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
This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an...This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an initial wet body weight of 1.115 g±0.012 g. The salinity of the control treatment （represented by DO） was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The range of salinity fluctuation was 4. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8d, respectively; each original salinity was decreased abruptly to salinity 24, which first lasted for another 2 d and was then raised to its initial value 28. This constituted a salinity fluctuation cycle and afterwards the cycle repeated. It was found that： 1） The weight gain of shrimp in treatment D4 was 202.9% and significantly higher than that in treatment DO （P〈0.05）. The molting rate in treatment D2 was the lowest, while that in treatment D6 was the highest and significantly higher than those in treatments DO and D2 （P〈0.05）. 2） The hemolymph 20-HE concentration of shrimps in all treatments was at low levels and increased first gradually during the inter-molt period and then increased sharply. It reached a peak value during the pre-molt stage, and then decreased abruptly during the post-molt stage when the lowest level occurred. 3） During the post-molt stage, the hemolymph 20-HE concentration in treatment D2 was 7.47pg μL^-1 and significantly higher than that in treatment DO （P〈0.05）. There were, however, no significant differences in hemolymph 20-HE concentration among all five treatments during the inter-molt stage （P〉0.05）. During the pre-molt stage, the hemolymph 20-HE concentration in treatment D6 was significantly higher than that in treatment DO （P〈0.05）, whereas the hemolymph 20-HE concentration in treatment D2 was significantly lower than that in other treatments （P〈0.05）. Adequate salinity fluctuation promoted the molting rate through increasing hemolymph 20-HE concentration at the pre-molt stage.展开更多
To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4(group S4) and 10(grou...To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4(group S4) and 10(group S10) were designed. The constant salinity of 30(group S0) was used as the control. Levels of shrimp growth, molting frequency(MF), cellular energy status(ATP, ADP and AMP), as well as the expression of genes encoding molt-inhibiting hormone(MIH), crustacean hyperglycemic hormone(CHH), ecdysteroid-regulated protein(ERP), and energy-related AMP-activated protein kinase(AMPK) were determined. The results showed that periodical salinity fluctuation significantly influenced all indicators except MF which ranged from 13.3% in group S10 to15.4% in group S4. In comparison with shrimps cultured at the constant salinity of 30, those in group S4 showed a significant elevation in growth rate, food conversion efficiency, cellular energy status, ERP and MIH gene transcript abundance, and a significant reduction in CHH and AMPK transcript abundance(P < 0.05). However, salinity fluctuation of 10 only resulted in a significant variation in MIH and CHH gene expression when compared to the control(P < 0.05). According to our findings, L. vannamei may be highly capable of tolerating salinity fluctuation. When ambient salinity fluctuated at approx. 4, the increased MF and energy stores in organisms may aid to promoting shrimp growth.展开更多
The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of...The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of the swimming crab(Portunus trituberculatus).We found that dark pigmentation as a result of boiling has an influence on the observation of the eyestalk microstructure.Choosing an unboiled eyestalk,this study compared the cross section and longitudinal section,and concluded that the cross section is suitable for the observation of growth increments with 6.1%CV(coefficient of variation),and growth bands are suitable for the observation of the longitudinal section with 5.4%CV.The width of growth increments near the edge of the endocuticle is small,and the width of growth increments of the middle part of the endocuticle is large.Relationship of number of growth bands to molting time was fitted to a linear function with the slope not significantly different from 1,indicating that growth bands are formed associated with molting.Periodicity of growth increment formation was calculated as 3.7 d,however was not verified.Our results provide a new improved technique for identification of crustacean molting and growth.展开更多
