The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Wilhelm Pinsker - One of the best experts on this subject based on the ideXlab platform.
-
Horizontal transmission versus vertical inheritance of P elements in Drosophila and Scaptomyza: has the M‐type subfamily spread from East Asia?
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: Sylvia Hagemann, Elisabeth Haring, Wilhelm PinskerAbstract:Polymerase chain reaction (PCR) screening for P elements was carried out in 77 species with a primer set highly specific for the M-type subfamily. In the course of this search M-type elements were detected in 29 species: In the melanogaster (subgroups montium and rhopaloa) and obscura species groups of Drosophila (25 out of 71 species examined), and in the genus Scaptomyza (four out of six species). M-type elements are present in all species of the montium subgroup investigated so far (21), but occur only sporadically in other groups. Within the montium subgroup 20 species possess only incomplete copies, only one species (D. lacteicornis) harbours apparently full-sized elements. In contrast, outside the montium subgroup almost all species with M-type elements carry full-sized copies suggesting transpositional activity, at least in the recent past. The interior section of the full-sized M-type element of D. lacteicornis was partially sequenced (936 bp). In addition, the complete sequences of four internally deleted M-type elements of D. lacteicornis, D. rufa, D. quadraria, and D. triauraria were determined. Sequence comparisons (including sequence data from previous investigations) revealed striking discrepancies between P element phylogeny and the cladogenesis of their host species. Among several possible pathways for interspecific transfers of M-type elements, we favour the hypothesis assuming the invasion of Scaptomyza as well as the obscura group species of Drosophila via independent transmission routes originating from Asian species of the montium subgroup of Drosophila. The logical geographic scenario for these events would be East-Asia.
-
horizontal transmission versus vertical inheritance of p elements in drosophila and Scaptomyza has the m type subfamily spread from east asia
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: Sylvia Hagemann, Elisabeth Haring, Wilhelm PinskerAbstract:Polymerase chain reaction (PCR) screening for P elements was carried out in 77 species with a primer set highly specific for the M-type subfamily. In the course of this search M-type elements were detected in 29 species: In the melanogaster (subgroups montium and rhopaloa) and obscura species groups of Drosophila (25 out of 71 species examined), and in the genus Scaptomyza (four out of six species). M-type elements are present in all species of the montium subgroup investigated so far (21), but occur only sporadically in other groups. Within the montium subgroup 20 species possess only incomplete copies, only one species (D. lacteicornis) harbours apparently full-sized elements. In contrast, outside the montium subgroup almost all species with M-type elements carry full-sized copies suggesting transpositional activity, at least in the recent past. The interior section of the full-sized M-type element of D. lacteicornis was partially sequenced (936 bp). In addition, the complete sequences of four internally deleted M-type elements of D. lacteicornis, D. rufa, D. quadraria, and D. triauraria were determined. Sequence comparisons (including sequence data from previous investigations) revealed striking discrepancies between P element phylogeny and the cladogenesis of their host species. Among several possible pathways for interspecific transfers of M-type elements, we favour the hypothesis assuming the invasion of Scaptomyza as well as the obscura group species of Drosophila via independent transmission routes originating from Asian species of the montium subgroup of Drosophila. The logical geographic scenario for these events would be East-Asia.
-
Identification of a complete P-element in the genome of Drosophila bifasciata.
Nucleic Acids Research, 1992Co-Authors: Sylvia Hagemann, Wolfgang J. Miller, Wilhelm PinskerAbstract:A full-size P-element (IbifM3) was isolated from a genomic library of Drosophila bifasciata. The sequence has a length of 2935 bp and is flanked by 8 bp duplications of the target site. The termini are formed by 31 bp inverted repeats. The four exons have intact reading frames and possess the coding capacity for a protein of 753 amino acids and a molecular weight of 86.4 kd. The sections of the D. melanogaster transposase presumed to be functionally important (three leucine zippers and a helix turn helix motif) are conserved in the D. bifasciata P-element. Copy number and genomic distribution resemble the situation in true P-strains of D. melanogaster. Both findings support the idea that IbifM3 represents an active transposon. The sequence comparison between the P-elements of D. bifasciata, D. melanogaster and Scaptomyza pallida reveals relationships not in accordance with the phylogeny of the species. This result suggests a further case of horizontal transmission involving mobile elements in the genus Drosophila.
Noah K. Whiteman - One of the best experts on this subject based on the ideXlab platform.
