Diapause is defined as a period of suspended development in insects and other invertebrates during unfavorable environmental conditions. Diapause is commonly confused with term ＂quiescence＂ as both are dormant devel...Diapause is defined as a period of suspended development in insects and other invertebrates during unfavorable environmental conditions. Diapause is commonly confused with term ＂quiescence＂ as both are dormant development stages. Here this paper aimed to review the research work done on different aspects of diapause. Attempt was made to explain definitions of diapause, incidence, stages and termination of diapause, genetic control, factors affecting diapauses, including temperature, photoperiod, moisture and food, etc..展开更多
[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from di...[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different development stages were detected by the colorimetry. [Result] RNA content of non-diapause pupae was 4.614 0-7.946 3 μg/mg, while diapause pupae was 4.326 0-5.885 3 μg/mg and eclosion-adult from diapause pupae was 20.779 3 μg/mg at initial stage. DNA content of non-diapause pupae was 0.448 7-0.535 0 μg/mg, while diapause pupae was 0.452 0-0.828 3 μg/mg and eclosion-adult from diapause pupae was 1.727 0 μg/mg at initial stage. [Conclusion] The nucleic acid content and change is related to the development stage.展开更多
[ Objective] The experiment aimed to explore the diapause mechanism of Papilio memnon L. further. [ Method] The colorimetry method was used to detect protein content of non-diapause pupae, diapause pupae and eclosion-...[ Objective] The experiment aimed to explore the diapause mechanism of Papilio memnon L. further. [ Method] The colorimetry method was used to detect protein content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different developmental stages. [Result] It was showed that the protein content of non-diapause pupae was from 111.768 to 115.030 7 mg/g and the change of protein content during whole pupal stage, while diapause pupae were from 81.218 to 131.623 7 mg/g and the change of protein content was not big from last ten-day period of October to last ten-day pariod of November, however, the content increased from the last ten-day period of November. The protein content of emerging adult was 296.969 3 mg/g. [Conclusion] The change of protein content was related to Papilio memnon at different development stage.展开更多
Diapause hormone (DH) is a neurohormone which is secreted from suboesophageal ganglion and responsible for induction of embryonic diapause in Bombyx mori.Here,using bioassay,we present evidence that Has-SGNPⅠ,which c...Diapause hormone (DH) is a neurohormone which is secreted from suboesophageal ganglion and responsible for induction of embryonic diapause in Bombyx mori.Here,using bioassay,we present evidence that Has-SGNPⅠ,which clearly exhibited diapause egg inducing activity as does Bom-DH,is likely to be DH.We reported the molecular characterization of the Helicoverpa assulta diapause hormone analog by polymerase chain reaction.A 665?bp fragment containing the entire DH-like gene was isolated and characterized.DH-like gene comprised two exons interspersed by a single intron,and the consensus sequence for splicing junction is identified at the exon/intron boundary.The result shows that DH-like gene is localized in the genome of Helicoverpa assulta.展开更多
Maternal photoperiodic response is a key factor that affects offspring diapause in migratory locust,Locusta migratoria L.(Orthoptera:Acridoidea).Although many aspects of insect diapause have been studied,little is kno...Maternal photoperiodic response is a key factor that affects offspring diapause in migratory locust,Locusta migratoria L.(Orthoptera:Acridoidea).Although many aspects of insect diapause have been studied,little is known about the molecular mechanisms of maternal photoperiodic response that influence diapause regulation.To gain insight into the possible mechanisms of maternal photoperiod influence on diapause regulation,proteomics data by label-free quantification analysis were generated from non-diapause and diapause eggs.A total of 175 proteins were differentially expressed between diapause and non-diapause eggs.Among them,24 proteins were upregulated,and 151 proteins were downregulated.Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichments were performed on all differentially expressed proteins(DEPs)and showed that peroxisome,insect hormone biosynthesis,and longevity regulating pathway may be related to diapause of migratory locust.Furthermore,we used qRT-PCR to verify some results of the proteomic analysis.Proteins such as hexamerin-like protein 4,juvenile hormone epoxide hydrolase 1(JHEH1),cytochrome P450 and heat shock protein(HSP)20.7 were predicted to be involved in diapause.This study provides an important reference for future research that will explore the mechanisms of diapause induced by maternal effects in migratory locust.展开更多
Temperate-zone insects typically survive winter by entering diapause. Although many aspects of insect diapause have been studied, the underlying molecular mechanism of insect diapause is not well understood. Here we r...Temperate-zone insects typically survive winter by entering diapause. Although many aspects of insect diapause have been studied, the underlying molecular mechanism of insect diapause is not well understood. Here we report the results of the transcriptional and translational differences of migratory locust eggs at different embryonic states using diapause （low temperature） and non-diapause （high temperature） regimes. Compared with non-diapause eggs at 100 degree-days （N2） treatment, 29671 transcripts and 296 proteins were differentially expressed at the diapause maintenance stage （D2）. While compared with 150 degree-days （N3） treatment, 45 922 transcripts and 404 proteins were differentially expressed in the post-diapause stage （D3）. Among them, 51 and 102 transcripts had concurrent transcription and translation profiles in D2 vs. N2 and D3 vs. N3 treatments, respectively. Analysis of Gene Ontology categorized these genes and proteins into three categories： biological processes, cellular components, and molecular functions. Biological pathway analysis indicat- ed that three pathways： （1） insect hormone biosynthesis （KEGG： Map 00981）, （2） the insulin signaling pathway （KEGG： Map 04910）, and （3） the peroxisome proliferator-activated receptor （PPAR） signaling pathway （KEGG： Map 03320） play an important role in locust diapause regulation. Most of these transcripts and proteins were up-regulated in the diapause treatments, and were highly linked to juvenile hormone biosynthesis, insulin and PPAR signaling pathways, suggesting these three pathways may be Jnvolved Jn diapause and development regulation. This study demonstrates the applicability of high-throughput omics tools to identify biochemical pathways linked to diapause in locust egg development. In addition, it reveals that cellular metabolism in diapause eggs is more inactive than in non-diapause eggs, and most of the down-reg- ulated enzymes and pathways are related to reduce energy loss.展开更多
