Effects of dopamine injection on the hemocyte count, phenoloxidase activity, serine proteinase activity, proteinase in-hibitor activity and α2-macroglobulin-like activity in L. vannamei were studied. Results showed t...Effects of dopamine injection on the hemocyte count, phenoloxidase activity, serine proteinase activity, proteinase in-hibitor activity and α2-macroglobulin-like activity in L. vannamei were studied. Results showed that dopamine injection resulted in a significant effect on the parameters measured (P < 0.05), while no significant difference was observed in the control group (0.85% NaCl). In the experimental groups,the hemocyte count reached the minimum in 3 h;granular and semi-granular cells became stable after 12 h and hyaline cells and the total hemocyte count became stable after 18 h. Phenoloxidase activity reached the minimum in 6 h, and then became stable after 9 h. Serine protease activity and proteinase inhibitor activity reached the minimum in 3 h, and α2-macro-globulin-like activity reached the maximum in 3 h,and all the three parameters became stable after 12 h. The results suggest that the activating mechanisms of the proPO system triggered by dopamine are different from those triggered by invasive agents or sponta-neously activated under a normal physical condition.展开更多
In this study,we investigated the effects of low salinity(26 and 21) on the prophenoloxidase(proPO) system and related defence parameters in the shrimp Litopenaeus vannamei.The results showed that low salinity induced...In this study,we investigated the effects of low salinity(26 and 21) on the prophenoloxidase(proPO) system and related defence parameters in the shrimp Litopenaeus vannamei.The results showed that low salinity induced a significant increase of dopamine(DA) concentration in haemolymph at 6 h of the experiment;on the other hand,total haemocyte count(THC),differential haemocyte count(DHC) and PO activity decreased over time to the lowest level at 24 h and remained low thereafter.Serine Protease(SP) and Proteinase Inhibitor(PI) activity in the two lower salinity treatments decreased to the lowest level at 12 and 24 h,respectively,and both recovered to the control level at 72 h.In contrast,α2-macroglobulin(α2M) activity in the two lower salinity treatments peaked at 24 h and then decreased to the control level at 72 h.Therefore,it may be concluded that stress-induced DA plays an important temporary role in neurotransmission and causes immune response in L.vannamei in adapting to salinity changes.展开更多
The ridgetail white prawn Exopalaemon carinicauda is a euryhaline shrimp species in the estuarine and coastal areas of China.In this study,survival rates,transcription levels of two prophenoloxidase system-related gen...The ridgetail white prawn Exopalaemon carinicauda is a euryhaline shrimp species in the estuarine and coastal areas of China.In this study,survival rates,transcription levels of two prophenoloxidase system-related genes(Ec LGBP and Ecpro PO)and PO activity were determined quantitatively in juvenile and adult E.carinicauda under different salinity levels.The results showed that E.carinicauda juveniles could survive in a wider range of salinity conditions than adults.For juvenile E.carinicauda,the expression levels of Ec LGBP and Ec Pro PO were upregulated in low salinities and showed no significant difference at 20–40,while PO activities in low salinities were higher compared to those in high salinities.For adult E.carinicauda,the expression profiles of Ec LGBP and Ecpro PO had a different trend of up-regulation in salinity stress treatments and no obvious difference was observed in the gene expression levels and PO activity between 30 and 40.The salinity tolerance range of immunity for juvenile and adult E.carinicauda is 20–40 and 30–40,respectively.展开更多
Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant ...Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant impact on total hemocyte count(THC),differential hemocyte count(DHC),and intracelluar and extracelluar phenoloxidase(PO)activity.Among these Bas,DA had the strongest effect on the above parameters,whereas 5-HT had the least effect.Preincubation with D1 receptor antagonist SCH23390,D2 receptor antagonist Sulpiride and 1:1 admixture of the two could significantly inhibit the effect of DA on these parameters.SCH23390 showed a stronger inhibitory effect than Sulpiride,and the admixture exhibited the strongest effect.These results suggested that the change of hemocyte count and activation of prophenoloxidase(proPO)system in Litopenaeusvan-namei hemocyte can be regulated by BAs,and DA modulates the two parameters via its receptors.展开更多
