintain the memory of silent transcriptional states of homeotic genes throughout development. In Drosophila, they form multimeric complexes that bind to specific DNA regulatory elements named PcG response elements (PREs). To date, few PREs have been identified and the chromosomal distribution of PcG proteins during development is unknown. We used chromatin immunoprecipitation (ChIP) with genomic tiling path microarrays to analyze the binding profile of the PcG proteins Polycomb (PC) and Polyhomeotic (PH) across 10 Mb of euchromatin. We also analyzed the distribution of GAGA factor (GAF), a sequence-specific DNA binding protein that is found at most previously identified PREs. Our data show that PC and PH often bind to clustered regions within large loci that encode transcription factors which play multiple roles in developmental patterning and in the regulation of cell proliferation. GAF co-localizes with PC and PH to a limited extent, suggesting that GAF is not a necessary component of chromatin at PREs. Finally, the chromosome-association profile of PC and PH changes during development, suggesting that the function of these proteins in the regulation of some of their target genes might be more dynamic than previously anticipated. PMID:16613483

  1. Predatory cannibalism in Drosophila melanogaster larvae.

    PubMed

    Vijendravarma, Roshan K; Narasimha, Sunitha; Kawecki, Tadeusz J

    2013-01-01

    Hunting live prey is risky and thought to require specialized adaptations. Therefore, observations of predatory cannibalism in otherwise non-carnivorous animals raise questions about its function, adaptive significance and evolutionary potential. Here we document predatory cannibalism on larger conspecifics in Drosophila melanogaster larvae and address its evolutionary significance. We found that under crowded laboratory conditions younger larvae regularly attack and consume 'wandering-stage' conspecifics, forming aggregations mediated by chemical cues from the attacked victim. Nutrition gained this way can be significant: an exclusively cannibalistic diet was sufficient for normal development from eggs to fertile adults. Cannibalistic diet also induced plasticity of larval mouth parts. Finally, during 118 generations of experimental evolution, replicated populations maintained under larval malnutrition evolved enhanced propensity towards cannibalism. These results suggest that, at least under laboratory conditions, predation on conspecifics in Drosophila is a functional, adaptive behaviour, which can rapidly evolve in response to nutritional conditions.

  2. Post-larval development of the commercial sponge Spongia officinalis L. (Porifera, Demospongiae).

    PubMed

    Gaino, E; Baldacconi, R; Corriero, G

    2007-10-01

    This study investigated the development of the larvae of Spongia officinalis in experimental conditions, after settlement on plastic substrates, using electron and light microscopy. The released larvae show a dark pigmented ring distinguishes the posterior larval pole. The youngest larvae, covered with a flagellate epithelium, move onwards by rotating on their longitudinal axis. Over time a creeping-like motion prevails, probably linked to the need for settlement. After a free-swimming period of 24-48 h, larvae settle on the artificial substrate by the anterior pole. At settlement, the flagellate epithelium is substituted by flattened cells, which delimit the outermost surface. Post-larvae were reared to about three months. The early phase of post-larval differentiation shows a solid interior mainly consisting of granular cells varying in shape and size. They are included in a dense collagen matrix that contains a conspicuous amount of bacteria. Lacunae are already evident in the initial phase of metamorphosis. In several of them, cell debris and nucleate cells are visible. This feature is consistent with a progressive reduction of the cell mass (autolysis). Neither choanocyte chambers nor canals differentiate. The morphogenetic process leads to a metamorph only consisting of vacuolated cells and collagen fibrils included in a thin fibrous coat.

  3. Toxicity of endosulfan on embryo-larval development of the South American toad Rhinella arenarum.

    PubMed

    Svartz, Gabriela V; Wolkowicz, Ianina R Hutler; Coll, Cristina S Pérez

    2014-04-01

    Endosulfan is a widely used pesticide despite its extreme toxicity to a variety of taxa and its worldwide ban. The aim of the present study was to evaluate the acute and chronic toxicity of endosulfan on the embryonic-larval development of the common South American toad Rhinella arenarum. The results showed that lethal and sublethal effects increased with concentration and exposure time. The sensitivity to endosulfan increased during the larval period, the complete operculum stage (S.25) being the most sensitive (504-h median lethal concentration [LC50] = 0.01 mg endosulfan/L; 10% lethal concentration [LC10] = 0.004 mg endosulfan/L). Endosulfan exposure caused morphological abnormalities such as general underdevelopment, edema, gill malformations, and cellular dissociation as well as neurotoxicity. Our results also showed that larvae exposed to concentrations of 0.005 mg endosulfan/L and 0.01 mg endosulfan/L completed metamorphosis earlier than controls, but with underdevelopment. The 240-h teratogenic index was 6.13, implying a high risk for embryos to be malformed in the absence of significant embryonic lethality. Because the hazard quotients for chronic exposure were over 1, the level of concern value and toxicity endpoints obtained in the present study for R. arenarum occurred at concentrations lower than the levels of endosulfan reported in the environment, this pesticide should be considered a potential risk for this species.

  4. Chiton myogenesis: perspectives for the development and evolution of larval and adult muscle systems in molluscs.

    PubMed

    Wanninger, Andreas; Haszprunar, Gerhard

    2002-02-01

    We investigated muscle development in two chiton species, Mopalia muscosa and Chiton olivaceus, from embryo hatching until 10 days after metamorphosis. The anlagen of the dorsal longitudinal rectus muscle and a larval prototroch muscle ring are the first detectable muscle structures in the early trochophore-like larva. Slightly later, a ventrolaterally situated pair of longitudinal muscles appears, which persists through metamorphosis. In addition, the anlagen of the putative dorsoventral shell musculature and the first fibers of a muscular grid, which is restricted to the pretrochal region and consists of outer ring and inner diagonal muscle fibers, are generated. Subsequently, transversal muscle fibers form underneath each future shell plate and the ventrolateral enrolling muscle is established. At metamorphic competence, the dorsoventral shell musculature consists of numerous serially repeated, intercrossing muscle fibers. Their concentration into seven (and later eight) functional shell plate muscle bundles starts after the completion of metamorphosis. The larval prototroch ring and the pretrochal muscle grid are lost at metamorphosis. The structure of the apical grid and its atrophy during metamorphosis suggests ontogenetic repetition of (parts of) the original body-wall musculature of a proposed worm-shaped molluscan ancestor. Moreover, our data show that the "segmented" character of the polyplacophoran shell musculature is a secondary condition, thus contradicting earlier theories that regarded the Polyplacophora (and thus the entire phylum Mollusca) as primarily eumetameric (annelid-like). Instead, we propose an unsegmented trochozoan ancestor at the base of molluscan evolution.

  5. Does atrazine affect larval development and sexual differentiation of South African clawed frogs?

    PubMed

    Kloas, Werner; Lutz, Ilka; Urbatzka, Ralph; Springer, Tim; Krueger, Hank; Wolf, Jeffrey; Holden, Larry; Hosmer, Alan

    2009-04-01

    The potential impact of atrazine (ATZ) on gonadal malformations in larval Xenopus laevis has been controversially discussed, and a hypothesis has been generated that ATZ might induce the estrogen-synthesizing enzyme aromatase, leading to feminization or demasculinization. Recently, extensive long-term studies clearly indicate that no adverse effect of ATZ on larval development and sexual differentiation could be found. Therefore, to determine potential transient impacts of ATZ on sexual differentiation processes, short-term exposures were conducted using tadpoles treated for 4 days with ATZ at 25 microg/L. The expression levels of the key players for sexual differentiation in amphibians were determined in the brain, assessing aromatase, 5alpha-reductase type 1 (S1) and type 2 (S2), and the gonadotropins luteinizing hormone and follicle-stimulating hormone, and in the gonads, measuring aromatase, S1, and S2, by means of quantitative RT-PCR. No significant changes in any of these parameters have been found, implicating, in accordance with recent long-term exposures, that no aromatase induction by ATZ could be observed, and it seems likely that no further endocrine mechanism of ATZ affecting sexual differentiation in X. laevis exists.

  6. Cloning of aquaporin-1 of the blue crab, Callinectes sapidus: its expression during the larval development in hyposalinity

    PubMed Central

    2012-01-01

    Background Ontogenetic variation in salinity adaptation has been noted for the blue crab, Callinectes sapidus, which uses the export strategy for larval development: females migrate from the estuaries to the coast to spawn, larvae develop in the ocean, and postlarvae (megalopae) colonize estuarine areas. We hypothesized that C. sapidus larvae may be stenohaline and have limited osmoregulatory capacity which compromises their ability to survive in lower salinity waters. We tested this hypothesis using hatchery-raised larvae that were traceable to specific life stages. In addition, we aimed to understand the possible involvement of AQP-1 in salinity adaptation during larval development and during exposure to hyposalinity. Results A full-length cDNA sequence of aquaporin (GenBank JQ970426) was isolated from the hypodermis of the blue crab, C. sapidus, using PCR with degenerate primers and 5′ and 3′ RACE. The open reading frame of CasAQP-1 consists of 238 amino acids containing six helical structures and two NPA motifs for the water pore. The expression pattern of CasAQP-1 was ubiquitous in cDNAs from all tissues examined, although higher in the hepatopancreas, thoracic ganglia, abdominal muscle, and hypodermis and lower in the antennal gland, heart, hemocytes, ovary, eyestalk, brain, hindgut, Y-organs, and gill. Callinectes larvae differed in their capacity to molt in hyposalinity, as those at earlier stages from Zoea (Z) 1 to Z4 had lower molting rates than those from Z5 onwards, as compared to controls kept in 30 ppt water. No difference was found in the survival of larvae held at 15 and 30 ppt. CasAQP-1 expression differed with ontogeny during larval development, with significantly higher expression at Z1-2, compared to other larval stages. The exposure to 15 ppt affected larval-stage dependent CasAQP-1 expression which was significantly higher in Z2- 6 stages than the other larval stages. Conclusions We report the ontogenetic variation in CasAQP-1

  7. Small Peptides as Newcomers in the Control of Drosophila Development.

    PubMed

    Zanet, J; Chanut-Delalande, H; Plaza, Serge; Payre, Francios

    2016-01-01

    Throughout the last century, studies using the fruit fly have contributed to the discovery of many key genetic elements that control animal development. Recent work has shed light on an unexpectedly large number of RNAs that lack the classical hallmarks of protein-coding genes and are thus referred to as noncoding RNAs. However, there is mounting evidence that both mRNA and noncoding RNAs often contain small open reading frames (sORFs/smORFs), which can be translated into peptides. While genome-wide profiling supports a pervasive translation of these noncanonical sORF/smORF/SEP peptides, their functions remain poorly understood. Here, we review recent data obtained in Drosophila demonstrating the overlooked role of smORF peptides in the control of development and adult life. Focusing on a few smORF peptides whose functions have been elucidated recently, we discuss the importance of these newly identified regulatory molecules and how they act to regulate the building and function of the whole organism. PMID:26969979

  8. Glial cell development and function in the Drosophila visual system

    PubMed Central

    CHOTARD, CAROLE; SALECKER, IRIS

    2008-01-01

    In the developing nervous system, building a functional neuronal network relies on coordinating the formation, specification and survival to diverse neuronal and glial cell subtypes. The establishment of neuronal connections further depends on sequential neuron–neuron and neuron–glia interactions that regulate cell-migration patterns and axon guidance. The visual system of Drosophila has a highly regular, retinotopic organization into reiterated interconnected synaptic circuits. It is therefore an excellent invertebrate model to investigate basic cellular strategies and molecular determinants regulating the different developmental processes that lead to network formation. Studies in the visual system have provided important insights into the mechanisms by which photoreceptor axons connect with their synaptic partners within the optic lobe. In this review, we highlight that this system is also well suited for uncovering general principles that underlie glial cell biology. We describe the glial cell subtypes in the visual system and discuss recent findings about their development and migration. Finally, we outline the pivotal roles of glial cells in mediating neural circuit assembly, boundary formation, neural proliferation and survival, as well as synaptic function. PMID:18333286

  9. Small Peptides as Newcomers in the Control of Drosophila Development.

    PubMed

    Zanet, J; Chanut-Delalande, H; Plaza, Serge; Payre, Francios

    2016-01-01

    Throughout the last century, studies using the fruit fly have contributed to the discovery of many key genetic elements that control animal development. Recent work has shed light on an unexpectedly large number of RNAs that lack the classical hallmarks of protein-coding genes and are thus referred to as noncoding RNAs. However, there is mounting evidence that both mRNA and noncoding RNAs often contain small open reading frames (sORFs/smORFs), which can be translated into peptides. While genome-wide profiling supports a pervasive translation of these noncanonical sORF/smORF/SEP peptides, their functions remain poorly understood. Here, we review recent data obtained in Drosophila demonstrating the overlooked role of smORF peptides in the control of development and adult life. Focusing on a few smORF peptides whose functions have been elucidated recently, we discuss the importance of these newly identified regulatory molecules and how they act to regulate the building and function of the whole organism.

  10. Evolved differences in larval social behavior mediated by novel pheromones

    PubMed Central

    Mast, Joshua D; De Moraes, Consuelo M; Alborn, Hans T; Lavis, Luke D; Stern, David L

    2014-01-01

    Pheromones, chemical signals that convey social information, mediate many insect social behaviors, including navigation and aggregation. Several studies have suggested that behavior during the immature larval stages of Drosophila development is influenced by pheromones, but none of these compounds or the pheromone-receptor neurons that sense them have been identified. Here we report a larval pheromone-signaling pathway. We found that larvae produce two novel long-chain fatty acids that are attractive to other larvae. We identified a single larval chemosensory neuron that detects these molecules. Two members of the pickpocket family of DEG/ENaC channel subunits (ppk23 and ppk29) are required to respond to these pheromones. This pheromone system is evolving quickly, since the larval exudates of D. simulans, the sister species of D. melanogaster, are not attractive to other larvae. Our results define a new pheromone signaling system in Drosophila that shares characteristics with pheromone systems in a wide diversity of insects. DOI: http://dx.doi.org/10.7554/eLife.04205.001 PMID:25497433

  11. Effects of temperature on embryonic and early larval growth and development in the rough-skinned newt (Taricha granulosa).

    PubMed

    Smith, Geoffrey D; Hopkins, Gareth R; Mohammadi, Shabnam; M Skinner, Heather; Hansen, Tyler; Brodie, Edmund D; French, Susannah S

    2015-07-01

    We investigated the effects of temperature on the growth and development of embryonic and early larval stages of a western North American amphibian, the rough-skinned newt (Taricha granulosa). We assigned newt eggs to different temperatures (7, 14, or 21°C); after hatching, we re-assigned the newt larvae into the three different temperatures. Over the course of three to four weeks, we measured total length and developmental stage of the larvae. Our results indicated a strong positive relationship over time between temperature and both length and developmental stage. Importantly, individuals assigned to cooler embryonic temperatures did not achieve the larval sizes of individuals from the warmer embryonic treatments, regardless of larval temperature. Our investigation of growth and development at different temperatures demonstrates carry-over effects and provides a more comprehensive understanding of how organisms respond to temperature changes during early development. PMID:25965021

  12. Effects of temperature on embryonic and early larval growth and development in the rough-skinned newt (Taricha granulosa).

    PubMed

    Smith, Geoffrey D; Hopkins, Gareth R; Mohammadi, Shabnam; M Skinner, Heather; Hansen, Tyler; Brodie, Edmund D; French, Susannah S

    2015-07-01

    We investigated the effects of temperature on the growth and development of embryonic and early larval stages of a western North American amphibian, the rough-skinned newt (Taricha granulosa). We assigned newt eggs to different temperatures (7, 14, or 21°C); after hatching, we re-assigned the newt larvae into the three different temperatures. Over the course of three to four weeks, we measured total length and developmental stage of the larvae. Our results indicated a strong positive relationship over time between temperature and both length and developmental stage. Importantly, individuals assigned to cooler embryonic temperatures did not achieve the larval sizes of individuals from the warmer embryonic treatments, regardless of larval temperature. Our investigation of growth and development at different temperatures demonstrates carry-over effects and provides a more comprehensive understanding of how organisms respond to temperature changes during early development.

  13. The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development.

    PubMed

    De Marco, Rodrigo J; Groneberg, Antonia H; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

    2014-01-01

    The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging.

  14. The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development

    PubMed Central

    De Marco, Rodrigo J.; Groneberg, Antonia H.; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

    2014-01-01

    The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging. PMID:25368561

  15. The behavior of larval zebrafish reveals stressor-mediated anorexia during early vertebrate development.

    PubMed

    De Marco, Rodrigo J; Groneberg, Antonia H; Yeh, Chen-Min; Treviño, Mario; Ryu, Soojin

    2014-01-01

    The relationship between stress and food consumption has been well documented in adults but less so in developing vertebrates. Here we demonstrate that an encounter with a stressor can suppress food consumption in larval zebrafish. Furthermore, we provide indication that food intake suppression cannot be accounted for by changes in locomotion, oxygen consumption and visual responses, as they remain unaffected after exposure to a potent stressor. We also show that feeding reoccurs when basal levels of cortisol (stress hormone in humans and teleosts) are re-established. The results present evidence that the onset of stress can switch off the drive for feeding very early in vertebrate development, and add a novel endpoint for analyses of metabolic and behavioral disorders in an organism suitable for high-throughput genetics and non-invasive brain imaging. PMID:25368561

  16. Volumetric Measurements of Amnioserosa Cells in Developing Drosophila

    NASA Astrophysics Data System (ADS)

    Mashburn, David; Jayasinghe, Aroshan; Hutson, Shane

    2013-03-01

    The behavior of cells in tissue in developing Drosophila melanogaster has become increasingly clearer over the past few decades, in large part due to advances in imaging techniques, genetic markers, predictive modeling, and micromanipulation (notably laser microsurgery). We now know apical contractions in amnioserosa cells are a significant factor in large scale processes like germ band retraction and dorsal closure. Also, laser microsurgery induces cellular recoil that strongly mimics a 2D elastic sheet. Still, what we know about these processes comes entirely from the apical surface where the standard fluorescent markers like cadherin are located, but many open questions exist concerning the remaining ``dark'' portion of cells. Does cell volume remain constant during contraction or do cells leak? Also, what shape changes do cells undergo? Do they bulge, wedge, contract prismatically, or something else? By using a marker that labels the entire membrane of amnioserosa cells (Resille, 117) and adapting our watershed segmentation routines for 4D datasets, we have been able to quantify the entire volumetric region of cells in tissue through time and compare changes in apical area and volume. Preliminary results suggest a fairly constant volume over the course of a contraction cycle.

  17. Switching cell fates in the developing Drosophila eye.

    PubMed

    Mavromatakis, Yannis Emmanuel; Tomlinson, Andrew

    2013-11-01

    The developing Drosophila ommatidium is characterized by two distinct waves of pattern formation. In the first wave, a precluster of five cells is formed by a complex cellular interaction mechanism. In the second wave, cells are systematically recruited to the cluster and directed to their fates by developmental cues presented by differentiating precluster cells. These developmental cues are mediated through the receptor tyrosine kinase (RTK) and Notch (N) signaling pathways and their combined activities are crucial in specifying cell type. The transcription factor Lozenge (Lz) is expressed exclusively in second wave cells. Here, we ectopically supply Lz to precluster cells and concomitantly supply the various RTK/N codes that specify each of three second wave cell fates. We thereby reproduce molecular markers of each of the second wave cell types in precluster cells and draw three inferences. First, we confirm that Lz provides key intrinsic information to second wave cells. We can now combine this with the RTK/N signaling to provide a cell fate specification code that entails both extrinsic and intrinsic information. Second, the reproduction of each second wave cell type in the precluster confirms the accuracy of the RTK/N signaling code. Third, RTK/N signaling and Lz need only be presented to the cells for a short period of time in order to specify their fate. PMID:24067351

  18. Embryonic, Larval, and Early Juvenile Development of the Tropical Sea Urchin, Salmacis sphaeroides (Echinodermata: Echinoidea)

    PubMed Central

    Rahman, M. Aminur; Yusoff, Fatimah Md.; Arshad, A.; Shamsudin, Mariana Nor; Amin, S. M. N.

    2012-01-01

    Salmacis sphaeroides (Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10−5 dilution) was 96.6 ± 1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72 ± 4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition. PMID:23055824

  19. Embryonic, larval, and early juvenile development of the tropical sea urchin, Salmacis sphaeroides (Echinodermata: Echinoidea).

    PubMed

    Rahman, M Aminur; Yusoff, Fatimah Md; Arshad, A; Shamsudin, Mariana Nor; Amin, S M N

    2012-01-01

    Salmacis sphaeroides (Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10(-5) dilution) was 96.6 ± 1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72 ± 4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition. PMID:23055824

  20. Embryonic, larval, and early juvenile development of the tropical sea urchin, Salmacis sphaeroides (Echinodermata: Echinoidea).

    PubMed

    Rahman, M Aminur; Yusoff, Fatimah Md; Arshad, A; Shamsudin, Mariana Nor; Amin, S M N

    2012-01-01

    Salmacis sphaeroides (Linnaeus, 1758) is one of the regular echinoids, occuring in the warm Indo-West Pacific, including Johor Straits, between Malaysia and Singapore. In order to investigate the developmental basis of morphological changes in embryos and larvae, we documented the ontogeny of S. sphaeroides in laboratory condition. Gametes were obtained from adult individuals by 0.5 M KCl injection into the coelomic cavity. Fertilization rate at limited sperm concentration (10(-5) dilution) was 96.6 ± 1.4% and the resulting embryos were reared at 24°C. First cleavage (2-cell), 4-cell, 8-cell, 16-cell, 32-cell, and multicell (Morulla) stages were achieved 01.12, 02.03, 02.28, 02.51, 03.12, and 03.32 h postfertilization. Ciliated blastulae with a mean length of 174.72 ± 4.43 μm hatched 08.45 h after sperm entry. The gastrulae formed 16.15 h postfertilization and the archenteron elongated constantly while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larva started to feed unicellular algae in 2 d, grew continuously, and finally attained metamorphic competence in 35 d after fertilization. Metamorphosis took approximately 1 h 30 min from attachment to the complete resorption of larval tissues and the development of complete juvenile structure with adult spines, extended tubefeet and well-developed pedicellaria, the whole event of which usually took place within 1 d postsettlement. This study represents the first successful investigation on embryonic, larval, and early juvenile development of S. sphaeroides. The findings would greatly be helpful towards the understanding of ontogeny and life-history strategies, which will facilitate us to develop the breeding, seed production, and culture techniques of sea urchins in captive condition.

  1. Ocean warming ameliorates the negative effects of ocean acidification on Paracentrotus lividus larval development and settlement.

    PubMed

    García, Eliseba; Clemente, Sabrina; Hernández, José Carlos

    2015-09-01

    Ocean warming and acidification both impact marine ecosystems. All organisms have a limited body temperature range, outside of which they become functionally constrained. Beyond the absolute extremes of this range, they cannot survive. It is hypothesized that some stressors can present effects that interact with other environmental variables, such as ocean acidification (OA) that have the potential to narrow the thermal range where marine species are functional. An organism's response to ocean acidification can therefore be highly dependent on thermal conditions. This study evaluated the combined effects of predicted ocean warming conditions and acidification, on survival, development, and settlement, of the sea urchin Paracentrotus lividus. Nine combined treatments of temperature (19.0, 20.5 and 22.5 °C) and pH (8.1, 7.7 and 7.4 units) were carried out. All of the conditions tested were either within the current natural ranges of seawater pH and temperature or are within the ranges that have been predicted for the end of the century, in the sampling region (Canary Islands). Our results indicated that the negative effects of low pH on P. lividus larval development and settlement will be mitigated by a rise in seawater temperature, up to a thermotolerance threshold. Larval development and settlement performance of the sea urchin P. lividus was enhanced by a slight increase in temperature, even under lowered pH conditions. However, the species did show negative responses to the levels of ocean warming and acidification that have been predicted for the turn of the century. PMID:26275754

  2. Ocean warming ameliorates the negative effects of ocean acidification on Paracentrotus lividus larval development and settlement.

    PubMed

    García, Eliseba; Clemente, Sabrina; Hernández, José Carlos

    2015-09-01

    Ocean warming and acidification both impact marine ecosystems. All organisms have a limited body temperature range, outside of which they become functionally constrained. Beyond the absolute extremes of this range, they cannot survive. It is hypothesized that some stressors can present effects that interact with other environmental variables, such as ocean acidification (OA) that have the potential to narrow the thermal range where marine species are functional. An organism's response to ocean acidification can therefore be highly dependent on thermal conditions. This study evaluated the combined effects of predicted ocean warming conditions and acidification, on survival, development, and settlement, of the sea urchin Paracentrotus lividus. Nine combined treatments of temperature (19.0, 20.5 and 22.5 °C) and pH (8.1, 7.7 and 7.4 units) were carried out. All of the conditions tested were either within the current natural ranges of seawater pH and temperature or are within the ranges that have been predicted for the end of the century, in the sampling region (Canary Islands). Our results indicated that the negative effects of low pH on P. lividus larval development and settlement will be mitigated by a rise in seawater temperature, up to a thermotolerance threshold. Larval development and settlement performance of the sea urchin P. lividus was enhanced by a slight increase in temperature, even under lowered pH conditions. However, the species did show negative responses to the levels of ocean warming and acidification that have been predicted for the turn of the century.

  3. Combined endosulfan and cypermethrin-induced toxicity to embryo-larval development of Rhinella arenarum.

    PubMed

    Svartz, Gabriela V; Aronzon, Carolina M; Pérez Coll, Cristina S

    2016-01-01

    The combined effects of two widely used pesticides, endosulfan and cypermethrin, on survival of embryo-larval development of the South American toad (Rhinella arenarum) were examined. The toxicity bioassays were performed according to the AMPHITOX test. Embryos and larvae were exposed to mixtures of these pesticides at equitoxic ratios from acute or chronic exposure to evaluate interaction effects. The results were analyzed using both Marking's additive index and combination index (CI)-isobologram methods. Acute (96-h) and intermediate (168-h) toxicity of endosulfan-cypermethrin mixtures remained almost constant for larvae and embryos, but when exposure duration was increased, there was a significant elevation in toxicity, obtaining chronic (240-h) no-observed-effect concentrations (NOEC) values of 0.045 and 0.16 mg/L for embryos and larvae, respectively. These are environmentally relevant concentrations that reflect a realistic risk of this pesticide mixture to this native amphibian species. The toxicity increment with the exposure duration was coincident with the central nervous system development on embryos reaching the larval period, the main target organ of these pesticides. The interactions of the pesticide mixtures at acute and chronic exposure were antagonistic for embryo development (CI > 1), and additive (CI = 1) for larvae, while chronic exposure interactions were synergistic (CI < 1) for both developmental periods. Data indicated that endosulfan-cypermethrin mixtures resulted in different interaction types depending on duration and developmental stage exposed. As a general pattern and considering conditions of overall developmental period and chronic exposure, this pesticide mixture usually applied in Argentine crop fields is synergistic with respect to toxicity for this native amphibian species.

  4. Effects of food limitation and pharmaceutical compounds on the larval development and morphology of Palaemon serratus.

    PubMed

    González-Ortegón, Enrique; Giménez, Luis; Blasco, Julian; Le Vay, Lewis

    2015-01-15

    Few ecotoxicological studies consider the roles of maternal influences and suboptimal environmental conditions when assessing the impact of pollutants on organisms. We studied the combined effects of pharmaceutical compounds, food condition and maternal body size on growth, development, body mass and morphology of larvae of the marine shrimp Palaemon serratus. Limited food availability is considered a factor leading to reduced survival and growth in marine crustacean larvae. It is known that P. serratus responses to food limitation vary among larvae hatched from females of different body length. The pharmaceuticals tested were the anti-inflammatory and analgesic diclofenac sodium (DS: at 77 μg L-1 and 720 μg L-1) the lipid regulator clofibric acid (CA: at 42 μg L-1 and 394 μg L-1) and the fungicide clotrimazole (CLZ: at 0.07 μg L-1 and 3.16 μg L-1). We observed morphological abnormalities in larvae exposed to CLZ. In addition, effects of this compound were stronger under food limitation leading to (1) reduced survival by 30%, (2) reduced juvenile body mass (22%) and (3) reduction in the number of molt stages (from 13 to 9) during larval development. This latter effect may indicate that CLZ reduced the larval capacity to respond to food limitation because development through a longer route, with additional stages, is considered an adaptive response to prioritize maintenance over morphogenesis. CA and DS affected developmental rate under food limitation but not growth or body mass. The toxic effects of CLZ, at lower concentrations than CA and DS, were stronger in larvae with higher body mass, hatched from the largest females. This suggests that maternal influences and suboptimal environmental conditions should be further studied to inform modeling of the effects of emergent compounds on larvae of marine coastal species.

  5. Temperature, Larval Diet, and Density Effects on Development Rate and Survival of Aedes aegypti (Diptera: Culicidae)

    PubMed Central

    Couret, Jannelle; Dotson, Ellen; Benedict, Mark Q.