The brine shrimp Artemia exhibits two reproductive modes: 1) oviparity, producing diapause embryos;and 2) ovoviviparity, producing free-swimming nauplii. Previous studies have suggested the existence of a critical sta...The brine shrimp Artemia exhibits two reproductive modes: 1) oviparity, producing diapause embryos;and 2) ovoviviparity, producing free-swimming nauplii. Previous studies have suggested the existence of a critical stage that determines the reproductive mode. Physicochemical factors, such as photoperiod, temperature, and salinity, have been suggested to irreversibly aff ect the reproductive mode of oocytes during this critical stage. In this study, experiments were carried out using a photoperiod and temperature-sensitive parthenogenetic Artemia clone where maternal Artemia were shifted bidirectionally between ovoviviparity (18 h L:6 h D, 27℃) and oviparity (6 h L:18 h D, 19℃) culture conditions. In the main experiment ( Artemia shifted at six diff erent stages including the post-larva Ⅱ to adult Ⅱ), the reproductive mode of fi rst brood was converted when shifting was performed on post-larva Ⅱ and Ⅲ but was not converted when females were shifted after post-larva Ⅲ. A supplementary experiment further revealed that the reproductive mode of fi rst brood could be altered when shifting females at an "early phase of postlarva Ⅳ", characterized by a developing ovisac reaching the middle of the third abdominal segment, ventral spines, and some oocytes growing larger than the others. In both experiments, reproductive modes of the second brood were signifi cantly aff ected when the shifting was performed on post-larva Ⅳ. These results suggest that the critical stage for inducing oviparity and embryonic diapause is at the previtellogenic stage of oocytes, or at maternal "early phase of post-larva Ⅳ" for the first-brood off spring. During this stage, diff erential gene expression patterns of the two destined oocytes may be triggered by the token stimuli signals received by the oocytes.展开更多
Diapause is a long-lived stage which has evolved into an important strategy for insects to circumvent extreme environments.In the pupal stage,Helicoverpa armigera can enter diapause,a state characterized by significan...Diapause is a long-lived stage which has evolved into an important strategy for insects to circumvent extreme environments.In the pupal stage,Helicoverpa armigera can enter diapause,a state characterized by significantly decreased metabolic activity and enhanced stress resistance,to survive cold winters.Previous studies have shown that reactive oxygen species(ROS)can promote the diapause process by regulating a distinct insulin signaling pathway.However,the source of ROS in the diapause-destined pupal brains and mechanisms by which ROS regulate diapause are still unknown.In this study,we showed that diapause-destined pupal brains accumulated high levels of mitochondrial ROS(mtROS)and total ROS during the diapause process,suggesting that mitochondria are the main source of ROS in diapause-destined pupal brains.In addition,injection of 2-deoxy-D-glucose(DOG),a glucose metabolism inhibitor,could delay pupal development by elevating mtROS levels in the nondiapause-destined pupal brains.Furthermore,the injection of a metabolite mixture to increase metabolic activity could avert the diapause process in diapause-destined pupae by decreasing mtROS levels.We also found that ROS could activate HSP60 expression and promote the stability of the HSP60-Lon complex,increasing its ability to degrade mitochondrial transcription factor A(TFAM)and decreasing mitochondrial activity or biogenesis under oxidative stress.Thus,this study illustrated the beneficial function of ROS in diapause or lifespan extension by decreasing mitochondrial activity.展开更多
Female adults of the migratory locust,Locusta migratoria manilensis(Meyen),can sense seasonal photoperiod changes,which induces embryonic diapause as a key strategy to overwinter.Serine protease inhibitor genes(SPNs)w...Female adults of the migratory locust,Locusta migratoria manilensis(Meyen),can sense seasonal photoperiod changes,which induces embryonic diapause as a key strategy to overwinter.Serine protease inhibitor genes(SPNs)were thought to play key roles during diapause,while few SPNs were functionally characterized.LmSPN2 was one of those genes differentially expressed between diapause and non-diapause eggs;however,its biological function remained to be explored.So,we conducted RNAi knockdown of LmSPN2,resulting in a significant decrease of the egg diapause rate by 29.7%.Using yeast two-hybrid assays,co-immunoprecipitation,and pull-down methods,we found an interaction between LmSPN2 and LmSPN3,which was proved to be mediated by a glutamate(E331)binding site of LmSPN2.RNAi knockdown of LmSPN3 resulted in a significant increase in diapause rate by 14.6%,indicating an inverse function of LmSPN2 and LmSPN3 on diapause regulation.Double knockdown of two SPN genes resulted in a 26.4%reduction in diapause rate,indicating that LmSPN2 was the dominant regulatory signal.Moreover,we found four Toll pathway genes(easter,spätzle,pelle,and dorsal)upregulated significantly after the knockdown of LmSPN2 while downregulated after the knockdown of LmSPN3.Therefore,we speculate that two SPNs regulate diapause through the Toll pathway.Our results indicated that LmSPN2 positively regulates locust egg entry into diapause,while LmSPN3 is a negative regulator of embryonic commitment to diapause.Their interaction is mediated by the binding site of E331 and influences egg diapause through the Toll pathway.This mechanistic understanding of diapause regulation expands our understanding of insect developmental regulation and provides functional targets for developing locust management strategies.展开更多
