Coilia nasus,a migratory fish species found in the middle and lower reaches of the Yangtze River and along offshore areas of China,possesses considerable aquacultural and economic potential.However,the species faces c...Coilia nasus,a migratory fish species found in the middle and lower reaches of the Yangtze River and along offshore areas of China,possesses considerable aquacultural and economic potential.However,the species faces challenges due to significant variation in the gonadal development rate among females,resulting in inconsistent ovarian maturation times at the population level,an extended reproductive period,and limitations on fish growth rate due to ovarian prematurity.In the present study,we combined genome-wide association study(GWAS)and comparative transcriptome analysis to investigate the potential single nucleotide polymorphisms(SNPs)and candidate genes associated with population-asynchronous ovarian development in C.nasus.Genotyping of the female population based on whole-genome resequencing yielded 2120695 high-quality SNPs,39 of which were suggestively associated with ovarian development.Of note,a significant SNP peak on LG21 containing 30 suggestively associated SNPs was identified,with cpne5a determined as the causal gene of the peak.Therefore,single-marker and haplotype association analyses were performed on cpne5a,revealing four genetic markers(P<0.05)and seven haplotypes(r2>0.9)significantly associated with the phenotype.Comparative transcriptome analysis of precociously and normally maturing individuals screened out 29 and 426 overlapping differentially expressed genes in the brain and ovary,respectively,between individuals of different body sizes.Integrating the GWAS and transcriptome analysis results,this study identified genes and pathways related to hypothalamic-pituitary-gonadal axis hormone secretion,extracellular matrix,angiogenesis,and gap junctions involved in population-asynchronous ovarian development.The insights gained from this study provide a basis for a deeper understanding of the molecular mechanisms underlying ovarian development in fish and may facilitate the genetic breeding of C.nasus strains exhibiting population-synchronous ovarian development in the future.展开更多
The ovary generally undergoes tissue remodeling during larval to pupal transition,which includes membrane degeneration and ovariole growth.At the same time,the hormones produced by insects significantly change during ...The ovary generally undergoes tissue remodeling during larval to pupal transition,which includes membrane degeneration and ovariole growth.At the same time,the hormones produced by insects significantly change during metamorphosis.However,the regulatory mechanism for ovarian development and hormones is not fully understood in insects.Herein,we found that matrix metalloproteinase 2(MMP2)was highly expressed in the ovarian capsules and ovarioles,and the development was abnormal after knocking out MMP2 in Bombyx mori.The process of abnormal degradation of collagen I due to MMP2 deletion,which resulted in abnormal development of ovarioles and eggs,was analyzed in detail.The proteomics of ovaries in the MMP2-knock out and wild type strains showed a critically significant difference in the expression of a protein,insulin-like peptide(ILP).Additional analysis revealed significant alteration of ILP during ovarian development,and abnormal expression of ILP significantly affected ovarian development in vivo and MMP2 expression in vitro and in vivo.These results showed that MMP2 regulation of ovarian tissue remodeling is closely related to ILP expression.Our study provides new insights into the regulatory mechanism of MMP2 and ovarian development in B.mori.展开更多
In social insects, workers of different morphological castes and age are known to act differently. Yet, it is unclear how body size and ovarian development influence worker personalities （i.e. consistent behavioral v...In social insects, workers of different morphological castes and age are known to act differently. Yet, it is unclear how body size and ovarian development influence worker personalities （i.e. consistent behavioral variation） and task allocation in similar aged ant workers of monomorphic species. Behavioral variation is thought to be a key element of division of labor, but few studies have linked worker personality to task allocation. We investigated individual behavior in Leptothorax acervorum ant workers at two time points during the first three months of their life and in two different settings. We observed worker behavior in the nest （i.e. task allocation） and in standardized aggression, exploration and brood care experiments （i.e. personality） and found behavioral repeatability in foraging and exploration. Further, workers acted consistently across settings： workers with a more ag gressive and exploratory personality type were more active in the nest. Moreover, ovarian development was associated with worker personality and task allocation： older workers with welldeveloped ovaries foraged less, but were more aggressive and exploratory. In accordance with the typical agepolyethism of social insects, workers became more active and foraged more as they grew older. Consequently, our study suggests that task allocation in Leptothorax acervorum is not only influenced by ovari an development and age, but moreover by the personalities of its workers .展开更多
Cuticular proteins(CPs)are critical components of the insect cuticle and play important roles in maintaining normal insect development and defense against various environmental stresses.The oriental fruit fly(Bactroce...Cuticular proteins(CPs)are critical components of the insect cuticle and play important roles in maintaining normal insect development and defense against various environmental stresses.The oriental fruit fly(Bactrocera dorsalis)is one of the most destructive pests worldwide,and its eight CPs analogous to peritrophin 3(BdCPAP3)family genes have been identified in our prev ious study.In the present study,we further explored the possible roles of CPAP3 genes in B.dorsalis development.Each sequence of BdCPAP3 genes contained three conserved ChtBD2(chitin-binding)domains.Spatial and temporal expression patterns revealed that the four BdCPAP3 genes(BdCPAP3-AI,B,E,and E2)might play important roles in larval pupariation of B.dorsalis.Moreover,treatment with a juvenile hormone analog(methoprene)significantly restricted expression of these four CPAP3 genes,whereas treatment with 20-hydroxy-ecdysone induced expression.The RNA interference(RNAi)results revealed that down-regulated CPAP3 genes led to signif-icant delay of pupariation,and injection of dsBdCPAP3-E into 5-d-old B.dorsalis larvae caused approximately 40%mortality.Interestingly,we also confirmed that BdCPAP3-D2 was involved in B.dorsalis ovarian development.This study showed that some specific CP4P3 genes had crucial roles in B.dorsalis development,and these CP genes could be used as potential targets to control this pest via RNAi.展开更多
Background:Replacement gilts are typically fed ad libitum,whereas emerging evidence from human and rodent studies has revealed that time-restricted access to food has health benefits.The objective of this study was to...Background:Replacement gilts are typically fed ad libitum,whereas emerging evidence from human and rodent studies has revealed that time-restricted access to food has health benefits.The objective of this study was to investigate the effect of meal frequency on the metabolic status and ovarian follicular development in gilts.Methods:A total of 36 gilts(Landrace×Yorkshire)with an age of 150±3 d and a body weight of 77.6±3.8 kg were randomly allocated into one of three groups(n=12 in each group),and based on the group allocation,the gilts were fed at a frequency of one meal(T1),two meals(T2),or six meals per day(T6)for 14 consecutive weeks.The effects of the meal frequency on growth preference,nutrient utilization,short-chain fatty acid production by gut microbial,the post-meal dynamics in the metabolic status,reproductive hormone secretions,and ovarian follicular development in the gilts were measured.Results:The gilts in the T1 group presented a higher average daily gain(+48 g/d,P<0.05)and a higher body weight(+4.9 kg,P<0.05)than those in the T6 group.The meal frequency had no effect on the apparent digestibility of dry matter,crude protein,ether extract,ash,and gross energy,with the exception that the T1 gilts exhibited a greater NDF digestibility than the T6 gilts(P<0.05).The nitrogen balance analysis revealed that the T1 gilts presented decreased urine excretion of nitrogen(−8.17 g/d,P<0.05)and higher nitrogen retention(+9.81 g/d,P<0.05),and thus exhibited higher nitrogen utilization than the T6 gilts.The time-course dynamics of glucose,α-amino nitrogen,urea,lactate,and insulin levels in serum revealed that the T1 group exhibited higher utilization of nutrients after a meal than the T2 or T6 gilts.The T1 gilts also had a higher acetate content and SCFAs in feces than the T6 gilts(P<0.05).The age,body weight and backfat thickness of the gilts at first estrous expression were not affected by the meal frequency,but the gilts in the T1 group had higher levels of serum luteinizing hormone on the 18th day of the 3rd estrus cycle and 17β-estradiol,a larger number of growing follicles and corpora lutea,and higher mRNA expression levels of genes related to follicular development on the 19th day of the 3rd estrus cycle.Conclusions:The current findings revealed the benefits of a lower meal frequency equal feed intake on nutrient utilization and reproductive function in replacement gilts,and thus provide new insights into the nutritional strategy for replacement gilts,and the dietary pattern for other mammals,such as humans.展开更多
