Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investig...Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investigated the effects of turmeric aqueous extract(TAE)on the growth performance,antioxidant status,and hydrogen peroxide(H2O2)-induced oxidative stress in spotted seabass(Lateolabrax maculatus).Fish were fed diets supplemented with 0(Con),2(TAE2),or 4(TAE4)g/kg TAE for eight weeks,then were injected with H2O2.The results showed that dietary supplementation of TAE did not affect fish growth,feed utilization,or body composition.TAE treatment increased liver antioxidant enzyme activities and decreased liver malondialdehyde content and serum levels of glutamate oxalate transaminase,glutamate pyruvate transaminase,and lactate dehydrogenase.Furthermore,the increases in mortality,liver malondialdehyde content,and serum biomarkers of liver injury in the H2O2-treated fish were inhibited as a consequence of the TAE treatment.In addition,TAE treatment activated the Nrf2/Keap1 pathway in the liver,supported by the up-regulated expression of nrf2,ho-1,and gclc,and down-regulated keap1 expression.Overall,dietary incorporation of TAE protected against H2O2-induced oxidative stress in spotted seabass probably by enhancing antioxidant capacity through the Nrf2/Keap1 pathway.展开更多
Objective:To test fumigant and repellent properties of sesquiterpene—rich essential oil from Teucrium polium subsp.capitation(L.).Methods:The fumigant toxicity test was performed at(27±1)℃.(65± 5)%relative...Objective:To test fumigant and repellent properties of sesquiterpene—rich essential oil from Teucrium polium subsp.capitation(L.).Methods:The fumigant toxicity test was performed at(27±1)℃.(65± 5)%relative humidity,and under darkness condition and 24 h exposure time.The chemical composition of the isolated oils was examined by gas chromatography—mass spectrometry.Results:The major compounds were α-cadiuol(46.2%),earyophyllene oxide(25.9%),α muurolol epi(8.1%),cadalene(3.7%) and longiverbenone(2.9%).In all cases,considerable differences in mortality of insect to essential oil vapor were observed in different concentrations and exposure times.Callosobruchus maculatus(C.maculates)(LC_(50)=148.9μL/L air) was more susceptible to the tested plant product than Teucrium castaneum(T.castaneum)(LC_(50)=360.2μL/L ain based on LC_(50)values.In the present investigation,the concentration of 3μ L /mL acetone showed 60% and 52% repellency against T.casteneum and C.maculatus adults,respectively.Conclusions:The results suggests that sesquiterpene—rich essential oils from the tested plant could be used as a potential control agent for stored—product insects.展开更多
采用人工催产和干法授精技术,在ZOOM645S解剖镜下对花(Hemibarbus maculatus)(♀)×唇(H.labeo)(♂)杂交子一代(F1)胚胎发育过程中各发育时期的发育时序和形态特征进行了观察。结果表明,受精卵为强黏性卵,卵径为1.60～1.80 mm。在...采用人工催产和干法授精技术,在ZOOM645S解剖镜下对花(Hemibarbus maculatus)(♀)×唇(H.labeo)(♂)杂交子一代(F1)胚胎发育过程中各发育时期的发育时序和形态特征进行了观察。结果表明,受精卵为强黏性卵,卵径为1.60～1.80 mm。在孵化水温为(20±1)℃条件下,受精后1 h胚盘隆起;1 h20 min进入卵裂期;6 h 20 min进入桑椹期;8 h 20 min进入囊胚期;13 h 10 min进入原肠期;16 h 20min进入神经胚期;受精后18 h进入胚孔封闭期;21 h 30 min进入肌节出现期;27 h 20 min进入眼基出现期;28 h 40 min进入眼囊期;30 h 40 min进入尾芽期;32 h 30 min进入晶体出现期;34 h 40 min进入肌肉效应期;36 h 40 min进入耳石出现期;44 h进入心跳期;53 h 40 min进入眼色素形成期;60 h 40min进入血液循环期;68 h 30 min后开始出膜。杂交F1胚胎发育时序及形态特征均偏向母本花。展开更多
The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in...The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in spotted seabass(Lateolabrax maculatus).Seven diets were prepared to contain available P levels of 0.48%(the control group),0.69%,0.89%,1.10%,1.28%,1.51%and 1.77%and feed fish(4.26±0.03 g)to satiety twice daily for 10 weeks.Significantly higher weight gain and specific growth rate were recorded at P levels of 0.69%-1.51%compared to the control group.Feed conversion ratio decreased with increasing P levels up to 0.89%and increased thereafter.The lowest liver lipid