Insects enter in diapause in response to diverse environmental cues. During diapause, insects arrest their development and many genes are down-regulated while a small number of genes uniquely expressed at this time. T...Insects enter in diapause in response to diverse environmental cues. During diapause, insects arrest their development and many genes are down-regulated while a small number of genes uniquely expressed at this time. This review aims to present available data regarding the regulation of diapause in the moth Sesamia nonagrioides （Lepidoptera： Noctuidae）. Studying the transcriptional regulation of several genes （five heat shock proteins, two storage proteins and one juvenile hormone esterase） showed that these genes may play various roles in the diapause programming. The results show that SnoHsp19.5 gene was consistently expressed, while SnoHsp20.8 was down-regulated in deep diapause and was up-regulated at the termination of diapause. SnoHsc70 may play important roles in assisting protein conformation during specific stages of diapause. SnoHsp83 displays a similar pattern to SnoHsc70 under diapause conditions, when extra larval moults occur, indicating that could be involved in the developmental process that occurs between two moults. Expression of two SnoSP1 and SnoSP2 hexamerin genes was also observed throughout diapause. And the results lead us to the conclusion that larval diapause of S. nonagrioides is associated with continuous synthesis and accumulation of storage proteins. In addition, the transcript level of the carboxylesterase SnoJHER was higher in non-diapausing larvae than in diapausing ones. During the fifth instar of the non-diapausing and the ninth instar of the diapausing larvae, SnoJHER mRNAs reached higher expression levels on the days close to each larval molt.展开更多
The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and...The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and the open reading frame (ORF) of 2106 bp encoded 701 amino acid with a calculated molecular weight of 80.5 kDa and an isoelectric point of 5.87. The onion maggot LSp-2 shows highest homology (83%) to that ofCalliphora vicinaat amino acid level. Its signal peptides, domains and structures were predicted and analyzed by using bioinformatic methods. The amino acid sequence of LSP-2 suggests that it would be a typical hexamerin.展开更多
A hyperparasitic system with prolonged diapause for host is investigated. It is assumed that host prolonged diapause occur at larval stage, and parasitoid attack is limited to egg stage before the initiation of host d...A hyperparasitic system with prolonged diapause for host is investigated. It is assumed that host prolonged diapause occur at larval stage, and parasitoid attack is limited to egg stage before the initiation of host diapause. Such behavior has been reported for many ichneumons. Hyperparasite only attacks the parasitoids that parasitize the hosts. Hyperparasitic system is often used in biological control. The existence and stability of nonnegative fixed points are explored. Numerical simulations are carried out to explore the global dynamics of the system, which demonstrate appropriate prolonged diapause rate and appropriate intrinsic growth rate can stabilize the system. The reasons are explained according to the ecological perspective. Furthermore, many other complexities which include quasi-periodicity, period-doubling bifurcations leading to chaos, chaotic attractor, intermittent and supertransients are observed.展开更多
Diapause is an adaptive strategy employed by insects to endure adverse environmental conditions and is characterized by reduced metabolic activity,primarily due to a decreased respiratory rate.AMP-activated protein ki...Diapause is an adaptive strategy employed by insects to endure adverse environmental conditions and is characterized by reduced metabolic activity,primarily due to a decreased respiratory rate.AMP-activated protein kinase(AMPK)serves as an intracellular energy regulator,modulating energy metabolism in response to metabolic fluctuations.However,its role in pupal diapause of the cotton bollworm,Helicoverpa armigera,remains unclear.In this study,we found that AMPK and its active form,P-AMPK,are highly expressed in diapause-destined pupae.Furthermore,activation of AMPK delayed the development of nondiapause-destined pupae,suggesting a critical role for AMPK in the regulation of pupal diapause in H.armigera.Manipulating AMPK activity in H.armigera epidermal(HaEpi)cells and pupae significantly influenced the expression of hypoxia-inducible factor-1α(HIF-1α),which our laboratory previously reported as a key inducer of pupal diapause through the reduction of mitochondrial activity in H.armigera.Histone deacetylase 4(HDAC4),a shuttle protein phosphorylated by AMPK which translocates between the cytoplasm and the nucleus,was found to exhibit significantly higher expression in diapause-destined pupal brains compared to their nondiapause counterparts.AMPK in both HaEpi cells and pupae positively regulated the protein levels of P-HDAC4 by binding to the HDAC4 promoter.Additionally,HDAC4 was shown to enhance HIF-1αexpression in diapause-destined individuals.HDAC4 binds to and deacetylates heat shock protein 70(HSP70),and reduced acetylation of HSP70 was found to significantly elevate HIF-1αprotein levels.The AMPK-HIF-1αsignaling pathway appears to play a pivotal role in reducing mitochondrial activity and facilitating diapause induction in H.armigera pupae.展开更多
Due to the risk of extinction and ornamental value of the swallowtail butterfly, Sericinus montelus Gray （Lepidoptera： Papilionidae） in China, knowledge about local adaptations is important for the conservation and...Due to the risk of extinction and ornamental value of the swallowtail butterfly, Sericinus montelus Gray （Lepidoptera： Papilionidae） in China, knowledge about local adaptations is important for the conservation and economical utilization of the species. In the present study, photoperiodie diapause induction and diapause intensity of S. montelus populations from Jiamusi （46°37＇N）, Beijing （40° 15＇N）, Zibo （36°48＇N）, Fangxian （32°36＇N）, Wuhan （30°33＇N） and Huaihua （27°33＇N） were characterized at 25℃. Logistic regression analysis revealed a significant population x hours of light interaction, confirming that photoperiodic responses varied among populations. The critical photoperiod was positively correlated with latitude and increased toward the north at a rate of about 1 h for each 6.67 degrees of latitude. Survival analyses indicated that survival time of diapausing pupae before adult eclosion differed significantly among populations at 25℃ and 16 ： 8 L ＂D h. The mean duration of pupal diapause was also positively correlated with latitude. Our study reveals geographic variation in the critical photoperiod for diapause induction and in diapause intensity of S. montelus. These results provide useful information for our general understanding about seasonal adaptation in insects and may also be used to predict how geographic populations respond to climate warming.展开更多