    2014-01-01

    Many environmental factors, biotic and abiotic interact to influence organismal development. Given the importance of Aedes aegypti as a vector of human pathogens including dengue and yellow fever, understanding the impact of environmental factors such as temperature, resource availability, and intraspecific competition during development is critical for population control purposes. Despite known associations between developmental traits and factors of diet and density, temperature has been considered the primary driver of development rate and survival. To determine the relative importance of these critical factors, wide gradients of conditions must be considered. We hypothesize that 1) diet and density, as well as temperature influence the variation in development rate and survival, 2) that these factors interact, and this interaction is also necessary to understand variation in developmental traits. Temperature, diet, density, and their two-way interactions are significant factors in explaining development rate variation of the larval stages of Ae. aegypti mosquitoes. These factors as well as two and three-way interactions are significantly associated with the development rate from hatch to emergence. Temperature, but not diet or density, significantly impacted juvenile mortality. Development time was heteroskedastic with the highest variation occurring at the extremes of diet and density conditions. All three factors significantly impacted survival curves of experimental larvae that died during development. Complex interactions may contribute to variation in development rate. To better predict variation in development rate and survival in Ae. aegypti, factors of resource availability and intraspecific density must be considered in addition, but never to the exclusion of temperature. PMID:24498328

  6. Temperature, larval diet, and density effects on development rate and survival of Aedes aegypti (Diptera: Culicidae).

    PubMed

    Couret, Jannelle; Dotson, Ellen; Benedict, Mark Q

    2014-01-01

    Many environmental factors, biotic and abiotic interact to influence organismal development. Given the importance of Aedes aegypti as a vector of human pathogens including dengue and yellow fever, understanding the impact of environmental factors such as temperature, resource availability, and intraspecific competition during development is critical for population control purposes. Despite known associations between developmental traits and factors of diet and density, temperature has been considered the primary driver of development rate and survival. To determine the relative importance of these critical factors, wide gradients of conditions must be considered. We hypothesize that 1) diet and density, as well as temperature influence the variation in development rate and survival, 2) that these factors interact, and this interaction is also necessary to understand variation in developmental traits. Temperature, diet, density, and their two-way interactions are significant factors in explaining development rate variation of the larval stages of Ae. aegypti mosquitoes. These factors as well as two and three-way interactions are significantly associated with the development rate from hatch to emergence. Temperature, but not diet or density, significantly impacted juvenile mortality. Development time was heteroskedastic with the highest variation occurring at the extremes of diet and density conditions. All three factors significantly impacted survival curves of experimental larvae that died during development. Complex interactions may contribute to variation in development rate. To better predict variation in development rate and survival in Ae. aegypti, factors of resource availability and intraspecific density must be considered in addition, but never to the exclusion of temperature.

  7. Methods to determine resistance to anthelmintics when continuing larval development occurs.

    PubMed

    Lyndal-Murphy, M; Swain, A J; Pepper, P M

    2014-01-31

    The in vivo faecal egg count reduction test (FECRT) is the most commonly used test to detect anthelmintic resistance (AR) in gastrointestinal nematodes (GIN) of ruminants in pasture based systems. However, there are several variations on the method, some more appropriate than others in specific circumstances. While in some cases labour and time can be saved by just collecting post-drench faecal worm egg counts (FEC) of treatment groups with controls, or pre- and post-drench FEC of a treatment group with no controls, there are circumstances when pre- and post-drench FEC of an untreated control group as well as from the treatment groups are necessary. Computer simulation techniques were used to determine the most appropriate of several methods for calculating AR when there is continuing larval development during the testing period, as often occurs when anthelmintic treatments against genera of GIN with high biotic potential or high re-infection rates, such as Haemonchus contortus of sheep and Cooperia punctata of cattle, are less than 100% efficacious. Three field FECRT experimental designs were investigated: (I) post-drench FEC of treatment and controls groups, (II) pre- and post-drench FEC of a treatment group only and (III) pre- and post-drench FEC of treatment and control groups. To investigate the performance of methods of indicating AR for each of these designs, simulated animal FEC were generated from negative binominal distributions with subsequent sampling from the binomial distributions to account for drench effect, with varying parameters for worm burden, larval development and drench resistance. Calculations of percent reductions and confidence limits were based on those of the Standing Committee for Agriculture (SCA) guidelines. For the two field methods with pre-drench FEC, confidence limits were also determined from cumulative inverse Beta distributions of FEC, for eggs per gram (epg) and the number of eggs counted at detection levels of 50 and 25. Two

  8. Activities of natural methyl farnesoids on pupariation and metamorphosis of Drosophila melanogaster

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Specification of the somatic musculature in Drosophila.

    PubMed

    Dobi, Krista C; Schulman, Victoria K; Baylies, Mary K

    2015-01-01

    The somatic muscle system formed during Drosophila embryogenesis is required for larvae to hatch, feed, and crawl. This system is replaced in the pupa by a new adult muscle set, responsible for activities such as feeding, walking, and flight. Both the larval and adult muscle systems are comprised of distinct muscle fibers to serve these specific motor functions. In this way, the Drosophila musculature is a valuable model for patterning within a single tissue: while all muscle cells share properties such as the contractile apparatus, properties such as size, position, and number of nuclei are unique for a particular muscle. In the embryo, diversification of muscle fibers relies first on signaling cascades that pattern the mesoderm. Subsequently, the combinatorial expression of specific transcription factors leads muscle fibers to adopt particular sizes, shapes, and orientations. Adult muscle precursors (AMPs), set aside during embryonic development, proliferate during the larval phases and seed the formation of the abdominal, leg, and flight muscles in the adult fly. Adult muscle fibers may either be formed de novo from the fusion of the AMPs, or are created by the binding of AMPs to an existing larval muscle. While less is known about adult muscle specification compared to the larva, expression of specific transcription factors is also important for its diversification. Increasingly, the mechanisms required for the diversification of fly muscle have found parallels in vertebrate systems and mark Drosophila as a robust model system to examine questions about how diverse cell types are generated within an organism.

  10. Drosophila small heat shock protein CryAB ensures structural integrity of developing muscles, and proper muscle and heart performance.

    PubMed

    Wójtowicz, Inga; Jabłońska, Jadwiga; Zmojdzian, Monika; Taghli-Lamallem, Ouarda; Renaud, Yoan; Junion, Guillaume; Daczewska, Malgorzata; Huelsmann, Sven; Jagla, Krzysztof; Jagla, Teresa

    2015-03-01

    Molecular chaperones, such as the small heat shock proteins (sHsps), maintain normal cellular function by controlling protein homeostasis in stress conditions. However, sHsps are not only activated in response to environmental insults, but also exert developmental and tissue-specific functions that are much less known. Here, we show that during normal development the Drosophila sHsp CryAB [L(2)efl] is specifically expressed in larval body wall muscles and accumulates at the level of Z-bands and around myonuclei. CryAB features a conserved actin-binding domain and, when attenuated, leads to clustering of myonuclei and an altered pattern of sarcomeric actin and the Z-band-associated actin crosslinker Cheerio (filamin). Our data suggest that CryAB and Cheerio form a complex essential for muscle integrity: CryAB colocalizes with Cheerio and, as revealed by mass spectrometry and co-immunoprecipitation experiments, binds to Cheerio, and the muscle-specific attenuation of cheerio leads to CryAB-like sarcomeric phenotypes. Furthermore, muscle-targeted expression of CryAB(R120G), which carries a mutation associated with desmin-related myopathy (DRM), results in an altered sarcomeric actin pattern, in affected myofibrillar integrity and in Z-band breaks, leading to reduced muscle performance and to marked cardiac arrhythmia. Taken together, we demonstrate that CryAB ensures myofibrillar integrity in Drosophila muscles during development and propose that it does so by interacting with the actin crosslinker Cheerio. The evidence that a DRM-causing mutation affects CryAB muscle function and leads to DRM-like phenotypes in the fly reveals a conserved stress-independent role of CryAB in maintaining muscle cell cytoarchitecture.

  11. Drosophila small heat shock protein CryAB ensures structural integrity of developing muscles, and proper muscle and heart performance.

    PubMed

    Wójtowicz, Inga; Jabłońska, Jadwiga; Zmojdzian, Monika; Taghli-Lamallem, Ouarda; Renaud, Yoan; Junion, Guillaume; Daczewska, Malgorzata; Huelsmann, Sven; Jagla, Krzysztof; Jagla, Teresa

    2015-03-01

    Molecular chaperones, such as the small heat shock proteins (sHsps), maintain normal cellular function by controlling protein homeostasis in stress conditions. However, sHsps are not only activated in response to environmental insults, but also exert developmental and tissue-specific functions that are much less known. Here, we show that during normal development the Drosophila sHsp CryAB [L(2)efl] is specifically expressed in larval body wall muscles and accumulates at the level of Z-bands and around myonuclei. CryAB features a conserved actin-binding domain and, when attenuated, leads to clustering of myonuclei and an altered pattern of sarcomeric actin and the Z-band-associated actin crosslinker Cheerio (filamin). Our data suggest that CryAB and Cheerio form a complex essential for muscle integrity: CryAB colocalizes with Cheerio and, as revealed by mass spectrometry and co-immunoprecipitation experiments, binds to Cheerio, and the muscle-specific attenuation of cheerio leads to CryAB-like sarcomeric phenotypes. Furthermore, muscle-targeted expression of CryAB(R120G), which carries a mutation associated with desmin-related myopathy (DRM), results in an altered sarcomeric actin pattern, in affected myofibrillar integrity and in Z-band breaks, leading to reduced muscle performance and to marked cardiac arrhythmia. Taken together, we demonstrate that CryAB ensures myofibrillar integrity in Drosophila muscles during development and propose that it does so by interacting with the actin crosslinker Cheerio. The evidence that a DRM-causing mutation affects CryAB muscle function and leads to DRM-like phenotypes in the fly reveals a conserved stress-independent role of CryAB in maintaining muscle cell cytoarchitecture. PMID:25715399

  12. The effects of larval crowding and food type on the size and development of the blowfly, Calliphora vomitoria.

    PubMed

    Ireland, Sarah; Turner, Bryan

    2006-06-01

    The use of entomological evidence in the estimation of the post mortem interval (PMI) often depends on the size and developmental stage of blowfly larvae collected from a corpse. Therefore, factors which can have an effect on the larval size and growth rate can have implications for reliable PMI determinations. This study explores the competitive effects of larval overcrowding on Calliphora vomitoria reared on three different pig tissues--liver, brain and muscle. The competitive feeding environment within the more crowded larval cultures resulted in increased development rates and the production of undersized larvae and adults. Variation in the extent of these effects was observed on each of the three body tissues, highlighting the importance of documenting the positions from which entomological evidence is recovered from a corpse.

  13. [Embrionary and larval development of Lytechinus variegatus (Echinoidea: Toxopneustidae) in laboratory conditions at Isla de Margarita-Venezuela].

    PubMed

    Gómez, Olga; Gómez, Alfredo

    2005-12-01

    The sea urchin Lytechinus variegatus is a promissory species for aquaculture activities in tropical countries. In Venezuela, this species has some economical importance but their embryonic and larval development had not been studied. We collected specimens from seagrass beds in Margarita Island (Venezuela) and kept them in the laboratory, where they spawned naturally. With filtered sea water (temperature 28 degrees C, salinity 37 psu) and moderate aeration, the eggs and sperm were mixed (relation 1:100) and reached a 90% fertilization rate. The fertilization envelope was observed after two minutes, the first cellular division after 45 minutes and the prism larval stage after 13 hours. The echinopluteus larval stage was reached after 17 hours and metamorphosis after 18 days of planktonic life, when the larvae start their benthic phase. PMID:17469261

  14. The formation of the nervous system during larval development in Triops cancriformis (Bosc) (crustacea, Branchiopoda): An immunohistochemical survey.

    PubMed

    Fritsch, Martin; Richter, Stefan

    2010-12-01

    We provide data of the development of thenervous system during the first five larval stages of Triops cancriformis. We use immunohistochemical labeling (against acetylated α-tubulin, serotonin, histamine, and FMRFamide), confocal laser scanning microscopy analysis, and 3D-reconstruction. The development of the nervous system corresponds with the general anamorphic development in T. cancriformis. In larval stage I (L I), all brain parts (proto-, deuto-, and tritocerebrum), the circumoral connectives, and the mandibular neuromere are already present. Also, the frontal filaments and the developing nauplius eye are already present. However, until stage L III, the nauplius eye only consists of three cups. Throughout larval development, the protocerebral network differentiates into distinct subdivisions. In the postnaupliar region, additional neuromeres and their commissures emerge in an anteroposterior gradient. The larval nervous system in L V consists of a differentiated protocerebrum including a central body, a nauplius eye comprising four cups, a circumoral nerve ring, mandibular- and postnaupliar neuromeres up to the seventh thoracic segment, each featuring an anterior and a posterior commissure, and two parallel connectives. The presence of a protocerebral bridge is questionable. The distribution of neurotransmitters in L I is restricted to the naupliar nervous system. Over the course of the five stages of development, neurotransmitter distribution also follows an anteroposterior gradient. Each neuromere is equipped with two ganglia innervating the locomotional appendages and possesses a specific neurotransmitter distribution pattern. We suggest a correlation between neurotransmitter expression and locomotion.

  15. The formation of the nervous system during larval development in Triops cancriformis (Bosc) (crustacea, Branchiopoda): An immunohistochemical survey.

    PubMed

    Fritsch, Martin; Richter, Stefan

    2010-12-01

    We provide data of the development of thenervous system during the first five larval stages of Triops cancriformis. We use immunohistochemical labeling (against acetylated α-tubulin, serotonin, histamine, and FMRFamide), confocal laser scanning microscopy analysis, and 3D-reconstruction. The development of the nervous system corresponds with the general anamorphic development in T. cancriformis. In larval stage I (L I), all brain parts (proto-, deuto-, and tritocerebrum), the circumoral connectives, and the mandibular neuromere are already present. Also, the frontal filaments and the developing nauplius eye are already present. However, until stage L III, the nauplius eye only consists of three cups. Throughout larval development, the protocerebral network differentiates into distinct subdivisions. In the postnaupliar region, additional neuromeres and their commissures emerge in an anteroposterior gradient. The larval nervous system in L V consists of a differentiated protocerebrum including a central body, a nauplius eye comprising four cups, a circumoral nerve ring, mandibular- and postnaupliar neuromeres up to the seventh thoracic segment, each featuring an anterior and a posterior commissure, and two parallel connectives. The presence of a protocerebral bridge is questionable. The distribution of neurotransmitters in L I is restricted to the naupliar nervous system. Over the course of the five stages of development, neurotransmitter distribution also follows an anteroposterior gradient. Each neuromere is equipped with two ganglia innervating the locomotional appendages and possesses a specific neurotransmitter distribution pattern. We suggest a correlation between neurotransmitter expression and locomotion. PMID:20938985

  16. Drosophila wing development in the absence of dorsal identity.

    PubMed

    O'Keefe, D D; Thomas, J B

    2001-03-01

    The developing wing disc of Drosophila is divided into distinct lineage-restricted compartments along both the anterior/posterior (A/P) and dorsal/ventral (D/V) axes. At compartment boundaries, morphogenic signals pattern the disc epithelium and direct appropriate outgrowth and differentiation of adult wing structures. The mechanisms by which affinity boundaries are established and maintained, however, are not completely understood. Compartment-specific adhesive differences and inter-compartment signaling have both been implicated in this process. The selector gene apterous (ap) is expressed in dorsal cells of the wing disc and is essential for D/V compartmentalization, wing margin formation, wing outgrowth and dorsal-specific wing structures. To better understand the mechanisms of Ap function and compartment formation, we have rescued aspects of the ap mutant phenotype with genes known to be downstream of Ap. We show that Fringe (Fng), a secreted protein involved in modulation of Notch signaling, is sufficient to rescue D/V compartmentalization, margin formation and wing outgrowth when appropriately expressed in an ap mutant background. When Fng and alphaPS1, a dorsally expressed integrin subunit, are co-expressed, a nearly normal-looking wing is generated. However, these wings are entirely of ventral identity. Our results demonstrate that a number of wing development features, including D/V compartmentalization and wing vein formation, can occur independently of dorsal identity and that inter-compartmental signaling, refined by Fng, plays the crucial role in maintaining the D/V affinity boundary. In addition, it is clear that key functions of the ap selector gene are mediated by only a small number of downstream effectors.

  17. Fine-scale temperature fluctuation and modulation of Dirofilaria immitis larval development in Aedes aegypti.

    PubMed

    Ledesma, Nicholas; Harrington, Laura

    2015-04-15

    We evaluated degree-day predictions of Dirofilaria immitis development (HDU) under constant and fluctuating temperature treatments of equal average daily temperature. Aedes aegypti mosquitoes were infected with D. immitis microfilariae and parasite development was recorded at set time points in dissected mosquitoes. Time to L3 development in Malpighian tubules and detection in mosquito heads was shorter for larvae experiencing a daily regime of 19±9°C than larvae at constant 19°C; larval development rate in Malpighian tubules was slower in fluctuating regimes maintained above the 14°C developmental threshold than larvae under constant temperatures. We showed that hourly temperature modeling more accurately predicted D. immitis development to infective L3 stage. Development time differed between fluctuating and constant temperature treatments spanning the 14°C development threshold, implicating a physiological basis for these discrepancies. We conclude that average daily temperature models underestimate L3 development-and consequently dog heartworm transmission risk-at colder temperatures, and spatiotemporal models of D. immitis transmission risk should use hourly temperature data when analyzing high daily temperature ranges spanning 14°C.

  18. Exploration of the “larval pool”: development and ground-truthing of a larval transport model off leeward Hawai‘i

    PubMed Central

    Kobayashi, Donald R.

    2016-01-01

    Most adult reef fish show site fidelity thus dispersal is limited to the mobile larval stage of the fish, and effective management of such species requires an understanding of the patterns of larval dispersal. In this study, we assess larval reef fish distributions in the waters west of the Big Island of Hawai‘i using both in situ and model data. Catches from Cobb midwater trawls off west Hawai‘i show that reef fish larvae are most numerous in offshore waters deeper than 3,000 m and consist largely of pre-settlement Pomacanthids, Acanthurids and Chaetodontids. Utilizing a Lagrangian larval dispersal model, we were able to replicate the observed shore fish distributions from the trawl data and we identified the 100 m depth strata as the most likely depth of occupancy. Additionally, our model showed that for larval shore fish with a pelagic larval duration longer than 40 days there was no significant change in settlement success in our model. By creating a general additive model (GAM) incorporating lunar phase and angle we were able to explain 67.5% of the variance between modeled and in situ Acanthurid abundances. We took steps towards creating a predictive larval distribution model that will greatly aid in understanding the spatiotemporal nature of the larval pool in west Hawai‘i, and the dispersal of larvae throughout the Hawaiian archipelago. PMID:26855873

  19. Fine-scale temperature fluctuation and modulation of Dirofilaria immitis larval development in Aedes aegypti

    PubMed Central

    Ledesma, Nicholas; Harrington, Laura

    2015-01-01

    We evaluated degree-day predictions of Dirofilaria immitis development (HDU) under constant and fluctuating temperature treatments of equal average daily temperature. Aedes aegypti mosquitoes were infected with D. immitis microfilariae and parasite development was recorded at set time points in dissected mosquitoes. Time to L3 development in Malpighian tubules and detection in mosquito heads was shorter for larvae experiencing a daily regime of 19±9°C than larvae at constant 19°C; larval development rate in Malpighian tubules was slower in fluctuating regimes maintained above the 14°C developmental threshold than larvae under constant temperatures. We showed that hourly temperature modeling more accurately predicted D. immitis development to infective L3 stage. Development time differed between fluctuating and constant temperature treatments spanning the 14°C development threshold, implicating a physiological basis for these discrepancies. We conclude that average daily temperature models underestimate L3 development—and consequently dog heartworm transmission risk—at colder temperatures, and spatio-temporal models of D. immitis transmission risk should use hourly temperature data when analyzing high daily temperature ranges spanning 14°C. PMID:25747489

  20. GROWTH AND CHANGES IN BIOCHEMICAL COMPOSITION DURING LARVAL DEVELOPMENT OF THE STONE CRAB, MENIPPE ADINA WILLIAMS AND FELDER, 1986

    EPA Science Inventory

    Larval development in Menippe adina was associated with changes in weight and biochemical composition. Larvae of the stone crab, M. adina, were mass-reared under laboratory conditions (28|C; 20o/ooS) from hatching to the megalopal stage. Growth in M. adina is exponential througho...

  1. Embryonic and larval development in the caecilian Ichthyophis kohtaoensis (Amphibia, gymnophiona): a staging table.

    PubMed

    Dünker, N; Wake, M H; Olson, W M

    2000-01-01

    Little is known about the developmental biology of caecilians-tropical, elongate, limbless, mostly fossorial amphibians that are members of the Order Gymnophiona. Ichthyophis kohtaoensis (Family Ichthyophiidae; southeast Asia) is an oviparous species in which maternal care of the clutch is provided. The clutch is laid in a burrow on land, and the embryos develop in their egg membranes, curved around a large yolk mass. Larvae are aquatic and exhibit characteristic features that are not present in the terrestrial adults. Because accurate descriptions of ontogenies and the establishment of standardized stages of embryonic and larval development are useful for both experimental and comparative embryology, a staging table for I.kohtaoensis was developed based on external morphological features. Development from the end of neurulation to metamorphosis was divided into 20 stages. Principal diagnostic features include development of the lateral line organs, formation of three pairs of external gills, development of the eyes, changes in yolk structure, changes in the structure of the cloacal aperture and growth of the tail, including the formation and regression of the tail fin. This study provides a comparison with descriptions of embryonic stages of I.glutinosus and Hypogeophis rostratus and with a recent staging table for the aquatic, viviparous caecilian Typhlonectes compressicauda, the only other caecilians for which reasonably complete ontogenetic information exists in the literature. Comparisons with established staging tables for selected frogs and salamanders are also presented.

  2. Embryonic and larval development in the caecilian Ichthyophis kohtaoensis (Amphibia, gymnophiona): a staging table.

    PubMed

    Dünker, N; Wake, M H; Olson, W M

    2000-01-01

    Little is known about the developmental biology of caecilians-tropical, elongate, limbless, mostly fossorial amphibians that are members of the Order Gymnophiona. Ichthyophis kohtaoensis (Family Ichthyophiidae; southeast Asia) is an oviparous species in which maternal care of the clutch is provided. The clutch is laid in a burrow on land, and the embryos develop in their egg membranes, curved around a large yolk mass. Larvae are aquatic and exhibit characteristic features that are not present in the terrestrial adults. Because accurate descriptions of ontogenies and the establishment of standardized stages of embryonic and larval development are useful for both experimental and comparative embryology, a staging table for I.kohtaoensis was developed based on external morphological features. Development from the end of neurulation to metamorphosis was divided into 20 stages. Principal diagnostic features include development of the lateral line organs, formation of three pairs of external gills, development of the eyes, changes in yolk structure, changes in the structure of the cloacal aperture and growth of the tail, including the formation and regression of the tail fin. This study provides a comparison with descriptions of embryonic stages of I.glutinosus and Hypogeophis rostratus and with a recent staging table for the aquatic, viviparous caecilian Typhlonectes compressicauda, the only other caecilians for which reasonably complete ontogenetic information exists in the literature. Comparisons with established staging tables for selected frogs and salamanders are also presented. PMID:10629095

  3. Ontogeny and phylogeny: molecular signatures of selection, constraint, and temporal pleiotropy in the development of Drosophila

    PubMed Central

    Artieri, Carlo G; Haerty, Wilfried; Singh, Rama S

    2009-01-01

    Background Karl Ernst Von Baer noted that species tend to show greater morphological divergence in later stages of development when compared to earlier stages. Darwin originally interpreted these observations via a selectionist framework, suggesting that divergence should be greatest during ontogenic stages in which organisms experienced varying 'conditions of existence' and opportunity for differential selection. Modern hypotheses have focused on the notion that genes and structures involved in early development will be under stronger purifying selection due to the deleterious pleiotropic effects of mutations propagating over the course of ontogeny, also known as the developmental constraint hypothesis. Results Using developmental stage-specific expressed sequence tag (EST) libraries, we tested the 2 hypotheses by comparing the rates of evolution of 7,180 genes obtained from 6 species of the Drosophila melanogaster group with respect to ontogeny, and sex and reproduction-related functions in gonadal tissues. Supporting morphological observations, we found evidence of a pattern of increasing mean evolutionary rate in genes that are expressed in subsequent stages of development. Furthermore, supporting expectations that early expressed genes are constrained in divergence, we found that embryo stage genes are involved in a higher mean number of interactions as compared to later stages. We noted that the accelerated divergence of genes in the adult stage is explained by those expressed specifically in the male gonads, whose divergence is driven by positive selection. In addition, accelerated gonadal gene divergence occurs only in the adult stage, suggesting that the effects of selection are observed primarily at the stages during which they are expected occur. Finally, we also found a significant correlation between temporal specificity of gene expression and evolutionary rate, supporting expectations that genes with ubiquitous expression are under stronger constraint

  4. The transmembrane protein, Tincar, is involved in the development of the compound eye in Drosophila melanogaster.

    PubMed

    Hirota, Yuki; Sawamoto, Kazunobu; Takahashi, Kuniaki; Ueda, Ryu; Okano, Hideyuki

    2005-02-01

    We previously cloned and characterized the Drosophila gene, tincar (tinc), which encodes a novel protein with eight putative transmembrane domains. Here, we have studied the expression pattern and functions of tinc during developmental processes. tinc mRNA is expressed in the central and peripheral nervous systems, and midgut during embryogenesis. In the third-instar larval eye disc, tinc mRNA is strongly expressed in all the differentiating ommatidial cells within and in the vicinity of the morphogenetic furrow. Loss-of-function analysis using the RNA-interference method revealed severe defects of eye morphogenesis during the late developmental stages. Our results suggested that tinc may have an indispensable role in the normal differentiation of ommatidial cells. PMID:15654626

  5. Evolution of poecilogony from planktotrophy: cryptic speciation, phylogeography, and larval development in the gastropod genus Alderia.

    PubMed

    Ellingson, Ryan A; Krug, Patrick J

    2006-11-01

    Poecilogony, a rare phenomenon in marine invertebrates, occurs when alternative larval morphs differing in dispersal potential or trophic mode are produced from a single genome. Because both poecilogony and cryptic species are prevalent among sea slugs in the suborder Sacoglossa (Gastropoda: Opisthobranchia), molecular data are needed to confirm cases of variable development and to place them in a phylogenetic context. The nominal species Alderia modesta produces long-lived, feeding larvae throughout the North Atlantic and Pacific, but in California can also produce short-lived larvae that metamorphose without feeding. We collected morphological, developmental, and molecular data for Alderia from 17 sites spanning the eastern and western Pacific and North Atlantic. Estuaries south of Bodega Harbor, California, contained a cryptic species (hereafter Alderia sp.) with variable development, sister to the strictly planktotrophic A. modesta. The smaller Alderia sp. seasonally toggled between planktotrophy and lecithotrophy, with some individuals differing in development but sharing mitochondrial DNA haplotypes. The sibling species overlapped in Tomales Bay, California, but showed no evidence of hybridization; laboratory mating trials suggest postzygotic isolation has arisen. Intra- and interspecific divergence times were estimated using a molecular clock calibrated with geminate sacoglossans. Speciation occurred about 4.1 million years ago during a major marine radiation in the eastern Pacific, when large inland embayments in California may have isolated ancestral populations. Atlantic and Pacific A. modesta diverged about 1.7 million years ago, suggesting trans-Arctic gene flow was interrupted by Pleistocene glaciation. Both Alderia species showed evidence of late Pleistocene population expansion, but the southern Alderia sp. likely experienced a more pronounced bottleneck. Reduced body size may have incurred selection against obligate planktotrophy in Alderia sp. by

  6. Function of Lipid Storage Droplet 1 (Lsd1) in Wing Development of Drosophila melanogaster

    PubMed Central

    Men, Tran Thanh; Binh, Tran Duy; Yamaguchi, Masamitsu; Huy, Nguyen Tien; Kamei, Kaeko

    2016-01-01

    Perilipins are evolutionarily conserved from Drosophila to humans, the lipid storage droplet 1 (Lsd1) is a Drosophila homolog of human perilipin 1. The function of Lsd1 as a regulator of lipolysis in Drosophila has been demonstrated, as the Lsd1 mutant causes an increase of lipid droplet size. However, the functions of this gene during development are still under investigation. In order to determine the function of Lsd1 during development, Lsd1 was knocked down in Drosophila using the GAL4-UAS system. Selective knockdown of Lsd1 in the dorsal wing disc caused an atrophied wing phenotype. The generation of reactive oxygen species in the wing pouch compartment of the Lsd1-knockdown flies was significantly higher than in the control. Immunostaining with caspase-3 antibody revealed a greater number of apoptotic cells in Lsd1-knockdown wing discs than in the control. Cell death by autophagy was also induced in the knockdown flies. Moreover, cells deprived of Lsd1 showed mitochondrial expansion and decreased ATP levels. These results strongly suggest that knockdown of Lsd1 induces mitochondrial stress and the production of reactive oxygen species that result in cell death, via apoptosis and the autophagy pathway. These results highlight the roles of Drosophila Lsd1 during wing development. PMID:27136547

  7. Microarray Analysis of Juvenile Hormone Response in Drosophila melanogaster S2 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A microchip array encompassing probes for 14,010 genes of Drosophila melanogaster was used to analyze the effect of juvenile hormone (JH) on genome-wide gene expression. JH is a member of a key group of insect hormones involved in regulating larval development and adult reproductive processes. Altho...