The presence of adequate nectar sources along the migratory pathway is a prerequisite for moths of oriental armyworm, Mythimna separata, to reach target habitats and lay eggs. Identification of plant species and asses...The presence of adequate nectar sources along the migratory pathway is a prerequisite for moths of oriental armyworm, Mythimna separata, to reach target habitats and lay eggs. Identification of plant species and assessment of their suitability as wild nectar sources along the summer migration pathway of adult M. separata are critical steps in making effective forecasts of second-and third-generation armyworm outbreaks in North China. We explored five aspects of moth-nectar source relationships：（1） Field investigations in 2014 and 2015 showed that the florescence of chaste tree, Vitex negundo var. heterophylla, a primary nectar plant in apiculture, coincided with the summer migration of oriental armyworm moths. The flowers of chaste tree opened day and night and M. separata moths were found actively flying around and resting on tree.（2） Identification of moth-borne pollen by scanning electronic microscopy（SEM） micrographs in 2015 and 2016 revealed that 15.4% of 369 moths trapped by blacklight traps, 17.1% of 557 moths captured by vertical-pointing searchlight traps and 24.4% of 311 moths caught by pheromone traps were found with pollen attached to their proboscis. A total of 228 pollen-carrying individuals out of 1237 armyworm moths were captured by the three types of traps. The three highest percentages of pollen-bearing armyworm moths were carrying pollen of Toona sp.（59.65%）, Ligustrum sp.（27.19%） and Syringa sp.（4.39%）. In total, 14 types of pollen were detected where three were identified to species, 10 to genus and one as an unknown species.（3） Analysis of geographical distribution, flowering periods and relative abundances of candidate nectar plants suggested that Chinese toon, Toona sinensis, and privet, Ligustrum lucidum, were two important nectar plant species.（4） Analysis on relationship between pollen and ovarian development showed that 14, 15 and 10 females carrying pollen of T. sinensis had ovaries at developmental stages Ⅰ, Ⅱ and Ⅲ, respectively. Many T. sinensis pollen grains were present on the proboscises of female moths.（5） Comparison of trap effectiveness between blacklight and vertical-pointing searchlight traps indicated blacklight traps caught the highest proportion（35.2%） of female in ovarian stage Ⅴ, whereas vertical-pointing searchlight traps caught the highest proportion（43.5%） of female in ovarian stage I with additional proportions of decreasing percentages for stages Ⅱ, Ⅲ and Ⅳ. Integrated analysis on these five aspects suggests that T. sinensis is an important, suitable summer nectar source that potentially influences migration and reproduction of M. separata moths andthus contributes to outbreaks of this pest. The vertical-pointing searchlight trap was the most effective tool for monitoring the migratory flight of adult M. separata. Privet, Ligustrum lucidum, and clove, Syringa sp., are possible suitable summer nectar plants that need further study to elucidate their importance. The reason why field investigation results on chaste tree differed from the results of moth-borne pollen analyses was discussed.展开更多
The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females （summer females） and its relations to temperature, female...The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females （summer females） and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34 ℃ in the laboratory. Percentage of females having oocytes, number of oocytes of different stages （stage-Ⅰ, from early previtellogenesis to middle vitellogenesis; stage-Ⅱ, late vitellogenesis; and matute-oocyte stage）, and length of ovarioles were determined every 10 d of feeding. At each temperature, oogenesis took place in over 40% of females after 20-40 d of feeding, but only 0.0-3.3 stage-Ⅰ, 0.0-0.8 stage-Ⅱ and 0.0-1.1 mature oocytes were observed at each observation date. Temperature had significant effect on number of stage-Ⅰ oocytes but not on number of stage-Ⅱ and mature oocytes in early July females; temperature had no significant effect on number of oocytes of either stage in mid-July females. Conclusively, in southern Zhejiang, summer L. oryzophilus females have great potential to become reproductive on rice, but their oogenesis activity is very low, with the overall procedures little affected by temperature.展开更多
