The Experts below are selected from a list of 279 Experts worldwide ranked by ideXlab platform
Cheryl Y Hayashi - One of the best experts on this subject based on the ideXlab platform.
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Molecular Evolution of Lepidopteran Silk Proteins: Insights from the Ghost Moth, Hepialus californicus
Journal of Molecular Evolution, 2010Co-Authors: Matthew A. Collin, Frantisek Sehnal, Kazuei Mita, Cheryl Y HayashiAbstract:Silk production has independently evolved in numerous arthropod lineages, such as Lepidoptera, the moths and butterflies. Lepidopteran larvae (caterpillars) synthesize silk proteins in modified salivary glands and spin silk fibers into protective tunnels, escape lines, and pupation cocoons. Molecular sequence data for these proteins are necessary to determine critical features of their function and evolution. To this end, we constructed an expression library from the silk glands of the ghost moth, Hepialus californicus , and characterized light chain fibroin and heavy chain fibroin gene transcripts. The predicted H. californicus silk fibroins share many elements with other lepidopteran and trichopteran fibroins, such as conserved placements of cysteine, aromatic, and polar amino acid residues. Further comparative analyses were performed to determine site-specific signatures of selection and to assess whether fibroin genes are informative as phylogenetic markers. We found that purifying selection has constrained mutation within the fibroins and that light chain fibroin is a promising molecular marker. Thus, by characterizing the H. californicus fibroins, we identified key functional amino acids and gained insight into the evolutionary processes that have shaped these adaptive molecules.
Matthew A. Collin - One of the best experts on this subject based on the ideXlab platform.
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Molecular Evolution of Lepidopteran Silk Proteins: Insights from the Ghost Moth, Hepialus californicus
Journal of Molecular Evolution, 2010Co-Authors: Matthew A. Collin, Frantisek Sehnal, Kazuei Mita, Cheryl Y HayashiAbstract:Silk production has independently evolved in numerous arthropod lineages, such as Lepidoptera, the moths and butterflies. Lepidopteran larvae (caterpillars) synthesize silk proteins in modified salivary glands and spin silk fibers into protective tunnels, escape lines, and pupation cocoons. Molecular sequence data for these proteins are necessary to determine critical features of their function and evolution. To this end, we constructed an expression library from the silk glands of the ghost moth, Hepialus californicus , and characterized light chain fibroin and heavy chain fibroin gene transcripts. The predicted H. californicus silk fibroins share many elements with other lepidopteran and trichopteran fibroins, such as conserved placements of cysteine, aromatic, and polar amino acid residues. Further comparative analyses were performed to determine site-specific signatures of selection and to assess whether fibroin genes are informative as phylogenetic markers. We found that purifying selection has constrained mutation within the fibroins and that light chain fibroin is a promising molecular marker. Thus, by characterizing the H. californicus fibroins, we identified key functional amino acids and gained insight into the evolutionary processes that have shaped these adaptive molecules.
Donald R Strong - One of the best experts on this subject based on the ideXlab platform.
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Host resistance reverses the outcome of competition between microparasites
Ecology, 2009Co-Authors: Daniel S. Gruner, Arunima Kolekar, John P. Mclaughlin, Donald R StrongAbstract:Predators and parasites can control the abundance or biomass of herbivores with indirect effects on producer communities and ecosystems, but the interplay of multiple natural enemies may yield unexpected dynamics. We experimentally examined interactions between two microparasites (entomopathogenic nematodes) isolated from sandy grassland soils of coastal California: Heterorhabditis marelatus (Heterorhabditidae) and Steinernema feltiae (Steinernematidae). Heterorhabditis marelatus drives trophic cascades by attacking root- and stem-boring ghost moth caterpillars (Hepialus californicus, Hepialidae), thereby indirectly protecting bush lupine shrubs (Lupinus arboreus, Fabaceae). Extensive field surveys demonstrated sympatric overlap in microhabitat use under lupine canopies and similar mean prevalence of the two nematode species. Using a response-surface design in the laboratory, we varied relative and absolute microparasite densities to test for competitive outcomes within an evolutionary naive host, larvae of the greater wax moth Galleria mellonella (Pyralidae), and within the native host Hepialus californicus. Independent of conspecific or interspecific density, S. feltiae dominated as expected over H. marelatus within the naive Galleria, but S. feltiae infected hosts at low frequency and showed lower reproductive fitness than H. marelatus within native Hepialus hosts. Contrary to studies that demonstrate the pairwise dominance of steinernematid over heterorhabditid species in laboratory hosts, host resistance to S. feltiae may provide a mechanism for coexistence of multiple microparasite species. We hypothesize that the ubiquitous field prevalence and rapid life history of S. feltiae imply its use of widespread, abundant but small-bodied hosts and indicate the lack of direct competition with H. marelatus in the Hepialus-Lupinus trophic cascade.
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Phoresy of the entomopathogenic nematode Heterorhabditis marelatus by a non-host organism, the isopod Porcellio scaber.
Journal of invertebrate pathology, 2005Co-Authors: Michael S. Eng, Evan L. Preisser, Donald R StrongAbstract:Entomopathogenic nematodes are widespread in nature and commonly used in the biological control of insect pests. However, we understand little about how these organisms disperse. We show in a laboratory setting that the entomopathogenic nematode Heterorhabditis marelatus is phoretically dispersed by a non-host organism, the isopod Porcellio scaber. These species both inhabit tunnels excavated in the roots and lower stems of bush lupine (Lupinus arboreus) by the nematodes' primary prey, larvae of the ghost moth Hepialus californicus. Phoretic dispersal via P. scaber may play a role in the metapopulation dynamics of this nematode.