Molting and metamorphosis are important physiological processes in insects that are tightly controlled by ecdysone receptor(EcR)through the 20-hydroxyecdysone(20E)signaling pathway.EcR is a steroid nuclear receptor(SR...Molting and metamorphosis are important physiological processes in insects that are tightly controlled by ecdysone receptor(EcR)through the 20-hydroxyecdysone(20E)signaling pathway.EcR is a steroid nuclear receptor(SR).Several FK506-binding proteins(FKBPs)have been identified from the mammal SR complex,and are thought to be involved in the subcellular trafficking of SR.However,their roles in insects are poorly understood.To explore whether FKBPs are involved in insect molting or metamorphosis,we injected an FKBP inhibitor(FK506)into a lepidopteran insect,Spodoptera litura,and found that molting was inhibited in 61.11%of the larvae,and that the time for larvae to pupate was significantly extended.A total of 10 FKBP genes were identified from the genome of s.litura and were clustered into 2 distinct groups,according to their subcellular localization,with FKBP13 and FKBP14 belonging to the endoplasmic reticulum(ER)group and with the other members belonging to the cytoplasmic(Cy)group.All the CyFKBPs were significantly upregulated in the prepupal or pupal stages,with the opposite being observed for the ER group members.FK506 completely blocked the transfer of EcR to the nucleus under 20E induction,and significantly downregulated the transcriptional expression of many 20E signaling genes.A similar phenomenon was observed after RNA interference of2 CyFKBPs(FKBP45 and FKBP12b),but not for FKBP13.Taken together,our data indicate that the cytoplasmic FKBPs,especially FKBP45 and FKBP12b,mediate the nuclear localization of EcR,thereby regulating the 20E signaling and ultimately affecting molting and metamorphosis in insects.展开更多
Cytochrome P450 monooxygenases(CYPs)play essential physiological functions in insects.CYP303A1 is highly conserved in insect species studied to date,and shows an indispensable role for adult eclosion in both Locusta m...Cytochrome P450 monooxygenases(CYPs)play essential physiological functions in insects.CYP303A1 is highly conserved in insect species studied to date,and shows an indispensable role for adult eclosion in both Locusta migratoria and Drosophila melanogaster.However,how CYP303A1 is regulated to control insect developmental processes remains uninvestigated.In this study,we discovered functional binding sites for miR-184 in the coding sequence of LmCYP303A1.The luciferase reporter assay showed that miR-184 could target LmCYP303A1 and regulate its expression in vitro.Furthermore,overexpression of miR-184 through microinjection of agomir to locusts reduced the transcripts of LmCYP303A1 and led to abnormal molting,which is similar to the phenotype of silencing LmCYP303A1 by direct injection of dsLmCYP303A1 to locusts.Meanwhile,down-regulation of miR-184 by injection of antagomir increased the LmCYP303A1 transcript and caused molting defects.These findings suggested that miR-184 could target LmCYP303A1 to regulate the molting process in L.migratoria,which might be considered as a novel target for pest control.展开更多
The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps with multiple functions in many organisms. In this study, we performed structural and functional analysis of vha55 gene that encodes V-ATPase subunit B...The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps with multiple functions in many organisms. In this study, we performed structural and functional analysis of vha55 gene that encodes V-ATPase subunit B in the smokybrown cockroach Periplaneta fuliginosa (Blattodea). We observed a high homology score of the deduced amino acid sequences between 10 species in seven orders. RNAi of the vha55 gene in R fuliginosa caused nymphal/nymphal molting defects with incomplete shedding of old cuticles, growth inhibition, as well as bent and wrinkled cuticles of thoraxes and abdominal segments. Since growth inhibition caused by vha55 RNAi did not interfere in the commencement of cockroach molting, molting timing and body growth might be controlled by independent mechanism. Our study suggested V-ATPases might be a good candidate molecule for evolutionary and developmental studies of insect molting.展开更多
The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific ...The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific research.Two calcium-associated cuticular protein genes,named NdCAP-1 and NdCAP-2,were obtained from N.denticulata sinensis.Molecular docking simulated the binding effect of both proteins and calcium ions.Semi-quantitative reverse transcription PCR results show that NdCAP-1 is expressed in D_(2-4) stage,NdCAP-2 expressed in D_(2-4) and A-B stages,and both were significantly expressed in the cephalothorax cuticle and pereiopods.Then,it was revealed that NdCAP-1 and NdCAP-2 are regulated by NdEcR-mediated 20 E signaling pathways.Knockdown of NdCAP-1 and NdCAP-2 was observed to cause surface defects.The recombinant proteins(rNdCAP-1 and rNdCAP-2),obtained by prokaryotic expression,had calcium-binding and chitin-binding ability,inhibited formation of calcium carbonate precipitate.These results show that calcium-associated cuticular proteins play important roles in cuticle formation and calcification.展开更多