The onion fly, Delia antiqua, is a major underground agricultural pest that can enter pupal diapause in the summer and winter seasons. However, little is known about its molecular regulation due to the lack of genomic...The onion fly, Delia antiqua, is a major underground agricultural pest that can enter pupal diapause in the summer and winter seasons. However, little is known about its molecular regulation due to the lack of genomic resources. To gain insight into the possible mechanism of summer diapause （SD）, high-throughput RNA-Seq data were generated from non-diapause （ND） and SD （initial, maintenance and quiescence phase） pupae. Three pair-wise comparisons were performed and identified, 1380, 1471 and 435, and were significantly regulated transcripts. Further analysis revealed that the enrichment of several functional terms related to juvenile hormone regulation, cell cycle, carbon hydrate and lipid metabolism, innate immune and stress responses, various signalling transductions, ubiquitin-dependent proteosome, and variation in cuticular and cytoskeleton components were found between ND and SD and between different phases of SD. Global characterization oftranscriptome profiling between SD and ND contributes to the in-depth elucidation of the molecular mechanism of SD. Our results also offer insights into the evolution of insect diapause and support the importance of using the onion fly as a model to compare the molecular regulation events of summer and winter diapauses.展开更多
The embryonic diapause of the silkworm, Bombyx mori, is induced by the diapause hormone (DH) which is secreted from the suboesophageal ganglion of pupae. The diapause nature of bivoltine strains uses environmental sti...The embryonic diapause of the silkworm, Bombyx mori, is induced by the diapause hormone (DH) which is secreted from the suboesophageal ganglion of pupae. The diapause nature of bivoltine strains uses environmental stimuli as the initial signal to determine the diapause nature. The experiments showed that DH gene expression is a direct response to the environmental stimulus, such as high incubation temperature. The cDNA from the embryonic stage was cloned and sequence analysis showed the cDNA encoding DH. Expression patterns of the DH gene in embryonic stage are different at incubation temperatures 15℃ and 25℃, suggesting that the incubation temperature as an environmental signal is kept within the body to control the DH gene expression at the pupal stage, so that the embryonic diapause of next generation can be determined.展开更多
Seasonal changes in the fatty acid composition of the total lipid extracted from the whole body of Cydia pomonella L. larvae were determined by gas chromatography. The six most abundant fatty acids in both non-diapaus...Seasonal changes in the fatty acid composition of the total lipid extracted from the whole body of Cydia pomonella L. larvae were determined by gas chromatography. The six most abundant fatty acids in both non-diapause and diapause larvae of codling moth were oleic （35%-39%）, palmitic （23%-33%）, linoleic （16%-30%）, palmitoleic （5%-10%）, stearic （1.5%-3.0%） and linolenic acids （1.0%-2.5%）. This represents a typical complement of Lepidopteran fatty acids. The fatty acid composition of total lipid of C. pomonella larvae was related to diapause. In similarity to most other reports, the proportion of unsaturated fatty acids increased in diapause initiation state. The total lipid of diapause larvae contained more linoleic acid （25.8% vs. 16.1%） and less palmitic acid （24.7% vs. 33.4%）, than that of non-diapause larvae. The weight percentage of linoleic acid （C 18：2） increased from 16% to 26% from early-August through early-September during transition to diapause, while palmitic acid （C16：0） decreased from 33% to 25% at the same time. These changes resulted in an increase in the ratio of unsaturated to saturated fatty acids （UFA/SFA） from 1.72 in non-diapause larvae to 2.63 in diapause larvae.展开更多
To understand the adaptive strategies of the overwintering adults of Steno- catantops splendens, the mechanism of maintenance and termination of the reproductive diapause, the variation in mortality between overwinter...To understand the adaptive strategies of the overwintering adults of Steno- catantops splendens, the mechanism of maintenance and termination of the reproductive diapause, the variation in mortality between overwintering females and males, and the mating strategy of the males were investigated. The results indicated that the adult repro- ductive diapause in natural conditions was mainly regulated by photoperiod in the fall - long photoperiods promoted reproductive development and short photoperiods maintained reproductive diapause, and the sensitivity of the overwintering adults to photoperiod was over before the end of the winter. When transferred from natural conditions to controlled laboratory conditions on dates from September through February, pre-oviposition became increasingly shorter with increasingly deferred transfer dates regardless of photoperiod conditions. The adults treated with low temperature for 30 days in September through November had significantly shorter pre-oviposition, suggesting that low temperatures in winter had an important role in the termination of reproductive diapause. The female had a significantly lower supercooling point than the male, which was related to their lower mortality after winter. In addition, observations of wild populations of the species indicated that mating behavior prior to winter and the duration of pre-mating period were not affected by photoperiod; mating and sperm transfer were mostly completed by November. Compared with females only mating before winter, females mating in the spring had shorter life span, longer pre-oviposition, lower hatching rate and laid fewer egg pods while showing no significant difference with regard to ovipositional interval, per pod number of eggs and nymph dry weight.展开更多
To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for...To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for the germline transformation of diapause silkworm strains. Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains. By incu- bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃ （15℃-IME）, we were able to prevent the diapause of their daughter eggs; a similar strategy （15℃-IMES） for the germline transformation of the same strains was that the mother eggs were incubated at 15℃, and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs. By combining tempera- ture and light controls, the improved 15℃-IMES strategy prevented diapause in daughter eggs, and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains. Although each of the strategies developed here has advantages and disadvantages, we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects. These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.展开更多
The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperatur...The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.展开更多
文摘Diapause is defined as a period of suspended development in insects and other invertebrates during unfavorable environmental conditions. Diapause is commonly confused with term ＂quiescence＂ as both are dormant development stages. Here this paper aimed to review the research work done on different aspects of diapause. Attempt was made to explain definitions of diapause, incidence, stages and termination of diapause, genetic control, factors affecting diapauses, including temperature, photoperiod, moisture and food, etc..