Despite the importance of reproduction in insects,its relation with multi-stop flight remains poorly understood in migratory species.To clarify whether reproductive maturation commences during the multi-stop flight or...Despite the importance of reproduction in insects,its relation with multi-stop flight remains poorly understood in migratory species.To clarify whether reproductive maturation commences during the multi-stop flight or after the completion of migration,we conducted physiological and behavioral assays in the rice leaf roller Cnaphalocrocis medinalis with laboratory-simulated conditions and field-captured populations.We found that the ovarian development was significantly promoted by tethered flight treatment for 1-2 nights when compared to the unflown group,while the flight muscle development was not impaired.There was no significant difference in flight duration,flight distance and flight velocity between mated and virgin female moths,indicating that mated moths remained competent for the subsequent flights as did the virgins.Using an integrated field assay,we identified that over 60%of the female moths in the migrating populations cap-tured by high-altitude searchlights in the Immigration period of a season had completed the ovarian development and mating.Sexually mature and mated moths collected in the rice field in the Emigration period were found capable of engaging in migratory take-off,as observed using an indoor monitoring platform.Overall,our findings point out that C.med-inalis managed to complete reproductive maturation to a large extent during the multi-stop migratory flight without compromising the migration performance.Such a cost-effective strategy ensures a successful migration for the moths.These findings advance our under-standing of the relationship between reproduction and migration,thus shedding light on the development of novel control measures for the outbreak of migratory insect pests.展开更多
基金supported by the National Key R&D Program of China(2022YFD2400904)Key R&D Projects in Hubei Province(2022BBA008)+1 种基金Zhenjiang Jinshan TalentsWuhan Yangtze River Characteristic Fish Breeding and Domestication Project。
文摘Coilia nasus,a migratory fish species found in the middle and lower reaches of the Yangtze River and along offshore areas of China,possesses considerable aquacultural and economic potential.However,the species faces challenges due to significant variation in the gonadal development rate among females,resulting in inconsistent ovarian maturation times at the population level,an extended reproductive period,and limitations on fish growth rate due to ovarian prematurity.In the present study,we combined genome-wide association study(GWAS)and comparative transcriptome analysis to investigate the potential single nucleotide polymorphisms(SNPs)and candidate genes associated with population-asynchronous ovarian development in C.nasus.Genotyping of the female population based on whole-genome resequencing yielded 2120695 high-quality SNPs,39 of which were suggestively associated with ovarian development.Of note,a significant SNP peak on LG21 containing 30 suggestively associated SNPs was identified,with cpne5a determined as the causal gene of the peak.Therefore,single-marker and haplotype association analyses were performed on cpne5a,revealing four genetic markers(P<0.05)and seven haplotypes(r2>0.9)significantly associated with the phenotype.Comparative transcriptome analysis of precociously and normally maturing individuals screened out 29 and 426 overlapping differentially expressed genes in the brain and ovary,respectively,between individuals of different body sizes.Integrating the GWAS and transcriptome analysis results,this study identified genes and pathways related to hypothalamic-pituitary-gonadal axis hormone secretion,extracellular matrix,angiogenesis,and gap junctions involved in population-asynchronous ovarian development.The insights gained from this study provide a basis for a deeper understanding of the molecular mechanisms underlying ovarian development in fish and may facilitate the genetic breeding of C.nasus strains exhibiting population-synchronous ovarian development in the future.
基金supported by the National NaturaSl cience Foundation of China(Nos.31872428,31872427)the Natural Science Foundation of Chongqing(cstc2021ycjh-bgzxm0191 and cstc2021ycjhbgzxm0190)the Municipal Graduate Student Research Innovation Project of Chongqing(No.CYB20116).