-
evolution and genetic basis of the plant penetrating ovipositor a key adaptation in the transition to herbivory within the drosophilidae
bioRxiv, 2020Co-Authors: Julianne N Pelaez, Andrew N Gloss, Julianne F Ray, Noah K. WhitemanAbstract:Herbivorous insects are extraordinarily diverse, yet are found in only one-third of insect orders. This skew may be driven by barriers to plant colonization coupled with phylogenetic constraint on plant-colonizing adaptations. Physical barriers can be surmounted by key innovations like the plant-penetrating ovipositor. Within Drosophilidae, ovipositor margins densely adorned with hard bristles used to cut into plants evolved repeatedly, but their evolutionary, developmental and genomic basis has only been explored in Drosophila suzukii. Here, we addressed this gap using Scaptomyza, an herbivorous radiation nested in a detritivorous clade. First, we found that ovipositor bristle number increased markedly as herbivory evolved in Scaptomyza. We then dissected the genomic architecture of variation in ovipositor bristle number within S. flava using a pooled genome wide association study (pool-GWAS). Variation in ovipositor bristle number in S. flava was heritable and associated with single nucleotide polymorphisms (SNPs) within non-coding regions involved in neural development. Genotyping of individual flies replicated the association at a candidate SNP upstream of Gai, a neural development gene, and estimated that it contributes to an average gain of ~0.58 bristles/ovipositor in S. flava. Neural developmental genes thus underlie variation in this key morphological adaptation, possibly facilitating the evolution of this trait and the colonization of tough tissue of living plants.
-
Habitat preference of an herbivore shapes the habitat distribution of its host plant.
Ecosphere, 2018Co-Authors: Nicolas M. Alexandre, Parris T. Humphrey, Andrew D. Gloss, Jimmy Lee, Joseph Frazier, Henry A. Affeldt, Noah K. WhitemanAbstract:Plant distributions can be limited by habitat‐biased herbivory, but the proximate causes of such biases are rarely known. Distinguishing plant‐centric from herbivore‐centric mechanisms driving differential herbivory between habitats is difficult without experimental manipulation of both plants and herbivores. Here, we tested alternative hypotheses driving habitat‐biased herbivory in bittercress (Cardamine cordifolia), which is more abundant under the shade of shrubs and trees (shade) than in nearby meadows (sun) where herbivory is intense from the specialist fly Scaptomyza nigrita. This system has served as a textbook example of habitat‐biased herbivory driving a plant's distribution across an ecotone, but the proximate mechanisms underlying differential herbivory are still unclear. First, we found that higher S. nigrita herbivory in sun habitats contrasts sharply with their preference to attack plants from shade habitats in laboratory‐choice experiments. Second, S. nigrita strongly preferred leaves in simulated sun over simulated shade habitats, regardless of plant source habitat. Thus, herbivore preference for brighter, warmer habitats overrides their preference for more palatable shade plants. This promotes the sun‐biased herbivore pressure that drives the distribution of bittercress into shade habitats.
-
habitat preference of an herbivore shapes the habitat distribution of its host plant
bioRxiv, 2017Co-Authors: Nicolas M. Alexandre, Parris T. Humphrey, Andrew D. Gloss, Jimmy Lee, Joseph Frazier, Henry A. Affeldt, Noah K. WhitemanAbstract:Habitat distributions of plants are often driven by abiotic factors, but growing evidence suggests an important role for consumers. A textbook example of consumers limiting the habitat distribution of a plant is in bittercress (Cardamine cordifolia). Bittercress is more abundant in shade than in sun habitats, and this is thought to arise because herbivore pressure is lower in the shade. Yet we still do not understand why herbivory is lower in the shade. Herbivores may avoid shaded bittercress because the plants are lower quality, or because herbivores simply prefer brighter, warmer habitats. We tested these alternative hypotheses through a series of herbivore choice experiments. Scaptomyza nigrita, a locally abundant specialist and dominant herbivore of bittercress, strongly preferred feeding and laying eggs on bittercress we collected from shade versus sun habitats. Thus, shaded bittercress are more, not less, palatable to these herbivores. Separately, S. nigrita strongly preferred feeding and laying eggs on leaves held in treatments that simulated sun rather than shade habitats--regardless of whether leaves came from sun or shade habitats originally. The underlying mechanism for an herbivore-driven plant distribution appears to be a simple behavioral preference of herbivores for brighter, warmer habitats.