  8. EGFR Signaling in the Brain Is Necessary for Olfactory Learning in "Drosophila" Larvae

    ERIC Educational Resources Information Center

    Rahn, Tasja; Leippe, Matthias; Roeder, Thomas; Fedders, Henning

    2013-01-01

    Signaling via the epidermal growth factor receptor (EGFR) pathway has emerged as one of the key mechanisms in the development of the central nervous system in "Drosophila melanogaster." By contrast, little is known about the functions of EGFR signaling in the differentiated larval brain. Here, promoter-reporter lines of EGFR and its most prominent…

  9. Shared mechanisms between Drosophila peripheral nervous system development and human neurodegenerative diseases.

    PubMed

    Charng, Wu-Lin; Yamamoto, Shinya; Bellen, Hugo J

    2014-08-01

    Signaling pathways and cellular processes that regulate neural development are used post-developmentally for proper function and maintenance of the nervous system. Genes that have been studied in the context of the development of Drosophila peripheral nervous system (PNS) and neuromuscular junction (NMJ) have been identified as players in the pathogenesis of human neurodegenerative diseases, including spinocerebellar ataxia, amyotrophic lateral sclerosis, and spinal muscular atrophy. Hence, by unraveling the molecular mechanisms that underlie proneural induction, cell fate determination, axonal targeting, dendritic branching, and synapse formation in Drosophila, novel features related to these disorders have been revealed. In this review, we summarize and discuss how studies of Drosophila PNS and NMJ development have provided guidance in experimental approaches for these diseases.

  10. Influence of starvation on the larval development of Hyas araneus (Decapoda, Majidae)

    NASA Astrophysics Data System (ADS)

    Anger, K.; Dawirs, R. R.

    1981-09-01

    The influence of starvation on larval development of the spider crab Hyas araneus (L.) was studied in laboratory experiments. No larval stage suffering from continual lack of food had sufficient energy reserves to reach the next instar. Maximal survival times were observed at four different constant temperatures (2°, 6°, 12° and 18 °C). In general, starvation resistance decreased as temperatures increased: from 72 to 12days in the zoea-1, from 48 to 18 days in the zoea-2, and from 48 to 15 days in the megalopa stage. The length of maximal survival is of the same order of magnitude as the duration of each instar at a given temperature. “Sublethal limits” of early starvation periods were investigated at 12 °C: Zoea larvae must feed right from the beginning of their stage (at high food concentration) and for more than one fifth, approximately, of that stage to have at least some chance of surviving to the next instar, independent of further prey availability. The minimum time in which enough reserves are accumulated for successfully completing the instar without food is called “point-of-reserve-saturation” (PRS). If only this minimum period of essential initial feeding precedes starvation, development in both zoeal stages is delayed and mortality is greater, when compared to the fed control. Starvation periods beginning right after hatching of the first zoea cause a prolongation of this instar and, surprisingly, a slight shortening of the second stage. The delay in the zoea-1 increases proportionally to the length of the initial fasting period. If more than approximately 70 % of the maximum possible survival time has elapsed without food supply, the larvae become unable to recover and to moult to the second stage even when re-fed (“point-of-no-return”, PNR). The conclusion, based on own observations and on literature data, is that initial feeding is of paramount importance in the early development of planktotrophic decapod larvae. Taking into account

  11. Three-dimensional epithelial morphogenesis in the developing Drosophila egg

    PubMed Central

    Osterfield, Miriam; Du, XinXin; Schüpbach, Trudi; Wieschaus, Eric; Shvartsman, Stanislav Y.

    2013-01-01

    Morphogenesis of the respiratory appendages on eggshells of Drosophila species provides a powerful experimental system for studying how cell sheets give rise to complex three-dimensional structures. In Drosophila melanogaster, each of the two tubular eggshell appendages is derived from a primordium comprising two distinct cell types. Using live imaging and three-dimensional image reconstruction, we demonstrate that the transformation of this two-dimensional primordium into a tube involves out-of-plane bending followed by a sequence of spatially ordered cell intercalations. These morphological transformations correlate with the appearance of complementary distributions of myosin and Bazooka in the primordium. These distributions suggest that a two-dimensional pattern of line tensions along cell-cell edges on the apical side of the epithelium is sufficient to produce the observed changes in morphology. Computational modeling shows that this mechanism could explain the main features of tissue deformation and cell rearrangements observed during three-dimensional morphogenesis. PMID:23449472

  12. Larval serum proteins of the gypsy moth, Lymantria dispar: Allometric changes during development suggest several functions for arylphorin and lipophorin

    SciTech Connect

    Karpells, S.T.

    1989-01-01

    Storage proteins are the major nutritive intermediates in insects and although the serum storage proteins are relatively well studied, definitive roles for many of them have yet to be established. To further characterize their roles in development and to establish quantitative baselines for future studies, two serum proteins, arylphorin (Ap) and lipophorin (Lp), of the gypsy moth, Lymantria dispar, were studied. Ap and Lp, isolated from larval hemolymph, were partially characterized biochemically and immunologically. Hemolymph concentrations throughout larval development were determined using quantitative immunoelectrophoresis and absolute hemolymph amounts of protein were determined by measuring hemolymph volume. Cyclic fluctuations in hemolymph concentrations of Ap in particular correlated with each molting cycle and an increase in Lp levels just prior to pupation suggest a metamorphic change in the role or demand for the protein. Sexual dimorphism in protein concentrations are explained in part by the sexual dimorphism in the number of larval instars. In fact, an additional instar of Ap accumulation in the female gypsy moth is suggested to compensate for the lack of a female-specific storage protein in this species. The last two days of each instar were found to be the optimum time to sample protein concentration with minimum variance. Allometric relationships among Ap accumulation, Lp accumulation and weight gain were uncovered. Ap labelled with ({sup 14}C)-N-ethylmaleimide was shown to be incorporated into newly synthesized cuticle and setae during a larval-larval molt. The antiserum developed against L. dispar Ap was used to identify the Ap of Trichoplusia in and study Ap titers in parasitized T. in larvae. The antiserum was also used to determine the immunological relatedness of 5 species of Lepidoptera.

  13. VARIATION IN GROWTH, LIPID CLASS AND FATTY ACID COMPOSITION OF THE MUD CRAB, RHITHROPANOPEUS HARRISII (GOULD) DURING LARVAL DEVELOPMENT FOLLOWING EXPOSURE TO AN INSECT JUVENILE HORMONE ANALOG (FENOXYCARB)

    EPA Science Inventory

    This study examines the effects of fenoxycarb?, an insect juvenile hormone analog, on larval growth, and lipid class and fatty acid composition in first crabs of the mud crab Rhithropanopeus harrisii reared through total larval development in nominal water concentrations from 1 ...

  14. Embryonic and larval development in barfin flounder Verasper moseri (Jordan and Gilbert)

    NASA Astrophysics Data System (ADS)

    Du, Rongbin; Wang, Yongqiang; Jiang, Haibin; Liu, Liming; Wang, Maojian; Li, Tianbao; Zhang, Shubao

    2010-01-01

    Broodstock of Verasper moseri (Jordan and Gilbert) aged 3-4 years old were selected, and reinforced cultivation was conducted to promote maturation under controlled water temperature and photoperiod conditions. Fertilized eggs were obtained by artificial fertilization, and the development of embryos, larvae and juveniles was observed continuously. The results showed that the fertilized eggs of V. moseri were spherical, with transparent yolk and homogeneous bioplasm, and had no oil globule inside. The average diameter of the eggs was 1.77±0.02 mm. The eggs of V. moseri were buoyant in water with salinity above 35. The cleavage type was typical discoidal. Young pigment cells appeared when olfactory plates began to form. Hatching occurred at 187 h after fertilization at a water temperature of 8.5°C. The newly hatched larvae, floating on the water surface, were transparent with an average total length of 4.69±0.15 mm. During the cultivation period, when the water temperature was raised from 9 to 14.5°C, 4-day old larvae showed more melanophores on the body surface, making the larvae gray in color. The pectoral fins began to develop, which enabled the larvae to swim horizontally and in a lively manner. On days 7-8, the digestive duct formed. The yolk sac was small and black. The yolk sac was absorbed on day 11. Larvae took food actively, and body length and body height clearly increased. The rudiments of dorsal and anal fin pterygiophores were discernible and caudal fin ray elements formed on day 19. On day 24, the larval notochord flexed upwards, and the rays of unpaired fins began to differentiate. Pigment cells converged on the dorsal and anal fin rays, and the mastoid teeth on the mandible appeared. On day 29, the left eyes of juveniles began to move upwards. Depigmentation began in some juveniles and they became sandy brown in color on day 37. Most juveniles began to settle on the bottom of the tank. The left eyes of juveniles migrated completely to the right

  15. Inter- and intra-specific density-dependent effects on life history and development strategies of larval mosquitoes.

    PubMed

    Tsurim, Ido; Silberbush, Alon; Ovadia, Ofer; Blaustein, Leon; Margalith, Yoel

    2013-01-01

    We explored how inter- and intra-specific competition among larvae of two temporary-pool mosquito species, Culiseta longiareolata and Ochlerotatus caspius, affect larval developmental strategy and life history traits. Given that their larvae have similar feeding habits, we expected negative reciprocal inter-specific interactions. In a microcosm experiment, we found sex-specific responses of larval survival and development to both intra- and inter-specific larval competition. C. longiareolata was the superior competitor, reducing adult size and modifying larval developmental time of O. caspius. We observed two distinct waves of adult emergence in O. caspius, with clear sex-specific responses to its inter-specific competitor. In males, this pattern was not affected by C. longiareolata, but in females, the timing and average body size of the second wave strongly varied with C. longiareolata density. Specifically, in the absence of C. longiareolata, the second wave immediately followed the first wave. However, as C. longiareolata abundance increased, the second wave was progressively delayed and the resulting females tended to be larger. This study improves our understanding of the way intra- and inter-specific competition combine to influence the life histories of species making up temporary pond communities. It also provides strong evidence that not all individuals of a cohort employ the same strategies in response to competition.

  16. Larval growth, development, and survival of laboratory-reared Aplysia californica: Effects of diet and veliger density*

    PubMed Central

    Capo, Thomas R.; Bardales, Ana T.; Gillette, Phillip R.; Lara, Monica R.; Schmale, Michael C.; Serafy, Joseph E.

    2009-01-01

    Over the last three decades, the California sea hare, Aplysia californica, has played an increasingly important role as a model organism in the neurosciences. Since 1995, the National Resource for Aplysia has supported a growing research community by providing a consistent supply of laboratory-reared individuals of known age, reproductive status, and environmental history. The purpose of the present study was to resolve the key biological factors necessary for successful culture of large numbers of high quality larval Aplysia. Data from a sequence of five experiments demonstrated that algal diet, food concentration, and veliger density significantly affected growth, attainment of metamorphic competency, and survival of Aplysia larvae. The highest growth and survival were achieved with a mixed algal diet of 1:1 Isochrysis sp (TISO) and Chaetoceros muelleri (CHGRA) at a total concentration of 250 x 103 cells/mL and a larval density of 0.5 – 1.0 per mL. Rapid growth was always correlated with faster attainment of developmental milestones and increased survival, indicating that the more rapidly growing larvae were healthier. Trials conducted with our improved protocol resulted in larval growth rates of >14 μm/d, which yielded metamorphically competent animals within 21 days with survival rates in excess of 90%. These data indicate the important effects of biotic factors on the critical larval growth period in the laboratory and show the advantages of developing optimized protocols for culture of such marine invertebrates. PMID:19000779

  17. Cloning of the growth hormone cDNA of alligator gar Atractosteus spatula and its expression through larval development.

    PubMed

    Revol, Agnès; Garza Rodríguez, Maria de Lourdes; Hernández Montenegro, Víctor; Aguilera, Carlos; Barrera Saldaña, Hugo; Mendoza, Roberto

    2005-04-01

    The alligator gar (Atractosteus spatula) is the largest freshwater fish inhabiting rivers draining into the Gulf of Mexico. This primitive fish shows a fast growth rate since its early larval stages. This is attributed to the action of growth hormone (GH), an anterior pituitary gland hormone responsible for linear growth in vertebrates that can also be expressed in extrapituitary adult tissues and in fish embryos. The present research was aimed at obtaining the GH coding sequence of the alligator gar and studying its expression through larval development. A cDNA was obtained by RT-PCR, cloned and sequenced. The alligator gar GH cDNA sequence shares 98% nucleotide similarity with that reported for Lepisosteus osseus, indicating a very slow evolution of the GH within the primitive fish, in contrast with the burst of changes observed in euteleosts. Using RT-PCR and RNA nuclease protection assays, GH transcripts were detected at very high levels in eggs, embryos and in several larval stages. These data suggest that the GH may play an important role during embryogenesis in fish. The better understanding of alligator gar larval physiology will facilitate the culture of larvae and juvenile gar and consequently may allow the restoration of their natural populations. PMID:15936701

  18. Cloning of the growth hormone cDNA of alligator gar Atractosteus spatula and its expression through larval development.

    PubMed

    Revol, Agnès; Garza Rodríguez, Maria de Lourdes; Hernández Montenegro, Víctor; Aguilera, Carlos; Barrera Saldaña, Hugo; Mendoza, Roberto

    2005-04-01

    The alligator gar (Atractosteus spatula) is the largest freshwater fish inhabiting rivers draining into the Gulf of Mexico. This primitive fish shows a fast growth rate since its early larval stages. This is attributed to the action of growth hormone (GH), an anterior pituitary gland hormone responsible for linear growth in vertebrates that can also be expressed in extrapituitary adult tissues and in fish embryos. The present research was aimed at obtaining the GH coding sequence of the alligator gar and studying its expression through larval development. A cDNA was obtained by RT-PCR, cloned and sequenced. The alligator gar GH cDNA sequence shares 98% nucleotide similarity with that reported for Lepisosteus osseus, indicating a very slow evolution of the GH within the primitive fish, in contrast with the burst of changes observed in euteleosts. Using RT-PCR and RNA nuclease protection assays, GH transcripts were detected at very high levels in eggs, embryos and in several larval stages. These data suggest that the GH may play an important role during embryogenesis in fish. The better understanding of alligator gar larval physiology will facilitate the culture of larvae and juvenile gar and consequently may allow the restoration of their natural populations.

  19. Role of the Deubiquitylating Enzyme DmUsp5 in Coupling Ubiquitin Equilibrium to Development and Apoptosis in Drosophila melanogaster

    PubMed Central

    Kovács, Levente; Nagy, Olga; Pál, Margit; Udvardy, Andor; Popescu, Octavian; Deák, Péter

    2015-01-01

    Protein ubiquitylation is a dynamic process that affects the function and stability of proteins and controls essential cellular processes ranging from cell proliferation to cell death. This process is regulated through the balanced action of E3 ubiquitin ligases and deubiquitylating enzymes (DUB) which conjugate ubiquitins to, and remove them from target proteins, respectively. Our genetic analysis has revealed that the deubiquitylating enzyme DmUsp5 is required for maintenance of the ubiquitin equilibrium, cell survival and normal development in Drosophila. Loss of the DmUsp5 function leads to late larval lethality accompanied by the induction of apoptosis. Detailed analyses at a cellular level demonstrated that DmUsp5 mutants carry multiple abnormalities, including a drop in the free monoubiquitin level, the excessive accumulation of free polyubiquitins, polyubiquitylated proteins and subunits of the 26S proteasome. A shortage in free ubiquitins results in the induction of a ubiquitin stress response previously described only in the unicellular budding yeast. It is characterized by the induction of the proteasome-associated deubiquitylase DmUsp14 and sensitivity to cycloheximide. Removal of DmUsp5 also activates the pro-apoptotic machinery thereby resulting in widespread apoptosis, indicative of an anti-apoptotic role of DmUsp5. Collectively, the pleiotropic effects of a loss of DmUsp5 function can be explained in terms of the existence of a limited pool of free monoubiquitins which makes the ubiquitin-dependent processes mutually interdependent. PMID:25806519

  20. CF2 represses Actin 88F gene expression and maintains filament balance during indirect flight muscle development in Drosophila.

    PubMed

    Gajewski, Kathleen M; Schulz, Robert A

    2010-01-01

    The zinc finger protein CF2 is a characterized activator of muscle structural genes in the body wall muscles of the Drosophila larva. To investigate the function of CF2 in the indirect flight muscle (IFM), we examined the phenotypes of flies bearing five homozygous viable mutations. The gross structure of the IFM was not affected, but the stronger hypomorphic alleles caused an increase of up to 1.5X in the diameter of the myofibrils. This size increase did not cause any disruption of the hexameric arrangement of thick and thin filaments. RT-PCR analysis revealed an increase in the transcription of several structural genes. Ectopic overexpression of CF2 in the developing IFM disrupts muscle formation. While our results indicate a role for CF2 as a direct negative regulator of the thin filament protein gene Actin 88F (Act88F), effects on levels of transcripts of myosin heavy chain (mhc) appear to be indirect. This role is in direct contrast to that described in the larval muscles, where CF2 activates structural gene expression. The variation in myofibril phenotypes of CF2 mutants suggest the CF2 may have separate functions in fine-tuning expression of structural genes to insure proper filament stoichiometry, and monitoring and/or controlling the final myofibril size. PMID:20520827

  1. Acidic intracellular pH shift during Caenorhabditis elegans larval development

    SciTech Connect

    Wadsworth, W.G.; Riddle, D.L. )

    1988-11-01

    During recovery from the developmentally arrested, nonfeeding dauer stage of the nemotode Caenorhabditis elegans, metabolic activation is accompanied by a decrease in intracellular pH (pH{sub i}). Phosphorus-31 nuclear magnetic resonance ({sup 31}P NMR) analyses of perchloric acid extracts show that inorganic phosphate predominates in dauer larvae, whereas ATP and other high-energy metabolites are abundant within 6 hr after dauer larvae have been placed in food to initiate development. Although metabolic activation has been associated with an alkaline pH{sub i} shift in other organisms, in vivo {sup 31}P NMR analysis of recovering dauer larvae shows a pH{sub i} decrease from {approx} 7.3 to {approx} 6.3 within 3 hr after the animals encounter food. This shift occurs before feeding begins, and it coincides with, or soon follows, the developmental commitment to recover from the dauer stage, suggesting that control of pH{sub i} may be important in the regulation of larval development in nematodes.

  2. Early embryo and larval development of inviable intergeneric hybrids derived from Crassostrea angulata and Saccostrea cucullata

    NASA Astrophysics Data System (ADS)

    Su, Jiaqi; Wang, Zhaoping; Zhang, Yuehuan; Yan, Xiwu; Li, Qiongzhen; Yu, Ruihai

    2016-06-01

    To detect the intergeneric hybridization between the oyster Crassostrea angulata and Saccostrea cucullata coexisting along the southern coast of China, reciprocal crosses were conducted between the two species. Barriers for sperm recognizing, binding, penetrating the egg, and forming the pronucleus were detected by fluorescence staining. From the results, although fertilization success was observed in hybrid crosses, the overall fertilization rate was lower than that of intraspecific crosses. A large number of hybrid larvae died at 6-8 d after hatching, and those survived could not complete metamorphosis. C. angulata ♀× S. cucullata ♂ larvae had a growth rate similar to that of the maternal species, whereas S. cucullata ♀ × C. angulata ♂ larvae grew the slowest among all crosses. Molecular genetics analysis revealed that hybrid progeny were amphimixis hybrids. This study demonstrated that hybrid embryos generated by crossing C. angulata and S. cucullata could develop normally to the larval state, but could not complete metamorphosis and then develop to the spat stage. Thus, there is a post-reproductive isolation between C. angulata and S. cucullata.

  3. Development of the GABA-ergic signaling system and its role in larval swimming in sea urchin.

    PubMed

    Katow, Hideki; Abe, Kouki; Katow, Tomoko; Zamani, Alemeh; Abe, Hirokazu

    2013-05-01

    The present study aimed to elucidate the development and γ-amino butyric acid (GABA)-ergic regulation of larval swimming in the sea urchin Hemicentrotus pulcherrimus by cloning glutamate decarboxylase (Hp-gad), GABAA receptor (Hp-gabrA) and GABAA receptor-associated protein (Hp-gabarap), and by performing immunohistochemistry. The regulation of larval swimming was increasingly dependent on the GABAergic system, which was active from the 2 days post-fertilization (d.p.f.) pluteus stage onwards. GABA-immunoreactive cells were detected as a subpopulation of secondary mesenchyme cells during gastrulation and eventually constituted the ciliary band and a subpopulation of blastocoelar cells during the pluteus stage. Hp-gad transcription was detected by RT-PCR during the period when Hp-Gad-positive cells were seen as a subpopulation of blastocoelar cells and on the apical side of the ciliary band from the 2 d.p.f. pluteus stage. Consistent with these observations, inhibition of GAD with 3-mercaptopropioninc acid inhibited GABA immunoreactivity and larval swimming dose dependently. Hp-gabrA amplimers were detected weakly in unfertilized eggs and 4 d.p.f. plutei but strongly from fertilized eggs to 2 d.p.f. plutei, and Hp-GabrA, together with GABA, was localized at the ciliary band in association with dopamine receptor D1 from the two-arm pluteus stage. Hp-gabarap transcription and protein expression were detected from the swimming blastula stage. Inhibition of the GABAA receptor by bicuculline inhibited larval swimming dose dependently. Inhibition of larval swimming by either 3-mercaptopropionic acid or bicuculline was more severe in older larvae (17 and 34 d.p.f. plutei) than in younger ones (1 d.p.f. prism larvae). PMID:23307803

  4. Disruption of Spodoptera exigua larval development by silencing chitin synthase gene A with RNA interference.

    PubMed

    Chen, X; Tian, H; Zou, L; Tang, B; Hu, J; Zhang, W

    2008-12-01

    RNA interference (RNAi) is a powerful tool for rapidly analyzing gene functions. However, little is known about the possible use of dsRNA/siRNA as a pest control method. Here, we demonstrate that dsRNA/siRNA can induce the silence of chitin synthase gene A (CHSA), which is an important gene for the growth and development of cuticles and trachea in beet armyworm, Spodoptera exigua. Based on the in vitro RNAi experiments in an insect cell line (Trichoplusia ni High 5), in vivo RNAi was performed by injecting synthesized dsRNA/siRNA into the 4th instar larvae of S. exigua. Significantly lower levels of CHSA transcripts were detected. In addition, the cuticle of these insects was disordered and the epithelial walls of larval trachea did not expand uniformly in injected individuals. Moreover, Injections significantly increased abnormalities relative to control larvae. These results highlighted the possibility of dsRNA/siRNA for gene function studies in lepidopteran insects and future pest control. PMID:18662430

  5. Megalodicopia hians in the Monterey submarine canyon: Distribution, larval development, and culture

    NASA Astrophysics Data System (ADS)

    Havenhand, Jon. N.; Matsumoto, George I.; Seidel, Ed

    2006-02-01

    The exclusively deep-sea ascidian family Octacnemidae comprises several genera in which the oral siphon has hypertrophied to form two large lips which create an "oral hood" capable of capturing motile prey. Megalodicopia hians is typical of this carnivorous family and has been reported to prey upon small epibenthic crustaceans. Distribution of M. hians in the Monterey Canyon system (36°45'N, 122°00'W) (California) was determined with remotely operated vehicles. M. hians was found sparsely to depths of at least 3800 m throughout the canyon; however, abundance was greatest within the oxygen-minimum zone (400-800 m). Eggs, sperm, and recently fertilized embryos were obtained repeatedly from adults returned to the laboratory in vivo, indicating that this species free-spawns routinely. Overall egg diameter (ovum plus chorion, plus follicle cells) was 175-190 μm—considerably smaller than previously reported for this species. Embryonic development at temperature and oxygen concentrations equivalent to the oxygen-minimum zone was 2-4 d and, embryos gave rise to typical phlebobranch "simple" tadpole larvae. Larval period was extremely variable, and settlement/metamorphosis occurred up to 3 months post-hatching. These results are discussed within the context of settlement-site selection and fertilization ecology of the species.

  6. Larval development of Angiostrongylus vasorum in the land snail Helix aspersa.

    PubMed

    Di Cesare, Angela; Crisi, Paolo Emidio; Bartolini, Roberto; Iorio, Raffaella; Talone, Tonino; Filippi, Laura; Traversa, Donato

    2015-10-01

    The metastrongyloid nematode Angiostrongylus vasorum affects the heart and pulmonary arteries of dogs and wild animals. Over the recent years, dog angiostrongylosis has gained great attention in the veterinary community for the expansion of its geographic range and for a rise in the number of clinical cases. Global warming, changes in phenology of mollusc intermediate hosts and movements of wild reservoirs have been evocated in the spreading of mollusc-borne parasites, including A. vasorum. The land snail Helix aspersa, a vector of other respiratory metastrongyloids, is endemic in most regions of the World, where it is a pest outside its native Mediterranean range. In the present study, the susceptibility and suitability of H. aspersa as an intermediate host of A. vasorum were investigated along with the characteristics of larval recovery and development following two different ways of inoculation, i.e. experimental (group A) vs natural infection (group B). After infections, the snails were kept at environmental conditions for 2 months. Five snails from groups A and B were randomly selected, digested and examined at 15-day intervals for 2 months. L1s, L2s and L3s were microscopically identified based on key morphological and morphometric characteristics and their identity was genetically confirmed. The results showed that A. vasorum may reach the infective stage in H. aspersa and that uptake of larvae and parasitic burden within the snails depend on the grazing capability of the molluscs. Biological and epidemiological implications are discussed.

  7. In vitro detection of benzimidazole resistance in Haemonchus contortus: egg hatch test versus larval development test.

    PubMed

    Várady, M; Cudeková, P; Corba, J

    2007-10-21

    The present study was designed to compare the egg hatch test (EHT) and the larval development test (LDT) as in vitro tools for detection of benzimidazole (BZ) resistance in Haemonchus contortus, a nematode parasite of small ruminants. Comparisons were made during a course of infection and changes in both EHT and LDT were monitored to measure the correlation between resistance and susceptibility in different parasite stages (eggs and larvae). In addition, mixed doses of known numbers of susceptible and BZ-resistant H. contortus eggs were used to assess the sensitivity of LDT for the detection of low levels of resistance. The degree of resistance for each test was expressed as resistance factor (RF). The LDT showed a greater ability to distinguish between four susceptible and four resistant isolates of H. contortus with higher resistance factors compared to the EHT. For the EHT the RF by using ED(50) criterion ranged from 3.2 to 13.3 and from 7.4 to 25.2 by using LC(99). For LDT the resistant isolates were 4.3-63.1 times more tolerant than the susceptible isolates using the ED(50) criterion and 91.1-1411.0 times more tolerant using the LC(99) criterion. The LDT was also able to clearly indicate the presence of low level (4%) of resistant larvae amongst a susceptible background population.