基金Supported by the International Advanced Forestry Science and Technology Project Imported by State Forestry Administration (2005-4-59 and 2008-4-68)~~
文摘[Objective] The aim of this study was to provide basis for deeply understanding the diapause mechanism of Papilio memnon L. [Method] RNA and DNA content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different development stages were detected by the colorimetry. [Result] RNA content of non-diapause pupae was 4.614 0-7.946 3 μg/mg, while diapause pupae was 4.326 0-5.885 3 μg/mg and eclosion-adult from diapause pupae was 20.779 3 μg/mg at initial stage. DNA content of non-diapause pupae was 0.448 7-0.535 0 μg/mg, while diapause pupae was 0.452 0-0.828 3 μg/mg and eclosion-adult from diapause pupae was 1.727 0 μg/mg at initial stage. [Conclusion] The nucleic acid content and change is related to the development stage.
文摘[ Objective] The experiment aimed to explore the diapause mechanism of Papilio memnon L. further. [ Method] The colorimetry method was used to detect protein content of non-diapause pupae, diapause pupae and eclosion-adult from diapause pupae at different developmental stages. [Result] It was showed that the protein content of non-diapause pupae was from 111.768 to 115.030 7 mg/g and the change of protein content during whole pupal stage, while diapause pupae were from 81.218 to 131.623 7 mg/g and the change of protein content was not big from last ten-day period of October to last ten-day pariod of November, however, the content increased from the last ten-day period of November. The protein content of emerging adult was 296.969 3 mg/g. [Conclusion] The change of protein content was related to Papilio memnon at different development stage.
文摘Diapause hormone (DH) is a neurohormone which is secreted from suboesophageal ganglion and responsible for induction of embryonic diapause in Bombyx mori.Here,using bioassay,we present evidence that Has-SGNPⅠ,which clearly exhibited diapause egg inducing activity as does Bom-DH,is likely to be DH.We reported the molecular characterization of the Helicoverpa assulta diapause hormone analog by polymerase chain reaction.A 665?bp fragment containing the entire DH-like gene was isolated and characterized.DH-like gene comprised two exons interspersed by a single intron,and the consensus sequence for splicing junction is identified at the exon/intron boundary.The result shows that DH-like gene is localized in the genome of Helicoverpa assulta.
基金funded by the earmarked fund of China Agriculture Research System (CARS-34-07)the National Natural Science Foundation of China (31672485)
文摘Maternal photoperiodic response is a key factor that affects offspring diapause in migratory locust,Locusta migratoria L.(Orthoptera:Acridoidea).Although many aspects of insect diapause have been studied,little is known about the molecular mechanisms of maternal photoperiodic response that influence diapause regulation.To gain insight into the possible mechanisms of maternal photoperiod influence on diapause regulation,proteomics data by label-free quantification analysis were generated from non-diapause and diapause eggs.A total of 175 proteins were differentially expressed between diapause and non-diapause eggs.Among them,24 proteins were upregulated,and 151 proteins were downregulated.Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichments were performed on all differentially expressed proteins(DEPs)and showed that peroxisome,insect hormone biosynthesis,and longevity regulating pathway may be related to diapause of migratory locust.Furthermore,we used qRT-PCR to verify some results of the proteomic analysis.Proteins such as hexamerin-like protein 4,juvenile hormone epoxide hydrolase 1(JHEH1),cytochrome P450 and heat shock protein(HSP)20.7 were predicted to be involved in diapause.This study provides an important reference for future research that will explore the mechanisms of diapause induced by maternal effects in migratory locust.
基金supported by the Ear-marked Fund for China Agriculture Research System (CARS-35-07)the China Postdoctoral Science Foundation (2014M561111, 2016T90157)
文摘Temperate-zone insects typically survive winter by entering diapause. Although many aspects of insect diapause have been studied, the underlying molecular mechanism of insect diapause is not well understood. Here we report the results of the transcriptional and translational differences of migratory locust eggs at different embryonic states using diapause （low temperature） and non-diapause （high temperature） regimes. Compared with non-diapause eggs at 100 degree-days （N2） treatment, 29671 transcripts and 296 proteins were differentially expressed at the diapause maintenance stage （D2）. While compared with 150 degree-days （N3） treatment, 45 922 transcripts and 404 proteins were differentially expressed in the post-diapause stage （D3）. Among them, 51 and 102 transcripts had concurrent transcription and translation profiles in D2 vs. N2 and D3 vs. N3 treatments, respectively. Analysis of Gene Ontology categorized these genes and proteins into three categories： biological processes, cellular components, and molecular functions. Biological pathway analysis indicat- ed that three pathways： （1） insect hormone biosynthesis （KEGG： Map 00981）, （2） the insulin signaling pathway （KEGG： Map 04910）, and （3） the peroxisome proliferator-activated receptor （PPAR） signaling pathway （KEGG： Map 03320） play an important role in locust diapause regulation. Most of these transcripts and proteins were up-regulated in the diapause treatments, and were highly linked to juvenile hormone biosynthesis, insulin and PPAR signaling pathways, suggesting these three pathways may be Jnvolved Jn diapause and development regulation. This study demonstrates the applicability of high-throughput omics tools to identify biochemical pathways linked to diapause in locust egg development. In addition, it reveals that cellular metabolism in diapause eggs is more inactive than in non-diapause eggs, and most of the down-reg- ulated enzymes and pathways are related to reduce energy loss.