-
Pseudomonas syringae enhances herbivory by suppressing the reactive oxygen burst in Arabidopsis
Journal of insect physiology, 2015Co-Authors: Simon C. Groen, Parris T. Humphrey, Frederick M. Ausubel, Daniela Chevasco, Naomi E. Pierce, Noah K. WhitemanAbstract:Plant-herbivore interactions have evolved in the presence of plant-colonizing microbes. These microbes can have important third-party effects on herbivore ecology, as exemplified by drosophilid flies that evolved from ancestors feeding on plant-associated microbes. Leaf-mining flies in the genus Scaptomyza, which is nested within the paraphyletic genus Drosophila, show strong associations with bacteria in the genus Pseudomonas, including Pseudomonas syringae. Adult females are capable of vectoring these bacteria between plants and larvae show a preference for feeding on P. syringae-infected leaves. Here we show that Scaptomyza flava larvae can also vector P. syringae to and from feeding sites, and that they not only feed more, but also develop faster on plants previously infected with P. syringae. Our genetic and physiological data show that P. syringae enhances S. flava feeding on infected plants at least in part by suppressing anti-herbivore defenses mediated by reactive oxygen species.
-
evolution of herbivory in drosophilidae linked to loss of behaviors antennal responses odorant receptors and ancestral diet
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Benjamin Goldmanhuertas, Richard T. Lapoint, Robert F Mitchell, Cecile P Faucher, John G Hildebrand, Noah K. WhitemanAbstract:Herbivory is a key innovation in insects, yet has only evolved in one-third of living orders. The evolution of herbivory likely involves major behavioral changes mediated by remodeling of canonical chemosensory modules. Herbivorous flies in the genus Scaptomyza (Drosophilidae) are compelling species in which to study the genomic architecture linked to the transition to herbivory because they recently evolved from microbe-feeding ancestors and are closely related to Drosophila melanogaster. We found that Scaptomyza flava, a leaf-mining specialist on plants in the family (Brassicaceae), was not attracted to yeast volatiles in a four-field olfactometer assay, whereas D. melanogaster was strongly attracted to these volatiles. Yeast-associated volatiles, especially short-chain aliphatic esters, elicited strong antennal responses in D. melanogaster, but weak antennal responses in electroantennographic recordings from S. flava. We sequenced the genome of S. flava and characterized this species’ odorant receptor repertoire. Orthologs of odorant receptors, which detect yeast volatiles in D. melanogaster and mediate critical host-choice behavior, were deleted or pseudogenized in the genome of S. flava. These genes were lost step-wise during the evolution of Scaptomyza. Additionally, Scaptomyza has experienced gene duplication and likely positive selection in paralogs of Or67b in D. melanogaster. Olfactory sensory neurons expressing Or67b are sensitive to green-leaf volatiles. Major trophic shifts in insects are associated with chemoreceptor gene loss as recently evolved ecologies shape sensory repertoires.
Sylvia Hagemann - One of the best experts on this subject based on the ideXlab platform.
-
Horizontal transmission versus vertical inheritance of P elements in Drosophila and Scaptomyza: has the M‐type subfamily spread from East Asia?
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: Sylvia Hagemann, Elisabeth Haring, Wilhelm PinskerAbstract:Polymerase chain reaction (PCR) screening for P elements was carried out in 77 species with a primer set highly specific for the M-type subfamily. In the course of this search M-type elements were detected in 29 species: In the melanogaster (subgroups montium and rhopaloa) and obscura species groups of Drosophila (25 out of 71 species examined), and in the genus Scaptomyza (four out of six species). M-type elements are present in all species of the montium subgroup investigated so far (21), but occur only sporadically in other groups. Within the montium subgroup 20 species possess only incomplete copies, only one species (D. lacteicornis) harbours apparently full-sized elements. In contrast, outside the montium subgroup almost all species with M-type elements carry full-sized copies suggesting transpositional activity, at least in the recent past. The interior section of the full-sized M-type element of D. lacteicornis was partially sequenced (936 bp). In addition, the complete sequences of four internally deleted M-type elements of D. lacteicornis, D. rufa, D. quadraria, and D. triauraria were determined. Sequence comparisons (including sequence data from previous investigations) revealed striking discrepancies between P element phylogeny and the cladogenesis of their host species. Among several possible pathways for interspecific transfers of M-type elements, we favour the hypothesis assuming the invasion of Scaptomyza as well as the obscura group species of Drosophila via independent transmission routes originating from Asian species of the montium subgroup of Drosophila. The logical geographic scenario for these events would be East-Asia.