The full-length cDNA sequence of prophenoloxidase was obtained through RACE technology. The complete cDNA sequence is 3 721-bp long, containing an open reading frame （ORF） of 1 881 bp, a 154-bp 5′-untranslated regi...The full-length cDNA sequence of prophenoloxidase was obtained through RACE technology. The complete cDNA sequence is 3 721-bp long, containing an open reading frame （ORF） of 1 881 bp, a 154-bp 5′-untranslated region, and a 1 686- bp 3′-untranslated region with three potential functional poly（A） signals （AATAAA）. The molecular mass of the deduced amino acid sequence （627 aa） was 72.3 kDa with an estimatedpI of 5.88. It contained putative copper-binding sites （copper A： 131, 135, 167 and copper B： 301,305, 341）, and a tentative complement-like motif （GCGWPDHL）. Eight potential N-linked glycosylation sites were predicted to be present in P. clarkii prophenoloxidase. Similar to those in other arthropod prophenoloxidases reported so far, no signal peptide was detected in the crayfish prophenoloxidase. The phylogenetic trees confirmed that P. clarkii prophenoloxidase was most closely related to that of freshwater crayfish P. leniusculus and more closely related to other crustacean prophenoloxidases from shrimp, prawn, and lobster than to the insect prophenoloxidases. Besides, two putative introns were found in this sequence of genomic DNA.展开更多
Prophenoloxidase (PPO) plays an important role in melanization, necessary for defense against intruding parasitoids. Parasitoids have evolved to inject maternal virulence factors into the host hemocoel to suppress hem...Prophenoloxidase (PPO) plays an important role in melanization, necessary for defense against intruding parasitoids. Parasitoids have evolved to inject maternal virulence factors into the host hemocoel to suppress hemolymph melanization for the successful development of their progeny. In this study, the full-length complementary DNA (cDNA) of a Pieris rapae PPO was cloned. Its cDNA contained a 2 076-base pair (bp) open reading frame (ORF) encoding 691 amino acids (aa). Two putative copper-binding sites, a proteolytic activation site, three conserved hemocyanin domains, and a thiol ester motif were found in the deduced amino acid sequence. According to both multiple alignment and phylogenetic analysis, P. rapae PPO gene cloned here is a member of the lepidopteran PPO-2 family. Injection of Cotesia glomerata venom or calyx fluid resulted in reduction of P. rapae hemolymph phenoloxidase activity, demonstrating the ability to inhibit the host's melanization. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) showed that transcripts of P. rapae PPO-2 in the haemocytes from larvae had not significantly changed following venom injection, suggesting that the regulation of PPO messenger RNA (mRNA) expression by venom was not employed by C. glomerata to cause failure of melanization in parasitized host. While decreased P. rapae PPO-2 gene expression was observed in the haemocytes after calyx fluid injection, no detectable transcriptional change was induced by parasitization, indicating that transcriptional down-regulation of PPO by calyx fluid might play a minor role involved in inhibiting the host's melanization.展开更多
Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) ...Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) in larvae of Helicoverpa armigera (Lepidoptera) was accompanied by inhibition of phenoloxidase (PO) activity and melanization reaction in host hemolymph in vitro. PO activity in host plasma was decreased about 83% 48 h post para-sitization. A similar result was found when the host insect was injected with 0.5 wasp equivalent calyx fluid. This indicated that the calyx fluid was concerned with suppression of PO activity after parasitization. Furthermore, the prophen-oloxidase (proPO) in host haemocytes could be activated by bovine trypsin in unparasitized insects, while it could not be activated in parasitized or calyx fluid-injected host. The results suggested that inhibition of PO activity by parasitization was related to the calyx fluid of Campoletis chlorideae, and the components of calyx展开更多