Based on the similarities in the conformation of VS008（N-（4-methylphenyl）-3-（tert-butyl）-1-（phenylmethyl）-1H-pyrazole-5-carboxamide） and BYIO6830（N＇-（3,5-dimethylbenzoyl）-N＇-tert-butyl-5-methyl-2,3-dihydr...Based on the similarities in the conformation of VS008（N-（4-methylphenyl）-3-（tert-butyl）-1-（phenylmethyl）-1H-pyrazole-5-carboxamide） and BYIO6830（N＇-（3,5-dimethylbenzoyl）-N＇-tert-butyl-5-methyl-2,3-dihydro-l,4-benzodioxine-6-carbohydrazide） bound to the active site of the EcR subunit of the ecdysone receptor（EcR）-ultraspiracle protein（USP） heterodimeric receptor,a series of new pyrazole amide derivatives were designed and synthesized.Their structures were confirmed by IR,~1H NMR,^（13）C NMR and elemental analysis.Results from a preliminary bioassay revealed that two of the pyrazole derivatives exhibited promising insecticidal activity.Specifically,compounds 6e and 6i exhibited good activity against Helicoverpa armigera（cotton bollworm） at low concentration.Symptoms displayed by tebufenozide-treated H.armigera were identical with those displayed by its treated counterpart.6i showed the same poisoning symptoms as those of tebufenozide.In addition,results from molecular docking result indicated that the binding modes of 6e and 6i at the active site of the EcR subunit of the heterodimeric receptor were similar to that of the bound tebufenozide.展开更多
Cathepsin L gene is a member of the cysteine proteinase gene group. In this study Cathepsin L gene was isolated from Kuruma shrimp Marsupenaeusjaponicus （Mj-Cathepsin L） and the full-length DNA sequence was 1 963 bp...Cathepsin L gene is a member of the cysteine proteinase gene group. In this study Cathepsin L gene was isolated from Kuruma shrimp Marsupenaeusjaponicus （Mj-Cathepsin L） and the full-length DNA sequence was 1 963 bp. Mj-Cathepsin L protein showed high homologies with other Cathepsin L proteins documented in vertebrates, mollusks and other crustaceans. Expression analysis of Mj-Cathepsin L gene in different tissues revealed that it was predominant in hepatopancreas. During early ontogenetic development stages Mj-Cathepsin L showed a development-regulated expression, and the Mj-Cathepsin L showed a molting stage-regulated expression during the five molting stages, inferring its role in the ontogenic development of M.japonicus. Two kinds of forms of Mj- Cathepsin L protein： pro-Cathepsin L and Cathepsin L were measured in hepatopancreas, stomach and intestine by Western Blotting.展开更多
We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanism...We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August-January, the breeding season in the wild, or in February- May （molting-reproductive season）, wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June-July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation （due to de-eyestalking） was minimal in June--July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the viteUine components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from the eyestalks could be a prerequisite for normal healthy maturation of the oocytes and spawning.展开更多
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.
基金supported by funds from the National Natural Science Foundation of China (Grant No. 30571441)the Project of Reward Research Foundation for Talented Young and Middle Aged Scientists of Shandong, China (Grant No. 2006BS07002)the National Great Project of Scientific and Technical Supporting Programs Funded by the Ministry of Science and Technology of China in the 11th Five-Year Plan (Grant No. 2006BAD09A07)
文摘This experiment was conducted to examine the effects of salinity fluctuation frequency on the growth, molting rate and hemolymph 20-hydroxyecdysone （20-HE） concentration for juvenile Fenneropenaeus chinensis with an initial wet body weight of 1.115 g±0.012 g. The salinity of the control treatment （represented by DO） was 28 throughout the experiment, whereas treatments D2, D4, D6 and D8 were subjected to different salinity fluctuation frequencies of 2, 4, 6 and 8 d, respectively. The range of salinity fluctuation was 4. The salinity in treatments D2, D4, D6 and D8 was kept at 28 for 2, 4, 6 and 8d, respectively; each original salinity was decreased abruptly to salinity 24, which first lasted for another 2 d and was then raised to its initial value 28. This constituted a salinity fluctuation cycle and afterwards the cycle repeated. It was found that： 1） The weight gain of shrimp in treatment D4 was 202.9% and significantly higher than that in treatment DO （P〈0.05）. The molting rate in treatment D2 was the lowest, while that in treatment D6 was the highest and significantly higher than those in treatments DO and D2 （P〈0.05）. 2） The hemolymph 20-HE concentration of shrimps in all treatments was at low levels and increased first gradually during the inter-molt period and then increased sharply. It reached a peak value during the pre-molt stage, and then decreased abruptly during the post-molt stage when the lowest level occurred. 3） During the post-molt stage, the hemolymph 20-HE concentration in treatment D2 was 7.47pg μL^-1 and significantly higher than that in treatment DO （P〈0.05）. There were, however, no significant differences in hemolymph 20-HE concentration among all five treatments during the inter-molt stage （P〉0.05）. During the pre-molt stage, the hemolymph 20-HE concentration in treatment D6 was significantly higher than that in treatment DO （P〈0.05）, whereas the hemolymph 20-HE concentration in treatment D2 was significantly lower than that in other treatments （P〈0.05）. Adequate salinity fluctuation promoted the molting rate through increasing hemolymph 20-HE concentration at the pre-molt stage.
