The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform
Thomas Eisner - One of the best experts on this subject based on the ideXlab platform.
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Shunning the night to elude the hunter: Diurnal fireflies and the "femmes fatales"
Chemoecology, 2006Co-Authors: Matthew Gronquist, Helen Ghiradella, Erin M. Mccoy, Frank C Schroeder, David Hill, Jerrold Meinwald, Thomas EisnerAbstract:Lucidota atra, a diurnal firefly, shares possession of defensive steroids (lucibufagins or LBGs) with nocturnal fireflies of the genus Photinus. Photinus are protected against predators by their LBGs, but not against fireflies of the genus Photuris, the so-called firefly femmes fatales, which prey upon Photinus, thereby acquiring LBGs for their own defense. We propose that L. atra may have been prompted evolutionarily to become diurnal by the opportunity to avoid, thereby, being hunted by Photuris. Indeed, L. atra, if offered to Photuris, were eagerly devoured by the latter, which sequestered their LBG's. In feeding on L. atra, Photuris may be driven by a gustatory affinity for LBGs. Persistent nocturnality might therefore have put L. atra at risk vis a vis Photuris. Diurnality freed the firefly from that risk, without compromising its defended status with respect to other predators. Possession of LBGs may in fact account for L. atra's unacceptability to birds and spiders.
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Chemical egg defense in Photuris firefly “femmes fatales”
Chemoecology, 1999Co-Authors: Andres Gonzalez, James F. Hare, Thomas EisnerAbstract:Female Photuris fireflies contain defensive chemicals of two types. They sequester steroidal pyrones (lucibufagins) from male fireflies of the genus Photinus that they eat, and themselves produce the defensive betaine N-methylquinolinium 2-carboxylate. Chemical analyses of Photuris eggs showed that females that fed on Photinus males endow their eggs with both lucibufagin and the betaine, while those that did not feed on Photinus lay eggs that contain betaine, but virtually no lucibufagin. Photuris females collected in the field during the Photinus flight season laid eggs that invariably contained betaine, but lucibufagin only at times. Predation experiments showed that Photuris eggs are essentially unacceptable to larvae of a coccinellid beetle (Harmonia axyridis) and an ant (Leptothorax longispinosus), but moderately acceptable to an earwig (Forficula auricularia). When applied experimentally to palatable insect eggs, lucibufagin proved deterrent to these three predators, while the betaine proved deterrent to the ant and coccinellid larva only. Both types of defensive compound decreased egg predation in the field. By endowing their eggs with both exogenous and endogenous chemicals, Photuris females are essentially “maximizing their options”– when feeding on Photinus, their eggs are doubly protected, but they are not entirely defenseless when the females are unable to procure lucibufagin.
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Metabolic transformations of acquired lucibufagins by firefly “femmes fatales”
CHEMOECOLOGY, 1999Co-Authors: Andres Gonzalez, Frank C Schroeder, Athula B. Attygalle, Jerrold Meinwald, Aleš Svatoš, Thomas EisnerAbstract:Female Photuris fireflies sequester defensive steroidal pyrones (lucibufagins) from male fireflies of the genus Photinus . Lucibufagin analyses of Photuris females and Photinus ignitus males show that the lucibufagin mixtures of predator and prey differ in their composition. Analyses of whole body extracts showed that P. ignitus males contain a mixture of eight non-glycosylated lucibufagins, composed mostly of compounds with two oxygenated positions in the steroidal A-ring (C-3, C-5). After feeding on P. ignitus males, Photuris females contain six major lucibufagins. Three of these compounds are not present in the prey, including the novel lucibufagin glycoside 5β,11α-dihydroxy-12-oxo-3β-O-β-D-xylopyranosylbufalin, and two other lucibufagins with a trioxygenated A-ring (C-2, C-3, C-5). These results indicate that Photuris females transform the sequestered lucibufagins both by glycosylation and oxidation, which could affect the systemic transportability of these compounds due to an increase in their polarity.
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N-methylquinolinium 2-carboxylate, a defensive betaine from Photuris versicolor fireflies
Journal of Natural Products, 1999Co-Authors: Andres Gonzalez, Frank Schroeder, Jerrold Meinwald, Thomas EisnerAbstract:From whole body extracts of Photuris versicolor fireflies, the defensive betaine N-methylquinolinium 2-carboxylate (1) was isolated and characterized on the basis of spectroscopic data and comparison with a synthetic sample
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Firefly “femmes fatales” acquire defensive steroids (lucibufagins) from their firefly prey
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Thomas Eisner, David E. Hill, Michael Goetz, Scott R Smedley, Jerrold MeinwaldAbstract:Female fireflies of the genus Photuris, the so-called firefly “femmes fatales,” prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus.
James Inglese - One of the best experts on this subject based on the ideXlab platform.