  8. Larval development of Angiostrongylus vasorum in the land snail Helix aspersa.

    PubMed

    Di Cesare, Angela; Crisi, Paolo Emidio; Bartolini, Roberto; Iorio, Raffaella; Talone, Tonino; Filippi, Laura; Traversa, Donato

    2015-10-01

    The metastrongyloid nematode Angiostrongylus vasorum affects the heart and pulmonary arteries of dogs and wild animals. Over the recent years, dog angiostrongylosis has gained great attention in the veterinary community for the expansion of its geographic range and for a rise in the number of clinical cases. Global warming, changes in phenology of mollusc intermediate hosts and movements of wild reservoirs have been evocated in the spreading of mollusc-borne parasites, including A. vasorum. The land snail Helix aspersa, a vector of other respiratory metastrongyloids, is endemic in most regions of the World, where it is a pest outside its native Mediterranean range. In the present study, the susceptibility and suitability of H. aspersa as an intermediate host of A. vasorum were investigated along with the characteristics of larval recovery and development following two different ways of inoculation, i.e. experimental (group A) vs natural infection (group B). After infections, the snails were kept at environmental conditions for 2 months. Five snails from groups A and B were randomly selected, digested and examined at 15-day intervals for 2 months. L1s, L2s and L3s were microscopically identified based on key morphological and morphometric characteristics and their identity was genetically confirmed. The results showed that A. vasorum may reach the infective stage in H. aspersa and that uptake of larvae and parasitic burden within the snails depend on the grazing capability of the molluscs. Biological and epidemiological implications are discussed. PMID:26122991

  9. Effects of Nitrite on Development of Embryos and Early Larval Stages of the Zebrafish (Danio rerio)

    PubMed Central

    Simmons, Alison E.; Karimi, Ida; Talwar, Mayank

    2012-01-01

    Abstract Epidemiological studies suggest that high nitrate levels in food and water may cause birth defects or spontaneous abortions in humans. Experimental mammalian studies show that high nitrite levels adversely affect reproductive outcomes, but have not shown congenital malformations. Consequently, the teratogenic potential of nitrite is unclear. In this study, the effects of nitrite on development of zebrafish embryos and early larval stages were investigated. Eggs were exposed to ethanol (a known teratogen), nitrite, or nitrate for 24 or 96 hours, and larvae examined at 120 hours. Sublethal exposure to 300 mM ethanol for 24 hours caused severe pericardial and yolk sac edema, craniofacial and axial malformations, and swim bladder noninflation. The 96 hour LC50 for nitrite was 411 mg/L. Less severe edema, craniofacial (but not axial) malformations, swim bladder noninflation, and immobility were observed after sublethal exposure to nitrite between 10 and 300 mg/L for 96 hours. Exposure to nitrite for 24 hours at concentrations as high as 2000 mg/L was not lethal. Only axial malformations and swim bladder noninflation were observed at 1500 mg/L. The results demonstrate that sublethal nitrite concentrations cause developmental defects. The type and magnitude of these defects differed after 24 and 96 hours of exposure. PMID:22823424

  10. Bt Maize Seed Mixtures for Helicoverpa zea (Lepidoptera: Noctuidae): Larval Movement, Development, and Survival on Non-transgenic Maize.

    PubMed

    Burkness, Eric C; Cira, T M; Moser, S E; Hutchison, W D

    2015-12-01

    In 2012 and 2013, field trials were conducted near Rosemount, MN, to assess the movement and development of Helicoverpa zea (Boddie) larvae on non-Bt refuge corn plants within a seed mixture of non-Bt and Bt corn. The Bt corn hybrid expressed three Bt toxins-Cry1Ab, Cry1F, and Vip3A. As the use of seed mixtures for insect resistance management (IRM) continues to be implemented, it is necessary to further characterize how this IRM approach impacts resistance development in ear-feeding Lepidopteran pests. The potential for Bt pollen movement and cross pollination of the non-Bt ears in a seed mixture may lead to Bt toxin exposure to larvae developing on those refuge ears. Larval movement and development by H. zea, feeding on non-Bt refuge plants adjacent to either transgenic Bt or non-Bt plants, were measured to investigate the potential for unintended Bt exposure. Non-Bt plants were infested with H. zea eggs and subplots were destructively sampled twice per week within each treatment to assess larval development, location, and kernel injury. Results indicate that H. zea larval movement between plants is relatively low, ranging from 2-16% of larvae, and occurs mainly after reaching the second instar. Refuge plants in seed mixtures did not produce equivalent numbers of H. zea larvae, kernel injury, and larval development differed as compared with a pure stand of non-Bt plants. This suggests that there may be costs to larvae developing on refuge plants within seed mixtures and additional studies are warranted to define potential impacts.

  11. Oral magnetite nanoparticles disturb the development of Drosophila melanogaster from oogenesis to adult emergence.

    PubMed

    Chen, Hanqing; Wang, Bing; Feng, Weiyue; Du, Wei; Ouyang, Hong; Chai, Zhifang; Bi, Xiaolin

    2015-05-01

    The potential impacts of nanomaterials (NMs) on fetal development have attracted great concerns because of the increased potential exposure to NMs during pregnancy. Drosophila melanogaster oogenesis and developmental transitions may provide an attractive system to study the biological and environmental effects of NMs on the embryonic development. In this study, the effects of three types of magnetite (Fe3O4) nanoparticles (MNPs): UN-MNPs (pristine), CA-MNPs (citric acid modified) and APTS-MNPs (3-aminopropyltriethoxylsilane coated) on the development of Drosophila at 300 and 600 μg/g dosage were studied. The uptake of MNPs by female and male flies caused obvious reduction in the female fecundity, and the developmental delay at the egg-pupae and pupae-adult transitions, especially in those treated by the positive APTS-MNPs. Further investigation demonstrates that the parental uptake of MNPs disturbs the oogenesis period, induces ovarian defect, reduces the length of eggs, decreases the number of nurse cells and delays egg chamber development, which may contribute to the decrease of fecundity of female Drosophila and the development delay of their offspring. Using the synchrotron radiation-based micro-X-ray fluorescence (SR-μXRF), the dyshomeostasis of trace elements such as Fe, Ca and Cu along the anterior-posterior axis of the fertilized eggs was found, which may be an important reason for the development delay of Drosophila.

  12. Coordinated Development of Muscles and Tendon-Like Structures: Early Interactions in the Drosophila Leg

    PubMed Central

    Soler, Cedric; Laddada, Lilia; Jagla, Krzysztof

    2016-01-01

    The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton) via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well-established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here, we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates) during the early steps of leg development, we affect the spatial localization of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes. PMID:26869938

  13. Investigation of the effects of estrogen on skeletal gene expression during zebrafish larval head development.

    PubMed

    Pashay Ahi, Ehsan; Walker, Benjamin S; Lassiter, Christopher S; Jónsson, Zophonías O

    2016-01-01

    The development of craniofacial skeletal structures requires well-orchestrated tissue interactions controlled by distinct molecular signals. Disruptions in normal function of these molecular signals have been associated with a wide range of craniofacial malformations. A pathway mediated by estrogens is one of those molecular signals that plays role in formation of bone and cartilage including craniofacial skeletogenesis. Studies in zebrafish have shown that while higher concentrations of 17-β estradiol (E 2) cause severe craniofacial defects, treatment with lower concentrations result in subtle changes in head morphology characterized with shorter snouts and flatter faces. The molecular basis for these morphological changes, particularly the subtle skeletal effects mediated by lower E 2 concentrations, remains unexplored. In the present study we address these effects at a molecular level by quantitative expression analysis of sets of candidate genes in developing heads of zebrafish larvae treated with two different E 2 concentrations. To this end, we first validated three suitable reference genes, ppia2, rpl8 and tbp, to permit sensitive quantitative real-time PCR analysis. Next, we profiled the expression of 28 skeletogenesis-associated genes that potentially respond to estrogen signals and play role in craniofacial development. We found E 2 mediated differential expression of genes involved in extracellular matrix (ECM) remodelling, mmp2/9/13, sparc and timp2a, as well as components of skeletogenic pathways, bmp2a, erf, ptch1/2, rankl, rarab and sfrp1a. Furthermore, we identified a co-expressed network of genes, including cpn1, dnajc3, esr1, lman1, rrbp1a, ssr1 and tram1 with a stronger inductive response to a lower dose of E 2 during larval head development. PMID:27069811

  14. Investigation of the effects of estrogen on skeletal gene expression during zebrafish larval head development

    PubMed Central

    Walker, Benjamin S.; Lassiter, Christopher S.; Jónsson, Zophonías O.

    2016-01-01

    The development of craniofacial skeletal structures requires well-orchestrated tissue interactions controlled by distinct molecular signals. Disruptions in normal function of these molecular signals have been associated with a wide range of craniofacial malformations. A pathway mediated by estrogens is one of those molecular signals that plays role in formation of bone and cartilage including craniofacial skeletogenesis. Studies in zebrafish have shown that while higher concentrations of 17-β estradiol (E2) cause severe craniofacial defects, treatment with lower concentrations result in subtle changes in head morphology characterized with shorter snouts and flatter faces. The molecular basis for these morphological changes, particularly the subtle skeletal effects mediated by lower E2 concentrations, remains unexplored. In the present study we address these effects at a molecular level by quantitative expression analysis of sets of candidate genes in developing heads of zebrafish larvae treated with two different E2 concentrations. To this end, we first validated three suitable reference genes, ppia2, rpl8 and tbp, to permit sensitive quantitative real-time PCR analysis. Next, we profiled the expression of 28 skeletogenesis-associated genes that potentially respond to estrogen signals and play role in craniofacial development. We found E2 mediated differential expression of genes involved in extracellular matrix (ECM) remodelling, mmp2/9/13, sparc and timp2a, as well as components of skeletogenic pathways, bmp2a, erf, ptch1/2, rankl, rarab and sfrp1a. Furthermore, we identified a co-expressed network of genes, including cpn1, dnajc3, esr1, lman1, rrbp1a, ssr1 and tram1 with a stronger inductive response to a lower dose of E2 during larval head development. PMID:27069811

  15. Ocean acidification boosts larval fish development but reduces the window of opportunity for successful settlement.

    PubMed

    Rossi, Tullio; Nagelkerken, Ivan; Simpson, Stephen D; Pistevos, Jennifer C A; Watson, Sue-Ann; Merillet, Laurene; Fraser, Peter; Munday, Philip L; Connell, Sean D

    2015-12-22

    Locating appropriate settlement habitat is a crucial step in the life cycle of most benthic marine animals. In marine fish, this step involves the use of multiple senses, including audition, olfaction and vision. To date, most investigations of larval fish audition focus on the hearing thresholds to various frequencies of sounds without testing an ecological response to such sounds. Identifying responses to biologically relevant sounds at the development stage in which orientation is most relevant is fundamental. We tested for the existence of ontogenetic windows of reception to sounds that could act as orientation cues with a focus on vulnerability to alteration by human impacts. Here we show that larvae of a catadromous fish species (barramundi, Lates calcarifer) were attracted towards sounds from settlement habitat during a surprisingly short ontogenetic window of approximately 3 days. Yet, this auditory preference was reversed in larvae reared under end-of-century levels of elevated CO2, such that larvae are repelled from cues of settlement habitat. These future conditions also reduced the swimming speeds and heightened the anxiety levels of barramundi. Unexpectedly, an acceleration of development and onset of metamorphosis caused by elevated CO2 were not accompanied by the earlier onset of attraction towards habitat sounds. This mismatch between ontogenetic development and the timing of orientation behaviour may reduce the ability of larvae to locate habitat or lead to settlement in unsuitable habitats. The misinterpretation of key orientation cues can have implications for population replenishment, which are only exacerbated when ontogenetic development decouples from the specific behaviours required for location of settlement habitats.

  16. Host insulin stimulates Echinococcus multilocularis insulin signalling pathways and larval development

    PubMed Central

    2014-01-01

    parasite persistence in larval cestode infections. Furthermore, our data show that Echinococcus insulin signalling pathways are promising targets for the development of novel drugs. PMID:24468049

  17. Context-dependent relationships between the BMPs gbb and dpp during development of the Drosophila wing imaginal disk.

    PubMed

    Ray, R P; Wharton, K A

    2001-10-01

    The Drosophila BMP5/6/7/8 homolog, glass bottom boat (gbb), has been shown to be involved in proliferation and vein patterning in the wing disk. To better understand the roles for gbb in wing development, as well as its relationship with the Drosophila BMP2/4 homolog decapentaplegic (dpp), we have used clonal analysis to define the functional foci of gbb during wing development. Our results show that gbb has both local and long-range functions in the disk that coincide both spatially and functionally with the established functions of dpp, suggesting that both BMPs contribute to the same processes during wing development. Indeed, comparison of the mutant phenotypes of dpp and gbb hypomorphs and null clones shows that both BMPs act locally along the longitudinal and cross veins to affect the process of vein promotion during pupal development, and long-range from a single focus along the A/P compartment boundary to affect the processes of disk proliferation and vein specification during larval development. Moreover, we show that duplications of dpp are able to rescue many of the phenotypes associated with gbb mutants and clones, indicating that the functions of gbb are at least partially redundant with those of dpp. While this relationship is similar to that described for dpp and the BMP screw (scw) in the embryo, we show that the mechanisms underlying both local and long-range functions of gbb and dpp in the wing are different. For the local foci, gbb function is confined to the regions of the veins that require the highest levels of dpp signaling, suggesting that gbb acts to augment dpp signaling in the same way as scw is proposed to do in the embryo. However, unlike scw-dependent signals in the embryo, these gbb signals are not transduced by the Type I receptor saxophone (sax), thus, the cooperativity between gbb and dpp is not achieved by signaling through distinct receptor complexes. For the long-range focus along the A/P compartment boundary, gbb function does

  18. Evolution of OTP-independent larval skeleton patterning in the direct-developing sea urchin, Heliocidaris erythrogramma.

    PubMed

    Zhou, Na; Wilson, Keen A; Andrews, Mary E; Kauffman, Jeffery S; Raff, Rudolf A

    2003-12-15

    Heliocidaris erythrogramma is a direct-developing sea urchin that has evolved a modified ontogeny, a reduced larval skeleton, and accelerated development of the adult skeleton. The Orthopedia gene (Otp) encodes a homeodomain transcription factor crucial in patterning the larval skeleton of indirect-developing sea urchins. We compare the role of Otp in larvae of the indirect-developing sea urchin Heliocidaris tuberculata and its direct-developing congener H. erythrogramma. Otp is a single-copy gene with an identical protein sequence in these species. Expression of Otp is initiated by the late gastrula, initially in two cells of the oral ectoderm in H. tuberculata. These cells are restricted to oral ectoderm and exhibit left-right symmetry. There are about 266 copies of Otp mRNA per Otp- expressing cell in H. tuberculata. We tested OTP function in H. tuberculata and H. erythrogramma embryos by microinjection of Otp mRNA. Mis-expression of Otp mRNA in H. tuberculata radialized the embryos and caused defects during larval skeletogenesis. Mis-expression of Otp mRNA in H. erythrogramma embryos did not affect skeleton formation. This is consistent with the observation by in situ hybridization of no concentration of Otp transcript in any particular cells or region of the H. erythrogramma larva, and measurement of a level of less than one copy of endogenous Otp mRNA per cell in H. erythrogramma. OTP plays an important role in patterning the larval skeleton of H. tuberculata, but this role apparently has been lost in the evolution of the H. erythrogramma larva, and replaced by a new patterning mechanism.

  19. Reproduction and development in Halocaridina rubra Holthuis, 1963 (Crustacea: Atyidae) clarifies larval ecology in the Hawaiian anchialine ecosystem.

    PubMed

    Havird, Justin C; Vaught, Rebecca C; Weese, David A; Santos, Scott R

    2015-10-01

    Larvae in aquatic habitats often develop in environments different from those they inhabit as adults. Shrimp in the Atyidae exemplify this trend, as larvae of many species require salt or brackish water for development, while adults are freshwater-adapted. An exception within the Atyidae family is the "anchialine clade," which are euryhaline as adults and endemic to habitats with subterranean fresh and marine water influences. Although the Hawaiian anchialine atyid Halocaridina rubra is a strong osmoregulator, its larvae have never been observed in nature. Moreover, larval development in anchialine species is poorly studied. Here, reproductive trends in laboratory colonies over a 5-y period are presented from seven genetic lineages and one mixed population of H. rubra; larval survivorship under varying salinities is also discussed. The presence and number of larvae differed significantly among lineages, with the mixed population being the most prolific. Statistical differences in reproduction attributable to seasonality also were identified. Larval survivorship was lowest (12% settlement rate) at a salinity approaching fresh water and significantly higher in brackish and seawater (88% and 72%, respectively). Correlated with this finding, identifiable gills capable of ion transport did not develop until metamorphosis into juveniles. Thus, early life stages of H. rubra are apparently excluded from surface waters, which are characterized by lower and fluctuating salinities. Instead, these stages are restricted to the subterranean (where there is higher and more stable salinity) portion of Hawaii's anchialine habitats due to their inability to tolerate low salinities. Taken together, these data contribute to the understudied area of larval ecology in the anchialine ecosystem.

  20. Reproduction and development in Halocaridina rubra Holthuis, 1963 (Crustacea: Atyidae) clarifies larval ecology in the Hawaiian anchialine ecosystem.

    PubMed

    Havird, Justin C; Vaught, Rebecca C; Weese, David A; Santos, Scott R

    2015-10-01

    Larvae in aquatic habitats often develop in environments different from those they inhabit as adults. Shrimp in the Atyidae exemplify this trend, as larvae of many species require salt or brackish water for development, while adults are freshwater-adapted. An exception within the Atyidae family is the "anchialine clade," which are euryhaline as adults and endemic to habitats with subterranean fresh and marine water influences. Although the Hawaiian anchialine atyid Halocaridina rubra is a strong osmoregulator, its larvae have never been observed in nature. Moreover, larval development in anchialine species is poorly studied. Here, reproductive trends in laboratory colonies over a 5-y period are presented from seven genetic lineages and one mixed population of H. rubra; larval survivorship under varying salinities is also discussed. The presence and number of larvae differed significantly among lineages, with the mixed population being the most prolific. Statistical differences in reproduction attributable to seasonality also were identified. Larval survivorship was lowest (12% settlement rate) at a salinity approaching fresh water and significantly higher in brackish and seawater (88% and 72%, respectively). Correlated with this finding, identifiable gills capable of ion transport did not develop until metamorphosis into juveniles. Thus, early life stages of H. rubra are apparently excluded from surface waters, which are characterized by lower and fluctuating salinities. Instead, these stages are restricted to the subterranean (where there is higher and more stable salinity) portion of Hawaii's anchialine habitats due to their inability to tolerate low salinities. Taken together, these data contribute to the understudied area of larval ecology in the anchialine ecosystem. PMID:26504154

  1. Development of embryonic and larval cells containing serotonin, catecholamines, and FMRFamide-related peptides in the gastropod mollusc Phestilla sibogae.

    PubMed

    Croll, Roger P

    2006-12-01

    The present immunocytochemical study provides one of the first detailed descriptions of the development of cells containing a variety of neurotransmitters during much of the larval life of a nudibranch gastropod. Throughout much of early development, serotonergic cells were located only in the apical organ; as larvae approached metamorphosis, serotonergic cells were also detected in the cerebropleural and pedal ganglia. Cells exhibiting tyrosine hydroxylase immunoreactivity (indicative of catecholamine synthesis) were first located near the mouth but by late embryonic stages were also located in the apical organ and near the velum and eyes. By late larval stages, numerous catecholaminergic cells were found in the foot, with concentrations in the propodium. Finally, the first cells exhibiting FMRFamide immunoreactivity were detected posterior to the neuropil of the cerebropleural ganglia in the early embryo. Fibers that presumably originated from these cells subsequently invaded the cerebral and pedal ganglia and the apical organ. By early larval stages, a second pair of peptidergic neurons was located near the first pair, and additional peptidergic neurons were located in the apical organ and peripheral positions in the foot and medial and dorsal to the eyes. In addition to providing a unique phyletic perspective to our understanding of gastropod neural development, the present study also sets the stage for future studies into changes in the nervous system as this gastropod undergoes metamorphosis. PMID:17179383

  2. Yolk-sac larval development of the substrate-brooding cichlid Archocentrus nigrofasciatus in relation to temperature.

    PubMed

    Vlahos, Nikolaos; Vasilopoulos, Michael; Mente, Eleni; Hotos, George; Katselis, George; Vidalis, Kosmas

    2015-09-01

    In order to conserve and culture the cichlid fish Archocentrus nigrofasciatus, more information about its reproductive biology and its larval behavior and morphogenesis is necessary. Currently, temperatures ranging from 21 to 27 °C are used in ornamental aquaculture hatcheries. Lower temperatures are preferred to reduce the costs of water heating, and 23 °C is usually the selected temperature. However, there is limited information on culturing protocols for ornamental species and most of the information generated on this topic remains scarce. Thus, the present study examines the morphological development of Archocentrus nigrofasciatus during the yolk-sac period up to the age of 100 h post-hatching in relation to 2 temperature regimes used in ornamental aquaculture: a temperature of 27 °C (thermal optimum) and a decreased temperature of 23 °C (thermal tolerance). The results of this study suggest that the 27 °C temperature generates intense morphological changes in yolk-sac development in a shorter period. This has advantages as it reduces the time of yolk-sac larval development, and, thus, minimizes the transition phase to exogenous feeding and maximizes the efficiency at which yolk is converted into body tissues. The present paper provides necessary information to produce freshwater ornamental fish with better practices so as to increase larval survival and capitalize on time for growth. PMID:26201370

  3. Drosophila Avoids Parasitoids by Sensing Their Semiochemicals via a Dedicated Olfactory Circuit

    PubMed Central

    Ebrahim, Shimaa A. M.; Dweck, Hany K. M.; Stökl, Johannes; Hofferberth, John E.; Trona, Federica; Weniger, Kerstin; Rybak, Jürgen; Seki, Yoichi; Stensmyr, Marcus C.; Sachse, Silke; Hansson, Bill S.; Knaden, Markus

    2015-01-01

    Detecting danger is one of the foremost tasks for a neural system. Larval parasitoids constitute clear danger to Drosophila, as up to 80% of fly larvae become parasitized in nature. We show that Drosophila melanogaster larvae and adults avoid sites smelling of the main parasitoid enemies, Leptopilina wasps. This avoidance is mediated via a highly specific olfactory sensory neuron (OSN) type. While the larval OSN expresses the olfactory receptor Or49a and is tuned to the Leptopilina odor iridomyrmecin, the adult expresses both Or49a and Or85f and in addition detects the wasp odors actinidine and nepetalactol. The information is transferred via projection neurons to a specific part of the lateral horn known to be involved in mediating avoidance. Drosophila has thus developed a dedicated circuit to detect a life-threatening enemy based on the smell of its semiochemicals. Such an enemy-detecting olfactory circuit has earlier only been characterized in mice and nematodes. PMID:26674493

  4. Myoblast fusion in Drosophila

    SciTech Connect

    Haralalka, Shruti; Abmayr, Susan M.

    2010-11-01

    The body wall musculature of a Drosophila larva is composed of an intricate pattern of 30 segmentally repeated muscle fibers in each abdominal hemisegment. Each muscle fiber has unique spatial and behavioral characteristics that include its location, orientation, epidermal attachment, size and pattern of innervation. Many, if not all, of these properties are dictated by founder cells, which determine the muscle pattern and seed the fusion process. Myofibers are then derived from fusion between a specific founder cell and several fusion competent myoblasts (FCMs) fusing with as few as 3-5 FCMs in the small muscles on the most ventral side of the embryo and as many as 30 FCMs in the larger muscles on the dorsal side of the embryo. The focus of the present review is the formation of the larval muscles in the developing embryo, summarizing the major issues and players in this process. We have attempted to emphasize experimentally-validated details of the mechanism of myoblast fusion and distinguish these from the theoretically possible details that have not yet been confirmed experimentally. We also direct the interested reader to other recent reviews that discuss myoblast fusion in Drosophila, each with their own perspective on the process . With apologies, we use gene nomenclature as specified by Flybase (http://flybase.org) but provide Table 1 with alternative names and references.

  5. Efficacy and longevity of the newly developed catnip oil microcapsules against stable fly oviposition larval growth

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stable fly, Stomoxys calcitrans (Diptera: Muscidae), is one of the most important pests of cattle and costs U.S. cattle producers billions of dollars in losses annually. In this study, the efficacy of catnip oil encapsulated in gelatin in oviposition deterrence and larval growth inhibition in st...

  6. Efficacy and longevity of newly developed catnip oil microcapsules against stable fly oviposition and larval growth.

    PubMed

    Zhu, J J; Wienhold, B J; Wehrle, J; Davis, D; Chen, H; Taylor, D; Friesen, K; Zurek, L

    2014-06-01

    The stable fly, Stomoxys calcitrans (Diptera: Muscidae), is one of the most important pests of cattle and costs U.S. cattle producers billions of dollars in losses annually. In this study, the efficacy of catnip oil encapsulated in gelatin in oviposition deterrence and larval growth inhibition in stable flies was examined under laboratory conditions. More than 98% inhibition of stable fly larval growth and female oviposition was observed in larval and oviposition media treated with encapsulated catnip oil (0.5 g). Further, dose-response tests showed that as little as 0.1 g of encapsulated catnip oil provided > 85% oviposition deterrence. The release of nepetalactones from the capsules was more rapid when the capsules were placed on a moist substrate rather than a dry substrate. Encapsulated catnip oil also exhibited antibacterial activity, supporting the hypothesis that its inhibition of larval growth may be based on its killing of the bacteria on which larvae feed. The use of encapsulated catnip oil can provide an alternative control strategy for stable fly management. PMID:24111783

  7. Efficacy and longevity of newly developed catnip oil microcapsules against stable fly oviposition and larval growth.

    PubMed

    Zhu, J J; Wienhold, B J; Wehrle, J; Davis, D; Chen, H; Taylor, D; Friesen, K; Zurek, L

    2014-06-01

    The stable fly, Stomoxys calcitrans (Diptera: Muscidae), is one of the most important pests of cattle and costs U.S. cattle producers billions of dollars in losses annually. In this study, the efficacy of catnip oil encapsulated in gelatin in oviposition deterrence and larval growth inhibition in stable flies was examined under laboratory conditions. More than 98% inhibition of stable fly larval growth and female oviposition was observed in larval and oviposition media treated with encapsulated catnip oil (0.5 g). Further, dose-response tests showed that as little as 0.1 g of encapsulated catnip oil provided > 85% oviposition deterrence. The release of nepetalactones from the capsules was more rapid when the capsules were placed on a moist substrate rather than a dry substrate. Encapsulated catnip oil also exhibited antibacterial activity, supporting the hypothesis that its inhibition of larval growth may be based on its killing of the bacteria on which larvae feed. The use of encapsulated catnip oil can provide an alternative control strategy for stable fly management.

  8. Control of larval and egg development in Aedes aegypti with RNA interference against juvenile hormone acid methyl transferase.

    PubMed

    Van Ekert, Evelien; Powell, Charles A; Shatters, Robert G; Borovsky, Dov

    2014-11-01

    RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA causes inhibition of jmtA transcript in adults and larvae, which is consistent with the observed inhibition of egg maturation and larval development. Taken together, these results suggest that jmtA LHP RNA expressed in heat inactivated genetically modified P. pastoris cells could be used to control mosquito populations in the marsh.

  9. Control of larval and egg development in Aedes aegypti with RNA interference against juvenile hormone acid methyl transferase.

    PubMed

    Van Ekert, Evelien; Powell, Charles A; Shatters, Robert G; Borovsky, Dov

    2014-11-01

    RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA causes inhibition of jmtA transcript in adults and larvae, which is consistent with the observed inhibition of egg maturation and larval development. Taken together, these results suggest that jmtA LHP RNA expressed in heat inactivated genetically modified P. pastoris cells could be used to control mosquito populations in the marsh. PMID:25111689

  10. Ctr9, a Key Component of the Paf1 Complex, Affects Proliferation and Terminal Differentiation in the Developing Drosophila Nervous System

    PubMed Central

    Bahrampour, Shahrzad; Thor, Stefan

    2016-01-01

    The Paf1 protein complex (Paf1C) is increasingly recognized as a highly conserved and broadly utilized regulator of a variety of transcriptional processes. These include the promotion of H3K4 and H3K36 trimethylation, H2BK123 ubiquitination, RNA Pol II transcriptional termination, and also RNA-mediated gene silencing. Paf1C contains five canonical protein components, including Paf1 and Ctr9, which are critical for overall complex integrity, as well as Rtf1, Leo1, and Cdc73/Parafibromin(Hrpt2)/Hyrax. In spite of a growing appreciation for the importance of Paf1C from yeast and mammalian studies, there has only been limited work in Drosophila. Here, we provide the first detailed phenotypic study of Ctr9 function in Drosophila. We found that Ctr9 mutants die at late embryogenesis or early larval life, but can be partly rescued by nervous system reexpression of Ctr9. We observed a number of phenotypes in Ctr9 mutants, including increased neuroblast numbers, increased nervous system proliferation, as well as downregulation of many neuropeptide genes. Analysis of cell cycle and regulatory gene expression revealed upregulation of the E2f1 cell cycle factor, as well as changes in Antennapedia and Grainy head expression. We also found reduction of H3K4me3 modification in the embryonic nervous system. Genome-wide transcriptome analysis points to additional downstream genes that may underlie these Ctr9 phenotypes, revealing gene expression changes in Notch pathway target genes, cell cycle genes, and neuropeptide genes. In addition, we find significant effects on the gene expression of metabolic genes. These findings reveal that Ctr9 is an essential gene that is necessary at multiple stages of nervous system development, and provides a starting point for future studies of the Paf1C in Drosophila. PMID:27520958

  11. Modeling congenital disease and inborn errors of development in Drosophila melanogaster

    PubMed Central

    Moulton, Matthew J.; Letsou, Anthea

    2016-01-01

    ABSTRACT Fly models that faithfully recapitulate various aspects of human disease and human health-related biology are being used for research into disease diagnosis and prevention. Established and new genetic strategies in Drosophila have yielded numerous substantial successes in modeling congenital disorders or inborn errors of human development, as well as neurodegenerative disease and cancer. Moreover, although our ability to generate sequence datasets continues to outpace our ability to analyze these datasets, the development of high-throughput analysis platforms in Drosophila has provided access through the bottleneck in the identification of disease gene candidates. In this Review, we describe both the traditional and newer methods that are facilitating the incorporation of Drosophila into the human disease discovery process, with a focus on the models that have enhanced our understanding of human developmental disorders and congenital disease. Enviable features of the Drosophila experimental system, which make it particularly useful in facilitating the much anticipated move from genotype to phenotype (understanding and predicting phenotypes directly from the primary DNA sequence), include its genetic tractability, the low cost for high-throughput discovery, and a genome and underlying biology that are highly evolutionarily conserved. In embracing the fly in the human disease-gene discovery process, we can expect to speed up and reduce the cost of this process, allowing experimental scales that are not feasible and/or would be too costly in higher eukaryotes. PMID:26935104

  12. The Development of Motor Coordination in Drosophila Embryos

    PubMed Central

    Crisp, Sarah; Evers, Jan Felix; Fiala, André; Bate, Michael

    2012-01-01

    We use non-invasive muscle imaging to study onset of motor activity and emergence of coordinated movement in Drosophila embryos. Earliest movements are myogenic and neurally controlled muscle contractions first appear with the onset of bursting activity 17 hours after egg laying. Initial episodes of activity are poorly organised and coordinated crawling sequences only begin to appear after a further hour of bursting. Thus network performance improves during this first period of activity. The embryo continues to exhibit bursts of crawling like sequences until shortly before hatching, while other reflexes also mature. Bursting does not begin as a reflex response to sensory input but appears to reflect the onset of spontaneous activity in the motor network. It does not require GABA-ergic transmission, and using a light activated channel to excite the network we demonstrate activity dependent depression that may cause burst termination. PMID:18927150

  13. [THE EFFECT OF DIETARY RESTRICTION DURING DEVELOPMENT OF DROSOPHILA MELANOGASTER ON THE ACTIVITY OF ANTIOXIDANT SYSTEM ENZYMES].