基金supported by the project of Natural Science Foundation of Shandong Province (ZR2014 CM042)the project of Marine Biotechnology Key Laboratory Opening Topic Fund of Guangxi (Grant No. GLMBT-201501)
文摘To determine the response of Litopenaeus vannamei to periodical salinity fluctuation, a 30-day experiment was conducted in laboratory. In this experiment, two salinity fluctuation amplitudes of 4(group S4) and 10(group S10) were designed. The constant salinity of 30(group S0) was used as the control. Levels of shrimp growth, molting frequency(MF), cellular energy status(ATP, ADP and AMP), as well as the expression of genes encoding molt-inhibiting hormone(MIH), crustacean hyperglycemic hormone(CHH), ecdysteroid-regulated protein(ERP), and energy-related AMP-activated protein kinase(AMPK) were determined. The results showed that periodical salinity fluctuation significantly influenced all indicators except MF which ranged from 13.3% in group S10 to15.4% in group S4. In comparison with shrimps cultured at the constant salinity of 30, those in group S4 showed a significant elevation in growth rate, food conversion efficiency, cellular energy status, ERP and MIH gene transcript abundance, and a significant reduction in CHH and AMPK transcript abundance(P < 0.05). However, salinity fluctuation of 10 only resulted in a significant variation in MIH and CHH gene expression when compared to the control(P < 0.05). According to our findings, L. vannamei may be highly capable of tolerating salinity fluctuation. When ambient salinity fluctuated at approx. 4, the increased MF and energy stores in organisms may aid to promoting shrimp growth.
基金The National Key R&D Program of China under contract No.2019YFD0901404the National Natural Science Foundation of China under contract No.41876141+3 种基金the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning under contract No.0810000243the Shanghai Pujiang Program under contract No.18PJ1404100the Shanghai Science and Technology Innovation Action Plan under contract No.19DZ1207502Programs Foundation of Ministry of Education of China under contract No.20133104120001。
文摘The analysis of growth bands in the eyestalk has been increasingly used for estimating crustacean ageing and molting.In this study,we developed an effective method to process and observe the eyestalk microstructure of the swimming crab(Portunus trituberculatus).We found that dark pigmentation as a result of boiling has an influence on the observation of the eyestalk microstructure.Choosing an unboiled eyestalk,this study compared the cross section and longitudinal section,and concluded that the cross section is suitable for the observation of growth increments with 6.1%CV(coefficient of variation),and growth bands are suitable for the observation of the longitudinal section with 5.4%CV.The width of growth increments near the edge of the endocuticle is small,and the width of growth increments of the middle part of the endocuticle is large.Relationship of number of growth bands to molting time was fitted to a linear function with the slope not significantly different from 1,indicating that growth bands are formed associated with molting.Periodicity of growth increment formation was calculated as 3.7 d,however was not verified.Our results provide a new improved technique for identification of crustacean molting and growth.
基金supported by grants from the National Natural Science Foundation of China(grant no.32272523)the Natural Science Foundation of Guangdong Province,China(grant no.2023A1515010178)the Laboratory of Lingnan Modern Agriculture Project(grant no.NT2021003).