基金Supported by the Fundamental Research Funds for the Central Universities(No.201762017)the National Natural Science Foundation of China(No.31760626)
文摘The brine shrimp Artemia exhibits two reproductive modes: 1) oviparity, producing diapause embryos;and 2) ovoviviparity, producing free-swimming nauplii. Previous studies have suggested the existence of a critical stage that determines the reproductive mode. Physicochemical factors, such as photoperiod, temperature, and salinity, have been suggested to irreversibly aff ect the reproductive mode of oocytes during this critical stage. In this study, experiments were carried out using a photoperiod and temperature-sensitive parthenogenetic Artemia clone where maternal Artemia were shifted bidirectionally between ovoviviparity (18 h L:6 h D, 27℃) and oviparity (6 h L:18 h D, 19℃) culture conditions. In the main experiment ( Artemia shifted at six diff erent stages including the post-larva Ⅱ to adult Ⅱ), the reproductive mode of fi rst brood was converted when shifting was performed on post-larva Ⅱ and Ⅲ but was not converted when females were shifted after post-larva Ⅲ. A supplementary experiment further revealed that the reproductive mode of fi rst brood could be altered when shifting females at an "early phase of postlarva Ⅳ", characterized by a developing ovisac reaching the middle of the third abdominal segment, ventral spines, and some oocytes growing larger than the others. In both experiments, reproductive modes of the second brood were signifi cantly aff ected when the shifting was performed on post-larva Ⅳ. These results suggest that the critical stage for inducing oviparity and embryonic diapause is at the previtellogenic stage of oocytes, or at maternal "early phase of post-larva Ⅳ" for the first-brood off spring. During this stage, diff erential gene expression patterns of the two destined oocytes may be triggered by the token stimuli signals received by the oocytes.
基金supported by the China Postdoctoral Science Foundation (2017M622872)
文摘Diapause is a long-lived stage which has evolved into an important strategy for insects to circumvent extreme environments.In the pupal stage,Helicoverpa armigera can enter diapause,a state characterized by significantly decreased metabolic activity and enhanced stress resistance,to survive cold winters.Previous studies have shown that reactive oxygen species(ROS)can promote the diapause process by regulating a distinct insulin signaling pathway.However,the source of ROS in the diapause-destined pupal brains and mechanisms by which ROS regulate diapause are still unknown.In this study,we showed that diapause-destined pupal brains accumulated high levels of mitochondrial ROS(mtROS)and total ROS during the diapause process,suggesting that mitochondria are the main source of ROS in diapause-destined pupal brains.In addition,injection of 2-deoxy-D-glucose(DOG),a glucose metabolism inhibitor,could delay pupal development by elevating mtROS levels in the nondiapause-destined pupal brains.Furthermore,the injection of a metabolite mixture to increase metabolic activity could avert the diapause process in diapause-destined pupae by decreasing mtROS levels.We also found that ROS could activate HSP60 expression and promote the stability of the HSP60-Lon complex,increasing its ability to degrade mitochondrial transcription factor A(TFAM)and decreasing mitochondrial activity or biogenesis under oxidative stress.Thus,this study illustrated the beneficial function of ROS in diapause or lifespan extension by decreasing mitochondrial activity.
基金This work was supported by the National Key R&D Program of China(2022YFD1400500)the China Agriculture Research System of MOF and MARA(CARS-34-07)+1 种基金the Publicinterest Scientific Institution Basal Research Fund,China(Y2022GH12)the Central Public-interest Scientific Institution Basal Research Fund,China(S2021XM22 and S2022XM21)。
文摘Female adults of the migratory locust,Locusta migratoria manilensis(Meyen),can sense seasonal photoperiod changes,which induces embryonic diapause as a key strategy to overwinter.Serine protease inhibitor genes(SPNs)were thought to play key roles during diapause,while few SPNs were functionally characterized.LmSPN2 was one of those genes differentially expressed between diapause and non-diapause eggs;however,its biological function remained to be explored.So,we conducted RNAi knockdown of LmSPN2,resulting in a significant decrease of the egg diapause rate by 29.7%.Using yeast two-hybrid assays,co-immunoprecipitation,and pull-down methods,we found an interaction between LmSPN2 and LmSPN3,which was proved to be mediated by a glutamate(E331)binding site of LmSPN2.RNAi knockdown of LmSPN3 resulted in a significant increase in diapause rate by 14.6%,indicating an inverse function of LmSPN2 and LmSPN3 on diapause regulation.Double knockdown of two SPN genes resulted in a 26.4%reduction in diapause rate,indicating that LmSPN2 was the dominant regulatory signal.Moreover,we found four Toll pathway genes(easter,spätzle,pelle,and dorsal)upregulated significantly after the knockdown of LmSPN2 while downregulated after the knockdown of LmSPN3.Therefore,we speculate that two SPNs regulate diapause through the Toll pathway.Our results indicated that LmSPN2 positively regulates locust egg entry into diapause,while LmSPN3 is a negative regulator of embryonic commitment to diapause.Their interaction is mediated by the binding site of E331 and influences egg diapause through the Toll pathway.This mechanistic understanding of diapause regulation expands our understanding of insect developmental regulation and provides functional targets for developing locust management strategies.
文摘Insects enter in diapause in response to diverse environmental cues. During diapause, insects arrest their development and many genes are down-regulated while a small number of genes uniquely expressed at this time. This review aims to present available data regarding the regulation of diapause in the moth Sesamia nonagrioides （Lepidoptera： Noctuidae）. Studying the transcriptional regulation of several genes （five heat shock proteins, two storage proteins and one juvenile hormone esterase） showed that these genes may play various roles in the diapause programming. The results show that SnoHsp19.5 gene was consistently expressed, while SnoHsp20.8 was down-regulated in deep diapause and was up-regulated at the termination of diapause. SnoHsc70 may play important roles in assisting protein conformation during specific stages of diapause. SnoHsp83 displays a similar pattern to SnoHsc70 under diapause conditions, when extra larval moults occur, indicating that could be involved in the developmental process that occurs between two moults. Expression of two SnoSP1 and SnoSP2 hexamerin genes was also observed throughout diapause. And the results lead us to the conclusion that larval diapause of S. nonagrioides is associated with continuous synthesis and accumulation of storage proteins. In addition, the transcript level of the carboxylesterase SnoJHER was higher in non-diapausing larvae than in diapausing ones. During the fifth instar of the non-diapausing and the ninth instar of the diapausing larvae, SnoJHER mRNAs reached higher expression levels on the days close to each larval molt.