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Short communication Phoresy of the entomopathogenic nematode Heterorhabditis marelatus by a non-host organism, the isopod Porcellio scaber
2005Co-Authors: Michael S. Eng, Evan L. Preisser, Donald R StrongAbstract:Entomopathogenic nematodes are widespread in nature and commonly used in the biological control of insect pests. However, we understand little about how these organisms disperse. We show in a laboratory setting that the entomopathogenic nematode Heterorhabditis marelatus is phoretically dispersed by a non-host organism, the isopod Porcellio scaber. These species both inhabit tunnels excavated in the roots and lower stems of bush lupine (Lupinus arboreus) by the nematodes’ primary prey, larvae of the ghost moth Hepialus californicus. Phoretic dispersal via P. scaber may play a role in the metapopulation dynamics of this nematode.
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climate affects predator control of an herbivore outbreak
The American Naturalist, 2004Co-Authors: Evan L. Preisser, Donald R StrongAbstract:Abstract: Herbivore outbreaks and the accompanying devastation of plant biomass can have enormous ecological effects. Climate directly affects such outbreaks through plant stress or alterations in herbivore life‐history traits. Large‐scale variation in climate can indirectly affect outbreaks through trophic interactions, but the magnitude of such effects is unknown. On the California coast, rainfall in years during and immediately previous to mass lupine mortality was two‐thirds that of years without such mortality. However, neither mature lupines nor their root‐feeding herbivores are directly affected by annual variation in rainfall. By increasing soil moisture to levels characteristic of summers following El Nino/Southern Oscillation (ENSO) events, we increased persistence of a predator (the entomopathogenic nematode Heterorhabditis marelatus). This led to suppression of an outbreak of the herbivorous moth Hepialus californicus, indirectly protecting bush lupine (Lupinus arboreus). Our results are consi...
John Turner - One of the best experts on this subject based on the ideXlab platform.
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the dawn flight of the gold swift Hepialus hecta predator avoidance and the integration of complex lek behaviour lepidoptera hepialidae
Biological Journal of The Linnean Society, 2013Co-Authors: John TurnerAbstract:Predator pressure is a considerable evolutionary force. The evening twilight flight of species in the family Hepialidae Swift moths has been attributed to the moths (which have no hearing and so cannot detect bats) flying in a bat/bird free window. Several species deploy elaborate lek behaviour in this period. The expected flight in the dawn twilight is little reported, except in the non-leking Hepialus (Korscheltellus) gracilis. A detailed study of the dawn flight in the leking species Hepialus (Phymatopus) hecta shows that it is less extensive than the evening lek flight (both in duration and in the number of moths participating), is confined to a much narrower window around sunrise, involves no reproductive behaviour, and functions only to re-locate the members of copulating pairs and sessile displaying males from the emergent ground vegetation to less conspicuous roosting sites. Compilation of individual biographies over the 24-h cycle permits a full construction of the diel activity in time and space. It consists of two twilight flight periods, separated by prolonged roosting during the hours of darkness and daylight. The moths use almost the whole available range of roosting sites, from the base of the ground vegetation to the tree canopy, and cyclically leave and re-enter the lek site from these positions. The copulating posture and position avoid mammalian predators, and facilitate escape from spiders and wasps by the efficient use of a dead drop. The narrowness of the dawn flight is attributed to the need for this prolonged but conspicuous copulation, which precludes a morning mating, and to a demonstrated asymmetry of twilight activity in birds. The whole integrated spatio-temporal cycle is attributable to evolutionary pressure to minimize the impact of predators, demonstrated to include birds, bats, wasps, and spiders, and probably also dragonflies, mice and shrews; the pre-existing dawn flight is permissive to the evolution of sessile male displays during the evening lek. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 305–319.
Frantisek Sehnal - One of the best experts on this subject based on the ideXlab platform.
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Molecular Evolution of Lepidopteran Silk Proteins: Insights from the Ghost Moth, Hepialus californicus
Journal of Molecular Evolution, 2010Co-Authors: Matthew A. Collin, Frantisek Sehnal, Kazuei Mita, Cheryl Y HayashiAbstract:Silk production has independently evolved in numerous arthropod lineages, such as Lepidoptera, the moths and butterflies. Lepidopteran larvae (caterpillars) synthesize silk proteins in modified salivary glands and spin silk fibers into protective tunnels, escape lines, and pupation cocoons. Molecular sequence data for these proteins are necessary to determine critical features of their function and evolution. To this end, we constructed an expression library from the silk glands of the ghost moth, Hepialus californicus , and characterized light chain fibroin and heavy chain fibroin gene transcripts. The predicted H. californicus silk fibroins share many elements with other lepidopteran and trichopteran fibroins, such as conserved placements of cysteine, aromatic, and polar amino acid residues. Further comparative analyses were performed to determine site-specific signatures of selection and to assess whether fibroin genes are informative as phylogenetic markers. We found that purifying selection has constrained mutation within the fibroins and that light chain fibroin is a promising molecular marker. Thus, by characterizing the H. californicus fibroins, we identified key functional amino acids and gained insight into the evolutionary processes that have shaped these adaptive molecules.