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a basis for reduced chemical library inhibition of firefly luciferase obtained from directed evolution
Journal of Medicinal Chemistry, 2009Co-Authors: Douglas S Auld, Marc Landsman, Jennifer Maclure, Craig J Thomas, Daniel Langevin, Christopher P Austin, Yaqin Zhang, Noel Southall, James IngleseAbstract:We measured the “druggability” of the ATP-dependent luciferase derived from the firefly Photuris pennsylvanica that was optimized using directed evolution (Ultra-Glo, Promega). Quantitative high-throughput screening (qHTS) was used to determine IC50s of 198899 samples against a formulation of Ultra-Glo luciferase (Kinase-Glo). We found that only 0.1% of the Kinase-Glo inhibitors showed an IC50 100K compounds) in addressing importan...
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A Basis for Reduced Chemical Library Inhibition of Firefly Luciferase Obtained from Directed Evolution
Journal of medicinal chemistry, 2009Co-Authors: Douglas S Auld, Marc Landsman, Jennifer Maclure, Craig J Thomas, Daniel Langevin, Christopher P Austin, Yaqin Zhang, Noel Southall, Ganesha Rai, James IngleseAbstract:We measured the "druggability" of the ATP-dependent luciferase derived from the firefly Photuris pennsylvanica that was optimized using directed evolution (Ultra-Glo, Promega). Quantitative high-throughput screening (qHTS) was used to determine IC(50)s of 198899 samples against a formulation of Ultra-Glo luciferase (Kinase-Glo). We found that only 0.1% of the Kinase-Glo inhibitors showed an IC(50) 100K compounds) in addressing important questions such as a target's druggability.
Jerrold Meinwald - One of the best experts on this subject based on the ideXlab platform.
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Shunning the night to elude the hunter: Diurnal fireflies and the "femmes fatales"
Chemoecology, 2006Co-Authors: Matthew Gronquist, Helen Ghiradella, Erin M. Mccoy, Frank C Schroeder, David Hill, Jerrold Meinwald, Thomas EisnerAbstract:Lucidota atra, a diurnal firefly, shares possession of defensive steroids (lucibufagins or LBGs) with nocturnal fireflies of the genus Photinus. Photinus are protected against predators by their LBGs, but not against fireflies of the genus Photuris, the so-called firefly femmes fatales, which prey upon Photinus, thereby acquiring LBGs for their own defense. We propose that L. atra may have been prompted evolutionarily to become diurnal by the opportunity to avoid, thereby, being hunted by Photuris. Indeed, L. atra, if offered to Photuris, were eagerly devoured by the latter, which sequestered their LBG's. In feeding on L. atra, Photuris may be driven by a gustatory affinity for LBGs. Persistent nocturnality might therefore have put L. atra at risk vis a vis Photuris. Diurnality freed the firefly from that risk, without compromising its defended status with respect to other predators. Possession of LBGs may in fact account for L. atra's unacceptability to birds and spiders.
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Metabolic transformations of acquired lucibufagins by firefly “femmes fatales”
CHEMOECOLOGY, 1999Co-Authors: Andres Gonzalez, Frank C Schroeder, Athula B. Attygalle, Jerrold Meinwald, Aleš Svatoš, Thomas EisnerAbstract:Female Photuris fireflies sequester defensive steroidal pyrones (lucibufagins) from male fireflies of the genus Photinus . Lucibufagin analyses of Photuris females and Photinus ignitus males show that the lucibufagin mixtures of predator and prey differ in their composition. Analyses of whole body extracts showed that P. ignitus males contain a mixture of eight non-glycosylated lucibufagins, composed mostly of compounds with two oxygenated positions in the steroidal A-ring (C-3, C-5). After feeding on P. ignitus males, Photuris females contain six major lucibufagins. Three of these compounds are not present in the prey, including the novel lucibufagin glycoside 5β,11α-dihydroxy-12-oxo-3β-O-β-D-xylopyranosylbufalin, and two other lucibufagins with a trioxygenated A-ring (C-2, C-3, C-5). These results indicate that Photuris females transform the sequestered lucibufagins both by glycosylation and oxidation, which could affect the systemic transportability of these compounds due to an increase in their polarity.
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N-methylquinolinium 2-carboxylate, a defensive betaine from Photuris versicolor fireflies
Journal of Natural Products, 1999Co-Authors: Andres Gonzalez, Frank Schroeder, Jerrold Meinwald, Thomas EisnerAbstract:From whole body extracts of Photuris versicolor fireflies, the defensive betaine N-methylquinolinium 2-carboxylate (1) was isolated and characterized on the basis of spectroscopic data and comparison with a synthetic sample
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Firefly “femmes fatales” acquire defensive steroids (lucibufagins) from their firefly prey
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Thomas Eisner, David E. Hill, Michael Goetz, Scott R Smedley, Jerrold MeinwaldAbstract:Female fireflies of the genus Photuris, the so-called firefly “femmes fatales,” prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus.