    PubMed

    Zabuga, O G; Koliada, A K; Kukharskyy, V M; Bazhynova, A I; Vaiserman, A M

    2015-01-01

    In the previous study we demonstrated that dietary restriction only at the development stage of Drosophila melanogaster may impact the life span of adult flies. It was important that we didn't use qualitative (restriction of proteins or other macro- or microelements) and not a calorie restriction as well, but quantitative dietary restriction that was the proportional reduction of all food components in the larval medium. In the situations when the larvae were reared in the medium types, that contained protein and carbohydrate components in concentrations of 90-10% of food components compared to the standard one (100%), the males were characterised with the significant increase in the maximum life span. The average life span was also increased, but only in those male individuals that developed in the medium types, that contained 50% and 60% of food components compared to controls. Such an effect we haven't detected in the female flies. To study the biochemical changes associated with the physiological effects we have determined the activity of the antioxidant enzymes--superoxide dismutase (SOD) and catalase. In the male flies the 50% dietary restriction implemented during the development has led to the significant increase in a SOD and catalase activity. Also the flies of both sexes reared in the medium with the 50% of food components have been characterised with the reduction in the accumulation of glycation end products. According to these results, we suggest that the changes in the activity of antioxidant enzymes may play a role in the increase of the flies life span caused by the dietary restriction during the development.

  14. The implications of temperature-mediated plasticity in larval instar number for development within a marine invertebrate, the shrimp Palaemonetes varians.

    PubMed

    Oliphant, Andrew; Hauton, Chris; Thatje, Sven

    2013-01-01

    Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30 °C to assess their thermal scope for development. Larvae developed at 17, 25, and 30 °C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures) and consisted of additional instars as 'repeat' instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25 °C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight) became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20 °C). We conclude that at settlement P. varians juveniles do not follow the temperature-size rule; this is of

  15. The Implications of Temperature-Mediated Plasticity in Larval Instar Number for Development within a Marine Invertebrate, the Shrimp Palaemonetes varians

    PubMed Central

    Oliphant, Andrew; Hauton, Chris; Thatje, Sven

    2013-01-01

    Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30°C to assess their thermal scope for development. Larvae developed at 17, 25, and 30°C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures) and consisted of additional instars as ‘repeat’ instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25°C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight) became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20°C). We conclude that at settlement P. varians juveniles do not follow the temperature-size rule; this is of

  16. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. IX. Host plant and population specific epicuticular hydrocarbon expression influences mate choice and sexual selection.

    PubMed

    Havens, J A; Etges, W J

    2013-03-01

    Sexual signals in cactophilic Drosophila mojavensis include cuticular hydrocarbons (CHCs), contact pheromones that mediate female discrimination of males during courtship. CHCs, along with male courtship songs, cause premating isolation between diverged populations, and are influenced by genotype × environment interactions caused by different host cacti. CHC profiles of mated and unmated adult flies from a Baja California and a mainland Mexico population of D. mojavensis reared on two host cacti were assayed to test the hypothesis that male CHCs mediate within-population female discrimination of males. In multiple choice courtship trials, mated and unmated males differed in CHC profiles, indicating that females prefer males with particular blends of CHCs. Mated and unmated females significantly differed in CHC profiles as well. Adults in the choice trials had CHC profiles that were significantly different from those in pair-mated adults from no-choice trials revealing an influence of sexual selection. Females preferred different male CHC blends in each population, but the influence of host cactus on CHC variation was significant only in the mainland population indicating population-specific plasticity in CHCs. Different groups of CHCs mediated female choice-based sexual selection in each population suggesting that geographical and ecological divergence has the potential to promote divergence in mate communication systems.

  17. Mosquito larval habitat mapping using remote sensing and GIS: Implications of coalbed methane development and West Nile virus

    SciTech Connect

    Zou, L.; Miller, S.N.; Schmidtmann, E.T.

    2006-09-15

    Potential larval habitats of the mosquito Culex tarsalis (Coquillett), implicated as a primary vector of West Nile virus in Wyoming, were identified using integrated remote sensing and geographic information system (GIS) analyses. The study area is in the Powder River Basin of north central Wyoming, an area that has been undergoing a significant increase in coalbed methane gas extractions since the late 1990s. Large volumes of water are discharged, impounded, and released during the extraction of methane gas, creating aquatic habitats that have the potential to support immature mosquito development. Landsat TM and ETM + data were initially classified into spectrally distinct water and vegetation classes, which were in turn used to identify suitable larval habitat sites. This initial habitat classification was refined using knowledge-based GIS techniques requiring spatial data layers for topography, streams, and soils to reduce the potential for overestimation of habitat. Accuracy assessment was carried out using field data and high-resolution aerial photography commensurate with one of the Landsat images. The classifier can identify likely habitat for ponds larger than 0.8 ha (2 acres) with generally satisfactory results (72.1%) with a lower detection limit of approximate to 0.4 ha (1 acre). Results show a 75% increase in potential larval habitats from 1999 to 2004 in the study area, primarily because of the large increase in small coalbed methane water discharge ponds. These results may facilitate mosquito abatement programs in the Powder River Basin with the potential for application throughout the state and region.

  18. Development and organization of the larval nervous system in Phoronopsis harmeri: new insights into phoronid phylogeny

    PubMed Central

    2014-01-01

    Background The organization and development of the nervous system has traditionally been used as an important character for establishing the relationships among large groups of animals. According to this criterion, phoronids were initially regarded as deuterostomian but have more recently been regarded as protostomian. The resolving of this conflict requires detailed information from poorly investigated members of phoronids, such as Phoronopsis harmeri. Results The serotonin-like immunoreactive part of the P. harmeri nervous system changes during larval development. These changes mostly concern the nervous system of the hood and correlate with the appearance of the median and two marginal neurite bundles, the frontal organ, and the sensory field. The apical organ has bilateral symmetry. The tentacular neurite bundle passes under the tentacles, contains several types of perikarya, and gives rise to intertentacular bundles, which branch in the tentacle base and penetrate into adjacent tentacles by two lateroabfrontal bundles. There are two groups of dorsolateral perikarya, which exhibit serotonin-like immunoreactivity, contact the tentacular neurite bundle, and are located near the youngest tentacles. Larvae have a minor nerve ring, which originates from the posterior marginal neurite bundle of the hood, passes above the tentacle base, and gives rise to the mediofrontal neurite bundle in each tentacle. Paired laterofrontal neurite bundles of tentacles form a continuous nerve tract that conducts to the postoral ciliated band. Discussion The organization of the nervous system differs among the planktotrophic larvae of phoronid species. These differences may correlate with differences in phoronid biology. Data concerning the innervation of tentacles in different phoronid larvae are conflicting and require careful reinvestigation. The overall organization of the nervous system in phoronid larvae has more in common with the deuterostomian than with the protostomian

  19. Developing methods based on light sheet fluorescence microscopy for biophysical investigations of larval zebrafish

    NASA Astrophysics Data System (ADS)

    Taormina, Michael J.

    Adapting the tools of optical microscopy to the large-scale dynamic systems encountered in the development of multicellular organisms provides a path toward understanding the physical processes necessary for complex life to form and function. Obtaining quantitatively meaningful results from such systems has been challenging due to difficulty spanning the spatial and temporal scales representative of the whole, while also observing the many individual members from which complex and collective behavior emerges. A three-dimensional imaging technique known as light sheet fluorescence microscopy provides a number of significant benefits for surmounting these challenges and studying developmental systems. A thin plane of fluorescence excitation light is produced such that it coincides with the focal plane of an imaging system, providing rapid acquisition of optically sectioned images that can be used to construct a three-dimensional rendition of a sample. I discuss the implementation of this technique for use in larva of the model vertebrate Danio rerio (zebrafish). The nature of light sheet imaging makes it especially well suited to the study of large systems while maintaining good spatial resolution and minimizing damage to the specimen from excessive exposure to excitation light. I show the results from a comparative study that demonstrates the ability to image certain developmental processes non-destructively, while in contrast confocal microscopy results in abnormal growth due to phototoxicity. I develop the application of light sheet microscopy to the study of a previously inaccessible system: the bacterial colonization of a host organism. Using the technique, we are able to obtain a survey of the intestinal tract of a larval zebrafish and observe the location of microbes as they grow and establish a stable population in an initially germ free fish. Finally, I describe a new technique to measure the fluid viscosity of this intestinal environment in vivo using

  20. Xenopus BTBD6 and its Drosophila homologue lute are required for neuronal development.

    PubMed

    Bury, Frédéric J; Moers, Virginie; Yan, Jiekun; Souopgui, Jacob; Quan, Xiao-Jiang; De Geest, Natalie; Kricha, Sadia; Hassan, Bassem A; Bellefroid, Eric J

    2008-11-01

    BBP proteins constitute a subclass of CUL3 interacting BTB proteins whose in vivo function remains unknown. Here, we show that the Xenopus BBP gene BTBD6 and the single Drosophila homologue of mammalian BBP genes lute are strongly expressed in the developing nervous system. In Xenopus, BTBD6 expression responds positively to proneural and negatively to neurogenic gene overexpression. Knockdown of BTBD6 in Xenopus or loss of Drosophila lute result in embryos with strong defects in late neuronal markers and strongly reduced and disorganized axons while early neural development is unaffected. XBTBD6 knockdown in Xenopus also affects muscle development. Together, these data indicate that BTBD6/lute is required for proper embryogenesis and plays an essential evolutionary conserved role during neuronal development.

  1. Premating isolation is determined by larval rearing substrates in cactophilic Drosophila mojavensis. X. Age-specific dynamics of adult epicuticular hydrocarbon expression in response to different host plants

    PubMed Central

    Etges, William J; de Oliveira, Cassia C

    2014-01-01

    Analysis of sexual selection and sexual isolation in Drosophila mojavensis and its relatives has revealed a pervasive role of rearing substrates on adult courtship behavior when flies were reared on fermenting cactus in preadult stages. Here, we assessed expression of contact pheromones comprised of epicuticular hydrocarbons (CHCs) from eclosion to 28 days of age in adults from two populations reared on fermenting tissues of two host cacti over the entire life cycle. Flies were never exposed to laboratory food and showed significant reductions in average CHC amounts consistent with CHCs of wild-caught flies. Overall, total hydrocarbon amounts increased from eclosion to 14–18 days, well past age at sexual maturity, and then declined in older flies. Most flies did not survive past 4 weeks. Baja California and mainland populations showed significantly different age-specific CHC profiles where Baja adults showed far less age-specific changes in CHC expression. Adults from populations reared on the host cactus typically used in nature expressed more CHCs than on the alternate host. MANCOVA with age as the covariate for the first six CHC principal components showed extensive differences in CHC composition due to age, population, cactus, sex, and age × population, age × sex, and age × cactus interactions. Thus, understanding variation in CHC composition as adult D. mojavensis age requires information about population and host plant differences, with potential influences on patterns of mate choice, sexual selection, and sexual isolation, and ultimately how these pheromones are expressed in natural populations. Studies of drosophilid aging in the wild are badly needed. PMID:25360246

  2. Exposure to domoic acid affects larval development of king scallop Pecten maximus (Linnaeus, 1758).

    PubMed

    Liu, Hui; Kelly, Maeve S; Campbell, Dirk A; Dong, Shuang Lin; Zhu, Jian Xin; Wang, Su Feng

    2007-02-28

    Domoic acid (DA) is a highly toxic phycotoxin produced by bloom forming marine diatoms Pseudo-nitzschia spp. Bivalves can accumulate this toxin to a high level through their feeding activities, and thus illness or death in can occur in consumers of bivalves. In this study, king scallop, Pecten maximus, larvae were exposed to dissolved domoic acid (DA) for 25d, and the toxin accumulation and effects of harbouring this toxin were investigated. Scallop larvae incorporated DA continuously during the larval culture period and accumulated a maximum DA level of 5.21pgind(-1) when exposed to a solution of 50ngml(-1) dissolved DA. As a result of the DA treatment, larval growth, measured in terms of shell length and the appearance of the eye-spot, and larval survival were significantly compromised. This is the first study on DA incorporation dynamics in P. maximus larvae, signifying the potential of using shellfish larvae for the study on mechanisms of phycotoxin accumulation. The negative effect of DA exposure suggests that this toxin could possibly influence natural recruitment in P. maximus, and it may be necessary to protect hatchery-cultured scallop larvae from DA during toxic Pseudo-nitzschia blooms.

  3. Is Palaeospondylus gunni a fossil larval lungfish? Insights from Neoceratodus forsteri development.

    PubMed

    Joss, Jean; Johanson, Zerina

    2007-03-15

    The enigmatic Devonian fossil Palaeospondylus gunni was identified as a larval form, metamorphosing into the lungfish Dipterus valenciennesi. Morphological features used to identify P. gunni as a larval lungfish include enlarged cranial ribs, rudimentary limb girdles, and absence of teeth. However, this combination of features does not characterize the extant lungfish Neoceratodus forsteri, even at very young stages, nor early stages of Devonian and younger fossil lungfish. Absence of teeth is problematic because early ontogenetic stages of fossil and living lungfish possess full dentitions including marginal teeth. Also problematic are cranial ribs as a defining character of lungfish, as these also occur in certain actinopterygians. It is argued that Neoceratodus is an obligate neotene (reproductively mature larva), with the implication that metamorphosis was a feature of the ontogeny of early lungfish. Pedomorphic characters have been recognized in Neoceratodus and other post-Devonian lungfish, including large cells and correspondingly large genome size; these latter characters correlate with neoteny in salamanders. Small cells preserved in fossil bone suggest that Devonian lungfish had a smaller genome than post-Devonian lungfish, implying that they were not neotenic. As fossil lungfish cell sizes (and genomes) increased in the late Paleozoic, the diversity of lungfish morphologies decreased, so that taxa like Sagenodus and Conchopoma show morphological similarity to Neoceratodus, marking a point in phylogeny at which metamorphosis was potentially lost. Since ancestral larval characters are retained in neotenic adults, we predict that Devonian larvae should resemble these post-Devonian taxa, a prediction which Palaeospondylus does not fulfill.

  4. Insulin and Target of rapamycin signaling orchestrate the development of ovarian niche-stem cell units in Drosophila.

    PubMed

    Gancz, Dana; Gilboa, Lilach

    2013-10-01

    Tissue-specific stem cells and their niches are organized into functional units that respond to external cues in order to maintain organ homeostasis. Insulin and Target of rapamycin (Tor) signaling mediate external cues that control adult niches and stem cells. Whether these pathways play a role in the establishment of niche-stem cell units during organogenesis has been little explored. We show that during larval development both Insulin-like receptor (InR) and Tor participate in the establishment of ovarian niches and germline stem cells (GSCs) in Drosophila melanogaster. Tor and InR are required cell-autonomously for the proliferation of precursors for both somatic niches and GSCs. These pathways also promote the formation of terminal filaments (part of the somatic niche). Significantly, InR, but not Tor, signaling non-autonomously promotes primordial germ cell (PGC) differentiation. Somatic attenuation of the pathway retards PGC differentiation, whereas its activation results in their precocious differentiation. We also show that InR-mediated PGC differentiation is independent of somatic ecdysone signaling, but that further differentiation into cysts requires an ecdysone input. These results demonstrate that Tor and InR signaling actively participate in the formation of ovarian niches and stem cells by affecting both cell numbers and differentiation. The dual influence of Tor and InR on both somatic cells and PGCs ensures that these two cell populations develop coordinately. Our work further identifies a novel step in the regulation of germ cell differentiation by demonstrating that following bag of marbles expression, cyst formation requires an additional hormonal input.

  5. Physiological and biochemical changes during the larval development of a brachyuran crab reared under constant conditions in the laboratory

    NASA Astrophysics Data System (ADS)

    Anger, K.; Harms, J.; Püschel, C.; Seeger, B.

    1989-06-01

    Larvae of the spider crab Hyas araneus were reared in the laboratory at constant conditions (12°C; 32‰S), and their feeding rate ( F), oxygen consumption ( R), nitrogen excretion ( U), and growth were measured in regular intervals of time during development from hatching to metamorphosis. Growth was measured as dry weight ( W), carbon ( C), nitrogen ( N), hydrogen ( H) protein, and lipid. All these physiological and biochemical traits revealed significant changes both from instar to instar and during individual larval moult cycles. Average F was low in the zoea I, reached a maximum in the zoea II, and decreased again in the megalopa. In the zoeal instars, it showed a bell-shaped pattern, with a maximum in the middle (zoea I) or during the first half of the moult cycle (zoea II). Maximum F in the megalopa was observed still earlier, during postmoult. Respiration ( R) increased in the zoeal instars as a linear function of time, whereas it showed a sinusoidal pattern in the megalopa. These findings on variation in F and R during larval development confirm results obtained in previous studies on H. araneus and other decapod species. Excretion ( U) was measured for the first time with a high temporal resolution in crab larvae. It showed in all three larval instars a bell-shaped variation pattern, with a maximum near the middle of the moult cycle, and significantly increasing average values from instar to instar. The atomic O/N ratio followed an inverse pattern, suggesting a maximum utilization of protein as a metabolic substrate during intermoult. Growth data from the present study and from a number of previous studies were compiled, showing consistency of growth patterns, but a considerable degree of variability between larvae from different hatches reared under identical conditions. The data show the following consistent tendencies: during the first part of each larval moult cycle (in postmoult, partly in intermoult), lipids are accumulated at a higher rate than

  6. [From random mutagenesis to precise genome editing: the development and evolution of genome editing techniques in Drosophila].

    PubMed

    Su, Fang; Huang, Zongliang; Guo, Yawen; Jiao, Renjie; Zi, Li; Chen, Jianming; Liu, Jiyong

    2016-01-01

    Drosophila melanogaster, an important model organism for studying life science, has contributed more to the research of genetics, developmental biology and biomedicine with the development of genome editing techniques. Drosophila genome-editing techniques have evolved from random mutagenesis to precise genome editing and from simple mutant construction to diverse genome editing methods since the 20th century. Chemical mutagenesis, using Ethyl methanesulfonate (EMS), is an important technique to study gene function in forward genetics, however, the precise knockout of Drosophila genes could not be achieved. The gene targeting technology, based on homologous recombination, has accomplished the precise editing of Drosophila genome for the first time, but with low efficiency. The CRISPR/Cas9 (Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein)-mediated precise genome editing is simple, fast and highly efficient compared with the gene targeting technology in Drosophila. In this review, we focus on Drosophila gene knockout, and summarize the evolution of genome editing techniques in Drosophila, emphasizing the development and applications of gene targeting, zinc-finger nuclease (ZFN), transcription activator-like effector nuclease (TALEN) and CRISPR/Cas9 techniques. PMID:26787520

  7. The Impact of Seawater Saturation State on Early Skeletal Development in Larval Corals: Insights into Scleractinian Biomineralization

    NASA Astrophysics Data System (ADS)

    Cohen, A. L.; McCorkle, D. C.; de Putron, S.

    2007-12-01

    contrast to the fine, closed, densely packed spherulitic bundles accreted in the control system, larvae in the lower Omega treatments produced a disorganized conglomerate of large, highly faceted crystals, consistent with slow growth under low saturation state conditions. Our results suggest that the coral calcification response to changes in seawater saturation state is linked to a physiological limitation on the organism's ability to elevate the saturation state of seawater within the calcifying space. Further, our data indicate that ocean acidification due to fossil fuel CO2 emissions will likely have a strong negative effect on the recruitment and early skeletal development of larval corals over the next several decades.

  8. Stage-Specific Changes in Physiological and Life-History Responses to Elevated Temperature and Pco2 during the Larval Development of the European Lobster Homarus gammarus (L.).

    PubMed

    Small, Daniel P; Calosi, Piero; Boothroyd, Dominic; Widdicombe, Steve; Spicer, John I

    2015-01-01

    An organism's physiological processes form the link between its life-history traits and the prevailing environmental conditions, especially in species with complex life cycles. Understanding how these processes respond to changing environmental conditions, thereby affecting organismal development, is critical if we are to predict the biological implications of current and future global climate change. However, much of our knowledge is derived from adults or single developmental stages. Consequently, we investigated the metabolic rate, organic content, carapace mineralization, growth, and survival across each larval stage of the European lobster Homarus gammarus, reared under current and predicted future ocean warming and acidification scenarios. Larvae exhibited stage-specific changes in the temperature sensitivity of their metabolic rate. Elevated Pco2 increased C∶N ratios and interacted with elevated temperature to affect carapace mineralization. These changes were linked to concomitant changes in survivorship and growth, from which it was concluded that bottlenecks were evident during H. gammarus larval development in stages I and IV, the transition phases between the embryonic and pelagic larval stages and between the larval and megalopa stages, respectively. We therefore suggest that natural changes in optimum temperature during ontogeny will be key to larvae survival in a future warmer ocean. The interactions of these natural changes with elevated temperature and Pco2 significantly alter physiological condition and body size of the last larval stage before the transition from a planktonic to a benthic life style. Thus, living and growing in warm, hypercapnic waters could compromise larval lobster growth, development, and recruitment.

  9. Stage-Specific Changes in Physiological and Life-History Responses to Elevated Temperature and Pco2 during the Larval Development of the European Lobster Homarus gammarus (L.).

    PubMed

    Small, Daniel P; Calosi, Piero; Boothroyd, Dominic; Widdicombe, Steve; Spicer, John I

    2015-01-01

    An organism's physiological processes form the link between its life-history traits and the prevailing environmental conditions, especially in species with complex life cycles. Understanding how these processes respond to changing environmental conditions, thereby affecting organismal development, is critical if we are to predict the biological implications of current and future global climate change. However, much of our knowledge is derived from adults or single developmental stages. Consequently, we investigated the metabolic rate, organic content, carapace mineralization, growth, and survival across each larval stage of the European lobster Homarus gammarus, reared under current and predicted future ocean warming and acidification scenarios. Larvae exhibited stage-specific changes in the temperature sensitivity of their metabolic rate. Elevated Pco2 increased C∶N ratios and interacted with elevated temperature to affect carapace mineralization. These changes were linked to concomitant changes in survivorship and growth, from which it was concluded that bottlenecks were evident during H. gammarus larval development in stages I and IV, the transition phases between the embryonic and pelagic larval stages and between the larval and megalopa stages, respectively. We therefore suggest that natural changes in optimum temperature during ontogeny will be key to larvae survival in a future warmer ocean. The interactions of these natural changes with elevated temperature and Pco2 significantly alter physiological condition and body size of the last larval stage before the transition from a planktonic to a benthic life style. Thus, living and growing in warm, hypercapnic waters could compromise larval lobster growth, development, and recruitment. PMID:26658247

  10. Expression profile of heat shock response factors during hookworm larval activation and parasitic development.

    PubMed

    Gelmedin, Verena; Delaney, Angela; Jennelle, Lucas; Hawdon, John M

    2015-07-01

    protein expression, slightly down regulated both genes under similar conditions. Both modulators inhibited activation-associated feeding, but neither had an effect on hsp-1 levels in activated L3 at 16h. Both celastrol and KNK437 prevent the up-regulation of daf-21 and hsf-1 seen in non-activated control larvae during activation, and significantly down regulated expression of the HSF-1 negative regulator Aca-hsb-1 in activated larvae. Expression levels of heat shock response factors were examined in developing Ancylostoma ceylanicum larvae recovered from infected hosts and found to differ significantly from the expression profile of activated L3, suggesting that feeding during in vitro activation is regulated differently than parasitic development. Our results indicate that a classical heat shock response is not induced at host temperature and is suppressed during larval recovery and parasitic development in the host, but a partial heat shock response is induced after extended incubation at host temperature in the absence of a developmental signal, possibly to protect against heat stress.

  11. The effect of space environment on the development and aging of Drosophila Melanogaster (7-IML-1)

    NASA Technical Reports Server (NTRS)

    Marco, Roberto

    1992-01-01

    This experiment involves the study of the development of eggs of the fly, Drosophila, exposed to microgravity. It is presumed that oogenesis, rather than further states of embryonic development, is sensitive to gravity. This hypothesis will be tested by collecting eggs layered at specific times inflight and postflight from flies exposed to 0 and 1 g. This portion of the experiment is a repetition of an earlier experiment flown in Biorack during the Spacelab D1 Mission. An added feature of the experiment for the First International Microgravity Laboratory (IML-1) Mission is to study the effect of microgravity on the life span of Drosophila male flies. Various aspects of the investigation are discussed.

  12. A Drosophila Reporter for the Translational Activation of ATF4 Marks Stressed Cells during Development.

    PubMed

    Kang, Kwonyoon; Ryoo, Hyung Don; Park, Jung-Eun; Yoon, Jee-Hyun; Kang, Min-Ji

    2015-01-01

    Eukaryotic cells have evolved signaling pathways that help to restore cellular homeostasis in response to various physiological or pathological conditions. ATF4 is a transcription factor whose mRNA translation is stimulated in response to stress-activated eIF2alpha kinases. Established conditions that activate eIF2alpha phosphorylation and ATF4 translation include excessive stress in the endoplasmic reticulum (ER) and amino acid deprivation. ATF4 is activated through a unique translational activation mechanism that involves multiple upstream open reading frames (uORFs) in the 5'-untranslated region (UTR), which is conserved from yeast to mammals. Taking advantage of this, we developed a translational activation reporter of ATF4 in Drosophila, in which the dsRed reporter coding sequence was placed downstream of the Drosophila ATF4 5' UTR. This reporter remained inactive in most tissues under normal conditions, but showed dsRed expression when starved, or when challenged with conditions that imposed ER stress. In normally developing flies, a small number of cell types showed reporter expression even without exogenous stress, which included the salivary gland, gut, the male reproductive organ, and the photoreceptor cells, suggestive of inherent stress during the normal development of these cell types. These results establish a new tool to study ATF4-mediated stress response in Drosophila development and disease.

  13. Experimental study of Lucilia sericata (Diptera Calliphoridae) larval development on rat cadavers: Effects of climate and chemical contamination.

    PubMed

    Aubernon, Cindy; Charabidzé, Damien; Devigne, Cédric; Delannoy, Yann; Gosset, Didier

    2015-08-01

    Household products such as bleach, gasoline or hydrochloric acid have been used to mask the presence of a cadaver or to prevent the colonization of insects. These types of chemicals affect insect development and alter the forensic entomology analysis. This study was designed to test the effects of six household products (bleach, mosquito repellent, perfume, caustic soda, insecticide and unleaded gasoline) on blowfly (Lucilia sericata, Diptera: Calliphoridae) larval development. Furthermore, the effects of climate (rain or dry conditions) on larval development were analyzed. For each replication, 100 first instars were placed on a rat cadaver on which one household product was spilled. We observed a decrease in the survival rates of the larvae but no significant effect on their development times or the adult size. The same trends were observed under rainy conditions. However, the rain altered the effects of some tested household products, especially gasoline. These results demonstrate for the first time the successful development of necrophagous larvae on chemically contaminated cadavers, and provide evidence for the range of possible effects to expect. PMID:26123620

  14. Experimental study of Lucilia sericata (Diptera Calliphoridae) larval development on rat cadavers: Effects of climate and chemical contamination.