文摘The full-length cDNA encoding Larval serum protein 2 (LSp-2) in the onion maggot,Delia antiqua, was cloned and sequenced by rapid ampli?cation of cDNA ends methods. The result showed that the cDNA was 2203 bp long and the open reading frame (ORF) of 2106 bp encoded 701 amino acid with a calculated molecular weight of 80.5 kDa and an isoelectric point of 5.87. The onion maggot LSp-2 shows highest homology (83%) to that ofCalliphora vicinaat amino acid level. Its signal peptides, domains and structures were predicted and analyzed by using bioinformatic methods. The amino acid sequence of LSP-2 suggests that it would be a typical hexamerin.
文摘A hyperparasitic system with prolonged diapause for host is investigated. It is assumed that host prolonged diapause occur at larval stage, and parasitoid attack is limited to egg stage before the initiation of host diapause. Such behavior has been reported for many ichneumons. Hyperparasite only attacks the parasitoids that parasitize the hosts. Hyperparasitic system is often used in biological control. The existence and stability of nonnegative fixed points are explored. Numerical simulations are carried out to explore the global dynamics of the system, which demonstrate appropriate prolonged diapause rate and appropriate intrinsic growth rate can stabilize the system. The reasons are explained according to the ecological perspective. Furthermore, many other complexities which include quasi-periodicity, period-doubling bifurcations leading to chaos, chaotic attractor, intermittent and supertransients are observed.
基金supported by grants from the National Natural Science Foundation of China(31730085 and 31970457)the Guangdong Basic and Applied Basic Research Foundation(2022A1515012574)the Science and Technology Projects in Guangzhou(202201010827).
文摘Diapause is an adaptive strategy employed by insects to endure adverse environmental conditions and is characterized by reduced metabolic activity,primarily due to a decreased respiratory rate.AMP-activated protein kinase(AMPK)serves as an intracellular energy regulator,modulating energy metabolism in response to metabolic fluctuations.However,its role in pupal diapause of the cotton bollworm,Helicoverpa armigera,remains unclear.In this study,we found that AMPK and its active form,P-AMPK,are highly expressed in diapause-destined pupae.Furthermore,activation of AMPK delayed the development of nondiapause-destined pupae,suggesting a critical role for AMPK in the regulation of pupal diapause in H.armigera.Manipulating AMPK activity in H.armigera epidermal(HaEpi)cells and pupae significantly influenced the expression of hypoxia-inducible factor-1α(HIF-1α),which our laboratory previously reported as a key inducer of pupal diapause through the reduction of mitochondrial activity in H.armigera.Histone deacetylase 4(HDAC4),a shuttle protein phosphorylated by AMPK which translocates between the cytoplasm and the nucleus,was found to exhibit significantly higher expression in diapause-destined pupal brains compared to their nondiapause counterparts.AMPK in both HaEpi cells and pupae positively regulated the protein levels of P-HDAC4 by binding to the HDAC4 promoter.Additionally,HDAC4 was shown to enhance HIF-1αexpression in diapause-destined individuals.HDAC4 binds to and deacetylates heat shock protein 70(HSP70),and reduced acetylation of HSP70 was found to significantly elevate HIF-1αprotein levels.The AMPK-HIF-1αsignaling pathway appears to play a pivotal role in reducing mitochondrial activity and facilitating diapause induction in H.armigera pupae.
文摘Due to the risk of extinction and ornamental value of the swallowtail butterfly, Sericinus montelus Gray （Lepidoptera： Papilionidae） in China, knowledge about local adaptations is important for the conservation and economical utilization of the species. In the present study, photoperiodie diapause induction and diapause intensity of S. montelus populations from Jiamusi （46°37＇N）, Beijing （40° 15＇N）, Zibo （36°48＇N）, Fangxian （32°36＇N）, Wuhan （30°33＇N） and Huaihua （27°33＇N） were characterized at 25℃. Logistic regression analysis revealed a significant population x hours of light interaction, confirming that photoperiodic responses varied among populations. The critical photoperiod was positively correlated with latitude and increased toward the north at a rate of about 1 h for each 6.67 degrees of latitude. Survival analyses indicated that survival time of diapausing pupae before adult eclosion differed significantly among populations at 25℃ and 16 ： 8 L ＂D h. The mean duration of pupal diapause was also positively correlated with latitude. Our study reveals geographic variation in the critical photoperiod for diapause induction and in diapause intensity of S. montelus. These results provide useful information for our general understanding about seasonal adaptation in insects and may also be used to predict how geographic populations respond to climate warming.
基金Acknowledgments This work was supported by Par-Eu Scholars Program, and The National Natural Science Foundation of China （31372265）, Coordinated Research Project of the International Atomic Energy Agency （18268/R0）, and National Key Program of Science and Technology Foun- dation Work of China （2015FY210300）. Conceived and designed the research： BC. Performed the experiments： FLS, DYE ZBH Analyzed the data and wrote the paper： YJH, BC, YJZ.
文摘The onion fly, Delia antiqua, is a major underground agricultural pest that can enter pupal diapause in the summer and winter seasons. However, little is known about its molecular regulation due to the lack of genomic resources. To gain insight into the possible mechanism of summer diapause （SD）, high-throughput RNA-Seq data were generated from non-diapause （ND） and SD （initial, maintenance and quiescence phase） pupae. Three pair-wise comparisons were performed and identified, 1380, 1471 and 435, and were significantly regulated transcripts. Further analysis revealed that the enrichment of several functional terms related to juvenile hormone regulation, cell cycle, carbon hydrate and lipid metabolism, innate immune and stress responses, various signalling transductions, ubiquitin-dependent proteosome, and variation in cuticular and cytoskeleton components were found between ND and SD and between different phases of SD. Global characterization oftranscriptome profiling between SD and ND contributes to the in-depth elucidation of the molecular mechanism of SD. Our results also offer insights into the evolution of insect diapause and support the importance of using the onion fly as a model to compare the molecular regulation events of summer and winter diapauses.