content,viscerosomatic index and lipid content of whole-body were obtained in the 0.89%-P group among dietary treatments.P and calcium(Ca)contents in whole body were increased,while liver triglyceride and cholesterol contents were decreased with increasing dietary P levels from 0.48%to 1.77%.The highest activity of hepatic lipase was recorded in the 1.10%-P group among dietary treatments.Compared to the control group,1.10%P enhanced the proportion of HUFA and reduced the proportion of SFA and MUFA.The histological observations showed that P deficiency(0.48%)led to the vacuolization of hepatocytes and increased number of lipid droplets.Meanwhile,overall liver tissue structure was improved when P level increased to 1.28%.Compared to the control group,expression of lipid metabolism-related genes such as FAS,ACC-2 and SREBP-1 was decreased at 0.89%-1.10%P group while an opposite trend was observed in the expression of PPARa2 and CPT-1 genes.The current study showed that 0.89%dietary P levels could promote growth performance of spotted seabass and reduce lipid accumulation in the liver.A broken-line regression analysis based on weight gain showed that the optimum dietary P level(available P)for juvenile spotted seabass reared in freshwater was 0.72%.展开更多
An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted s...An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted seabass(Lateolabrax maculatus).Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil(n-3)and linoleic acid-enriched oil(n-6)leading to n-3/n-6 PUFA ratios of 0.04,0.35,0.66,1.35,2.45 and16.17.Each diet was fed to triplicate groups of juvenile L.maculatus(11.06±0.20 g,30 fish/tank).Final body weight(FBW),weight gain(WG),specific growth rates(SGR),protein efficiency ratio(PER)and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level,and then decreased thereafter.Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW,WG,SGR and PER and the lowest feed conversion ratio.Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes(fas,acc2 and srebp-1c)and down-regulated expression of lipolysis related genes(atgl,ppara,cpt-1 and aox).Higher expression of lipolysis-related genes(atgl,ppara and cpt-1)was recorded at moderate n-3/n-6 PUFA ratios(0.66 to 1.35).Moreover,inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes(il-6 and tnf-a)and down-regulation of antiinflammatory genes(il-4 and il-10)in the intestine.The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation,improved intestinal flora richness,increased the abundance of beneficial bacteria such as Lactobacillus,Alloprevotella and Ruminococcus,and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus.In summary,it could be suggested that a dietary n-3/n-6PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus,as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.展开更多
The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b ...The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b and nkcc2 in spotted sea bass(Lateolabrax maculatus)genomic and transcriptomic databases.We also characterized these genes via phylogenetic and structural analyses.The results showed that both cftr and nkcc were highly conservative in L.maculatus.Quantitative real-time polymerase chain reaction(qRT-PCR)analysis in ten tissues showed that cftr,nkcc1 a and nkcc2 highly express in osmoregulatory organs such as gill,kidney and intestine.Furthermore,the expressions of cftr and nkcc1 a in gill as well as nkcc2 in intestine were up-regulated by high salinity,indicating that these genes function potentially in osmoregulation.Our findings provided the insights into the cftr and nkcc functions in euryhaline teleost.展开更多
Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle C...Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.展开更多