    PubMed

    Aubernon, Cindy; Charabidzé, Damien; Devigne, Cédric; Delannoy, Yann; Gosset, Didier

    2015-08-01

    Household products such as bleach, gasoline or hydrochloric acid have been used to mask the presence of a cadaver or to prevent the colonization of insects. These types of chemicals affect insect development and alter the forensic entomology analysis. This study was designed to test the effects of six household products (bleach, mosquito repellent, perfume, caustic soda, insecticide and unleaded gasoline) on blowfly (Lucilia sericata, Diptera: Calliphoridae) larval development. Furthermore, the effects of climate (rain or dry conditions) on larval development were analyzed. For each replication, 100 first instars were placed on a rat cadaver on which one household product was spilled. We observed a decrease in the survival rates of the larvae but no significant effect on their development times or the adult size. The same trends were observed under rainy conditions. However, the rain altered the effects of some tested household products, especially gasoline. These results demonstrate for the first time the successful development of necrophagous larvae on chemically contaminated cadavers, and provide evidence for the range of possible effects to expect.

  15. Adult-like complexity of the larval antennal lobe of D. melanogaster despite markedly low numbers of odorant receptor neurons.

    PubMed

    Python, François; Stocker, Reinhard F

    2002-04-15

    We provide a detailed analysis of the larval head chemosensory system of Drosophila melanogaster, based on confocal microscopy of cell-specific reporter gene expression in P[GAL4] enhancer trap lines. In particular, we describe the neuronal composition of three external and three pharyngeal chemosensory organs, the nerve tracts chosen by their afferents, and their central target regions. With a total of 21 olfactory and 80 gustatory neurons, the sensory level is numerically much simpler than that of the adult. Moreover, its design is different than in the adult, showing an association between smell and taste sensilla. In contrast, the first-order relay of the olfactory afferents, the larval antennal lobe (LAL), exhibits adult-like features both in terms of structure and cell number. It shows a division into approximately 30 subunits, reminiscent of glomeruli in the adult antennal lobe. Taken together, the design of the larval chemosensory system is a "hybrid," with larval-specific features in the periphery and central characteristics in common with the adult. The largely reduced numbers of afferents and the similar architecture of the LAL and the adult antennal lobe, render the larval chemosensory system of Drosophila a valuable model system, both for studying smell and taste and for examining the development of its adult organization.

  16. Effects of offshore oil and gas development activities in southern California on larval settlement

    SciTech Connect

    Raimondi, P.T.; Barnett, A.; Krause, P.R.

    1995-12-31

    A series of in situ field experiments were conducted to determine effects of oil and gas drilling activities on the settlement of marine larvae in the deep ocean (180 m). The study sites were a series of three drilling rigs and three reference sites between Pt. Arguello and Pt. Conception in California. Experiments were carried out in both pre-drilling and drilling phases to test the effects of drilling activities (e.g. drilling, drilling mud release, and produced water discharges) on the ability of red abalone (Haliotis rufescens) larvae to settle using an in situ experiment. Their in situ experiment involved reciprocal transplants of settling plates that were ``filmed`` with bacteria from each site. After filming in the field at each of two heights, plates were mounted into chambers, covered with mesh and placed onto recoverable larval arrays for deployment in the field. Before deployment the authors injected approximately 300 competent red abalone larvae into each chamber. One larval array was deployed at each site for three days and each array contained plates filmed at all sites. In addition sterile plates (no surface filming) were included at each site. Upon recovery the number of settled abalone larvae were counted. Therefore, the experiment tested location-related (drilling sites versus reference), waterborne, and height effects on settlement in both the pre-drilling and drilling phases. Their results show that red abalone served as a sensitive indicator for in situ studies of larval settlement. The authors found significantly higher numbers of abalone settling onto plates that were filmed versus those that were not. The authors also found significantly lower settlement rates between the pre-drilling and drilling periods.

  17. Effect of mercuric chloride on fertilization and larval development in the River Frog, Rana heckscheri (Wright) (Anura: Ranidae)

    SciTech Connect

    Punzo, F. )

    1993-10-01

    Previous investigations have indicated that heavy metals such as copper, cadmium, lead and mercury can act as systemic toxicants in many species of wildlife. Although numerous studies have emphasized the effects of metals and pesticides on metabolism, growth, survivorship, neural processes and reproduction in a number of taxa, little information is available on the effects of sublethal concentrations of metals on the reproductive physiology of amphibians. Industrial processes and mining activities can release substantial concentrations of heavy metals such as mercury into aquatic habitats. Since most amphibians have obligate aquatic larval stages, they are exposed to pollutants discharged into the aquatic environment. Amphibians can act as accumulators of heavy metals and their larval stages are useful indicators of pollution levels in the field. What little data are available, indicate that metals can significantly reduce viability in amphibians through their actions on metabolism, development and gametogenesis. The recent concerns over worldwide declines in amphibian populations and the susceptibility of amphibian populations to environmental toxicants, led me to assess the effect of mercuric chloride, one of the most common and persistent toxicants in aquatic environments, on fertilization and larval development in the river frog, Rana heckscheri (Wright). Although there is some information on fish, very little data are available on the effects of mercury on fertilization in amphibians generally, and no published data exist for R. heckscheri. This species is a conspicuous component of the aquatic fauna of parts of the southeastern United States where mercury levels have increased significantly over the last two decades. 22 refs., 2 tabs.

  18. Interactions of environmental stressors impact survival and development of parasitized larval amphibians.

    PubMed

    Koprivnikar, J

    2010-12-01

    Infected hosts are exposed to many environmental stressors that must be taken into account in order to determine the importance of disease, as various combinations can interact in unpredictable ways. Here, northern leopard frog (Rana pipiens) tadpoles, a species in decline, were exposed to stressors singly or in combination. Stressors included infection by Echinostoma trivolvis (a trematode parasite), exposure to predator chemical cues (larval dragonflies), and exposure to varying concentrations of the herbicide atrazine. Parasitism decreased survival only in combination with exposure to 3 microg/L atrazine, with a negative interaction observed for mass as well. Similarly, a negative interaction of parasitism and predation on survival occurred. However, atrazine exposure alone negatively affected the survival, mass, and developmental stage of tadpoles. These results indicate that certain stressor combinations are particularly deleterious for young parasitized tadpoles. Notably, very common low-intensity parasite infection can be particularly harmful in certain situations. Such negative impacts on larval amphibians in certain scenarios may contribute to ongoing amphibian population declines, emphasizing that the combination of environmental stressors must be considered when evaluating the general role of disease in species extinctions.

  19. Overcrowding-mediated stress alters cell proliferation in key neuroendocrine areas during larval development in Rhinella arenarum.

    PubMed

    Distler, Mijal J; Jungblut, Lucas D; Ceballos, Nora R; Paz, Dante A; Pozzi, Andrea G

    2016-02-01

    Exposure to adverse environmental conditions can elicit a stress response, which results in an increase in endogenous corticosterone levels. In early life stages, it has been thoroughly demonstrated that amphibian larval growth and development is altered as a consequence of chronic stress by interfering with the metamorphic process, however, the underlying mechanisms involved have only been partially disentangled. We examined the effect of intraspecific competition on corticosterone levels during larval development of the toad Rhinella arenarum and its ultimate effects on cell proliferation in particular brain areas as well as the pituitary gland. While overcrowding altered the number of proliferating cells in the pituitary gland, hypothalamus, and third ventricle of the brain, no differences were observed in areas which are less associated with neuroendocrine processes, such as the first ventricle of the brain. Apoptosis was increased in hypothalamic regions but not in the pituitary. With regards to pituitary cell populations, thyrotrophs but not somatoatrophs and corticotrophs showed a decrease in the cell number in overcrowded larvae. Our study shows that alterations in growth and development, produced by stress, results from an imbalance in the neuroendocrine systems implicated in orchestrating the timing of metamorphosis.

  20. The ontogeny of Pseudis platensis (Anura, Hylidae): Heterochrony and the effects of larval development on postmetamorphic life.

    PubMed

    Fabrezi, Marissa; Quinzio, Silvia I; Goldberg, Javier

    2010-04-01

    Recent studies have described the giant tadpole, delayed metamorphic transformations, and absence of postmetamorphic growth of the skeleton of Pseudis Platensis. These features address questions about derived patterns of life cycles and the role of the heterochrony during the metamorphosis in anurans. Using anatomical methods, we provide new data on the development of reproductive, digestive and integument systems, and age inference obtained from ontogenetic series of Pseudis platensis. Our results indicate that at the end of metamorphosis, the adult skin is completely differentiated, including the calcified dermal layer; the testis has seminiferous tubules with spermatogonia, spermatocytes, and spermatids; ovarian sacs present previtellogenic ova; and the adult digestive tract is fully formed. The froglets differ from adults only in being unable to reproduce. The entire life cycle of P. platensis can occur in 4 years. In the first year, larval development, growth to adult size, and gonad differentiation are completed. Long larval development rather than size of the tadpoles seems to be involved in the absence of juvenile stages.

  1. Patterns of Cranial Development in Larval Rana macrocnemis: Chondrocranial Size and Shape Relationship With Pelophylax bedriagae (Anura: Ranidae).

    PubMed

    Yildirim, Elıf; Kaya, Uğur

    2016-06-01

    Notwithstanding the abundance of amphibians, there are few descriptions about ranid cranial development. Herein, larval chondrocranial development of Uludağ frog, Rana macrocnemis (Boulenger, 1885), is described on cleared and double-stained specimens. Descriptions are related with the ontogeny of the chondrocranium and osteogenesis of the cranial skeleton. The larval chondrocranial development of R. macrocnemis is compared to those of Rana and Pelophylax larvae (Pelophylax bedriagae, Rana pipiens, R. palustris, R. sphenocephala, R. catesbeiana, R. clamitans and R. sylvatica). In R. macrocnemis, the first bones to ossify are the parasphenoid and exoccipital (Stage 33), followed by the frontoparietal and prootic (stages 35 and 40, respectively). The major reconstruction of the chondrocranium begins at Stage 41. The ossification sequence of R. macrocnemis is distinguished from other ranids. Adult cranial osteology of R. macrocnemis is compared to that of P. bedriagae. Osteologically, R. macrocnemis is different from P. bedriagae by the shape and size of the vomer and number of teeth. Additionally, geometric morphometric methods are used to analyze chondrocranial size and shape changes of ranid larva of R. macrocnemis and P. bedriagae. Anat Rec, 299:711-721, 2016. © 2016 Wiley Periodicals, Inc.

  2. Effects of the dinoflagellate Karenia brevis on larval development in three species of bivalve mollusc from Florida.

    PubMed

    Leverone, Jay R; Blake, Norman J; Pierce, Richard H; Shumway, Sandra E

    2006-07-01

    The effects of Karenia brevis (Wilson clone) on larval survival and development of the northern quahog, Mercenaria mercenaria, eastern oyster, Crassostrea virginica and bay scallop, Argopecten irradians, were studied in the laboratory. Larvae were exposed to cultures of whole and lysed cells, with mean total brevetoxin concentrations of 53.8 and 68.9 microgL(-1), respectively. Survival of early (3-day-old) larvae was generally over 85% for all shellfish species at K. brevis densities of 100 cells ml(-1) or less, and not significantly different between whole and lysed culture. At 1000 cells ml(-1), survival was significantly less in lysed culture than whole culture for both M. mercenaria and C. virginica. Survival of late (7-day-old) larvae in all three species was not significantly affected by K. brevis densities of 1000 cells ml(-1) or less. At 5000 cells ml(-1), however, survival was reduced to 37%, 26% and 19% for A. irradians, M. mercenaria and C. virginica, respectively. Development of C. virginica and M. mercenaria larvae was protracted at K. brevis densities of 1000 cells ml(-1). These results suggest that blooms of K. brevis, and particularly their associated brevetoxins, may have detrimental consequences for Florida's shellfisheries by disrupting critical larval processes. Special attention should be paid to blooms of K. brevis where these shellfish occur naturally or where aquaculture and restoration activities are either ongoing or planned.

  3. Investigating the effects of nanoparticles on reproduction and development in Drosophila melanogaster and CD-1 mice

    NASA Astrophysics Data System (ADS)

    Philbrook, Nicola Anne

    Manufactured nanoparticles (NPs) are a class of small (≤ 100 nm) materials that are being used for a variety of purposes, including industrial lubricants, food additives, antibacterial agents, as well as delivery systems for drug and gene therapies. Their unique characteristics due to their small size as well as their parent materials allow them to be exploited in convenience applications; however, some of these properties also allow them to interact with and invade biological systems. Few studies have been performed to determine the potential harm that NPs can inflict on reproductive and developmental processes in organisms. In this study, Drosophila melanogaster and CD-1 mice were orally exposed to varying doses of titanium dioxide (TiO 2) NPs, silver (Ag) NPs, or hydroxyl-functionalized carbon nanotubes (fCNTs) and Drosophila were also exposed to microparticles (MPs) as a control for particle size. The subsequent effect of these materials on reproduction and development were evaluated. Strikingly, each type of NP studied negatively affected either reproduction or development in one or both of the two model systems. TiO2 NPs significantly negative effected both CD-1 mouse development (100 mg/kg or 1000 mg/kg) as well as Drosophila female fecundity (0.005%-0.5% w/v). Ag NPs significantly reduced mouse fetus viability after prenatal exposure to10 mg/kg. Ag NPs also significantly decreased the developmental success of Drosophila when they were directly exposed to these NPs (0.05% - 0.5% w/v) compared to both the vehicle and MP controls. fCNTs significantly increased the presence of morphological defects, resorptions and skeletal abnormalities in CD-1 mice, but had little effect on Drosophila. We speculate that the differences seen in the effects of NP types may be partially due to differences in reproductive physiology as well as each organism's ability to internalize these NPs. Whereas the differing response of each organism to a NP type was likely due in part to

  4. Retarded Onchocerca volvulus L1 to L3 larval development in the Simulium damnosum vector after anti-wolbachial treatment of the human host

    PubMed Central

    2012-01-01

    Background The human parasite Onchocerca volvulus harbours Wolbachia endosymbionts essential for worm embryogenesis, larval development and adult survival. In this study, the development of Wolbachia-depleted microfilariae (first stage larvae) to infective third stage larvae (L3) in the insect vector Simulium damnosum was analysed. Methods Infected volunteers in Cameroon were randomly and blindly allocated into doxycycline (200 mg/day for 6 weeks) or placebo treatment groups. After treatment, blackflies were allowed to take a blood meal on the volunteers, captured and dissected for larval counting and DNA extraction for quantitative real-time PCR analysis. Results PCR results showed a clear reduction in Wolbachia DNA after doxycycline treatment in microfilariae from human skin biopsies with > 50% reduction at one month post-treatment, eventually reaching a reduction of > 80%. Larval stages recovered from the insect vector had similar levels of reduction of endosymbiotic bacteria. Larval recoveries were analysed longitudinally after treatment to follow the kinetics of larval development. Beginning at three months post-treatment, significantly fewer L3 were seen in the blackflies that had fed on doxycycline treated volunteers. Concomitant with this, the proportion of second stage larvae (L2) was significantly increased in this group. Conclusions Doxycycline treatment and the resulting decline of Wolbachia endobacteria from the microfilaria resulted in retarded development of larvae in the insect vector. Thus, anti-wolbachial treatment could have an additive effect for interrupting transmission by reducing the number of L3 that can be transmitted by blackflies. PMID:22236497

  5. Optomotor-Blind Negatively Regulates Drosophila Eye Development by Blocking Jak/STAT Signaling

    PubMed Central

    Tsai, Yu-Chen; Grimm, Stefan; Chao, Ju-Lan; Wang, Shih-Chin; Hofmeyer, Kerstin; Shen, Jie; Eichinger, Fred; Michalopoulou, Theoni; Yao, Chi-Kuang; Chang, Chih-Hsuan; Lin, Shih-Han; Sun, Y. Henry; Pflugfelder, Gert O.

    2015-01-01

    Organ formation requires a delicate balance of positive and negative regulators. In Drosophila eye development, wingless (wg) is expressed at the lateral margins of the eye disc and serves to block retinal development. The T-box gene optomotor-blind (omb) is expressed in a similar pattern and is regulated by Wg. Omb mediates part of Wg activity in blocking eye development. Omb exerts its function primarily by blocking cell proliferation. These effects occur predominantly in the ventral margin. Our results suggest that the primary effect of Omb is the blocking of Jak/STAT signaling by repressing transcription of upd which encodes the Jak receptor ligand Unpaired. PMID:25781970

  6. Embryonic, Larval, and Juvenile Development of the Sea Biscuit Clypeaster subdepressus (Echinodermata: Clypeasteroida)

    PubMed Central

    Vellutini, Bruno C.; Migotto, Alvaro E.

    2010-01-01

    Sea biscuits and sand dollars diverged from other irregular echinoids approximately 55 million years ago and rapidly dispersed to oceans worldwide. A series of morphological changes were associated with the occupation of sand beds such as flattening of the body, shortening of primary spines, multiplication of podia, and retention of the lantern of Aristotle into adulthood. To investigate the developmental basis of such morphological changes we documented the ontogeny of Clypeaster subdepressus. We obtained gametes from adult specimens by KCl injection and raised the embryos at 26C. Ciliated blastulae hatched 7.5 h after sperm entry. During gastrulation the archenteron elongated continuously while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larvae began to feed in 3 d and were 20 d old at metamorphosis; starved larvae died 17 d after fertilization. Postlarval juveniles had neither mouth nor anus nor plates on the aboral side, except for the remnants of larval spicules, but their bilateral symmetry became evident after the resorption of larval tissues. Ossicles of the lantern were present and organized in 5 groups. Each group had 1 tooth, 2 demipyramids, and 2 epiphyses with a rotula in between. Early appendages consisted of 15 spines, 15 podia (2 types), and 5 sphaeridia. Podial types were distributed in accordance to Lovén's rule and the first podium of each ambulacrum was not encircled by the skeleton. Seven days after metamorphosis juveniles began to feed by rasping sand grains with the lantern. Juveniles survived in laboratory cultures for 9 months and died with wide, a single open sphaeridium per ambulacrum, aboral anus, and no differentiated food grooves or petaloids. Tracking the morphogenesis of early juveniles is a necessary step to elucidate the developmental mechanisms of echinoid growth and important groundwork to clarify homologies between irregular urchins. PMID:20339592

  7. Embryonic, larval, and juvenile development of the sea biscuit Clypeaster subdepressus (Echinodermata: Clypeasteroida).

    PubMed

    Vellutini, Bruno C; Migotto, Alvaro E

    2010-03-22

    Sea biscuits and sand dollars diverged from other irregular echinoids approximately 55 million years ago and rapidly dispersed to oceans worldwide. A series of morphological changes were associated with the occupation of sand beds such as flattening of the body, shortening of primary spines, multiplication of podia, and retention of the lantern of Aristotle into adulthood. To investigate the developmental basis of such morphological changes we documented the ontogeny of Clypeaster subdepressus. We obtained gametes from adult specimens by KCl injection and raised the embryos at 26 degrees C. Ciliated blastulae hatched 7.5 h after sperm entry. During gastrulation the archenteron elongated continuously while ectodermal red-pigmented cells migrated synchronously to the apical plate. Pluteus larvae began to feed in 3 d and were 20 d old at metamorphosis; starved larvae died 17 d after fertilization. Postlarval juveniles had neither mouth nor anus nor plates on the aboral side, except for the remnants of larval spicules, but their bilateral symmetry became evident after the resorption of larval tissues. Ossicles of the lantern were present and organized in 5 groups. Each group had 1 tooth, 2 demipyramids, and 2 epiphyses with a rotula in between. Early appendages consisted of 15 spines, 15 podia (2 types), and 5 sphaeridia. Podial types were distributed in accordance to Lovén's rule and the first podium of each ambulacrum was not encircled by the skeleton. Seven days after metamorphosis juveniles began to feed by rasping sand grains with the lantern. Juveniles survived in laboratory cultures for 9 months and died with wide, a single open sphaeridium per ambulacrum, aboral anus, and no differentiated food grooves or petaloids. Tracking the morphogenesis of early juveniles is a necessary step to elucidate the developmental mechanisms of echinoid growth and important groundwork to clarify homologies between irregular urchins.

  8. Caffeine Induces High Expression of cyp-35A Family Genes and Inhibits the Early Larval Development in Caenorhabditis elegans

    PubMed Central

    Min, Hyemin; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2015-01-01

    Intake of caffeine during pregnancy can cause retardation of fetal development. Although the significant influence of caffeine on animal development is widely recognized, much remains unknown about its mode of action because of its pleiotropic effects on living organisms. In the present study, by using Caenorhabditis elegans as a model organism, the effects of caffeine on development were examined. Brood size, embryonic lethality, and percent larval development were investigated, and caffeine was found to inhibit the development of C. elegans at most of the stages in a dosage-dependent fashion. Upon treatment with 30 mM caffeine, the majority (86.1 ± 3.4%) of the L1 larvae were irreversibly arrested without further development. In contrast, many of the late-stage larvae survived and grew to adults when exposed to the same 30 mM caffeine. These results suggest that early-stage larvae are more susceptible to caffeine than later-stage larvae. To understand the metabolic responses to caffeine treatment, the levels of expression of cytochrome P450 (cyp) genes were examined with or without caffeine treatment using comparative micro-array, and it was found that the expression of 24 cyp genes was increased by more than 2-fold (p < 0.05). Among them, induction of the cyp-35A gene family was the most prominent. Interestingly, depletion of the cyp-35A family genes one-by-one or in combination through RNA interference resulted in partial rescue from early larval developmental arrest caused by caffeine treatment, suggesting that the high-level induction of cyp-35A family genes can be fatal to the development of early-stage larvae. PMID:25591395

  9. Caffeine induces high expression of cyp-35A family genes and inhibits the early larval development in Caenorhabditis elegans.

    PubMed

    Min, Hyemin; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2015-03-01

    Intake of caffeine during pregnancy can cause retardation of fetal development. Although the significant influence of caffeine on animal development is widely recognized, much remains unknown about its mode of action because of its pleiotropic effects on living organisms. In the present study, by using Caenorhabditis elegans as a model organism, the effects of caffeine on development were examined. Brood size, embryonic lethality, and percent larval development were investigated, and caffeine was found to inhibit the development of C. elegans at most of the stages in a dosage-dependent fashion. Upon treatment with 30 mM caffeine, the majority (86.1 ± 3.4%) of the L1 larvae were irreversibly arrested without further development. In contrast, many of the late-stage larvae survived and grew to adults when exposed to the same 30 mM caffeine. These results suggest that early-stage larvae are more susceptible to caffeine than later-stage larvae. To understand the metabolic responses to caffeine treatment, the levels of expression of cytochrome P450 (cyp) genes were examined with or without caffeine treatment using comparative micro-array, and it was found that the expression of 24 cyp genes was increased by more than 2-fold (p < 0.05). Among them, induction of the cyp-35A gene family was the most prominent. Interestingly, depletion of the cyp-35A family genes one-by-one or in combination through RNA interference resulted in partial rescue from early larval developmental arrest caused by caffeine treatment, suggesting that the high-level induction of cyp-35A family genes can be fatal to the development of early-stage larvae.

  10. [Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild].

    PubMed

    Rosas, Jesús; Mata, Ernesto; Velásquez, Aidé; Cabrera, Tomas

    2008-09-01

    The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10 degrees 50'55.2" N y 64 degrees 09'467" W). The eggs were spherical, 1 923.54 +/- 72.35 microm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii. PMID:19419056

  11. Imaginal Disc Transplantation in Drosophila.

    PubMed

    Katsuyama, Tomonori; Paro, Renato

    2016-01-01

    Since Ephrussi and Beadle introduced imaginal disc transplantation to Drosophila research in 1936, the method played an important part towards a better understanding of disc patterning, tissue regeneration, and reprogramming phenomena like transdetermination. Despite increasing usage of high-throughput approaches towards solving biological problems this classical manual method is still in use for studying disc development in a semi-physiological context. Here we describe in detail a protocol and provide recommendations on the procedure in particular for analyzing the regenerative potential of imaginal disks. The steps consist of disc dissection and fragmentation, transplantation into the larval or adult abdomen, and the recovery of implants from the host abdomen. Additionally, we also describe how to make the special transplantation needle from a glass capillary. PMID:27659995

  12. Larval defense against attack from parasitoid wasps requires nociceptive neurons.

    PubMed

    Robertson, Jessica L; Tsubouchi, Asako; Tracey, W Daniel

    2013-01-01

    Parasitoid wasps are a fierce predator of Drosophila larvae. Female Leptopilina boulardi (LB) wasps use a sharp ovipositor to inject eggs into the bodies of Drosophila melanogaster larvae. The wasp then eats the Drosophila larva alive from the inside, and an adult wasp ecloses from the Drosophila pupal case instead of a fly. However, the Drosophila larvae are not defenseless as they may resist the attack of the wasps through somatosensory-triggered behavioral responses. Here we describe the full range of behaviors performed by the larval prey in immediate response to attacks by the wasps. Our results suggest that Drosophila larvae primarily sense the wasps using their mechanosensory systems. The range of behavioral responses included both "gentle touch" like responses as well as nociceptive responses. We found that the precise larval response depended on both the somatotopic location of the attack, and whether or not the larval cuticle was successfully penetrated during the course of the attack. Interestingly, nociceptive responses are more likely to be triggered by attacks in which the cuticle had been successfully penetrated by the wasp. Finally, we found that the class IV neurons, which are necessary for mechanical nociception, were also necessary for a nociceptive response to wasp attacks. Thus, the class IV neurons allow for a nociceptive behavioral response to a naturally occurring predator of Drosophila.

  13. Larval Defense against Attack from Parasitoid Wasps Requires Nociceptive Neurons

    PubMed Central

    Robertson, Jessica L.; Tsubouchi, Asako; Tracey, W. Daniel

    2013-01-01

    Parasitoid wasps are a fierce predator of Drosophila larvae. Female Leptopilina boulardi (LB) wasps use a sharp ovipositor to inject eggs into the bodies of Drosophila melanogaster larvae. The wasp then eats the Drosophila larva alive from the inside, and an adult wasp ecloses from the Drosophila pupal case instead of a fly. However, the Drosophila larvae are not defenseless as they may resist the attack of the wasps through somatosensory-triggered behavioral responses. Here we describe the full range of behaviors performed by the larval prey in immediate response to attacks by the wasps. Our results suggest that Drosophila larvae primarily sense the wasps using their mechanosensory systems. The range of behavioral responses included both “gentle touch” like responses as well as nociceptive responses. We found that the precise larval response depended on both the somatotopic location of the attack, and whether or not the larval cuticle was successfully penetrated during the course of the attack. Interestingly, nociceptive responses are more likely to be triggered by attacks in which the cuticle had been successfully penetrated by the wasp. Finally, we found that the class IV neurons, which are necessary for mechanical nociception, were also necessary for a nociceptive response to wasp attacks. Thus, the class IV neurons allow for a nociceptive behavioral response to a naturally occurring predator of Drosophila. PMID:24205297

  14. Effects of glyphosate-based herbicides on embryo-larval development and metamorphosis in the Pacific oyster, Crassostrea gigas.

    PubMed

    Mottier, Antoine; Kientz-Bouchart, Valérie; Serpentini, Antoine; Lebel, Jean Marc; Jha, Awadhesh N; Costil, Katherine

    2013-03-15

    Pesticides may be involved in oyster summer mortality events, not necessarily as a single causative agent but as an additional stressor. In this context, the present study aimed to assess the toxicity of glyphosate, its by-product, aminomethylphosphonic acid (AMPA) and two commercial formulations, Roundup Express(®) (R(EX)) and Roundup Allées et Terrasses(®) (R(AT)), containing glyphosate as the active ingredient, on the early life stages of the Pacific oyster, Crassostrea gigas. The embryotoxicity of these chemicals were quantified by considering both the rates of abnormalities and the arrested development or types of abnormalities in D-shaped larvae after 48 h exposure. The success of metamorphosis was examined in pediveliger larvae exposed for 24 h. Experiments involving both endpoints included range finding experiments for herbicide concentrations ranging from 0.1 to 100,000 μg L(-1). This range was then narrowed down in order to determine precise EC(50) values. Actual concentrations of the herbicide were determined at the beginning and after 48 h (embryotoxicity) and 24 h (metamorphosis) to evaluate the potential temporal variation in the concentrations. During embryo-larval development, no mortalities were recorded at any of the concentrations of glyphosate and AMPA, whereas no embryos or D-shaped larvae could be observed after exposure to 10,000 μg L(-1) of R(EX) or R(AT). Compared with the controls, no effects on embryo-larval development were recorded between 0.1 and 1000 μg L(-1), regardless of the chemical tested. Above a threshold, which varied according to the chemical used, the gradient of herbicide concentrations correlated with a gradient of severity of abnormality ranging from normal larvae to arrested development (an "old embryo" stage). The EC(50) values were 28,315 and 40,617 μg L(-1) for glyphosate and its metabolite, respectively, but much lowered values of 1133 and 1675 μg L(-1) for R(EX) and R(AT), respectively. Metamorphosis tests

  15. Drosophila Models of Cardiac Disease

    PubMed Central

    Piazza, Nicole; Wessells, R.J.