文摘Molting and metamorphosis are important physiological processes in insects that are tightly controlled by ecdysone receptor(EcR)through the 20-hydroxyecdysone(20E)signaling pathway.EcR is a steroid nuclear receptor(SR).Several FK506-binding proteins(FKBPs)have been identified from the mammal SR complex,and are thought to be involved in the subcellular trafficking of SR.However,their roles in insects are poorly understood.To explore whether FKBPs are involved in insect molting or metamorphosis,we injected an FKBP inhibitor(FK506)into a lepidopteran insect,Spodoptera litura,and found that molting was inhibited in 61.11%of the larvae,and that the time for larvae to pupate was significantly extended.A total of 10 FKBP genes were identified from the genome of s.litura and were clustered into 2 distinct groups,according to their subcellular localization,with FKBP13 and FKBP14 belonging to the endoplasmic reticulum(ER)group and with the other members belonging to the cytoplasmic(Cy)group.All the CyFKBPs were significantly upregulated in the prepupal or pupal stages,with the opposite being observed for the ER group members.FK506 completely blocked the transfer of EcR to the nucleus under 20E induction,and significantly downregulated the transcriptional expression of many 20E signaling genes.A similar phenomenon was observed after RNA interference of2 CyFKBPs(FKBP45 and FKBP12b),but not for FKBP13.Taken together,our data indicate that the cytoplasmic FKBPs,especially FKBP45 and FKBP12b,mediate the nuclear localization of EcR,thereby regulating the 20E signaling and ultimately affecting molting and metamorphosis in insects.
基金This work was supported by National Natural Science Foundation of China(Grant No.31730074,31761133021,31802018,31320103921)the Program for Top Young Academic Leaders of Higher Learning Institutions of Shanxi Province(TYAL)2017,Key Research and Development Program of Shanxi Province(201803D221004-5)The Natural Science Foundation of Shanxi Province,China(201801D221247).
文摘Cytochrome P450 monooxygenases(CYPs)play essential physiological functions in insects.CYP303A1 is highly conserved in insect species studied to date,and shows an indispensable role for adult eclosion in both Locusta migratoria and Drosophila melanogaster.However,how CYP303A1 is regulated to control insect developmental processes remains uninvestigated.In this study,we discovered functional binding sites for miR-184 in the coding sequence of LmCYP303A1.The luciferase reporter assay showed that miR-184 could target LmCYP303A1 and regulate its expression in vitro.Furthermore,overexpression of miR-184 through microinjection of agomir to locusts reduced the transcripts of LmCYP303A1 and led to abnormal molting,which is similar to the phenotype of silencing LmCYP303A1 by direct injection of dsLmCYP303A1 to locusts.Meanwhile,down-regulation of miR-184 by injection of antagomir increased the LmCYP303A1 transcript and caused molting defects.These findings suggested that miR-184 could target LmCYP303A1 to regulate the molting process in L.migratoria,which might be considered as a novel target for pest control.
文摘The vacuolar (H+)-ATPases (V-ATPases) are ATP-driven proton pumps with multiple functions in many organisms. In this study, we performed structural and functional analysis of vha55 gene that encodes V-ATPase subunit B in the smokybrown cockroach Periplaneta fuliginosa (Blattodea). We observed a high homology score of the deduced amino acid sequences between 10 species in seven orders. RNAi of the vha55 gene in R fuliginosa caused nymphal/nymphal molting defects with incomplete shedding of old cuticles, growth inhibition, as well as bent and wrinkled cuticles of thoraxes and abdominal segments. Since growth inhibition caused by vha55 RNAi did not interfere in the commencement of cockroach molting, molting timing and body growth might be controlled by independent mechanism. Our study suggested V-ATPases might be a good candidate molecule for evolutionary and developmental studies of insect molting.
基金Supported by the National Natural Science Foundation of China(Nos.32172954,32373121)the Key Research and Development Project of Hebei Province(No.22323201D)+2 种基金the Science and Technology Project of Hebei Education Department(No.ZD 2022093)the Natural Science Foundation of Hebei Province(Nos.D2022201003,D2023201002)the Hangzhou Qianjiang Special Expert fund for Prof.Jiquan ZHANG。
文摘The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific research.Two calcium-associated cuticular protein genes,named NdCAP-1 and NdCAP-2,were obtained from N.denticulata sinensis.Molecular docking simulated the binding effect of both proteins and calcium ions.Semi-quantitative reverse transcription PCR results show that NdCAP-1 is expressed in D_(2-4) stage,NdCAP-2 expressed in D_(2-4) and A-B stages,and both were significantly expressed in the cephalothorax cuticle and pereiopods.Then,it was revealed that NdCAP-1 and NdCAP-2 are regulated by NdEcR-mediated 20 E signaling pathways.Knockdown of NdCAP-1 and NdCAP-2 was observed to cause surface defects.The recombinant proteins(rNdCAP-1 and rNdCAP-2),obtained by prokaryotic expression,had calcium-binding and chitin-binding ability,inhibited formation of calcium carbonate precipitate.These results show that calcium-associated cuticular proteins play important roles in cuticle formation and calcification.