Phenoloxidases(POs)are required for the pea aphid s defense against bacterial and fungal infection.Prophenoloxidases(PPOs)are protcolytically converted to its active form PO through a clip domain serine protease casca...Phenoloxidases(POs)are required for the pea aphid s defense against bacterial and fungal infection.Prophenoloxidases(PPOs)are protcolytically converted to its active form PO through a clip domain serine protease cascade.In this study,we identified five clip domain serine proteases in the pea aphids.The messenger RNA levels of two of them,Ap.SPLP and Ap_VP,were upregulated by Gram-positive bacterium Staphylococcus aureus and fungus Beauveha bassiana infections.Double-stranded RNA-based expression knockdown of these two genes resulted in reduced PO activity of the aphid hemolymph,higher loads of S.aureus and B.bassiana in the aphids,and lower survival rates of the aphids after infections.Our data suggest that Ap.SPLP and Ap_VP are involved in PPO activation pathway in the pea aphid.展开更多
A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas h...A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas hydrophila and several immune parameters(total hemocyte count and prophenoloxidase activity)were also assessed in the study.Iso-nitrogenous,iso-lipidic,and iso-caloric prawn feeds were prepared utilizing a fishmeal based positive control diet(F0)and four dietary treatments with C.vulgaris inclusion levels of 2(F2),4(F4),6(F6),and 8(F8)%.Post larvae of M.rosenbergii were stocked randomly(mean initial body weight of 0.39�0.38 g)in fifteen net cages(8.1 m�8.9 m with an average depth of 1 m)in an earthen pond for the assessment of growth parameters.Overall growth indices for prawn fed Chlorella containing diets were enhanced in comparison to the control treatment.Prawn fed diets with Chlorella showed significantly higher(P<0.05)prophenol oxidase activity,total hemocyte counts,and survival rates post bacterial infection.These findings demonstrated that inclusion of 4%,6%,and 8%C.vulgaris in prawn diets provided optimal growth rates and improved immunity of the post larvae.展开更多
基金supported by the Program for New century excellent talents in university(NCET-06-0597)the program transformation and expansion of achievement of agricultural science and technology in Tianjin,China(0604020)
文摘Effects of dopamine injection on the hemocyte count, phenoloxidase activity, serine proteinase activity, proteinase in-hibitor activity and α2-macroglobulin-like activity in L. vannamei were studied. Results showed that dopamine injection resulted in a significant effect on the parameters measured (P < 0.05), while no significant difference was observed in the control group (0.85% NaCl). In the experimental groups,the hemocyte count reached the minimum in 3 h;granular and semi-granular cells became stable after 12 h and hyaline cells and the total hemocyte count became stable after 18 h. Phenoloxidase activity reached the minimum in 6 h, and then became stable after 9 h. Serine protease activity and proteinase inhibitor activity reached the minimum in 3 h, and α2-macro-globulin-like activity reached the maximum in 3 h,and all the three parameters became stable after 12 h. The results suggest that the activating mechanisms of the proPO system triggered by dopamine are different from those triggered by invasive agents or sponta-neously activated under a normal physical condition.
基金supported by the Program for New Century Excellent Talents in University (NCET-06-0597)the project of Transformation and Expansion of Achievement of Agricultural Science and Technology in Tianjin, China (0604020)
文摘In this study,we investigated the effects of low salinity(26 and 21) on the prophenoloxidase(proPO) system and related defence parameters in the shrimp Litopenaeus vannamei.The results showed that low salinity induced a significant increase of dopamine(DA) concentration in haemolymph at 6 h of the experiment;on the other hand,total haemocyte count(THC),differential haemocyte count(DHC) and PO activity decreased over time to the lowest level at 24 h and remained low thereafter.Serine Protease(SP) and Proteinase Inhibitor(PI) activity in the two lower salinity treatments decreased to the lowest level at 12 and 24 h,respectively,and both recovered to the control level at 72 h.In contrast,α2-macroglobulin(α2M) activity in the two lower salinity treatments peaked at 24 h and then decreased to the control level at 72 h.Therefore,it may be concluded that stress-induced DA plays an important temporary role in neurotransmission and causes immune response in L.vannamei in adapting to salinity changes.