对人工繁育的花鲈（Lateolabrax maculatus）早期发育阶段的形态特征及苗种培育技术进行了观察与研究。结果表明：在水温17±1℃、盐度30、pH8.0、溶解氧〉7.0mg/L的条件下,花鲈受精卵经过72h完成胚胎发育过程。在胚后发育阶段,根...对人工繁育的花鲈（Lateolabrax maculatus）早期发育阶段的形态特征及苗种培育技术进行了观察与研究。结果表明：在水温17±1℃、盐度30、pH8.0、溶解氧〉7.0mg/L的条件下,花鲈受精卵经过72h完成胚胎发育过程。在胚后发育阶段,根据卵黄囊体积、鳍条发育情况,将花鲈前期发育划分为仔鱼期、稚鱼期、幼鱼期;仔鱼期又可分为前期仔鱼和后期仔鱼。本文对培育过程中死亡率较高的仔鱼期进行了详细观察,发现在水温16～17℃,盐度30的海水中培育,初孵仔鱼至5日龄（day post hatching,dph）仔鱼是前期仔鱼,6～35dph为后期仔鱼。花鲈个体之间发育速度差异较大、仔鱼之间的残食现象是整个培育过程中比较明显的特征,这些特征与冬季水温较低造成的越冬困难一起限制了花鲈苗种的全人工繁育技术的建立。展开更多
Gastrin(gas)is a peptide hormone that stimulates gastric acid secretion by gastric parietal cells and stimulates gastric motility.The cholecystokinin B receptor(cckbr)can act as a receptor for gastrin,conveying regula...Gastrin(gas)is a peptide hormone that stimulates gastric acid secretion by gastric parietal cells and stimulates gastric motility.The cholecystokinin B receptor(cckbr)can act as a receptor for gastrin,conveying regulatory information on gastrin,but there are fewer studies on its function in fish.The Lateolabrax maculatus is one of the marine aquaculture species in China,it widely distribute in coastal areas.In the study,we cloned the genes of Lateolabrax maculatus gastrin(Lm-gas)and Lateolabrax maculatus cholecystokinin B receptor(Lm-cckbr).The results showed that the full-length gene of Lm-gas is 638bp and the carboxy-terminal conserved domain(DFGRR)is the core functional domain of gastrin protein.The Lm-cckbr gene has a total nucleotide sequence of 2066 bp,and the open reading frame encodes a total of 453 amino acids.The result of protein sequence alignment showed that the similarity between Lm-cckbr protein and other different species was 50.11%-89.67%.The PCR results showed that Lm-gas and Lm-cckbr were expressed in brain and stomach.Further localization by immunehistochemical staining showed that Lm-gas protein was located in the mucosal layer of the gastric wall,but the expression signal was weak in the brain.Hunger causeed a significant decrease in these two genes.The results provided basic research data for further study on the function of Lm-gas and its recepter Lm-cckbr in the in the central nervous system and digestive system of Lateolabrax maculatus.展开更多
Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus ma...Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus maculatus. The commonly used control strategy is essentially based on chemicals whose use is toxic, expensive and restrictive. In the search for alternatives to chemical control, this work was undertaken to evaluate the insecticidal potential of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots. Powder toxicity and insecticidal efficacy tests were performed separately on groups of 20 Callosobruchus maculatus using 3 doses of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots in jars each containing 100 g cowpea. The mortality of Callosobruchus maculatus and the impact of powders were noted respectively for 96 h and 4 months after infestation. The germination capacity of the treated seeds was assessed at the start of the study. Doses of 1 and 8 g of Ageratum conyzoides leaf powders and Securidaca longepedunculata roots were applied respectively to every 100 g of cowpea and led to 100% mortality of Callosobruchus maculatus. At these same doses, more than half of the treated seeds were attacked during the 4 months of storage. Germination tests have shown that powders of Ageratum conyzoides leaves and roots of Securidaca longepedunculata have no negative effect on the germination power of cowpea seeds. Therefore, they could be considered as excellent bio-insecticides that socio-professional strata (farmers and warehouse workers) can use in the fight against cowpea insects intended for storage.展开更多
Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, re...Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, relies on the efficacy and residual activity of the insecticides applied, which to a certain extent are influenced by the nature of the sprayed surfaces. The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation for the control of malaria was compared with the current dose of deltamethrin wettable powder (WP) in malaria endemic areas in Balai Ringin, Sarawak. Doses of 20 mg/m2 WP (control), 20 mg/m2 WG, 30 mg/m2 WG and 40 mg/m2 WG were sprayed separately on different surfaces namely, wooden, rough-bamboo, smooth-bamboo and brick surfaces. Residual activity of WP and WG formulations was tested against lab-bred Anopheles maculatus using WHO standard procedure. Deltamethrin at 30 mg/m2 WG exhibited the highest sustainable level of effectiveness against An. maculatus (An. maculatus mortality was between 95% - 100%) up to week 60 post-spraying when sprayed on smooth- bamboo surface. These results indicated that 30 mg/m2 WG could be an ideal concentration for controlling malaria vector effectively up to 15 months of which long-lasting residual spraying was envisaged. The usual two spraying cycles per year with 20 mg/m2 deltamethrin WP could be replaced with 30 mg/m2 deltamethrin WG since the long residual activity was achieved by employing a single spraying only.展开更多
基金supported by China Agriculture Research System (CARS-47)the Natural Science Foundation of Fujian Province of China (grant number:2019J01060380).
文摘Intensive aquaculture-induced oxidative stress is detrimental to fish health and yield.Medicinal plants show promise as natural health boosters and antioxidants in the aquaculture industry.Therefore,this work investigated the effects of turmeric aqueous extract(TAE)on the growth performance,antioxidant status,and hydrogen peroxide(H2O2)-induced oxidative stress in spotted seabass(Lateolabrax maculatus).Fish were fed diets supplemented with 0(Con),2(TAE2),or 4(TAE4)g/kg TAE for eight weeks,then were injected with H2O2.The results showed that dietary supplementation of TAE did not affect fish growth,feed utilization,or body composition.TAE treatment increased liver antioxidant enzyme activities and decreased liver malondialdehyde content and serum levels of glutamate oxalate transaminase,glutamate pyruvate transaminase,and lactate dehydrogenase.Furthermore,the increases in mortality,liver malondialdehyde content,and serum biomarkers of liver injury in the H2O2-treated fish were inhibited as a consequence of the TAE treatment.In addition,TAE treatment activated the Nrf2/Keap1 pathway in the liver,supported by the up-regulated expression of nrf2,ho-1,and gclc,and down-regulated keap1 expression.Overall,dietary incorporation of TAE protected against H2O2-induced oxidative stress in spotted seabass probably by enhancing antioxidant capacity through the Nrf2/Keap1 pathway.
文摘Objective:To test fumigant and repellent properties of sesquiterpene—rich essential oil from Teucrium polium subsp.capitation(L.).Methods:The fumigant toxicity test was performed at(27±1)℃.(65± 5)%relative humidity,and under darkness condition and 24 h exposure time.The chemical composition of the isolated oils was examined by gas chromatography—mass spectrometry.Results:The major compounds were α-cadiuol(46.2%),earyophyllene oxide(25.9%),α muurolol epi(8.1%),cadalene(3.7%) and longiverbenone(2.9%).In all cases,considerable differences in mortality of insect to essential oil vapor were observed in different concentrations and exposure times.Callosobruchus maculatus(C.maculates)(LC_(50)=148.9μL/L air) was more susceptible to the tested plant product than Teucrium castaneum(T.castaneum)(LC_(50)=360.2μL/L ain based on LC_(50)values.In the present investigation,the concentration of 3μ L /mL acetone showed 60% and 52% repellency against T.casteneum and C.maculatus adults,respectively.Conclusions:The results suggests that sesquiterpene—rich essential oils from the tested plant could be used as a potential control agent for stored—product insects.
