Feeding and molting are particularly important physiological processes for insects,and it has been reported that neuropeptides are involved in the nervous regulation of these 2 processes.Sulfakinin(SK)is an important ...Feeding and molting are particularly important physiological processes for insects,and it has been reported that neuropeptides are involved in the nervous regulation of these 2 processes.Sulfakinin(SK)is an important neuropeptide that is widely distributed among insects and plays a pivotal role in regulating feeding,courtship,aggression,and locomotion.In this study,we investigated the involvement of SK in feeding and molting on a highly notorious pest insect,the fall armyworm,Spodoptera frugiperda.SK transcript levels were found in all larval stages and there was a predominant expression of SK in the brain of 5th instar larvae.By immunostaining,SK was detected in 2 pairs of cells in the median protocerebrum.But during prolonged periods of starvation,there was a significant reduction in SK messenger RNA levels;however,subsequent refeeding led to a notable increase.To investigate the role of SK in feeding and molting,SK was silenced in S.frugiperda larvae through RNA interference.This resulted in a significant increase in food intake,weight gain,and the molting process happened more rapidly in the double-stranded SK-treated larvae compared to the controls.Conversely,injection of sulfated SK peptide(sSK)caused opposite effects.Interestingly,SK-knockdown in larvae resulted in increased levels of 20-hydroxyecdysone and also of the expression of some of it signaling pathway genes.Altogether,this study highlights the important role played by SK in regulating feeding and molting in S.frugiperda.展开更多
Spiders frequently suffer abnormal molting and subsequent death when sustained on a monotypic diet of fruit flies Drosophila melanogaster.The fruit flies lack arachidonic acid(AA),a nutrient that may be critical for s...Spiders frequently suffer abnormal molting and subsequent death when sustained on a monotypic diet of fruit flies Drosophila melanogaster.The fruit flies lack arachidonic acid(AA),a nutrient that may be critical for successful molting of spiders.To test this hypothesis,we compared the survival rates of juvenile wolf spiders,Pardosa pseudoannulata,fed on three kinds of diets,midges(Tendipes sp.),fruit flies enriched in AA and fruit flies lacking in AA.In addition,we analyzed the fatty acid composition of spiders feeding on midges and fruit flies enriched in AA and their prey.Juvenile spiders fed on midges and AA-enriched fruit flies reached full maturity without molting issues,whereas nearly all spiders fed the flies lacking in AA did not survive.Among the 35 different fatty acids,only the AA levels in both prey and spiders correlated positively with spider survival.Our findings provide compelling evidence that AA is crucial for the survival and molting of P pseudoannulata.展开更多
基金supported in part by the Guizhou Provincial Science and Technology Projects(Department of Science and Technology,Guizhou Provincial Major Scientific and Technological Achievements Program,Qian KH achievement[2023]No.Great 004)National Natural Science Foundation of China(32202295)+2 种基金Scientific Research Project of Higher Education Institutions of Guizhou Province(Youth Project)(Qian Jiao Ji[2022]114)Guizhou Provincial Science and Technology Plan Project(Qiankehe Platform Talents-BQW[2024]008Qian KeHe Ji Chu-ZK[2022]General 051).
文摘Feeding and molting are particularly important physiological processes for insects,and it has been reported that neuropeptides are involved in the nervous regulation of these 2 processes.Sulfakinin(SK)is an important neuropeptide that is widely distributed among insects and plays a pivotal role in regulating feeding,courtship,aggression,and locomotion.In this study,we investigated the involvement of SK in feeding and molting on a highly notorious pest insect,the fall armyworm,Spodoptera frugiperda.SK transcript levels were found in all larval stages and there was a predominant expression of SK in the brain of 5th instar larvae.By immunostaining,SK was detected in 2 pairs of cells in the median protocerebrum.But during prolonged periods of starvation,there was a significant reduction in SK messenger RNA levels;however,subsequent refeeding led to a notable increase.To investigate the role of SK in feeding and molting,SK was silenced in S.frugiperda larvae through RNA interference.This resulted in a significant increase in food intake,weight gain,and the molting process happened more rapidly in the double-stranded SK-treated larvae compared to the controls.Conversely,injection of sulfated SK peptide(sSK)caused opposite effects.Interestingly,SK-knockdown in larvae resulted in increased levels of 20-hydroxyecdysone and also of the expression of some of it signaling pathway genes.Altogether,this study highlights the important role played by SK in regulating feeding and molting in S.frugiperda.
基金supported by the Outstanding Young and Middle-aged Science and Technology Innovation Team Project in Colleges and Universities of Hubei Province(T2022030)Guiding Project of Scientific and Technical Research Plan of Hubei Provincial Department of Education(B2022177)Open Project of Hubei Key Laboratory of Quality Control of Characteristic Fruits and Vegetables(2022K007).
文摘Spiders frequently suffer abnormal molting and subsequent death when sustained on a monotypic diet of fruit flies Drosophila melanogaster.The fruit flies lack arachidonic acid(AA),a nutrient that may be critical for successful molting of spiders.To test this hypothesis,we compared the survival rates of juvenile wolf spiders,Pardosa pseudoannulata,fed on three kinds of diets,midges(Tendipes sp.),fruit flies enriched in AA and fruit flies lacking in AA.In addition,we analyzed the fatty acid composition of spiders feeding on midges and fruit flies enriched in AA and their prey.Juvenile spiders fed on midges and AA-enriched fruit flies reached full maturity without molting issues,whereas nearly all spiders fed the flies lacking in AA did not survive.Among the 35 different fatty acids,only the AA levels in both prey and spiders correlated positively with spider survival.Our findings provide compelling evidence that AA is crucial for the survival and molting of P pseudoannulata.
