There is evidence that ant-derived chemical stimuli are involved in regulat- ing the digging behavior in Solenopsis invicta Buren. However, the source gland（s） and chemistry of such stimuli have never been revealed....There is evidence that ant-derived chemical stimuli are involved in regulat- ing the digging behavior in Solenopsis invicta Buren. However, the source gland（s） and chemistry of such stimuli have never been revealed. In this study, extracts of mandibular, Dufour＇s, postpharyngeal, and poison glands were evaluated for their effect on ant digging and residing preferences of S. invicta workers from three colonies. In the intracolonial bioassays, workers showed significant digging preferences to mandibular gland extracts in 2 of 3 colonies and significant residing preferences in 1 of 3 colonies; significant digging preferences to Dufour＇s gland extracts in 1 of 3 colonies and significant residing preferences in 2 of 3 colonies. No digging and residing preferences were found for postpharyngeal and poison gland extracts. In intercolonial bioassays, significant digging and residing prefer- ences were found for mandibular gland extracts in 3 of 6 colony combinations. Significant digging preferences to Dufour＇s gland extracts were found in 4 of 6 colony combinations and significant residing preferences in all 6 colony combinations. For postpharyngeal gland extracts, significant digging preferences were found only in 1 of 6 colonial combinations and no significant residing preferences were found. For poison gland extracts, no signif- icant digging preferences were found; significant residing preferences were found in 1 of 6 colony combinations. However, a significant residing deterrence （negative residing preference index） was found for 2 of 6 colony combinations. Statistical analyses using data pooled from all colonies showed that mandibular and Dufour＇s gland extracts caused sig- nificant digging and residing preferences in both intracolonial and intercolonial bioassays but not postpharyngeal and poison gland extracts. By analyzing the data pooled from the same three colonies used for gland extract bioassays, it was found that, in no cases, workers showed significant digging and residing preferences to 2-ethyl-3,6-dimethylpyrazine, an alarm pheromone component from mandibular gland.展开更多
Amphibians produce defensive chemicals which provide protection against both predators and infections.Within species,populations can differ considerably in the composition and amount of these chemical defenses.Studyin...Amphibians produce defensive chemicals which provide protection against both predators and infections.Within species,populations can differ considerably in the composition and amount of these chemical defenses.Studying intraspecific variation in toxins and linking it to environmental variables may help us to identify the selective drivers of toxin evolution,such as predation pressure and infection risk.Recently,there has been a renewed interest in the unique toxins produced by salamanders from the genus Salamandra:the samandarines.Despite this attention,intraspecific variation has largely been ignored within Salamandra-species.The aim of this study was to investigate whether geographic variation in profiles of samandarines exists,by sampling 4 populations of Salamandra atra over its range in the Dinaric Alps.In addition,we preliminary explored whether potential variation could be explained by predation(counting the number of snake species)and infection risk(cultivation and genomic analyses of collected soil samples).Salamanders from the 4 populations differed in toxin composition and in the size of their poison glands,although not in overall toxin quantity.Nor predation nor infection risk could explain this variation,as populations barely differed in these variables.Sampling over a much broader geographic range,using better estimators for predation and infection risk,will contribute to an improved understanding of how environment may shape variation in chemical defenses.Nevertheless,as the 4 populations of S.atra did differ in their toxin profiles,we propose that this species provides an interesting opportunity for further ecological and evolutionary studies on amphibian toxins.展开更多
文摘There is evidence that ant-derived chemical stimuli are involved in regulat- ing the digging behavior in Solenopsis invicta Buren. However, the source gland（s） and chemistry of such stimuli have never been revealed. In this study, extracts of mandibular, Dufour＇s, postpharyngeal, and poison glands were evaluated for their effect on ant digging and residing preferences of S. invicta workers from three colonies. In the intracolonial bioassays, workers showed significant digging preferences to mandibular gland extracts in 2 of 3 colonies and significant residing preferences in 1 of 3 colonies; significant digging preferences to Dufour＇s gland extracts in 1 of 3 colonies and significant residing preferences in 2 of 3 colonies. No digging and residing preferences were found for postpharyngeal and poison gland extracts. In intercolonial bioassays, significant digging and residing prefer- ences were found for mandibular gland extracts in 3 of 6 colony combinations. Significant digging preferences to Dufour＇s gland extracts were found in 4 of 6 colony combinations and significant residing preferences in all 6 colony combinations. For postpharyngeal gland extracts, significant digging preferences were found only in 1 of 6 colonial combinations and no significant residing preferences were found. For poison gland extracts, no signif- icant digging preferences were found; significant residing preferences were found in 1 of 6 colony combinations. However, a significant residing deterrence （negative residing preference index） was found for 2 of 6 colony combinations. Statistical analyses using data pooled from all colonies showed that mandibular and Dufour＇s gland extracts caused sig- nificant digging and residing preferences in both intracolonial and intercolonial bioassays but not postpharyngeal and poison gland extracts. By analyzing the data pooled from the same three colonies used for gland extract bioassays, it was found that, in no cases, workers showed significant digging and residing preferences to 2-ethyl-3,6-dimethylpyrazine, an alarm pheromone component from mandibular gland.
基金This research was funded by the Federal Ministry of Environmental Protection and Tourism in Sarajevo(grant to ES,grant ID:04-23-1105-IV/16-65-1)by the Fonds Wetenschappelijk Onderzoek Flandres through a Ph.D.fellowship(to GDM,grant ID:1144118N).
文摘Amphibians produce defensive chemicals which provide protection against both predators and infections.Within species,populations can differ considerably in the composition and amount of these chemical defenses.Studying intraspecific variation in toxins and linking it to environmental variables may help us to identify the selective drivers of toxin evolution,such as predation pressure and infection risk.Recently,there has been a renewed interest in the unique toxins produced by salamanders from the genus Salamandra:the samandarines.Despite this attention,intraspecific variation has largely been ignored within Salamandra-species.The aim of this study was to investigate whether geographic variation in profiles of samandarines exists,by sampling 4 populations of Salamandra atra over its range in the Dinaric Alps.In addition,we preliminary explored whether potential variation could be explained by predation(counting the number of snake species)and infection risk(cultivation and genomic analyses of collected soil samples).Salamanders from the 4 populations differed in toxin composition and in the size of their poison glands,although not in overall toxin quantity.Nor predation nor infection risk could explain this variation,as populations barely differed in these variables.Sampling over a much broader geographic range,using better estimators for predation and infection risk,will contribute to an improved understanding of how environment may shape variation in chemical defenses.Nevertheless,as the 4 populations of S.atra did differ in their toxin profiles,we propose that this species provides an interesting opportunity for further ecological and evolutionary studies on amphibian toxins.