-
horizontal transmission versus vertical inheritance of p elements in drosophila and Scaptomyza has the m type subfamily spread from east asia
Journal of Zoological Systematics and Evolutionary Research, 2009Co-Authors: Sylvia Hagemann, Elisabeth Haring, Wilhelm PinskerAbstract:Polymerase chain reaction (PCR) screening for P elements was carried out in 77 species with a primer set highly specific for the M-type subfamily. In the course of this search M-type elements were detected in 29 species: In the melanogaster (subgroups montium and rhopaloa) and obscura species groups of Drosophila (25 out of 71 species examined), and in the genus Scaptomyza (four out of six species). M-type elements are present in all species of the montium subgroup investigated so far (21), but occur only sporadically in other groups. Within the montium subgroup 20 species possess only incomplete copies, only one species (D. lacteicornis) harbours apparently full-sized elements. In contrast, outside the montium subgroup almost all species with M-type elements carry full-sized copies suggesting transpositional activity, at least in the recent past. The interior section of the full-sized M-type element of D. lacteicornis was partially sequenced (936 bp). In addition, the complete sequences of four internally deleted M-type elements of D. lacteicornis, D. rufa, D. quadraria, and D. triauraria were determined. Sequence comparisons (including sequence data from previous investigations) revealed striking discrepancies between P element phylogeny and the cladogenesis of their host species. Among several possible pathways for interspecific transfers of M-type elements, we favour the hypothesis assuming the invasion of Scaptomyza as well as the obscura group species of Drosophila via independent transmission routes originating from Asian species of the montium subgroup of Drosophila. The logical geographic scenario for these events would be East-Asia.
-
Identification of a complete P-element in the genome of Drosophila bifasciata.
Nucleic Acids Research, 1992Co-Authors: Sylvia Hagemann, Wolfgang J. Miller, Wilhelm PinskerAbstract:A full-size P-element (IbifM3) was isolated from a genomic library of Drosophila bifasciata. The sequence has a length of 2935 bp and is flanked by 8 bp duplications of the target site. The termini are formed by 31 bp inverted repeats. The four exons have intact reading frames and possess the coding capacity for a protein of 753 amino acids and a molecular weight of 86.4 kd. The sections of the D. melanogaster transposase presumed to be functionally important (three leucine zippers and a helix turn helix motif) are conserved in the D. bifasciata P-element. Copy number and genomic distribution resemble the situation in true P-strains of D. melanogaster. Both findings support the idea that IbifM3 represents an active transposon. The sequence comparison between the P-elements of D. bifasciata, D. melanogaster and Scaptomyza pallida reveals relationships not in accordance with the phylogeny of the species. This result suggests a further case of horizontal transmission involving mobile elements in the genus Drosophila.
Patrick M. O’grady - One of the best experts on this subject based on the ideXlab platform.
-
Microbial interactions and the ecology and evolution of Hawaiian Drosophilidae
Frontiers in Microbiology, 2014Co-Authors: Timothy K. O’connor, Noah K. Whiteman, Parris T. Humphrey, Richard T. Lapoint, Patrick M. O’gradyAbstract:Adaptive radiations are characterized by an increased rate of speciation and expanded range of habitats and ecological niches exploited by those species. The Hawaiian Drosophilidae is a classic adaptive radiation; a single ancestral species colonized Hawaii approximately 25 million years ago and gave rise to two monophyletic lineages, the Hawaiian Drosophila and the genus Scaptomyza. The Hawaiian Drosophila are largely saprophagous and rely on approximately 40 endemic plant families and their associated microbes to complete development. Scaptomyza are even more diverse in host breadth. While many species of Scaptomyza utilize decomposing plant substrates, some species have evolved to become herbivores, parasites on spider egg masses, and exploit microbes on living plant tissue. Understanding the origin of the ecological diversity encompassed by these nearly 700 described species has been a challenge. The central role of microbes in drosophilid ecology suggests bacterial and fungal associates may have played a role in the diversification of the Hawaiian Drosophilidae. Here we synthesize recent ecological and microbial community data from the Hawaiian Drosophilidae to examine the forces that may have led to this adaptive radiation. We propose that the evolutionary success of the Hawaiian Drosophilidae is due to a combination of factors, including adaptation to novel ecological niches facilitated by microbes.