基金The National Key R&D Program of China under contract No.2019YFD0900400the China Agriculture Research System under contract No.CARS-48+2 种基金the National Natural Science Foundation of China under contract No.31702319the Program of Shandong Leading Talent under contract No.LNJY2015002the Central Public-interest Scientific Institution Basal Research Fund,CAFS under contract No.2019ZD0603
文摘The ridgetail white prawn Exopalaemon carinicauda is a euryhaline shrimp species in the estuarine and coastal areas of China.In this study,survival rates,transcription levels of two prophenoloxidase system-related genes(Ec LGBP and Ecpro PO)and PO activity were determined quantitatively in juvenile and adult E.carinicauda under different salinity levels.The results showed that E.carinicauda juveniles could survive in a wider range of salinity conditions than adults.For juvenile E.carinicauda,the expression levels of Ec LGBP and Ec Pro PO were upregulated in low salinities and showed no significant difference at 20–40,while PO activities in low salinities were higher compared to those in high salinities.For adult E.carinicauda,the expression profiles of Ec LGBP and Ecpro PO had a different trend of up-regulation in salinity stress treatments and no obvious difference was observed in the gene expression levels and PO activity between 30 and 40.The salinity tolerance range of immunity for juvenile and adult E.carinicauda is 20–40 and 30–40,respectively.
基金supported by the Program for New Century Excellent Talents in University (No. NCET-06-0597)Ministry of Education 111 Project (No. B08049)
文摘Hemocyte counts and phenoloxidase(PO)activity were examined after hemolymph being incubated in dopamine(DA),noradrenaline(NE)and serotonin(5-HT).Results showed that all the three biogenic amines(BAs)had a significant impact on total hemocyte count(THC),differential hemocyte count(DHC),and intracelluar and extracelluar phenoloxidase(PO)activity.Among these Bas,DA had the strongest effect on the above parameters,whereas 5-HT had the least effect.Preincubation with D1 receptor antagonist SCH23390,D2 receptor antagonist Sulpiride and 1:1 admixture of the two could significantly inhibit the effect of DA on these parameters.SCH23390 showed a stronger inhibitory effect than Sulpiride,and the admixture exhibited the strongest effect.These results suggested that the change of hemocyte count and activation of prophenoloxidase(proPO)system in Litopenaeusvan-namei hemocyte can be regulated by BAs,and DA modulates the two parameters via its receptors.
基金financed by the Key Technology R&D Program from the Ministry of Science and Technology,China (2006BAD06A01)the Opening Subject of Hubei Key Lab of Animal Embryo & Molecular Breeding (2007ZD07)the Promoting Fund of Anhui Province Finance Department, China (05C1001)
文摘The full-length cDNA sequence of prophenoloxidase was obtained through RACE technology. The complete cDNA sequence is 3 721-bp long, containing an open reading frame （ORF） of 1 881 bp, a 154-bp 5′-untranslated region, and a 1 686- bp 3′-untranslated region with three potential functional poly（A） signals （AATAAA）. The molecular mass of the deduced amino acid sequence （627 aa） was 72.3 kDa with an estimatedpI of 5.88. It contained putative copper-binding sites （copper A： 131, 135, 167 and copper B： 301,305, 341）, and a tentative complement-like motif （GCGWPDHL）. Eight potential N-linked glycosylation sites were predicted to be present in P. clarkii prophenoloxidase. Similar to those in other arthropod prophenoloxidases reported so far, no signal peptide was detected in the crayfish prophenoloxidase. The phylogenetic trees confirmed that P. clarkii prophenoloxidase was most closely related to that of freshwater crayfish P. leniusculus and more closely related to other crustacean prophenoloxidases from shrimp, prawn, and lobster than to the insect prophenoloxidases. Besides, two putative introns were found in this sequence of genomic DNA.