文摘The ovary generally undergoes tissue remodeling during larval to pupal transition,which includes membrane degeneration and ovariole growth.At the same time,the hormones produced by insects significantly change during metamorphosis.However,the regulatory mechanism for ovarian development and hormones is not fully understood in insects.Herein,we found that matrix metalloproteinase 2(MMP2)was highly expressed in the ovarian capsules and ovarioles,and the development was abnormal after knocking out MMP2 in Bombyx mori.The process of abnormal degradation of collagen I due to MMP2 deletion,which resulted in abnormal development of ovarioles and eggs,was analyzed in detail.The proteomics of ovaries in the MMP2-knock out and wild type strains showed a critically significant difference in the expression of a protein,insulin-like peptide(ILP).Additional analysis revealed significant alteration of ILP during ovarian development,and abnormal expression of ILP significantly affected ovarian development in vivo and MMP2 expression in vitro and in vivo.These results showed that MMP2 regulation of ovarian tissue remodeling is closely related to ILP expression.Our study provides new insights into the regulatory mechanism of MMP2 and ovarian development in B.mori.
文摘In social insects, workers of different morphological castes and age are known to act differently. Yet, it is unclear how body size and ovarian development influence worker personalities （i.e. consistent behavioral variation） and task allocation in similar aged ant workers of monomorphic species. Behavioral variation is thought to be a key element of division of labor, but few studies have linked worker personality to task allocation. We investigated individual behavior in Leptothorax acervorum ant workers at two time points during the first three months of their life and in two different settings. We observed worker behavior in the nest （i.e. task allocation） and in standardized aggression, exploration and brood care experiments （i.e. personality） and found behavioral repeatability in foraging and exploration. Further, workers acted consistently across settings： workers with a more ag gressive and exploratory personality type were more active in the nest. Moreover, ovarian development was associated with worker personality and task allocation： older workers with welldeveloped ovaries foraged less, but were more aggressive and exploratory. In accordance with the typical agepolyethism of social insects, workers became more active and foraged more as they grew older. Consequently, our study suggests that task allocation in Leptothorax acervorum is not only influenced by ovari an development and age, but moreover by the personalities of its workers .
基金the National Key Research and.Development Program(2017YFD0202002)the National Natural Sciences Foundation(31872031,31672030)+3 种基金the Fundamental Research Funds for the Central Universities,China(2362015xk04,XDJK2018B041)the Fundamental and Advanced Research Projects of Chongqing(cstc2015jcyjA80009)the earmarked fund for the Modern Agroindustry(Cit-rus)Technology Research System of China(CARS-26)the l11 Project(B 18044)。
文摘Cuticular proteins(CPs)are critical components of the insect cuticle and play important roles in maintaining normal insect development and defense against various environmental stresses.The oriental fruit fly(Bactrocera dorsalis)is one of the most destructive pests worldwide,and its eight CPs analogous to peritrophin 3(BdCPAP3)family genes have been identified in our prev ious study.In the present study,we further explored the possible roles of CPAP3 genes in B.dorsalis development.Each sequence of BdCPAP3 genes contained three conserved ChtBD2(chitin-binding)domains.Spatial and temporal expression patterns revealed that the four BdCPAP3 genes(BdCPAP3-AI,B,E,and E2)might play important roles in larval pupariation of B.dorsalis.Moreover,treatment with a juvenile hormone analog(methoprene)significantly restricted expression of these four CPAP3 genes,whereas treatment with 20-hydroxy-ecdysone induced expression.The RNA interference(RNAi)results revealed that down-regulated CPAP3 genes led to signif-icant delay of pupariation,and injection of dsBdCPAP3-E into 5-d-old B.dorsalis larvae caused approximately 40%mortality.Interestingly,we also confirmed that BdCPAP3-D2 was involved in B.dorsalis ovarian development.This study showed that some specific CP4P3 genes had crucial roles in B.dorsalis development,and these CP genes could be used as potential targets to control this pest via RNAi.
基金This study was supported by National Key R&D Program of China(2018YFD0501005)National Natural Science Foundation of China,PR China(31772616).