文摘The embryonic diapause of the silkworm, Bombyx mori, is induced by the diapause hormone (DH) which is secreted from the suboesophageal ganglion of pupae. The diapause nature of bivoltine strains uses environmental stimuli as the initial signal to determine the diapause nature. The experiments showed that DH gene expression is a direct response to the environmental stimulus, such as high incubation temperature. The cDNA from the embryonic stage was cloned and sequence analysis showed the cDNA encoding DH. Expression patterns of the DH gene in embryonic stage are different at incubation temperatures 15℃ and 25℃, suggesting that the incubation temperature as an environmental signal is kept within the body to control the DH gene expression at the pupal stage, so that the embryonic diapause of next generation can be determined.
文摘Seasonal changes in the fatty acid composition of the total lipid extracted from the whole body of Cydia pomonella L. larvae were determined by gas chromatography. The six most abundant fatty acids in both non-diapause and diapause larvae of codling moth were oleic （35%-39%）, palmitic （23%-33%）, linoleic （16%-30%）, palmitoleic （5%-10%）, stearic （1.5%-3.0%） and linolenic acids （1.0%-2.5%）. This represents a typical complement of Lepidopteran fatty acids. The fatty acid composition of total lipid of C. pomonella larvae was related to diapause. In similarity to most other reports, the proportion of unsaturated fatty acids increased in diapause initiation state. The total lipid of diapause larvae contained more linoleic acid （25.8% vs. 16.1%） and less palmitic acid （24.7% vs. 33.4%）, than that of non-diapause larvae. The weight percentage of linoleic acid （C 18：2） increased from 16% to 26% from early-August through early-September during transition to diapause, while palmitic acid （C16：0） decreased from 33% to 25% at the same time. These changes resulted in an increase in the ratio of unsaturated to saturated fatty acids （UFA/SFA） from 1.72 in non-diapause larvae to 2.63 in diapause larvae.
文摘To understand the adaptive strategies of the overwintering adults of Steno- catantops splendens, the mechanism of maintenance and termination of the reproductive diapause, the variation in mortality between overwintering females and males, and the mating strategy of the males were investigated. The results indicated that the adult repro- ductive diapause in natural conditions was mainly regulated by photoperiod in the fall - long photoperiods promoted reproductive development and short photoperiods maintained reproductive diapause, and the sensitivity of the overwintering adults to photoperiod was over before the end of the winter. When transferred from natural conditions to controlled laboratory conditions on dates from September through February, pre-oviposition became increasingly shorter with increasingly deferred transfer dates regardless of photoperiod conditions. The adults treated with low temperature for 30 days in September through November had significantly shorter pre-oviposition, suggesting that low temperatures in winter had an important role in the termination of reproductive diapause. The female had a significantly lower supercooling point than the male, which was related to their lower mortality after winter. In addition, observations of wild populations of the species indicated that mating behavior prior to winter and the duration of pre-mating period were not affected by photoperiod; mating and sperm transfer were mostly completed by November. Compared with females only mating before winter, females mating in the spring had shorter life span, longer pre-oviposition, lower hatching rate and laid fewer egg pods while showing no significant difference with regard to ovipositional interval, per pod number of eggs and nymph dry weight.
文摘To overcome the disadvantages of current silkworm Bombyx mori transgenic technology, such as costly and time-consuming to maintain non-diapause transgenic silkworms, we report here on the development of treatments for the germline transformation of diapause silkworm strains. Our results showed that HC1 treatment within 3 h of oviposition was able to prevent the diapause of eggs from Japanese lineage diapause silkworm strains and was also suitable for germline transformation of the same strains. By incu- bating developing mother eggs from Chinese lineage diapause silkworm strains at 15℃ （15℃-IME）, we were able to prevent the diapause of their daughter eggs; a similar strategy （15℃-IMES） for the germline transformation of the same strains was that the mother eggs were incubated at 15℃, and the daughter eggs were then microinjected according to the conventional microinjection methods used for non-diapause eggs. By combining tempera- ture and light controls, the improved 15℃-IMES strategy prevented diapause in daughter eggs, and also enabled the germline transformation of both Japanese and Chinese lineage diapause silkworm strains. Although each of the strategies developed here has advantages and disadvantages, we suggest that the 15℃-IMES strategy is a good reference for the establishment of germline transformation technologies of other egg diapause insects. These new strategies for the efficient germline transformation of diapause silkworm strains are likely to improve the practical use of silkworm transgenic lines in sericulture and also highlight silkworm functional genomics research and its modeling.
文摘The yellow peach moth, Conogethes punctiferalis （Guenee）, a multivoltine species that overwinters as diapausing larvae, is one of the most serious insect pests on maize in China. Effect of photoperiod and temperature on larval diapause was examined under empirical laboratory conditions. Short-day treatments caused larval diapause at 25℃, and the critical photoperiod was between 12 and 13 h （or 12 h 51 min） light per day. No sensitive instar was identified for diapause induction under alternated short- （L ： D 11 ： 13 h） and long-day （L ： D 14 ： 10 h） treatments at different larval stages. However, accumulative treatment of three instars and 10 d under short-day treatment was required for the induction of 50% larval diapause. All larvae entered diapause at 20℃, whereas less than 3% did so at 30℃, irrespective of the long- or short-day treatment. Furthermore, under the short-day treatment, more than 90% of larvae went into diapause with temperatures ≤ 25℃, but less than 17% did so at 28℃. In contrast, under the long-day treatment, less than 19% of larvae went into diapause with temperatures ≥23 ℃. The forward shift （5℃） of critical temperature under the long-day regime demonstrated the compensatory effect of temperature and photoperiod on diapause induction. In conclusion, C. punctiferalis had a temperature-dependent type Ⅰ photoperiodic diapause response; there was no sensitive instar for diapause determination, but the photoperiodic accumulation time countermeasures both of the short-day cycles and the number ofinstars exposed, and the photoperiodic diapause response, was a temperature-compensated phenomenon.