-
Reviewed by: Rob DeSalle, American Museum of
2014Co-Authors: Patrick M. O’grady, Parris T. Humphrey, Noah K. Whiteman, Timothy K. O’connor, Richard T. Lapoint, Parris TAbstract:Humphrey have contributed equally to this work. Adaptive radiations are characterized by an increased rate of speciation and expanded range of habitats and ecological niches exploited by those species. The Hawaiian Drosophilidae is a classic adaptive radiation; a single ancestral species colonized Hawaii approximately 25 million years ago and gave rise to two monophyletic lineages, the Hawaiian Drosophila and the genus Scaptomyza. The Hawaiian Drosophila are largely saprophagous and rely on approximately 40 endemic plant families and their associated microbes to complete development. Scaptomyza are even more diverse in host breadth. While many species of Scaptomyza utilize decomposing plant substrates, some species have evolved to become herbivores, parasites on spider egg masses, and exploit microbes on living plant tissue. Understanding the origin of the ecological diversity encompassed by these nearly 700 described species has been a challenge.The central role of microbes in drosophilid ecology suggests bacterial and fungal associates may have played a role in the diversification of the Hawaiian Drosophilidae. Here we synthesize recent ecological and microbial communit
-
New combinations in Hawaiian Drosophila and Scaptomyza (Diptera: Drosophilidae)
Zootaxa, 2008Co-Authors: Karl N. Magnacca, Patrick M. O’gradyAbstract:The present paper transfers eight species from the genus Drosophila to the genus Scaptomyza based on characteristics of the male genitalia. One species, Scaptomyza (Titanochaeta) canuta (Hardy) new combination, fits within the concept of the subgenus Titanochaeta. The remaining seven taxa, S. improcera (Hardy) new combination, S. magnipalpa (Hardy) new combination, S. parva (Grimshawi) new combination, S. prolixa (Hardy) new combination, S. taractica (Hardy) new combination, S. totonigra (Hardy) new combination, and S. vinnula (Hardy) new combination, are included as unplaced species of Scaptomyza An additional species, Scaptomyza (Grimshawomyia) undulata (Grimshaw) new com- bination, is transferred from the subgenus EngiScaptomyza to Grimshawomyia based on morphological and molecular characters. An expanded key to the subgenera of Scaptomyza that includes these unplaced taxa is presented. In addition, Drosophila attigua Hardy & Kaneshiro is reduced to a junior new synonym of D. sharpi Grimshaw.
-
The placement of EngiScaptomyza, Grimshawomyia, and Titanochaeta, three clades of endemic Hawaiian Drosophilidae (Diptera)
Zootaxa, 2003Co-Authors: Patrick M. O’grady, James Bonacum, R. Desalle, Francisca Do ValAbstract:Based on a combination of molecular and morphological characters, two endemic Hawaiian genera, Titanochaeta Knab and Grimshawomyia Hardy, are transferred to subgenera within the genus Scaptomyza Hardy as is the Drosophila subgenus EngiScaptomyza Kaneshiro. Replacement names for three preoccupied species, Scaptomyza (Titanochaeta) neoevexa O’Grady et al., nom. nov. (for Titanochaeta evaza Hardy), S. (Titanochaeta) neokauaiensis O’Grady et al., nom. nov. (for Titanochaeta kauaiensis Hardy), and S. (Titanochaeta) neosilvicola O’Grady et al., nom. nov. (for Titanochaeta silvicola Hardy), are proposed. This brings the total number of described species in the genus Scaptomyza to 272, of which 141 are endemic to the Hawaiian Archipelago. In comparison, the genus Drosophila contains 368 species endemic to the Hawaiian Islands. Keys for the identification of the Hawaiian subgenera of Scaptomyza and species of EngiScaptomyza , Titanochaeta , and Grimshawomyia are also included.
-
Zygothrica desallei: A New Species of Drosophilidae (Diptera) from Ecuador
Annals of the Entomological Society of America, 2002Co-Authors: Patrick M. O’grady, Doris Vela, Violeta RafaelAbstract:An unusual new species of Zygothrica, Z. desallei, is described from Ecuador. This species possesses three supernumerary crossveins extending from vein R2 3 to the costa. Such a phenotype, while observed in other drosophilid genera such as Jeannelopsis and Scaptomyza (Tan- talia), has not been previously observed in Zygothrica.
Bill S. Hansson - One of the best experts on this subject based on the ideXlab platform.
-
Functional loss of yeast detectors parallels transition to herbivory
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Hany K. M. Dweck, Markus Knaden, Bill S. HanssonAbstract:Herbivorous insects are extraordinarily successful. Half of the world’s extant insects and one quarter of all living metazoan species belong to herbivorous insect lineages (1, 2). Although feeding on living plant tissue is an evolutionarily difficult transition, herbivorous insect lineages are more diverse than their nonherbivorous relatives (3, 4). In PNAS, Goldman-Huertas et al. (5) present both the underlying genetic basis and the resulting physiological changes that led to the evolution of herbivory in the fly Scaptomyza flava (Fig. 1).