文摘Background:Replacement gilts are typically fed ad libitum,whereas emerging evidence from human and rodent studies has revealed that time-restricted access to food has health benefits.The objective of this study was to investigate the effect of meal frequency on the metabolic status and ovarian follicular development in gilts.Methods:A total of 36 gilts(Landrace×Yorkshire)with an age of 150±3 d and a body weight of 77.6±3.8 kg were randomly allocated into one of three groups(n=12 in each group),and based on the group allocation,the gilts were fed at a frequency of one meal(T1),two meals(T2),or six meals per day(T6)for 14 consecutive weeks.The effects of the meal frequency on growth preference,nutrient utilization,short-chain fatty acid production by gut microbial,the post-meal dynamics in the metabolic status,reproductive hormone secretions,and ovarian follicular development in the gilts were measured.Results:The gilts in the T1 group presented a higher average daily gain(+48 g/d,P<0.05)and a higher body weight(+4.9 kg,P<0.05)than those in the T6 group.The meal frequency had no effect on the apparent digestibility of dry matter,crude protein,ether extract,ash,and gross energy,with the exception that the T1 gilts exhibited a greater NDF digestibility than the T6 gilts(P<0.05).The nitrogen balance analysis revealed that the T1 gilts presented decreased urine excretion of nitrogen(−8.17 g/d,P<0.05)and higher nitrogen retention(+9.81 g/d,P<0.05),and thus exhibited higher nitrogen utilization than the T6 gilts.The time-course dynamics of glucose,α-amino nitrogen,urea,lactate,and insulin levels in serum revealed that the T1 group exhibited higher utilization of nutrients after a meal than the T2 or T6 gilts.The T1 gilts also had a higher acetate content and SCFAs in feces than the T6 gilts(P<0.05).The age,body weight and backfat thickness of the gilts at first estrous expression were not affected by the meal frequency,but the gilts in the T1 group had higher levels of serum luteinizing hormone on the 18th day of the 3rd estrus cycle and 17β-estradiol,a larger number of growing follicles and corpora lutea,and higher mRNA expression levels of genes related to follicular development on the 19th day of the 3rd estrus cycle.Conclusions:The current findings revealed the benefits of a lower meal frequency equal feed intake on nutrient utilization and reproductive function in replacement gilts,and thus provide new insights into the nutritional strategy for replacement gilts,and the dietary pattern for other mammals,such as humans.
基金funded by the project under the National Department of Public Benefit Research Foundation of China (201403031)
文摘The presence of adequate nectar sources along the migratory pathway is a prerequisite for moths of oriental armyworm, Mythimna separata, to reach target habitats and lay eggs. Identification of plant species and assessment of their suitability as wild nectar sources along the summer migration pathway of adult M. separata are critical steps in making effective forecasts of second-and third-generation armyworm outbreaks in North China. We explored five aspects of moth-nectar source relationships：（1） Field investigations in 2014 and 2015 showed that the florescence of chaste tree, Vitex negundo var. heterophylla, a primary nectar plant in apiculture, coincided with the summer migration of oriental armyworm moths. The flowers of chaste tree opened day and night and M. separata moths were found actively flying around and resting on tree.（2） Identification of moth-borne pollen by scanning electronic microscopy（SEM） micrographs in 2015 and 2016 revealed that 15.4% of 369 moths trapped by blacklight traps, 17.1% of 557 moths captured by vertical-pointing searchlight traps and 24.4% of 311 moths caught by pheromone traps were found with pollen attached to their proboscis. A total of 228 pollen-carrying individuals out of 1237 armyworm moths were captured by the three types of traps. The three highest percentages of pollen-bearing armyworm moths were carrying pollen of Toona sp.（59.65%）, Ligustrum sp.（27.19%） and Syringa sp.（4.39%）. In total, 14 types of pollen were detected where three were identified to species, 10 to genus and one as an unknown species.（3） Analysis of geographical distribution, flowering periods and relative abundances of candidate nectar plants suggested that Chinese toon, Toona sinensis, and privet, Ligustrum lucidum, were two important nectar plant species.（4） Analysis on relationship between pollen and ovarian development showed that 14, 15 and 10 females carrying pollen of T. sinensis had ovaries at developmental stages Ⅰ, Ⅱ and Ⅲ, respectively. Many T. sinensis pollen grains were present on the proboscises of female moths.（5） Comparison of trap effectiveness between blacklight and vertical-pointing searchlight traps indicated blacklight traps caught the highest proportion（35.2%） of female in ovarian stage Ⅴ, whereas vertical-pointing searchlight traps caught the highest proportion（43.5%） of female in ovarian stage I with additional proportions of decreasing percentages for stages Ⅱ, Ⅲ and Ⅳ. Integrated analysis on these five aspects suggests that T. sinensis is an important, suitable summer nectar source that potentially influences migration and reproduction of M. separata moths andthus contributes to outbreaks of this pest. The vertical-pointing searchlight trap was the most effective tool for monitoring the migratory flight of adult M. separata. Privet, Ligustrum lucidum, and clove, Syringa sp., are possible suitable summer nectar plants that need further study to elucidate their importance. The reason why field investigation results on chaste tree differed from the results of moth-borne pollen analyses was discussed.