基金supported by the National Natural Science Foundation of China (No. 21272265)the National High Technology Research and Development Program of China (No. 2011AA10A204)
文摘Based on the similarities in the conformation of VS008（N-（4-methylphenyl）-3-（tert-butyl）-1-（phenylmethyl）-1H-pyrazole-5-carboxamide） and BYIO6830（N＇-（3,5-dimethylbenzoyl）-N＇-tert-butyl-5-methyl-2,3-dihydro-l,4-benzodioxine-6-carbohydrazide） bound to the active site of the EcR subunit of the ecdysone receptor（EcR）-ultraspiracle protein（USP） heterodimeric receptor,a series of new pyrazole amide derivatives were designed and synthesized.Their structures were confirmed by IR,~1H NMR,^（13）C NMR and elemental analysis.Results from a preliminary bioassay revealed that two of the pyrazole derivatives exhibited promising insecticidal activity.Specifically,compounds 6e and 6i exhibited good activity against Helicoverpa armigera（cotton bollworm） at low concentration.Symptoms displayed by tebufenozide-treated H.armigera were identical with those displayed by its treated counterpart.6i showed the same poisoning symptoms as those of tebufenozide.In addition,results from molecular docking result indicated that the binding modes of 6e and 6i at the active site of the EcR subunit of the heterodimeric receptor were similar to that of the bound tebufenozide.
基金The National High-tech R&D Program of China(863 Program)under contract No.2012AA10A409-03the Project of China Agriculture Research System under contract No.CARS-47+1 种基金the Project of Xiamen Southern Ocean Research Center under contract No.14CZY033HJ07China Spark Program under contract No.2015GA720002
文摘Cathepsin L gene is a member of the cysteine proteinase gene group. In this study Cathepsin L gene was isolated from Kuruma shrimp Marsupenaeusjaponicus （Mj-Cathepsin L） and the full-length DNA sequence was 1 963 bp. Mj-Cathepsin L protein showed high homologies with other Cathepsin L proteins documented in vertebrates, mollusks and other crustaceans. Expression analysis of Mj-Cathepsin L gene in different tissues revealed that it was predominant in hepatopancreas. During early ontogenetic development stages Mj-Cathepsin L showed a development-regulated expression, and the Mj-Cathepsin L showed a molting stage-regulated expression during the five molting stages, inferring its role in the ontogenic development of M.japonicus. Two kinds of forms of Mj- Cathepsin L protein： pro-Cathepsin L and Cathepsin L were measured in hepatopancreas, stomach and intestine by Western Blotting.
基金Supported by the International Foundation for Science(Stockholm,Sweden)(RGA:A/3520-1)the Junior Research Fellowship,Kannur University
文摘We present the results of eyestalk extirpation experiments performed on the fiddler crab, Uca triangularis at seasons of molting and reproduction, with a view to have a better understanding of the regulatory mechanisms of these two highly energy-demanding processes. Bilateral eyestalk ablation resulted in precocious acceleration of both molting and reproduction, irrespective of the season at which each experiment was conducted. The rate of accelerated ovarian growth, however, was maximum if the eyestalk ablation was conducted during August-January, the breeding season in the wild, or in February- May （molting-reproductive season）, wherein a section of the wild population would be engaged in molting and another section in breeding. The highest degree of precocious molt acceleration, on the other hand, was obtained during June-July when the population was primarily engaged in molting, but with no reproductive activity. The precocious oocyte maturation （due to de-eyestalking） was minimal in June--July. Significantly, the eyestalk ablation also resulted in a dramatic increase in the hemolymph ecdysteroid titer, revealing that a high ecdysteroid titer would have no restraining influence on vitellogenesis. No spawning was, however, observed among de-eyestalked females, even though their final oocyte size surpassed the size of the normal mature oocytes, implying that spawning is not exclusively under the control of eyestalk hormones. A comparative study performed on the viteUine components of the experimentals and the controls revealed that the precociously incorporated yolk under eyestalk ablation was biochemically impoverished. These results indicate that throughout the annual cycle, both the somatic and the reproductive growth of U. triangularis are under the influence of inhibitory principles from the eyestalks. It is also revealing that mere deprival of the inhibitory principles does not culminate into successful vitellogenesis. Arguably, the inhibitory influence from the eyestalks could be a prerequisite for normal healthy maturation of the oocytes and spawning.