文摘采用人工催产和干法授精技术,在ZOOM645S解剖镜下对花(Hemibarbus maculatus)(♀)×唇(H.labeo)(♂)杂交子一代(F1)胚胎发育过程中各发育时期的发育时序和形态特征进行了观察。结果表明,受精卵为强黏性卵,卵径为1.60～1.80 mm。在孵化水温为(20±1)℃条件下,受精后1 h胚盘隆起;1 h20 min进入卵裂期;6 h 20 min进入桑椹期;8 h 20 min进入囊胚期;13 h 10 min进入原肠期;16 h 20min进入神经胚期;受精后18 h进入胚孔封闭期;21 h 30 min进入肌节出现期;27 h 20 min进入眼基出现期;28 h 40 min进入眼囊期;30 h 40 min进入尾芽期;32 h 30 min进入晶体出现期;34 h 40 min进入肌肉效应期;36 h 40 min进入耳石出现期;44 h进入心跳期;53 h 40 min进入眼色素形成期;60 h 40min进入血液循环期;68 h 30 min后开始出膜。杂交F1胚胎发育时序及形态特征均偏向母本花。
基金This study was supported by National Natural Science Foundation of China(grant number:31972804)the China Agricultural Research System(grant number:CARS47-14).
文摘The present study was conducted to determine the effects of dietary phosphorus(P)levels on growth performance,body composition,liver histology and enzymatic activity,and expression of lipid metabolism-related genes in spotted seabass(Lateolabrax maculatus).Seven diets were prepared to contain available P levels of 0.48%(the control group),0.69%,0.89%,1.10%,1.28%,1.51%and 1.77%and feed fish(4.26±0.03 g)to satiety twice daily for 10 weeks.Significantly higher weight gain and specific growth rate were recorded at P levels of 0.69%-1.51%compared to the control group.Feed conversion ratio decreased with increasing P levels up to 0.89%and increased thereafter.The lowest liver lipid content,viscerosomatic index and lipid content of whole-body were obtained in the 0.89%-P group among dietary treatments.P and calcium(Ca)contents in whole body were increased,while liver triglyceride and cholesterol contents were decreased with increasing dietary P levels from 0.48%to 1.77%.The highest activity of hepatic lipase was recorded in the 1.10%-P group among dietary treatments.Compared to the control group,1.10%P enhanced the proportion of HUFA and reduced the proportion of SFA and MUFA.The histological observations showed that P deficiency(0.48%)led to the vacuolization of hepatocytes and increased number of lipid droplets.Meanwhile,overall liver tissue structure was improved when P level increased to 1.28%.Compared to the control group,expression of lipid metabolism-related genes such as FAS,ACC-2 and SREBP-1 was decreased at 0.89%-1.10%P group while an opposite trend was observed in the expression of PPARa2 and CPT-1 genes.The current study showed that 0.89%dietary P levels could promote growth performance of spotted seabass and reduce lipid accumulation in the liver.A broken-line regression analysis based on weight gain showed that the optimum dietary P level(available P)for juvenile spotted seabass reared in freshwater was 0.72%.