基金supported by the Applied Basic Research Program of Yunnan Province (No. 2010CD063)the Science Foundation of Southwest Forestry University (No. 110903)+2 种基金the Science Foundation of the Department of Education of Yunnan Province (No. 2010Y294)the Open Foundation of Key Laboratory of Forest Disaster Warning and Control of Yunnan Province (No. ZK09A101)the Key Subject of Forest Protection of Yunnan Province (No. XKZ200905),China
文摘Prophenoloxidase (PPO) plays an important role in melanization, necessary for defense against intruding parasitoids. Parasitoids have evolved to inject maternal virulence factors into the host hemocoel to suppress hemolymph melanization for the successful development of their progeny. In this study, the full-length complementary DNA (cDNA) of a Pieris rapae PPO was cloned. Its cDNA contained a 2 076-base pair (bp) open reading frame (ORF) encoding 691 amino acids (aa). Two putative copper-binding sites, a proteolytic activation site, three conserved hemocyanin domains, and a thiol ester motif were found in the deduced amino acid sequence. According to both multiple alignment and phylogenetic analysis, P. rapae PPO gene cloned here is a member of the lepidopteran PPO-2 family. Injection of Cotesia glomerata venom or calyx fluid resulted in reduction of P. rapae hemolymph phenoloxidase activity, demonstrating the ability to inhibit the host's melanization. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) showed that transcripts of P. rapae PPO-2 in the haemocytes from larvae had not significantly changed following venom injection, suggesting that the regulation of PPO messenger RNA (mRNA) expression by venom was not employed by C. glomerata to cause failure of melanization in parasitized host. While decreased P. rapae PPO-2 gene expression was observed in the haemocytes after calyx fluid injection, no detectable transcriptional change was induced by parasitization, indicating that transcriptional down-regulation of PPO by calyx fluid might play a minor role involved in inhibiting the host's melanization.
基金This work was supported by a special fund for the Major State Basic Research Project of China (Grant No. 2000016208) and the National Natural Science Foundation of China (Grant No. 30070517).
文摘Endoparasitoid wasps can develop inside permissive host due to their ability to overcome or to evade the host’s cellular and humoral immune response. Oviposition of Campoletis chlorideae (Hymenoptera: Ichneumonidae) in larvae of Helicoverpa armigera (Lepidoptera) was accompanied by inhibition of phenoloxidase (PO) activity and melanization reaction in host hemolymph in vitro. PO activity in host plasma was decreased about 83% 48 h post para-sitization. A similar result was found when the host insect was injected with 0.5 wasp equivalent calyx fluid. This indicated that the calyx fluid was concerned with suppression of PO activity after parasitization. Furthermore, the prophen-oloxidase (proPO) in host haemocytes could be activated by bovine trypsin in unparasitized insects, while it could not be activated in parasitized or calyx fluid-injected host. The results suggested that inhibition of PO activity by parasitization was related to the calyx fluid of Campoletis chlorideae, and the components of calyx
基金This work was financially supported by the National Natural Science Foundation of China grant 31772530Natural Science Foundation of Shaanxi Province(2017JM3003)to ZL.
文摘Phenoloxidases(POs)are required for the pea aphid s defense against bacterial and fungal infection.Prophenoloxidases(PPOs)are protcolytically converted to its active form PO through a clip domain serine protease cascade.In this study,we identified five clip domain serine proteases in the pea aphids.The messenger RNA levels of two of them,Ap.SPLP and Ap_VP,were upregulated by Gram-positive bacterium Staphylococcus aureus and fungus Beauveha bassiana infections.Double-stranded RNA-based expression knockdown of these two genes resulted in reduced PO activity of the aphid hemolymph,higher loads of S.aureus and B.bassiana in the aphids,and lower survival rates of the aphids after infections.Our data suggest that Ap.SPLP and Ap_VP are involved in PPO activation pathway in the pea aphid.
文摘A 70-day feeding trial was conducted to evaluate the efficacy of Chlorella vulgaris supplementation in diets of giant freshwater prawn(Macrobrachium rosenbergii)post larvae.Resistance of the prawns against Aeromonas hydrophila and several immune parameters(total hemocyte count and prophenoloxidase activity)were also assessed in the study.Iso-nitrogenous,iso-lipidic,and iso-caloric prawn feeds were prepared utilizing a fishmeal based positive control diet(F0)and four dietary treatments with C.vulgaris inclusion levels of 2(F2),4(F4),6(F6),and 8(F8)%.Post larvae of M.rosenbergii were stocked randomly(mean initial body weight of 0.39�0.38 g)in fifteen net cages(8.1 m�8.9 m with an average depth of 1 m)in an earthen pond for the assessment of growth parameters.Overall growth indices for prawn fed Chlorella containing diets were enhanced in comparison to the control treatment.Prawn fed diets with Chlorella showed significantly higher(P<0.05)prophenol oxidase activity,total hemocyte counts,and survival rates post bacterial infection.These findings demonstrated that inclusion of 4%,6%,and 8%C.vulgaris in prawn diets provided optimal growth rates and improved immunity of the post larvae.