基金Project supported by the National Natural Science Foundation of China (No. 30400290) and the National Basic Research Program(973) of China (No. 2002CB111403)
文摘The rice water weevil, Lissorhoptrus oryzophilus Kuschel, has two generations in southern Zhejiang, China. To determine oogenesis in first-generation females （summer females） and its relations to temperature, females were collected from a rice field in early and mid-July and reared on young rice plants at 28, 31 and 34 ℃ in the laboratory. Percentage of females having oocytes, number of oocytes of different stages （stage-Ⅰ, from early previtellogenesis to middle vitellogenesis; stage-Ⅱ, late vitellogenesis; and matute-oocyte stage）, and length of ovarioles were determined every 10 d of feeding. At each temperature, oogenesis took place in over 40% of females after 20-40 d of feeding, but only 0.0-3.3 stage-Ⅰ, 0.0-0.8 stage-Ⅱ and 0.0-1.1 mature oocytes were observed at each observation date. Temperature had significant effect on number of stage-Ⅰ oocytes but not on number of stage-Ⅱ and mature oocytes in early July females; temperature had no significant effect on number of oocytes of either stage in mid-July females. Conclusively, in southern Zhejiang, summer L. oryzophilus females have great potential to become reproductive on rice, but their oogenesis activity is very low, with the overall procedures little affected by temperature.
基金supported by National Natural Science Foundation of China(31822043)Fundamental Research Funds for the Central Universities(China)(KJJQ201803)+1 种基金National Key Research and Development Program of China(2016YFD0300702)Jiangsu Distinguished Professor Program to P.L.,and Zhejiang Provincial Natural Science Foundation of China(LQ22C140006).
文摘Despite the importance of reproduction in insects,its relation with multi-stop flight remains poorly understood in migratory species.To clarify whether reproductive maturation commences during the multi-stop flight or after the completion of migration,we conducted physiological and behavioral assays in the rice leaf roller Cnaphalocrocis medinalis with laboratory-simulated conditions and field-captured populations.We found that the ovarian development was significantly promoted by tethered flight treatment for 1-2 nights when compared to the unflown group,while the flight muscle development was not impaired.There was no significant difference in flight duration,flight distance and flight velocity between mated and virgin female moths,indicating that mated moths remained competent for the subsequent flights as did the virgins.Using an integrated field assay,we identified that over 60%of the female moths in the migrating populations cap-tured by high-altitude searchlights in the Immigration period of a season had completed the ovarian development and mating.Sexually mature and mated moths collected in the rice field in the Emigration period were found capable of engaging in migratory take-off,as observed using an indoor monitoring platform.Overall,our findings point out that C.med-inalis managed to complete reproductive maturation to a large extent during the multi-stop migratory flight without compromising the migration performance.Such a cost-effective strategy ensures a successful migration for the moths.These findings advance our under-standing of the relationship between reproduction and migration,thus shedding light on the development of novel control measures for the outbreak of migratory insect pests.