基金funded by the National Natural Science Foundation of China(32072984)the Natural Science Foundation of Fujian Province(2020J01664)China Agricultural Research System(CARS-47)。
文摘An 8-week feeding experiment was carried out to explore the effects of dietary n-3/n-6 polyunsaturated fatty acid(PUFA)ratio on growth performance,lipid metabolism,hepatic antioxidant status,and gut flora of spotted seabass(Lateolabrax maculatus).Six experimental diets were formulated to contain different levels of two purified oil sources including docosahexaenoic and eicosapentaenoic acids enriched oil(n-3)and linoleic acid-enriched oil(n-6)leading to n-3/n-6 PUFA ratios of 0.04,0.35,0.66,1.35,2.45 and16.17.Each diet was fed to triplicate groups of juvenile L.maculatus(11.06±0.20 g,30 fish/tank).Final body weight(FBW),weight gain(WG),specific growth rates(SGR),protein efficiency ratio(PER)and feed utilization efficiency increased as n-3/n-6 PUFA ratio increased up to a certain level,and then decreased thereafter.Fish fed the diet with n-3/n-6 PUFA ratio of 0.66 exhibited the highest FBW,WG,SGR and PER and the lowest feed conversion ratio.Lower n-3/n-6 PUFA ratios induced up-regulated expression of lipid synthesis-related genes(fas,acc2 and srebp-1c)and down-regulated expression of lipolysis related genes(atgl,ppara,cpt-1 and aox).Higher expression of lipolysis-related genes(atgl,ppara and cpt-1)was recorded at moderate n-3/n-6 PUFA ratios(0.66 to 1.35).Moreover,inappropriate n-3/n-6 PUFA ratios triggered up-regulation of pro-inflammatory genes(il-6 and tnf-a)and down-regulation of antiinflammatory genes(il-4 and il-10)in the intestine.The diet with n-3/n-6 PUFA ratio of 0.66 inhibited intestine inflammation,improved intestinal flora richness,increased the abundance of beneficial bacteria such as Lactobacillus,Alloprevotella and Ruminococcus,and reduced the abundance of harmful bacteria including Escherichia-Shigella and Enterococcus.In summary,it could be suggested that a dietary n-3/n-6PUFA ratio of 0.66 can improve growth performance and feed utilization in L.maculatus,as is deemed to be mediated through regulation of lipid metabolism and intestinal flora.
基金supported by the China Agriculture Research System (No. CARS-47)the National Natural Science Foundation of China (No. 31602147)
文摘The Na^+/K^+/2Cl^-cotransporter(NKCC)and the cystic fibrosis transmembrane conductance regulator(CFTR)proteins play crucial roles in the transportation of Na^+and Cl^-.In this study,we identified cftr,nkcc1 a,nkcc1 b and nkcc2 in spotted sea bass(Lateolabrax maculatus)genomic and transcriptomic databases.We also characterized these genes via phylogenetic and structural analyses.The results showed that both cftr and nkcc were highly conservative in L.maculatus.Quantitative real-time polymerase chain reaction(qRT-PCR)analysis in ten tissues showed that cftr,nkcc1 a and nkcc2 highly express in osmoregulatory organs such as gill,kidney and intestine.Furthermore,the expressions of cftr and nkcc1 a in gill as well as nkcc2 in intestine were up-regulated by high salinity,indicating that these genes function potentially in osmoregulation.Our findings provided the insights into the cftr and nkcc functions in euryhaline teleost.
文摘Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis （P. Beauv.） a plant occurring in West African forests, against the pulse beetle Callosobruchus maculattts （Fabricius）. Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest （1%） concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts ofA. difformis. The significance of these findings is discussed in relation to biopesticide-means of controlling cowpea bruchids.
文摘对人工繁育的花鲈（Lateolabrax maculatus）早期发育阶段的形态特征及苗种培育技术进行了观察与研究。结果表明：在水温17±1℃、盐度30、pH8.0、溶解氧〉7.0mg/L的条件下,花鲈受精卵经过72h完成胚胎发育过程。在胚后发育阶段,根据卵黄囊体积、鳍条发育情况,将花鲈前期发育划分为仔鱼期、稚鱼期、幼鱼期;仔鱼期又可分为前期仔鱼和后期仔鱼。本文对培育过程中死亡率较高的仔鱼期进行了详细观察,发现在水温16～17℃,盐度30的海水中培育,初孵仔鱼至5日龄（day post hatching,dph）仔鱼是前期仔鱼,6～35dph为后期仔鱼。花鲈个体之间发育速度差异较大、仔鱼之间的残食现象是整个培育过程中比较明显的特征,这些特征与冬季水温较低造成的越冬困难一起限制了花鲈苗种的全人工繁育技术的建立。
基金This project was supported by the National Key Research and Development Program of China(2017YFC0506003)Blue Granary Science and Technology Innovation Project,and Shanghai Collaborative Innovation Center of Animal Genetics and Breeding(ZF1206).
