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Douglas W. Tallamy - One of the best experts on this subject based on the ideXlab platform.
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male traits under cryptic female choice in the spotted cucumber beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female's bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Copyright 2002.
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male traits under cryptic female choice in the spotted cucumber beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexual selection. [Behav Ecol 13:511–518 (2002)]
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Male traits under cryptic female choice in the spotted cucumber beetle (Coleoptera: Chrysomelidae
2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed mus-culature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99 % of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexua
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Fate of Male-derived Cucurbitacins in Spotted Cucumber Beetle Females
Journal of Chemical Ecology, 2000Co-Authors: Douglas W. Tallamy, Piotr M. Górski, Julia K. BurzonAbstract:Using the spotted cucumber beetle, Diabrotica undecimpunctata howardi , as a model species, we begin an examination of the role of dietary Cucurbitacins, the bitter tetracyclic triterpenes produced by cucurbits, in the reproductive behavior of luperine chrysomelids that seek these compounds for purposes other than host-plant recognition or nutrition. By manipulating the Cucurbitacin content of adult diets, we determine: (1) how males and females partition Cucurbitacins between reproductive organs and other tissues, (2) the extent to which males pass Cucurbitacins to females during copulation, and (3) if females increase their Cucurbitacin stores via multiple matings. After two days of exposure to dietary Cucurbitacins, 8.3 times more Cucurbitacins per gram dry weight were sequestered in male spermatophores than in the aggregate of remaining male tissues. These Cucurbitacin-rich spermatophores were passed to females during mating, and 78.8% of the transferred Cucurbitacin was deposited in eggs, 11.8% was irreversibly sequestered in other female tissues, and 9.4% was apparently excreted. Females copulated with 0–15 males prior to accepting a complete spermatophere, but did not accept measurable amounts of Cucurbitacin from rejected males. Regardless of when it was received, females lost subsequent receptivity to additional males after accepting a complete spermatophore. The implications of these data are discussed in terms of sexual selection hypotheses and mating behavior in cucumber beetles.
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Cucurbitacins: A Role in Cucumber Beetle Steroid Nutrition?
Journal of Chemical Ecology, 1999Co-Authors: Fathi T. Halaweish, Douglas W. Tallamy, Eva SantanaAbstract:The conditional role of Cucurbitacins as phytosteroid supplements, cholesterol precursors, or ecdysteroid antagonists in the spotted cucumber beetle, Diabrotica undecimpunctata howardi , was investigated in two ways: by comparing larval survival and growth rate on Cucurbitacin-rich and Cucurbitacin-poor squash cultivars of Cucurbita pepo and by manipulating the presence of cholesterol, phytosteroids, and Cucurbitacins in an artificial diet and examining the effects on adult survival and fecundity. Larvae that developed on Cucurbitacin-rich roots grew significantly faster and survived as well as larvae on Cucurbitacin-poor roots. There was no evidence, however, that adults could substitute Cucurbitacins in vital phytosteroid roles. Beetles reared on a Cucurbitacin-rich, phytosteroid-poor diet laid significantly fewer eggs and died significantly younger than beetles with a full complement of dietary phytosteroids and also laid fewer eggs than beetles with no access to phytosteroids in their adult diet. The data are consistent with the hypothesis that, when the side chain of dietary Cucurbitacins can be successfully hydrogenated, these compounds play a nutritional role as substitutes or precursors for structural steroids. In contrast, when the carbon–carbon double bond cannot be hydrogenated, Cucurbitacins may become antagonists at ecdysteroid receptors, negatively affecting beetle fitness.
Jacques Magdalou - One of the best experts on this subject based on the ideXlab platform.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Abstract Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC50 values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (Km 22 μM, Vmax 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of Vmax/Km, the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC(50) values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (K(m) 22 μM, V(max) 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of V(max)/K(m), the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.
Suzanne Abbas - One of the best experts on this subject based on the ideXlab platform.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Abstract Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC50 values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (Km 22 μM, Vmax 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of Vmax/Km, the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC(50) values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (K(m) 22 μM, V(max) 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of V(max)/K(m), the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.
Julie A Mcclafferty - One of the best experts on this subject based on the ideXlab platform.
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male traits under cryptic female choice in the spotted cucumber beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female's bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Copyright 2002.
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male traits under cryptic female choice in the spotted cucumber beetle coleoptera chrysomelidae
Behavioral Ecology, 2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed musculature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99% of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexual selection. [Behav Ecol 13:511–518 (2002)]
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Male traits under cryptic female choice in the spotted cucumber beetle (Coleoptera: Chrysomelidae
2002Co-Authors: Douglas W. Tallamy, Bradford E Powell, Julie A McclaffertyAbstract:Males of the spotted cucumber beetle (Diabrotica undecimpunctata howardi) rhythmically stroke females with their antennae during copulation. Males that stroke quickly have a higher probability of being accepted as a mate. We determined (1) the mechanism by which females prevent unattractive males from passing spermatophores, (2) whether antennal stroking signals to females the likelihood of receiving a nuptial gift, and (3) if other male traits in addition to stroking are subjected to sexual selection from female preference. Dissections of pairs flash-frozen in copula during and after antennal stroking showed mus-culature that, when contracted, folded the vaginal duct leading to the female’s bursa copulatrix in a way that prevented complete penetration by the aedeagus. These muscles were always contracted while males were stroking and always relaxed after stroking had ceased. Males accepted as mates did not differ from males that failed to pass a spermatophore in either absolute or relative body weight, aedeagus length, or the amount of Cucurbitacins (potential nuptial gifts) sequestered in their spermatophores. Although 99 % of the beetles that came to Cucurbitacin-rich Cucurbita fruits in the field were males, males that had sequestered Cucurbitacins did not stroke females faster than males with no Cucurbitacins, and fast-stroking males were not more likely to find and sequester Cucurbitacins than were males that stroked more slowly. Males with a Cucurbitacin slurry painted on their antennae had no mating advantage over controls. We conclude that females discriminate among males after copulation has begun on the basis of antennal stroking displays (or some trait correlated with stroking speed) that males perform to entice females to relax their bursal sphincter. Key words: copulatory courtship, cryptic female choice, Diabrotica undecimpunctata, sexua
Helene Greigegerges - One of the best experts on this subject based on the ideXlab platform.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Abstract Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC50 values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (Km 22 μM, Vmax 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of Vmax/Km, the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.
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the Cucurbitacins e d and i investigation of their cytotoxicity toward human chondrosarcoma sw 1353 cell line and their biotransformation in man liver
Toxicology Letters, 2013Co-Authors: Suzanne Abbas, Pierre Netter, Jean-baptiste Vincourt, Lamice Habib, Helene Greigegerges, Jacques MagdalouAbstract:Cucurbitacins are a class of natural compounds known for their numerous potential pharmacological effects. The purpose of this work was to compare the cytotoxicity of three Cucurbitacins I, D, E on the chondrosarcoma SW 1353 cancer cell line and to investigate their biotransformation in man. Cucurbitacins I and D showed a very strong cytotoxicity, which was higher than that of cytochalasin D, used as a drug reference. Almost 100% of the cells were apoptotic as observed by DNA fragmentation (TUNEL assay) after 12 h with Cucurbitacins I and D (1 μM) and Cucurbitacin E (10 μM). In terms of IC(50) values, Cucurbitacins I and E presented a higher toxicity compared to that of Cucurbitacin D (MTT assay). Cucurbitacin E was readily hydrolyzed by human hepatic microsomes, leading to Cucurbitacin I (K(m) 22 μM, V(max) 571 nmol/mg proteins/min). On the other hand, the three Cucurbitacins were hydroxylated at a very low extent, but they were sulfated and glucuronidated. In terms of V(max)/K(m), the Cucurbitacin E was the best substrate of UDP-glucuronosyltransferases. This study shows that Cucurbitacins I, D and E present a potent cytotoxic activity toward the chondrosarcoma SW 1353 cell line and are metabolized as sulfate and glucuronide conjugates.