    2013-01-01

    The fruit fly Drosophila melanogaster has emerged as a useful model for cardiac diseases, both developmental abnormalities and adult functional impairment. Using the tools of both classical and molecular genetics, the study of the developing fly heart has been instrumental in identifying the major signaling events of cardiac field formation, cardiomyocyte specification, and the formation of the functioning heart tube. The larval stage of fly cardiac development has become an important model system for testing isolated preparations of living hearts for the effects of biological and pharmacological compounds on cardiac activity. Meanwhile, the recent development of effective techniques to study adult cardiac performance in the fly has opened new uses for the Drosophila model system. The fly system is now being used to study long-term alterations in adult performance caused by factors such as diet, exercise, and normal aging. The fly is a unique and valuable system for the study of such complex, long-term interactions, as it is the only invertebrate genetic model system with a working heart developmentally homologous to the vertebrate heart. Thus, the fly model combines the advantages of invertebrate genetics (such as large populations, facile molecular genetic techniques, and short lifespan) with physiological measurement techniques that allow meaningful comparisons with data from vertebrate model systems. As such, the fly model is well situated to make important contributions to the understanding of complicated interactions between environmental factors and genetics in the long-term regulation of cardiac performance. PMID:21377627

  16. Post-embryonic larval development and metamorphosis of the hydroid Eudendrium racemosum (Cavolini) (Hydrozoa, Cnidaria)

    NASA Astrophysics Data System (ADS)

    Sommer, C.

    1990-09-01

    The morphology and histology of the planula larva of Eudendrium racemosum (Cavolini) and its metamorphosis into the primary polyp are described from light microscopic observations. The planula hatches as a differentiated gastrula. During the lecithotrophic larval period, large ectodermal mucous cells, embedded between epitheliomuscular cells, secrete a sticky slime. Two granulated cell types occur in the ectoderm that are interpreted as secretory and sensorynervous cells, but might also be representatives of only one cell type with a multiple function. The entoderm consists of yolk-storing gastrodermal cells, digestive gland cells, interstitial cells, cnidoblasts, and premature cnidocytes. The larva starts metamorphosis by affixing its blunt aboral pole to a substratum. While the planula flattens down, the mucous cells penetrate the mesolamella and migrate through the entoderm into the gastral cavity where they are lysed. Subsequently, interstitial cells, cnidoblasts, and premature cnidocytes migrate in the opposite direction, i.e. from entoderm to ectoderm. Then, the polypoid body organization, comprising head (hydranth), stem and foot, all covered by peridermal secretion, becomes recognisable. An oral constriction divides the hypostomal portion of the gastral cavity from the stomachic portion. Within the hypostomal entoderm, cells containing secretory granules differentiate. Following growth and the multiplication of tentacles, the head periderm disappears. A ring of gland cells differentiates at the hydranth's base. The positioning of cnidae in the tentacle ectoderm, penetration of the mouth opening and the multiplication of digestive gland cells enable the polyp to change from lecithotrophic to planktotrophic nutrition.

  17. Mitochondrial fusion but not fission regulates larval growth and synaptic development through steroid hormone production

    PubMed Central

    Sandoval, Hector; Yao, Chi-Kuang; Chen, Kuchuan; Jaiswal, Manish; Donti, Taraka; Lin, Yong Qi; Bayat, Vafa; Xiong, Bo; Zhang, Ke; David, Gabriela; Charng, Wu-Lin; Yamamoto, Shinya; Duraine, Lita; Graham, Brett H; Bellen, Hugo J

    2014-01-01

    Mitochondrial fusion and fission affect the distribution and quality control of mitochondria. We show that Marf (Mitochondrial associated regulatory factor), is required for mitochondrial fusion and transport in long axons. Moreover, loss of Marf leads to a severe depletion of mitochondria in neuromuscular junctions (NMJs). Marf mutants also fail to maintain proper synaptic transmission at NMJs upon repetitive stimulation, similar to Drp1 fission mutants. However, unlike Drp1, loss of Marf leads to NMJ morphology defects and extended larval lifespan. Marf is required to form contacts between the endoplasmic reticulum and/or lipid droplets (LDs) and for proper storage of cholesterol and ecdysone synthesis in ring glands. Interestingly, human Mitofusin-2 rescues the loss of LD but both Mitofusin-1 and Mitofusin-2 are required for steroid-hormone synthesis. Our data show that Marf and Mitofusins share an evolutionarily conserved role in mitochondrial transport, cholesterol ester storage and steroid-hormone synthesis. DOI: http://dx.doi.org/10.7554/eLife.03558.001 PMID:25313867

  18. Regulatory Networks that Direct the Development of Specialized Cell Types in the Drosophila Heart

    PubMed Central

    Lovato, TyAnna L.; Cripps, Richard M.

    2016-01-01

    The Drosophila cardiac tube was once thought to be a simple linear structure, however research over the past 15 years has revealed significant cellular and molecular complexity to this organ. Prior reviews have focused upon the gene regulatory networks responsible for the specification of the cardiac field and the activation of cardiac muscle structural genes. Here we focus upon highlighting the existence, function, and development of unique cell types within the dorsal vessel, and discuss their correspondence to analogous structures in the vertebrate heart. PMID:27695700

  19. Effects of Madagascar yam extracts, Dioscorea antaly, on embryo-larval development of medaka fish, Oryzias latipes.

    PubMed

    Rakotobe, Lolona; Berkal, Miassa; Huet, Hélène; Djediat, Chakib; Jeannoda, Victor; Bodo, Bernard; Mambu, Lengo; Crespeau, François; Edery, Marc

    2010-01-01

    The yams edible starchy tubers, are of cultural, economic and nutritional importance in tropical and subtropical regions. The present study concerns the analysis at different levels of Dioscorea antaly toxicity to medaka embryo-larval development. The incubation of medaka fish embryos in a medium containing Dioscorea antaly extract resulted in a dose dependent reduction in survival rate. Survival rates were reduced up to 100% with extract concentrations of 4mg mL(-1). The LD(50) was estimated to be 0.86mg mL(-1)Dioscorea antaly. Anatomopathological studies did not show any caustic effects, irritation to mouth, throat or intestinal tract in surviving embryos but rather an inflammatory reaction in the liver. The data presented in this paper thus extends the use of medaka embryos as a valuable model to analyze the effects of food toxins.

  20. Foraging Path-length Protocol for Drosophila melanogaster Larvae.

    PubMed

    Anreiter, Ina; Vasquez, Oscar E; Allen, Aaron M; Sokolowski, Marla B

    2016-04-23

    The Drosophila melanogaster larval path-length phenotype is an established measure used to study the genetic and environmental contributions to behavioral variation. The larval path-length assay was developed to measure individual differences in foraging behavior that were later linked to the foraging gene. Larval path-length is an easily scored trait that facilitates the collection of large sample sizes, at minimal cost, for genetic screens. Here we provide a detailed description of the current protocol for the larval path-length assay first used by Sokolowski. The protocol details how to reproducibly handle test animals, perform the behavioral assay and analyze the data. An example of how the assay can be used to measure behavioral plasticity in response to environmental change, by manipulating feeding environment prior to performing the assay, is also provided. Finally, appropriate test design as well as environmental factors that can modify larval path-length such as food quality, developmental age and day effects are discussed.

  1. Foraging Path-length Protocol for Drosophila melanogaster Larvae.

    PubMed

    Anreiter, Ina; Vasquez, Oscar E; Allen, Aaron M; Sokolowski, Marla B

    2016-01-01

    The Drosophila melanogaster larval path-length phenotype is an established measure used to study the genetic and environmental contributions to behavioral variation. The larval path-length assay was developed to measure individual differences in foraging behavior that were later linked to the foraging gene. Larval path-length is an easily scored trait that facilitates the collection of large sample sizes, at minimal cost, for genetic screens. Here we provide a detailed description of the current protocol for the larval path-length assay first used by Sokolowski. The protocol details how to reproducibly handle test animals, perform the behavioral assay and analyze the data. An example of how the assay can be used to measure behavioral plasticity in response to environmental change, by manipulating feeding environment prior to performing the assay, is also provided. Finally, appropriate test design as well as environmental factors that can modify larval path-length such as food quality, developmental age and day effects are discussed. PMID:27167330

  2. A Dicer-1 gene from white shrimp Litopenaeus vannamei: expression pattern in the processes of immune response and larval development.

    PubMed

    Yao, Xuemei; Wang, Lingling; Song, Linsheng; Zhang, Huan; Dong, Chaohua; Zhang, Ying; Qiu, Limei; Shi, Yaohua; Zhao, Jianmin; Bi, Yongkun

    2010-10-01

    Dicer is a member of the RNAase III family which catalyzes the cleavage of double-stranded RNA to small interfering RNAs and micro RNAs, and then directs sequence-specific gene silencing. In this paper, the full-length cDNA of Dicer-1 was cloned from white shrimp Litopenaeus vannamei (designated as LvDcr1). It was of 7636 bp, including a poly A tail, a 5' UTR of 136 bp, a 3' UTR of 78 bp, and an open reading frame (ORF) of 7422 bp encoding a putative protein of 2473 amino acids. The predicted amino acid sequence comprised all recognized functional domains found in other Dicer-1 homologues and showed the highest (97.7%) similarity to the Dicer-1 from tiger shrimp Penaeus mondon. Quantitative real-time PCR was employed to investigate the tissue distribution of LvDcr1 mRNA, and its expression in shrimps under virus challenge and larvae at different developmental stages. The LvDcr1 mRNA could be detected in all examined tissues with the highest expression level in hemocyte, and was up-regulated in hemocytes and gills after virus injection. These results indicated that LvDcr1 was involved in antiviral defense in adult shrimp. During the developmental stages from fertilized egg to postlarva VII, LvDcr1 was constitutively expressed at all examined development stages, but the expression level varied significantly. The highest expression level was observed in fertilized eggs and followed a decrease from fertilized egg to nauplius I stage. Then, the higher levels of expression were detected at nauplius V and postlarva stages. LvDcr1 expression regularly increased at the upper phase of nauplius, zoea and mysis stages than their prophase. The different expression of LvDcr1 in the larval stages could provide clues for understanding the early innate immunity in the process of shrimp larval development.

  3. Klf15 Is Critical for the Development and Differentiation of Drosophila Nephrocytes

    PubMed Central

    Bodmer, Rolf; Ocorr, Karen; Paululat, Achim; Hartley, Paul S.

    2015-01-01

    Insect nephrocytes are highly endocytic scavenger cells that represent the only invertebrate model for the study of human kidney podocytes. Despite their importance, nephrocyte development is largely uncharacterised. This work tested whether the insect ortholog of mammalian Kidney Krüppel-Like Factor (Klf15), a transcription factor required for mammalian podocyte differentiation, was required for insect nephrocyte development. It was found that expression of Drosophila Klf15 (dKlf15, previously known as Bteb2) was restricted to the only two nephrocyte populations in Drosophila, the garland cells and pericardial nephrocytes. Loss of dKlf15 function led to attrition of both nephrocyte populations and sensitised larvae to the xenotoxin silver nitrate. Although pericardial nephrocytes in dKlf15 loss of function mutants were specified during embryogenesis, they failed to express the slit diaphragm gene sticks and stones and did not form slit diaphragms. Conditional silencing of dKlf15 in adults led to reduced surface expression of the endocytic receptor Amnionless and loss of in vivo scavenger function. Over-expression of dKlf15 increased nephrocyte numbers and rescued age-dependent decline in nephrocyte function. The data place dKlf15 upstream of sns and Amnionless in a nephrocyte-restricted differentiation pathway and suggest dKlf15 expression is both necessary and sufficient to sustain nephrocyte differentiation. These findings explain the physiological relevance of dKlf15 in Drosophila and imply that the role of KLF15 in human podocytes is evolutionarily conserved. PMID:26301956

  4. CREB Binding Protein Functions During Successive Stages of Eye Development in Drosophila

    PubMed Central

    Kumar, Justin P.; Jamal, Tazeen; Doetsch, Alex; Turner, F. Rudolf; Duffy, Joseph B.

    2004-01-01

    During the development of the compound eye of Drosophila several signaling pathways exert both positive and inhibitory influences upon an array of nuclear transcription factors to produce a near-perfect lattice of unit eyes or ommatidia. Individual cells within the eye are exposed to many extracellular signals, express multiple surface receptors, and make use of a large complement of cell-subtype-specific DNA-binding transcription factors. Despite this enormous complexity, each cell will make the correct developmental choice and adopt the appropriate cell fate. How this process is managed remains a poorly understood paradigm. Members of the CREB binding protein (CBP)/p300 family have been shown to influence development by (1) acting as bridging molecules between the basal transcriptional machinery and specific DNA-binding transcription factors, (2) physically interacting with terminal members of signaling cascades, (3) acting as transcriptional coactivators of downstream target genes, and (4) playing a key role in chromatin remodeling. In a screen for new genes involved in eye development we have identified the Drosophila homolog of CBP as a key player in both eye specification and cell fate determination. We have used a variety of approaches to define the role of CBP in eye development on a cell-by-cell basis. PMID:15514061

  5. She’s a femme fatale: low-density larval development produces good disease vectors

    PubMed Central

    Juliano, Steven A; Ribeiro, Gabriel Sylvestre; Maciel-de-Freitas, Rafael; Castro, Márcia G; Codeço, Claudia; Lourenço-de-Oliveira, Ricardo; Lounibos, L Philip

    2014-01-01

    Two hypotheses for how conditions for larval mosquitoes affect vectorial capacity make opposite predictions about the relationship of adult size and frequency of infection with vector-borne pathogens. Competition among larvae produces small adult females. The competition-susceptibility hypothesis postulates that small females are more susceptible to infection and predicts frequency of infection should decrease with size. The competition-longevity hypothesis postulates that small females have lower longevity and lower probability of becoming competent to transmit the pathogen and thus predicts frequency of infection should increase with size. We tested these hypotheses for Aedes aegypti in Rio de Janeiro, Brazil, during a dengue outbreak. In the laboratory, longevity increases with size, then decreases at the largest sizes. For field-collected females, generalised linear mixed model comparisons showed that a model with a linear increase of frequency of dengue with size produced the best Akaike’s information criterion with a correction for small sample sizes (AICc). Consensus prediction of three competing models indicated that frequency of infection increases monotonically with female size, consistent with the competition-longevity hypothesis. Site frequency of infection was not significantly related to site mean size of females. Thus, our data indicate that uncrowded, low competition conditions for larvae produce the females that are most likely to be important vectors of dengue. More generally, ecological conditions, particularly crowding and intraspecific competition among larvae, are likely to affect vector-borne pathogen transmission in nature, in this case via effects on longevity of resulting adults. Heterogeneity among individual vectors in likelihood of infection is a generally important outcome of ecological conditions impacting vectors as larvae. PMID:25591112

  6. Assaying Blood Cell Populations of the Drosophila melanogaster Larva

    PubMed Central

    Petraki, Sophia; Alexander, Brandy; Brückner, Katja

    2015-01-01

    In vertebrates, hematopoiesis is regulated by inductive microenvironments (niches). Likewise, in the invertebrate model organism Drosophila melanogaster, inductive microenvironments known as larval Hematopoietic Pockets (HPs) have been identified as anatomical sites for the development and regulation of blood cells (hemocytes), in particular of the self-renewing macrophage lineage. HPs are segmentally repeated pockets between the epidermis and muscle layers of the larva, which also comprise sensory neurons of the peripheral nervous system. In the larva, resident (sessile) hemocytes are exposed to anti-apoptotic, adhesive and proliferative cues from these sensory neurons and potentially other components of the HPs, such as the lining muscle and epithelial layers. During normal development, gradual release of resident hemocytes from the HPs fuels the population of circulating hemocytes, which culminates in the release of most of the resident hemocytes at the beginning of metamorphosis. Immune assaults, physical injury or mechanical disturbance trigger the premature release of resident hemocytes into circulation. The switch of larval hemocytes between resident locations and circulation raises the need for a common standard/procedure to selectively isolate and quantify these two populations of blood cells from single Drosophila larvae. Accordingly, this protocol describes an automated method to release and quantify the resident and circulating hemocytes from single larvae. The method facilitates ex vivo approaches, and may be adapted to serve a variety of developmental stages of Drosophila and other invertebrate organisms. PMID:26650404

  7. Morphogenesis of the somatic musculature in Drosophila melanogaster

    PubMed Central

    Schulman, Victoria K.; Dobi, Krista C.; Baylies, Mary K.

    2015-01-01

    In Drosophila melanogaster, the somatic muscle system is first formed during embryogenesis, giving rise to the larval musculature. Later during metamorphosis, this system is destroyed and replaced by an entirely new set of muscles in the adult fly. Proper formation of the larval and adult muscles is critical for basic survival functions such as hatching and crawling (in the larva), walking and flying (in the adult), and feeding (at both larval and adult stages). Myogenesis, from mononucleated muscle precursor cells to multinucleated functional muscles, is driven by a number of cellular processes that have begun to be mechanistically defined. Once themesodermal cells destined for themyogenic lineage have been specified, individual myoblasts fuse together iteratively to form syncytial myofibers. Combining cytoplasmic contents demands a level of intracellular reorganization that, most notably, leads to redistribution of the myonuclei to maximize internuclear distance. Signaling from extending myofibers induces terminal tendon cell differentiation in the ectoderm, which results in secure muscle-tendon attachments that are critical formuscle contraction. Simultaneously, muscles become innervated and undergo sarcomerogenesis to establish the contractile apparatus that will facilitate movement. The cellular mechanisms governing these morphogenetic events share numerous parallels to mammalian development, and the basic unit of all muscle, the myofiber, is conserved from flies to mammals. Thus, studies of Drosophila myogenesis and comparisons to muscle development in other systems highlight conserved regulatory programs of biomedical relevance to general muscle biology and studies of muscle disease. PMID:25758712

  8. The Drosophila 7SK snRNP and the essential role of dHEXIM in development

    PubMed Central

    Nguyen, Duy; Krueger, Brian J.; Sedore, Stanley C.; Brogie, John E.; Rogers, Jason T.; Rajendra, T. K.; Saunders, Abbie; Matera, A. Greg; Lis, John T.; Uguen, Patricia

    2012-01-01

    Regulation of the positive transcription elongation factor, P-TEFb, plays a major role in controlling mammalian transcription and this is accomplished in part by controlled release of P-TEFb from the 7SK snRNP that sequesters the kinase in an inactive state. We demonstrate here that a similar P-TEFb control system exists in Drosophila. We show that an RNA previously suggested to be a 7SK homolog is, in fact, associated with P-TEFb, through the action of a homolog of the human HEXIM1/2 proteins (dHEXIM). In addition, a Drosophila La related protein (now called dLARP7) is shown to be the functional homolog of human LARP7. The Drosophila 7SK snRNP (d7SK snRNP) responded to treatment of cells with P-TEFb inhibitors and to nuclease treatment of cell lysates by releasing P-TEFb. Supporting a critical role for the d7SK snRNP in Drosophila development, dLARP7 and dHEXIM were found to be ubiquitously expressed throughout embryos and tissues at all stages. Importantly, knockdown of dHEXIM was embryonic lethal, and reduction of dHEXIM in specific tissues led to serious developmental defects. Our results suggest that regulation of P-TEFb by the d7SK snRNP is essential for the growth and differentiation of tissues required during Drosophila development. PMID:22379134

  9. Dual functionality of O-GlcNAc transferase is required for Drosophila development.

    PubMed

    Mariappa, Daniel; Zheng, Xiaowei; Schimpl, Marianne; Raimi, Olawale; Ferenbach, Andrew T; Müller, H-Arno J; van Aalten, Daan M F

    2015-12-01

    Post-translational modification of intracellular proteins with O-linked N-acetylglucosamine (O-GlcNAc) catalysed by O-GlcNAc transferase (OGT) has been linked to regulation of diverse cellular functions. OGT possesses a C-terminal glycosyltransferase catalytic domain and N-terminal tetratricopeptide repeats that are implicated in protein-protein interactions. Drosophila OGT (DmOGT) is encoded by super sex combs (sxc), mutants of which are pupal lethal. However, it is not clear if this phenotype is caused by reduction of O-GlcNAcylation. Here we use a genetic approach to demonstrate that post-pupal Drosophila development can proceed with negligible OGT catalysis, while early embryonic development is OGT activity-dependent. Structural and enzymatic comparison between human OGT (hOGT) and DmOGT informed the rational design of DmOGT point mutants with a range of reduced catalytic activities. Strikingly, a severely hypomorphic OGT mutant complements sxc pupal lethality. However, the hypomorphic OGT mutant-rescued progeny do not produce F2 adults, because a set of Hox genes is de-repressed in F2 embryos, resulting in homeotic phenotypes. Thus, OGT catalytic activity is required up to late pupal stages, while further development proceeds with severely reduced OGT activity.

  10. Quantitative analysis of bristle number in Drosophila mutants identifies genes involved in neural development

    NASA Technical Reports Server (NTRS)

    Norga, Koenraad K.; Gurganus, Marjorie C.; Dilda, Christy L.; Yamamoto, Akihiko; Lyman, Richard F.; Patel, Prajal H.; Rubin, Gerald M.; Hoskins, Roger A.; Mackay, Trudy F.; Bellen, Hugo J.

    2003-01-01

    BACKGROUND: The identification of the function of all genes that contribute to specific biological processes and complex traits is one of the major challenges in the postgenomic era. One approach is to employ forward genetic screens in genetically tractable model organisms. In Drosophila melanogaster, P element-mediated insertional mutagenesis is a versatile tool for the dissection of molecular pathways, and there is an ongoing effort to tag every gene with a P element insertion. However, the vast majority of P element insertion lines are viable and fertile as homozygotes and do not exhibit obvious phenotypic defects, perhaps because of the tendency for P elements to insert 5' of transcription units. Quantitative genetic analysis of subtle effects of P element mutations that have been induced in an isogenic background may be a highly efficient method for functional genome annotation. RESULTS: Here, we have tested the efficacy of this strategy by assessing the extent to which screening for quantitative effects of P elements on sensory bristle number can identify genes affecting neural development. We find that such quantitative screens uncover an unusually large number of genes that are known to function in neural development, as well as genes with yet uncharacterized effects on neural development, and novel loci. CONCLUSIONS: Our findings establish the use of quantitative trait analysis for functional genome annotation through forward genetics. Similar analyses of quantitative effects of P element insertions will facilitate our understanding of the genes affecting many other complex traits in Drosophila.

  11. Involvement of a putative allatostatin in regulation of juvenile hormone titer and the larval development in Leptinotarsa decemlineata (Say).

    PubMed

    Meng, Qing-Wei; Liu, Xin-Ping; Lü, Feng-Gong; Fu, Kai-Yun; Guo, Wen-Chao; Li, Guo-Qing

    2015-01-01

    Juvenile hormone III (JH III) plays primary roles in regulation of metamorphosis, reproduction and diapause in Leptinotarsa decemlineata, a notorious defoliator of potato. The neurosecretory cell-borne substance(s) negatively affects the final two steps in JH biosynthesis, catalyzed respectively by an epoxidase CYP15A1 and a juvenile hormone acid methyltransferase (JHAMT). In a few insect species other than L. decemlineata, the inhibitory substance is allatostatin (AS) neuropeptide. In this study, two putative AS genes encoding LdAS-C and LdAS-B precursors were cloned. Both LdAS-C and LdAS-B were expressed in the egg, larvae, pupae and adults, and highly expressed in the brain and the gut. Dietary introduction of double-stranded RNAs (dsRNAs) targeting LdAS-C and LdAS-B successfully knocked down respective target genes. Ingestion during 3 and 6 consecutive days of dsLdAS-C significantly increased the LdJHAMT mRNA levels by 3.8 and 9.9 fold respectively. In contrast, ingestion of dsLdAS-B only slightly increased the LdJHAMT expression level by 1.1 and 1.7 fold. Moreover, after one, two and three days' ingestion of dsLdAS-C, the relative JH levels in the hemolymph of treated larvae were 2.5, 4.2 and 1.9 fold higher than those in control beetles. Furthermore, ingestion of dsLdAS-C and dsLdAS-B significantly affected larval growth and delayed larval development. Thus, we provide a line of experimental evidence in L. decemlineata to support the concept that AS-C acts as an allatostatin and inhibit JH biosynthesis. PMID:25452193

  12. Deletion of a conserved regulatory element in the Drosophila Adh gene leads to increased alcohol dehydrogenase activity but also delays development.

    PubMed Central

    Parsch, J; Russell, J A; Beerman, I; Hartl, D L; Stephan, W

    2000-01-01

    In vivo levels of enzymatic activity may be increased through either structural or regulatory changes. Here we use Drosophila melanogaster alcohol dehydrogenase (ADH) in an experimental test for selective differences between these two mechanisms. The well-known ADH-Slow (S)/Fast (F) amino acid replacement leads to a twofold increase in activity by increasing the catalytic efficiency of the enzyme. Disruption of a highly conserved, negative regulatory element in the Adh 3' UTR also leads to a twofold increase in activity, although this is achieved by increasing in vivo Adh mRNA and protein concentrations. These two changes appear to be under different types of selection, with positive selection favoring the amino acid replacement and purifying selection maintaining the 3' UTR sequence. Using transgenic experiments we show that deletion of the conserved 3' UTR element increases adult and larval Adh expression in both the ADH-F and ADH-S genetic backgrounds. However, the 3' UTR deletion also leads to a significant increase in developmental time in both backgrounds. ADH allozyme type has no detectable effect on development. These results demonstrate a negative fitness effect associated with Adh overexpression. This provides a mechanism whereby natural selection can discriminate between alternative pathways of increasing enzymatic activity. PMID:10978287

  13. Optogenetic stimulation of Drosophila heart rate at different temperatures and Ca2+ concentrations.

    PubMed

    Zhu, Yue C; Uradu, Henry; Majeed, Zana R; Cooper, Robin L

    2016-02-01

    Optogenetics is a revolutionary technique that enables noninvasive activation of electrically excitable cells. In mammals, heart rate has traditionally been modulated with pharmacological agents or direct stimulation of cardiac tissue with electrodes. However, implanted wires have been known to cause physical damage and damage from electrical currents. Here, we describe a proof of concept to optically drive cardiac function in a model organism, Drosophila melanogaster. We expressed the light sensitive channelrhodopsin protein ChR2.XXL in larval Drosophila hearts and examined light-induced activation of cardiac tissue. After demonstrating optical stimulation of larval heart rate, the approach was tested at low temperature and low calcium levels to simulate mammalian heart transplant conditions. Optical activation of ChR2.XXL substantially increased heart rate in all conditions. We have developed a system that can be instrumental in characterizing the physiology of optogenetically controlled cardiac function with an intact heart. PMID:26834237

  14. Identification and characterization of kraken, a gene encoding a putative hydrolytic enzyme in Drosophila melanogaster.

    PubMed

    Edwin Chan, H Y; Harris, S J; O'Kane, C J

    1998-11-19

    Kraken, a novel Drosophila gene isolated from a 4-8-h-old Drosophila embryo cDNA library, shows homology to a family of serine hydrolases whose common feature is that they all catalyse breakage of substrates with a carbonyl-containing group. It is a single-copy gene with at least two introns and maps to position 21D on polytene chromosomes. kraken is a member of a conserved gene family. Messenger RNA of kraken is expressed ubiquitously in early embryogenesis. Later, it is concentrated in the foregut and the posterior midgut primordium. Towards the end of embryogenesis, expression of kraken is confined to the gastric caeca. During the third-instar larval stage, kraken is expressed at low levels in the gastric caeca and parts of the gut, and at higher levels in the fat body. We suggest a role for Kraken in detoxification and digestion during embryogenesis and larval development. PMID:9831651

  15. Abbreviation of larval development and extension of brood care as key features of the evolution of freshwater Decapoda.

    PubMed

    Vogt, Günter

    2013-02-01

    The transition from marine to freshwater habitats is one of the major steps in the evolution of life. In the decapod crustaceans, four groups have colonized fresh water at different geological times since the Triassic, the freshwater shrimps, freshwater crayfish, freshwater crabs and freshwater anomurans. Some families have even colonized terrestrial habitats via the freshwater route or directly via the sea shore. Since none of these taxa has ever reinvaded its environment of origin the Decapoda appear particularly suitable to investigate life-history adaptations to fresh water. Evolutionary comparison of marine, freshwater and terrestrial decapods suggests that the reduction of egg number, abbreviation of larval development, extension of brood care and lecithotrophy of the first posthatching life stages are key adaptations to fresh water. Marine decapods usually have high numbers of small eggs and develop through a prolonged planktonic larval cycle, whereas the production of small numbers of large eggs, direct development and extended brood care until the juvenile stage is the rule in freshwater crayfish, primary freshwater crabs and aeglid anomurans. The amphidromous freshwater shrimp and freshwater crab species and all terrestrial decapods that invaded land via the sea shore have retained ocean-type planktonic development. Abbreviation of larval development and extension of brood care are interpreted as adaptations to the particularly strong variations of hydrodynamic parameters, physico-chemical factors and phytoplankton availability in freshwater habitats. These life-history changes increase fitness of the offspring and are obviously favoured by natural selection, explaining their multiple origins in fresh water. There is no evidence for their early evolution in the marine ancestors of the extant freshwater groups and a preadaptive role for the conquest of fresh water. The costs of the shift from relative r- to K-strategy in freshwater decapods are traded

  16. The potential of ocean acidification on suppressing larval development in the Pacific oyster Crassostrea gigas and blood cockle Arca inflata Reeve

    NASA Astrophysics Data System (ADS)

    Li, Jiaqi; Jiang, Zengjie; Zhang, Jihong; Mao, Yuze; Bian, Dapeng; Fang, Jianguang

    2014-11-01

    We evaluated the effect of pH on larval development in larval Pacific oyster ( Crassostrea gigas) and blood cockle ( Arca inflata Reeve). The larvae were reared at pH 8.2 (control), 7.9, 7.6, or 7.3 beginning 30 min or 24 h post fertilization. Exposure to lower pH during early embryonic development inhibited larval shell formation in both species. Compared with the control, larvae took longer to reach the D-veliger stage when reared under pH 7.6 and 7.3. Exposure to lower pH immediately after fertilization resulted in significantly delayed shell formation in the Pacific oyster larvae at pH 7.3 and blood cockle larvae at pH 7.6 and 7.3. However, when exposure was delayed until 24 h post fertilization, shell formation was only inhibited in blood cockle larvae reared at pH 7.3. Thus, the early embryonic stages were more sensitive to acidified conditions. Our results suggest that ocean acidification will have an adverse effect on embryonic development in bivalves. Although the effects appear subtle, they may accumulate and lead to subsequent issues during later larval development.

  17. Development of liquid larval diet with modified rearing system for Bactrocera dorsalis (Hendel) (Diptera:Tephritidae) for the application of sterile insect technique

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A liquid larval diet and its rearing system have been developed for mass rearing of Bactrocera dorsalis (Hendel) in Hawaii. Rearing facility in Institute of Food and Radiation Biology, Atomic Energy Research Establishment, Dhaka, Bangladesh, modified protein source from brewer's yeast to a combinat...

  18. Complete larval development of Thor amboinensis (De Man, 1888) Decapoda: Thoridae) described from laboratory-reared material
    and identified by DNA barcoding.

    PubMed

    Bartilotti, Cátia; Salabert, Joana; Santos, Antonina Dos

    2016-01-18

    Of the 12 species of Thor described until present date, only three (25%) have their complete larval development known. Present work describes the complete larval development of Thor amboinensis, based on laboratory-reared material. The spent females were identified through the analysis of the partial sequences of the mitochondrial DNA barcode, also used for the reconstruction of the phylogenetic relationships within the recently resurrected and recognized family Thoridae Kingsley, 1879. Eight zoeal stages and one decapodid complete this species larval development. In the genus Thor, the number of zoeal stages varies greatly from two (T. dobkini) to eight (T. amboinensis and T. floridanus). The larvae of T. ambionensis and T. floridanus are readily distinguished from each other by the ornamentation of the ventral margin of the carapace and the pereiopods development. The first zoeal stage of T. amboinensis described by Yang & Okuno (2004) and the one described in present study are very similar. A brief discussion on the morphological characters and on the number of zoeal stages of the genus, as well as of the previous larval descriptions is made. The phylogenetic analysis suggest cryptic speciation for geographical separated populations of T. amboinensis, paraphyly of the genus Eualus, and the reassignment of E. cranchii to a different genus.

  19. Complete larval development of Thor amboinensis (De Man, 1888) Decapoda: Thoridae) described from laboratory-reared material
    and identified by DNA barcoding.

    PubMed

    Bartilotti, Cátia; Salabert, Joana; Santos, Antonina Dos

    2016-01-01

    Of the 12 species of Thor described until present date, only three (25%) have their complete larval development known. Present work describes the complete larval development of Thor amboinensis, based on laboratory-reared material. The spent females were identified through the analysis of the partial sequences of the mitochondrial DNA barcode, also used for the reconstruction of the phylogenetic relationships within the recently resurrected and recognized family Thoridae Kingsley, 1879. Eight zoeal stages and one decapodid complete this species larval development. In the genus Thor, the number of zoeal stages varies greatly from two (T. dobkini) to eight (T. amboinensis and T. floridanus). The larvae of T. ambionensis and T. floridanus are readily distinguished from each other by the ornamentation of the ventral margin of the carapace and the pereiopods development. The first zoeal stage of T. amboinensis described by Yang & Okuno (2004) and the one described in present study are very similar. A brief discussion on the morphological characters and on the number of zoeal stages of the genus, as well as of the previous larval descriptions is made. The phylogenetic analysis suggest cryptic speciation for geographical separated populations of T. amboinensis, paraphyly of the genus Eualus, and the reassignment of E. cranchii to a different genus. PMID:27395843

  20. GROWTH AND VARIATIONS IN LIPID CLASS AND FATTY ACID COMPOSITION DURING LARVAL DEVELOPMENT OF THE STONE CRAB, MENIPPE ADINA WILLIAMS AND FELDER, 1986

    EPA Science Inventory

    Larval development in decapod crustaceans is marked by variable growth patterns and changes in weight and biochemical composition. Larvae of the stone crab, Menippe adina, were mass-reared under laboratory conditions (28|C; 20o/ooS) from hatching to the megalopal stage. Growth in...

  1. GROWTH AND VARIATIONS IN LIPID CLASS AND FATTY ACID COMPOSITION DURING LARVAL DEVELOPMENT OF THE STONE CRAB, MENIPPE ADINA WILLIAMS AND FELDER, 1986.

    EPA Science Inventory

    Larval development in decapod crustaceans is marked by variable growth patterns and changes in weight and biochemical composition. Larvae of the stone crab, Menippe adina, were mass-reared under laboratory conditions (28?C; 20o/ooS) from hatching to the megalopa stage. Growth in...

  2. Spen is required for pigment cell survival during pupal development in Drosophila.

    PubMed

    Querenet, Matthieu; Goubard, Valerie; Chatelain, Gilles; Davoust, Nathalie; Mollereau, Bertrand

    2015-06-15

    Apoptosis is required during development to eliminate superfluous cells and sculpt tissues; spatial and timed control of apoptosis ensures that the necessary number of cells is eliminated at a precise time in a given tissue. The elimination of supernumerary pigment or inter-ommatidial cells (IOCs) depends on cell-cell communication and is necessary for the formation of the honeycomb-like structure of the Drosophila eye. However, the mechanisms occurring during pupal development and controlling apoptosis of superfluous IOC in space and time remain unclear. Here, we found that split-ends (spen) is required for IOC survival at the time of removal of superfluous IOCs. Loss of spen function leads to abnormal removal of IOCs by apoptosis. We show that spen is required non-autonomously in cone cells for the survival of IOCs by positively regulating the Spitz/EGFR pathway. We propose that Spen is an important survival factor that ensures spatial control of the apoptotic wave that is necessary for the correct patterning and formation of the Drosophila eye.

  3. The role of the microbial environment in Drosophila post-embryonic development.

    PubMed

    Strigini, Maura; Leulier, François

    2016-11-01

    Development, growth and maturation of animals are under genetic and environmental control. Multicellular organisms interact throughout their lives with a variety of environment- and body-associated microorganisms. It has now been appreciated that the very conspicuous and varied microbial population associated with the food and the gastro-intestinal tract is a critical factor that can influence growth. Beyond the phenomenology, the mechanisms underlying the beneficial effects of microbes on development are being revealed from studies in Drosophila melanogaster, a particularly well suited system for a mechanistic understanding of host/microbiota interactions. Association of otherwise germ-free eggs with specific bacterial strains isolated from Drosophila gut samples can accelerate growth in larvae raised on restrictive diets. We review advances made possible by the exploitation of such simplified gnotobiotic systems in the search for the genes, molecules and physiological adaptations responsible for this effect in both host and microbes. Transposon mutagenesis and gene-trait match studies in bacteria can identify the key microbial genes and metabolites required for the beneficial effect, acetic acid being one of them. In the fly, functional genomic analysis, transcriptomics and metabolomics point to the modulation of systemic insulin and steroid hormone signalling as well as the regulation of intestinal physiology, including the enhancement of intestinal protease activity, as crucial mediators of the host's response.

  4. The Drosophila blood-brain barrier: development and function of a glial endothelium

    PubMed Central

    Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

    2014-01-01

    The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells. PMID:25452710

  5. The Drosophila blood-brain barrier: development and function of a glial endothelium.

    PubMed

    Limmer, Stefanie; Weiler, Astrid; Volkenhoff, Anne; Babatz, Felix; Klämbt, Christian

    2014-01-01

    The efficacy of neuronal function requires a well-balanced extracellular ion homeostasis and a steady supply with nutrients and metabolites. Therefore, all organisms equipped with a complex nervous system developed a so-called blood-brain barrier, protecting it from an uncontrolled entry of solutes, metabolites or pathogens. In higher vertebrates, this diffusion barrier is established by polarized endothelial cells that form extensive tight junctions, whereas in lower vertebrates and invertebrates the blood-brain barrier is exclusively formed by glial cells. Here, we review the development and function of the glial blood-brain barrier of Drosophila melanogaster. In the Drosophila nervous system, at least seven morphologically distinct glial cell classes can be distinguished. Two of these glial classes form the blood-brain barrier. Perineurial glial cells participate in nutrient uptake and establish a first diffusion barrier. The subperineurial glial (SPG) cells form septate junctions, which block paracellular diffusion and thus seal the nervous system from the hemolymph. We summarize the molecular basis of septate junction formation and address the different transport systems expressed by the blood-brain barrier forming glial cells. PMID:25452710

  6. miR-9a prevents apoptosis during wing development by repressing Drosophila LIM-only.

    PubMed

    Bejarano, Fernando; Smibert, Peter; Lai, Eric C

    2010-02-01

    Loss of Drosophila mir-9a induces a subtle increase in sensory bristles, but a substantial loss of wing tissue. Here, we establish that the latter phenotype is largely due to ectopic apoptosis in the dorsal wing primordium, and we could rescue wing development in the absence of this microRNA by dorsal-specific inhibition of apoptosis. Such apoptosis was a consequence of de-repressing Drosophila LIM-only (dLMO), which encodes a transcriptional regulator of wing and neural development. We observed cell-autonomous elevation of endogenous dLMO and a GFP-dLMO 3'UTR sensor in mir-9a mutant wing clones, and heterozygosity for dLMO rescued the apoptosis and wing defects of mir-9a mutants. We also provide evidence that dLMO, in addition to senseless, contributes to the bristle defects of the mir-9a mutant. Unexpectedly, the upregulation of dLMO, loss of Cut, and adult wing margin defects seen with mir-9a mutant clones were not recapitulated by clonal loss of the miRNA biogenesis factors Dicer-1 or Pasha, even though these mutant conditions similarly de-repressed miR-9a and dLMO sensor transgenes. Therefore, the failure to observe a phenotype upon conditional knockout of a miRNA processing factor does not reliably indicate the lack of critical roles of miRNAs in a given setting.

  7. Crumbs is required to achieve proper organ size control during Drosophila head development

    PubMed Central

    Richardson, Emily C. N.; Pichaud, Franck

    2010-01-01

    Crumbs (Crb) is a conserved apical polarity determinant required for zonula adherens specification and remodelling during Drosophila development. Interestingly, crb function in maintaining apicobasal polarity appears largely dispensable in primary epithelia such as the imaginal discs. Here, we show that crb function is not required for maintaining epithelial integrity during the morphogenesis of the Drosophila head and eye. However, although crb mutant heads are properly developed, they are also significantly larger than their wild-type counterparts. We demonstrate that in the eye, this is caused by an increase in cell proliferation that can be attributed to an increase in ligand-dependent Notch (N) signalling. Moreover, we show that in crb mutant cells, ectopic N activity correlates with an increase in N and Delta endocytosis. These data indicate a role for Crb in modulating endocytosis at the apical epithelial plasma membrane, which we demonstrate is independent of Crb function in apicobasal polarity. Overall, our work reveals a novel function for Crb in limiting ligand-dependent transactivation of the N receptor at the epithelial cell membrane. PMID:20110329

  8. Transcriptomic Analysis of Differentially Expressed Genes During Larval Development of Rapana venosa by Digital Gene Expression Profiling.

    PubMed

    Song, Hao; Yu, Zheng-Lin; Sun, Li-Na; Xue, Dong-Xiu; Zhang, Tao; Wang, Hai-Yan

    2016-07-07

    During the life cycle of shellfish, larval development, especially metamorphosis, has a vital influence on the dynamics, distribution, and recruitment of natural populations, as well as seed breeding. Rapana venosa, a carnivorous gastropod, is an important commercial shellfish in China, and is an ecological invader in the United States, Argentina, and France. However, information about the mechanism of its early development is still limited, because research in this area has long suffered from a lack of genomic resources. In this study, 15 digital gene expression (DGE) libraries from five developmental stages of R. venosa were constructed and sequenced on the IIIumina Hi-Sequation 2500 platform. Bioinformaticsanalysis identified numerous differentially and specifically expressed genes, which revealed that genes associated with growth, nervous system, digestive system, immune system, and apoptosis participate in important developmental processes. The functional analysis of differentially expressed genes was further implemented by gene ontology, and Kyoto encyclopedia of genes and genomes enrichment. DGE profiling provided a general picture of the transcriptomic activities during the early development of R. venosa, which may provide interesting hints for further study. Our data represent the first comparative transcriptomic information available for the early development of R. venosa, which is a prerequisite for a better understanding of the physiological traits controlling development.

  9. Transcriptomic Analysis of Differentially Expressed Genes During Larval Development of Rapana venosa by Digital Gene Expression Profiling.

    PubMed

    Song, Hao; Yu, Zheng-Lin; Sun, Li-Na; Xue, Dong-Xiu; Zhang, Tao; Wang, Hai-Yan

    2016-01-01

    During the life cycle of shellfish, larval development, especially metamorphosis, has a vital influence on the dynamics, distribution, and recruitment of natural populations, as well as seed breeding. Rapana venosa, a carnivorous gastropod, is an important commercial shellfish in China, and is an ecological invader in the United States, Argentina, and France. However, information about the mechanism of its early development is still limited, because research in this area has long suffered from a lack of genomic resources. In this study, 15 digital gene expression (DGE) libraries from five developmental stages of R. venosa were constructed and sequenced on the IIIumina Hi-Sequation 2500 platform. Bioinformaticsanalysis identified numerous differentially and specifically expressed genes, which revealed that genes associated with growth, nervous system, digestive system, immune system, and apoptosis participate in important developmental processes. The functional analysis of differentially expressed genes was further implemented by gene ontology, and Kyoto encyclopedia of genes and genomes enrichment. DGE profiling provided a general picture of the transcriptomic activities during the early development of R. venosa, which may provide interesting hints for further study. Our data represent the first comparative transcriptomic information available for the early development of R. venosa, which is a prerequisite for a better understanding of the physiological traits controlling development. PMID:27194808

  10. Transcriptomic Analysis of Differentially Expressed Genes During Larval Development of Rapana venosa by Digital Gene Expression Profiling

    PubMed Central

    Song, Hao; Yu, Zheng-Lin; Sun, Li-Na; Xue, Dong-Xiu; Zhang, Tao; Wang, Hai-Yan

    2016-01-01

    During the life cycle of shellfish, larval development, especially metamorphosis, has a vital influence on the dynamics, distribution, and recruitment of natural populations, as well as seed breeding. Rapana venosa, a carnivorous gastropod, is an important commercial shellfish in China, and is an ecological invader in the United States, Argentina, and France. However, information about the mechanism of its early development is still limited, because research in this area has long suffered from a lack of genomic resources. In this study, 15 digital gene expression (DGE) libraries from five developmental stages of R. venosa were constructed and sequenced on the IIIumina Hi-Sequation 2500 platform. Bioinformaticsanalysis identified numerous differentially and specifically expressed genes, which revealed that genes associated with growth, nervous system, digestive system, immune system, and apoptosis participate in important developmental processes. The functional analysis of differentially expressed genes was further implemented by gene ontology, and Kyoto encyclopedia of genes and genomes enrichment. DGE profiling provided a general picture of the transcriptomic activities during the early development of R. venosa, which may provide interesting hints for further study. Our data represent the first comparative transcriptomic information available for the early development of R. venosa, which is a prerequisite for a better understanding of the physiological traits controlling development. PMID:27194808

  11. Multifunctional RNA Processing Protein SRm160 Induces Apoptosis and Regulates Eye and Genital Development in Drosophila

    PubMed Central

    Fan, Yu-Jie; Gittis, Aryn H.; Juge, François; Qiu, Chen; Xu, Yong-Zhen; Rabinow, Leonard

    2014-01-01

    SRm160 is an SR-like protein implicated in multiple steps of RNA processing and nucleocytoplasmic export. Although its biochemical functions have been extensively described, its genetic interactions and potential participation in signaling pathways remain largely unknown, despite the fact that it is highly phosphorylated in both mammalian cells and Drosophila. To begin elucidating the functions of the protein in signaling and its potential role in developmental processes, we characterized mutant and overexpression SRm160 phenotypes in Drosophila and their interactions with the locus encoding the LAMMER protein kinase, Doa. SRm160 mutations are recessive lethal, while its overexpression generates phenotypes including roughened eyes and highly disorganized internal eye structure, which are due at least in part to aberrantly high levels of apoptosis. SRm160 is required for normal somatic sex determination, since its alleles strongly enhance a subtle sex transformation phenotype induced by Doa kinase alleles. Moreover, modification of SRm160 by DOA kinase appears to be necessary for its activity, since Doa alleles suppress phenotypes induced by SRm160 overexpression in the eye and enhance those in genital discs. Modification of SRm160 may occur through direct interaction because DOA kinase phosphorylates it in vitro. Remarkably, SRm160 protein was concentrated in the nuclei of precellular embryos but was very rapidly excluded from nuclei or degraded coincident with cellularization. Also of interest, transcripts are restricted almost exclusively to the developing nervous system in mature embryos. PMID:24907259

  12. Effects of sister chromatid cohesion proteins on cut gene expression during wing development in Drosophila

    PubMed Central

    Dorsett, Dale; Eissenberg, Joel C.; Misulovin, Ziva; Martens, Andrew; Redding, Bethany; McKim, Kim

    2006-01-01

    Summary The cohesin protein complex is a conserved structural component of chromosomes. Cohesin binds numerous sites along interphase chromosomes and is essential for sister chromatid cohesion and DNA repair. Here, we test the idea that cohesin also regulates gene expression. This idea arose from the finding that the Drosophila Nipped-B protein, a functional homolog of the yeast Scc2 factor that loads cohesin onto chromosomes, facilitates the transcriptional activation of certain genes by enhancers located many kilobases away from their promoters. We find that cohesin binds between a remote wing margin enhancer and the promoter at the cut locus in cultured cells, and that reducing the dosage of the Smc1 cohesin subunit increases cut expression in the developing wing margin. We also find that cut expression is increased by a unique pds5 gene mutation that reduces the binding of cohesin to chromosomes. On the basis of these results, we posit that cohesin inhibits long-range activation of the Drosophila cut gene, and that Nipped-B facilitates activation by regulating cohesin-chromosome binding. Such effects of cohesin on gene expression could be responsible for many of the developmental deficits that occur in Cornelia de Lange syndrome, which is caused by mutations in the human homolog of Nipped-B. PMID:16207752

  13. Multifunctional RNA processing protein SRm160 induces apoptosis and regulates eye and genital development in Drosophila.

    PubMed

    Fan, Yu-Jie; Gittis, Aryn H; Juge, François; Qiu, Chen; Xu, Yong-Zhen; Rabinow, Leonard

    2014-08-01

    SRm160 is an SR-like protein implicated in multiple steps of RNA processing and nucleocytoplasmic export. Although its biochemical functions have been extensively described, its genetic interactions and potential participation in signaling pathways remain largely unknown, despite the fact that it is highly phosphorylated in both mammalian cells and Drosophila. To begin elucidating the functions of the protein in signaling and its potential role in developmental processes, we characterized mutant and overexpression SRm160 phenotypes in Drosophila and their interactions with the locus encoding the LAMMER protein kinase, Doa. SRm160 mutations are recessive lethal, while its overexpression generates phenotypes including roughened eyes and highly disorganized internal eye structure, which are due at least in part to aberrantly high levels of apoptosis. SRm160 is required for normal somatic sex determination, since its alleles strongly enhance a subtle sex transformation phenotype induced by Doa kinase alleles. Moreover, modification of SRm160 by DOA kinase appears to be necessary for its activity, since Doa alleles suppress phenotypes induced by SRm160 overexpression in the eye and enhance those in genital discs. Modification of SRm160 may occur through direct interaction because DOA kinase phosphorylates it in vitro. Remarkably, SRm160 protein was concentrated in the nuclei of precellular embryos but was very rapidly excluded from nuclei or degraded coincident with cellularization. Also of interest, transcripts are restricted almost exclusively to the developing nervous system in mature embryos. PMID:24907259

  14. Drosophila cyfip regulates synaptic development and endocytosis by suppressing filamentous actin assembly.

    PubMed

    Zhao, Lu; Wang, Dan; Wang, Qifu; Rodal, Avital A; Zhang, Yong Q

    2013-04-01

    The formation of synapses and the proper construction of neural circuits depend on signaling pathways that regulate cytoskeletal structure and dynamics. After the mutual recognition of a growing axon and its target, multiple signaling pathways are activated that regulate cytoskeletal dynamics to determine the morphology and strength of the connection. By analyzing Drosophila mutations in the cytoplasmic FMRP interacting protein Cyfip, we demonstrate that this component of the WAVE complex inhibits the assembly of filamentous actin (F-actin) and thereby regulates key aspects of synaptogenesis. Cyfip regulates the distribution of F-actin filaments in presynaptic neuromuscular junction (NMJ) terminals. At cyfip mutant NMJs, F-actin assembly was accelerated, resulting in shorter NMJs, more numerous satellite boutons, and reduced quantal content. Increased synaptic vesicle size and failure to maintain excitatory junctional potential amplitudes under high-frequency stimulation in cyfip mutants indicated an endocytic defect. cyfip mutants exhibited upregulated bone morphogenetic protein (BMP) signaling, a major growth-promoting pathway known to be attenuated by endocytosis at the Drosophila NMJ. We propose that Cyfip regulates synapse development and endocytosis by inhibiting actin assembly.

  15. Protein O-mannosylation in animal development and physiology: from human disorders to Drosophila phenotypes

    PubMed Central

    Nakamura, Naosuke; Lyalin, Dmitry; Panin, Vladislav M.

    2010-01-01

    Protein O-mannosylation has a profound effect on the development and physiology of mammalian organisms. Mutations in genes affecting O-mannosyl glycan biosynthesis result in congenital muscular dystrophies. The main pathological mechanism triggered by O-mannosylation defects is a compromised interaction of cells with the extracellular matrix due to abnormal glycosylation of α-dystroglycan. Hypoglycosylation of α-dystroglycan impairs its ligand-binding activity and results in muscle degeneration and failure of neuronal migration. Recent experiments revealed the existence of compensatory mechanisms that could ameliorate defects of O-mannosylation. However, these mechanisms remain poorly understood. O-mannosylation and dystroglycan pathway genes show remarkable evolutionary conservation in a wide range of metazoans. Mutations and downregulation of these genes in zebrafish and Drosophila result in muscle defects and degeneration, also causing neurological phenotypes, which suggests that O-mannosylation has similar functions in mammals and lower animals. Thus, future studies in genetically tractable model organisms, such as zebrafish and Drosophila, should help to reveal molecular and genetic mechanisms of mammalian O-mannosylation and its role in the regulation of dystroglycan function. PMID:20362685

  16. Effete, an E2 ubiquitin-conjugating enzyme with multiple roles in Drosophila development and chromatin organization

    PubMed Central

    Cipressa, Francesca; Cenci, Giovanni

    2013-01-01

    The Drosophila effete gene encodes an extremely conserved class I E2 ubiquitin-conjugating enzyme. Growing evidence indicates that Eff is involved in many cellular processes including eye development, maintenance of female germline stem cells, and regulation of apoptosis. Eff is also a major component of Drosophila chromatin and it is particularly enriched in chromatin with repressive properties. In addition, Eff is required for telomere protection and to prevent telomere fusion. Consistent with its multiple roles in chromatin maintenance, Eff is also one of the rare factors that modulate both telomere-induced and heterochromatin-induced position effect variegation. PMID:24088712

  17. Effects of temperature and salinity on larval survival and development in the invasive shrimp Palaemon macrodactylus (Caridea: Palaemonidae) along the reproductive season

    NASA Astrophysics Data System (ADS)

    Guadalupe Vázquez, M.; Bas, Claudia C.; Kittlein, Marcelo; Spivak, Eduardo D.

    2015-05-01

    The invasive shrimp Palaemon macrodactylus is associated mainly with brackish waters. Previous studies raised the question if tolerance to low salinities differs between larvae and adults. To answer this question, the combined effects of two temperatures (20 and 25 °C) and four salinities (5, 12, 23 and 34 psu) on survival and development of larvae that hatched at the beginning, in the midpoint and near the end of a reproductive season (denoted early, middle season and late larvae respectively) were examined. The three types of larvae were able to survive and reach juvenile phase at salinities between 12 and 34 psu and at both temperatures. At 5 psu all larvae died, but 45% molted at least once. Temperature and salinity to a lesser extent, had effects on the duration of development and on the number of larval stages in all larval types. Development was longer at the lower temperature, especially in middle season and late larvae. Most early larvae reached the juvenile phase through 5 larval stages; the number of larval stages of middle season and late larvae was higher at 20 °C and in late larvae also low salinity produced extra stages. Low salinity (12 psu) and, in early and middle season larvae, low temperature produced lighter and smaller individuals. Response of larvae to environmental factors seems to be related in part to the previous conditions (maternal effects and/or embryo development conditions). The narrower salinity tolerance of larvae compared to adults and the ability of zoea I to survive at least some days at 5 psu may be related with an export larval strategy.

  18. Same but different: Larval development and gall-inducing process of a non-pollinating fig wasp compared to that of pollinating fig-wasps

    NASA Astrophysics Data System (ADS)

    Jansen-González, Sergio; Teixeira, Simone de Padua; Kjellberg, Finn; Pereira, Rodrigo A. Santinelo

    2014-05-01

    The receptacles of fig trees (Ficus spp.) can harbor a highly diversified and complex community of chalcid wasps. Functional groups of fig wasps (e.g. gallers, cleptoparasites and parasitoids) oviposit into the fig at different developmental stages, reflecting different feeding regimes for these insect larvae. There are few direct data available on larval feeding regimes and access to resources. We studied the gall induction and larval feeding strategy of an Idarnes (group flavicollis) species, a non-pollinating fig wasp (NPFW) associated to Ficus citrifolia P. Miller in Brazil. This Idarnes species shares with the pollinator characteristics such as time of oviposition, ovipositor insertion through flower and location of the egg inside plant ovaries. Nevertheless, we show that the gall induction differs considerably from that of the pollinating species. This Idarnes species relies on the induction of nucellus cell proliferation for gall formation and as the main larval resource. This strategy enables it to develop in both pollinated and unpollinated figs. The large differences between this NPFW and other fig wasps in how ovules are galled suggest that there are different ways to be a galler. A functional analysis of NPFW community structure may require descriptions of the histological processes associated with larval development.

  19. ParaHox gene expression in larval and postlarval development of the polychaete Nereis virens (Annelida, Lophotrochozoa)

    PubMed Central

    Kulakova, Milana A; Cook, Charles E; Andreeva, Tatiana F

    2008-01-01

    Background Transcription factors that encode ANTP-class homeobox genes play crucial roles in determining the body plan organization and specification of different organs and tissues in bilaterian animals. The three-gene ParaHox family descends from an ancestral gene cluster that existed before the evolution of the Bilateria. All three ParaHox genes are reported from deuterostomes and lophotrochozoans, but not to date from any ecdysozoan taxa, and there is evidence that the ParaHox genes, like the related Hox genes, were ancestrally a single chromosomal cluster. However, unlike the Hox genes, there is as yet no strong evidence that the ParaHox genes are expressed in spatial and temporal order during embryogenesis. Results We isolated fragments of the three Nereis virens ParaHox genes, then used these as probes for whole-mount in situ hybridization in larval and postlarval worms. In Nereis virens the ParaHox genes participate in antero-posterior patterning