文摘Gastrin(gas)is a peptide hormone that stimulates gastric acid secretion by gastric parietal cells and stimulates gastric motility.The cholecystokinin B receptor(cckbr)can act as a receptor for gastrin,conveying regulatory information on gastrin,but there are fewer studies on its function in fish.The Lateolabrax maculatus is one of the marine aquaculture species in China,it widely distribute in coastal areas.In the study,we cloned the genes of Lateolabrax maculatus gastrin(Lm-gas)and Lateolabrax maculatus cholecystokinin B receptor(Lm-cckbr).The results showed that the full-length gene of Lm-gas is 638bp and the carboxy-terminal conserved domain(DFGRR)is the core functional domain of gastrin protein.The Lm-cckbr gene has a total nucleotide sequence of 2066 bp,and the open reading frame encodes a total of 453 amino acids.The result of protein sequence alignment showed that the similarity between Lm-cckbr protein and other different species was 50.11%-89.67%.The PCR results showed that Lm-gas and Lm-cckbr were expressed in brain and stomach.Further localization by immunehistochemical staining showed that Lm-gas protein was located in the mucosal layer of the gastric wall,but the expression signal was weak in the brain.Hunger causeed a significant decrease in these two genes.The results provided basic research data for further study on the function of Lm-gas and its recepter Lm-cckbr in the in the central nervous system and digestive system of Lateolabrax maculatus.
文摘Cowpea is a vegetable that contributes to food security in Guinea. Despite its importance, more than 30% of its production is lost between harvesting, storage and consumption. The main cowpea pest is Callosobruchus maculatus. The commonly used control strategy is essentially based on chemicals whose use is toxic, expensive and restrictive. In the search for alternatives to chemical control, this work was undertaken to evaluate the insecticidal potential of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots. Powder toxicity and insecticidal efficacy tests were performed separately on groups of 20 Callosobruchus maculatus using 3 doses of Ageratum conyzoid leaf powders and Securidaca longepedunculata roots in jars each containing 100 g cowpea. The mortality of Callosobruchus maculatus and the impact of powders were noted respectively for 96 h and 4 months after infestation. The germination capacity of the treated seeds was assessed at the start of the study. Doses of 1 and 8 g of Ageratum conyzoides leaf powders and Securidaca longepedunculata roots were applied respectively to every 100 g of cowpea and led to 100% mortality of Callosobruchus maculatus. At these same doses, more than half of the treated seeds were attacked during the 4 months of storage. Germination tests have shown that powders of Ageratum conyzoides leaves and roots of Securidaca longepedunculata have no negative effect on the germination power of cowpea seeds. Therefore, they could be considered as excellent bio-insecticides that socio-professional strata (farmers and warehouse workers) can use in the fight against cowpea insects intended for storage.
文摘Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, relies on the efficacy and residual activity of the insecticides applied, which to a certain extent are influenced by the nature of the sprayed surfaces. The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation for the control of malaria was compared with the current dose of deltamethrin wettable powder (WP) in malaria endemic areas in Balai Ringin, Sarawak. Doses of 20 mg/m2 WP (control), 20 mg/m2 WG, 30 mg/m2 WG and 40 mg/m2 WG were sprayed separately on different surfaces namely, wooden, rough-bamboo, smooth-bamboo and brick surfaces. Residual activity of WP and WG formulations was tested against lab-bred Anopheles maculatus using WHO standard procedure. Deltamethrin at 30 mg/m2 WG exhibited the highest sustainable level of effectiveness against An. maculatus (An. maculatus mortality was between 95% - 100%) up to week 60 post-spraying when sprayed on smooth- bamboo surface. These results indicated that 30 mg/m2 WG could be an ideal concentration for controlling malaria vector effectively up to 15 months of which long-lasting residual spraying was envisaged. The usual two spraying cycles per year with 20 mg/m2 deltamethrin WP could be replaced with 30 mg/m2 deltamethrin WG since the long residual activity was achieved by employing a single spraying only.