Douglas S Auld - One of the best experts on this subject based on the ideXlab platform.
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a basis for reduced chemical library inhibition of firefly luciferase obtained from directed evolution
Journal of Medicinal Chemistry, 2009Co-Authors: Douglas S Auld, Marc Landsman, Jennifer Maclure, Craig J Thomas, Daniel Langevin, Christopher P Austin, Yaqin Zhang, Noel Southall, James IngleseAbstract:We measured the “druggability” of the ATP-dependent luciferase derived from the firefly Photuris pennsylvanica that was optimized using directed evolution (Ultra-Glo, Promega). Quantitative high-throughput screening (qHTS) was used to determine IC50s of 198899 samples against a formulation of Ultra-Glo luciferase (Kinase-Glo). We found that only 0.1% of the Kinase-Glo inhibitors showed an IC50 100K compounds) in addressing importan...
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A Basis for Reduced Chemical Library Inhibition of Firefly Luciferase Obtained from Directed Evolution
Journal of medicinal chemistry, 2009Co-Authors: Douglas S Auld, Marc Landsman, Jennifer Maclure, Craig J Thomas, Daniel Langevin, Christopher P Austin, Yaqin Zhang, Noel Southall, Ganesha Rai, James IngleseAbstract:We measured the "druggability" of the ATP-dependent luciferase derived from the firefly Photuris pennsylvanica that was optimized using directed evolution (Ultra-Glo, Promega). Quantitative high-throughput screening (qHTS) was used to determine IC(50)s of 198899 samples against a formulation of Ultra-Glo luciferase (Kinase-Glo). We found that only 0.1% of the Kinase-Glo inhibitors showed an IC(50) 100K compounds) in addressing important questions such as a target's druggability.
Scott R Smedley - One of the best experts on this subject based on the ideXlab platform.
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North American Fireflies Host Low Bacterial Diversity
Microbial Ecology, 2021Co-Authors: Emily A. Green, Scott R Smedley, Jonathan L. KlassenAbstract:Although there are numerous studies of firefly mating flashes, lantern bioluminescence, and anti-predation lucibufagin metabolites, almost nothing is known about their microbiome. We therefore used 16S rRNA community amplicon sequencing to characterize the gut and body microbiomes of four North American firefly taxa: Ellychnia corrusca , the Photuris versicolor species complex, Pyractomena borealis , and Pyropyga decipiens . These firefly microbiomes all have very low species diversity, often dominated by a single species, and each firefly type has a characteristic microbiome. Although the microbiomes of male and female fireflies did not differ from each other, Ph. versicolor gut and body microbiomes did, with their gut microbiomes being enriched in Pseudomonas and Acinetobacter . Ellychnia corrusca egg and adult microbiomes were unique except for a single egg microbiome that shared a community type with E . corrusca adults, which could suggest microbial transmission from mother to offspring. Mollicutes that had been previously isolated from fireflies were common in our firefly microbiomes. These results set the stage for further research concerning the function and transmission of these bacterial symbionts.
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Escape into Winter: Does a Phenological Shift by Ellychnia corrusca (Winter Firefly) Shield it from a Specialist Predator (Photuris)?
Northeastern Naturalist, 2017Co-Authors: Stephen T. Deyrup, Riley G. Risteen, Kathareeya K. Tonyai, Madalyn A. Farrar, Bailey E. D'antonio, Zenab B. Ahmed, Brian T. Christofel, Nicole R. Howells, Scott R SmedleyAbstract:Ellychnia corrusca (Winter Firefly) is one of few winter-active insects. Exposed throughout the season, this beetle appears vulnerable to insectivorous predators, but was recently shown to possess lucibufagins (LBGs), potent chemical defenses. The Winter Firefly is closely related to summer-active fireflies. To provide an adaptive explanation for this apparent phenological shift, we hypothesized that winter activity may protect the Winter Firefly from summer-active fireflies in the genus Photuris, predators that specialize on LBG-containing prey. To test this hypothesis, we studied the Winter Firefly and Photuris that occur sympatrically, but asynchronously as adults, at our Connecticut field sites. Through 2 experiments, we demonstrated that Photuris selectively consumes the Winter Firefly and sequesters its LBGs. Our findings are consistent with a hypothesis that winter activity by the Winter Firefly, by enabling early spring reproduction, provides phenological escape from a specialist predator.
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Firefly “femmes fatales” acquire defensive steroids (lucibufagins) from their firefly prey
Proceedings of the National Academy of Sciences of the United States of America, 1997Co-Authors: Thomas Eisner, David E. Hill, Michael Goetz, Scott R Smedley, Jerrold MeinwaldAbstract:Female fireflies of the genus Photuris, the so-called firefly “femmes fatales,” prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus.