To reproduce,males have to fertilize the female’s eggs,sometimes in competition with ejaculates of other males.In species where males display alternative reproductive tactics,whereby territorial males secure mating a...To reproduce,males have to fertilize the female’s eggs,sometimes in competition with ejaculates of other males.In species where males display alternative reproductive tactics,whereby territorial males secure mating and non-territorial males have to sneak copulations,the latter might be expected to invest relatively more resources towards sperm quality compared with the territorial males.Sperm cells are especially vulnerable to oxidative stress,which reduces male fertility.Therefore,antioxidant resources are expected to modulate sperm quality,and might be allocated differently between reproductive tactics.To test the link between reproductive tactics,redox profile and sperm quality,we experimentally induced changes in the reproductive tactics of 39 captive males Seba's short-tailed bats Carollia perspicillata.We monitored the blood and ejaculate oxidative balance,and the sperm quality before,7 days and 21 days after the manipulation of reproductive tactic.Although ejaculates'oxidative damage was negatively related to sperm velocity,males exhibited similar blood and ejaculates redox profiles and similar sperm quality,regardless of their reproductive tactic.Possibly,these results arise as a consequence of some constraints having been lifted during the experiment.Our results also suggest that,in Seba's short-tailed bats,the expression of alternative reproductive tactics is not subjected to strong oxidative constraints.Furthermore,our results could reflect an absence of trade-off between pre-and post-copulatory traits in harem males,as they could be selected to invest both in female attraction and sperm quality,as a consequence of their inability to fully monopolize females.展开更多
Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior.During the past decades,many trail pheromone components with various structures have been identified in ants,including the...Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior.During the past decades,many trail pheromone components with various structures have been identified in ants,including the red imported fire ant,Solenopsis invicta,a notorious invasive species worldwide.Four compounds,Z,E-(ZEF)and E,E-α-farnesene(EEF),Z,E-(ZEHF)and E,E-α-homofarnesene(EEHF),have been reported as components of S.invicta trail pheromone.However,another study reported an analog ofα-farnesene,Z,Z,Z-allofarnesene,as a key trail pheromone component.These contrasting results caused some uncertainty about the trail pheromone composition in S.invicta.In this study,we synthesized ZEF and EEF,ZEHF and EEHF,and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S.invicta worker body extract.The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity,with ZEF as the major compound,while no allofarnesene was found,neither in the Dufour gland extract nor in the whole-body extract.Our results confirm ZEF and EEF,ZEHF and EEHF as trail pheromone components of S.invicta.展开更多
Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional conte...Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional content, toxicity and digestibility as well as their role in the shaping of bee-flower interactions have been poorly studied. In this study we combined bioassays of the generalist bee Bombus terrestris on pollen of Cirsium, Trifolium, Salix, and Cistus genera with an assessment of nutritional content, toxicity, and digestibility of pollen. Microcolonies showed significant differences in their development, non-host pollen of Cirsium being the most unfavorable. This pollen was characterized by the presence of quite rare 37-sterols and a low digestibility. Cirsium consumption seemed increase syrup collection, which is probably related to a detoxification mixing behavior. These results strongly suggest that pollen traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in bee generalist diet.展开更多
文摘To reproduce,males have to fertilize the female’s eggs,sometimes in competition with ejaculates of other males.In species where males display alternative reproductive tactics,whereby territorial males secure mating and non-territorial males have to sneak copulations,the latter might be expected to invest relatively more resources towards sperm quality compared with the territorial males.Sperm cells are especially vulnerable to oxidative stress,which reduces male fertility.Therefore,antioxidant resources are expected to modulate sperm quality,and might be allocated differently between reproductive tactics.To test the link between reproductive tactics,redox profile and sperm quality,we experimentally induced changes in the reproductive tactics of 39 captive males Seba's short-tailed bats Carollia perspicillata.We monitored the blood and ejaculate oxidative balance,and the sperm quality before,7 days and 21 days after the manipulation of reproductive tactic.Although ejaculates'oxidative damage was negatively related to sperm velocity,males exhibited similar blood and ejaculates redox profiles and similar sperm quality,regardless of their reproductive tactic.Possibly,these results arise as a consequence of some constraints having been lifted during the experiment.Our results also suggest that,in Seba's short-tailed bats,the expression of alternative reproductive tactics is not subjected to strong oxidative constraints.Furthermore,our results could reflect an absence of trade-off between pre-and post-copulatory traits in harem males,as they could be selected to invest both in female attraction and sperm quality,as a consequence of their inability to fully monopolize females.
基金supported by National Key R&D Program of China(Grant No.2021YFD1000500)National Natural Science Foundation of China(Grant Nos.31702050 and 32070488)the State Key Laboratory of Integrated Management of Pest Insects and Rodents(Grant No.ChineseIPM1410).
文摘Ants use species-specific trail pheromones to coordinate their sophisticated foraging behavior.During the past decades,many trail pheromone components with various structures have been identified in ants,including the red imported fire ant,Solenopsis invicta,a notorious invasive species worldwide.Four compounds,Z,E-(ZEF)and E,E-α-farnesene(EEF),Z,E-(ZEHF)and E,E-α-homofarnesene(EEHF),have been reported as components of S.invicta trail pheromone.However,another study reported an analog ofα-farnesene,Z,Z,Z-allofarnesene,as a key trail pheromone component.These contrasting results caused some uncertainty about the trail pheromone composition in S.invicta.In this study,we synthesized ZEF and EEF,ZEHF and EEHF,and reanalyzed the chemicals in the Dufour gland extract and in the trail pheromone fraction of S.invicta worker body extract.The reported isomers of farnesene and homofarnesene were detected and showed trail-following activity,with ZEF as the major compound,while no allofarnesene was found,neither in the Dufour gland extract nor in the whole-body extract.Our results confirm ZEF and EEF,ZEHF and EEHF as trail pheromone components of S.invicta.
文摘Current evidence suggests that pollen is both chemically and structurally protected. Despite increasing interest in studying bee-flower networks, the constraints for bee development related to pollen nutritional content, toxicity and digestibility as well as their role in the shaping of bee-flower interactions have been poorly studied. In this study we combined bioassays of the generalist bee Bombus terrestris on pollen of Cirsium, Trifolium, Salix, and Cistus genera with an assessment of nutritional content, toxicity, and digestibility of pollen. Microcolonies showed significant differences in their development, non-host pollen of Cirsium being the most unfavorable. This pollen was characterized by the presence of quite rare 37-sterols and a low digestibility. Cirsium consumption seemed increase syrup collection, which is probably related to a detoxification mixing behavior. These results strongly suggest that pollen traits may act as drivers of plant selection by bees and partly explain why Asteraceae pollen is rare in bee generalist diet.
