Activation of Prophenoloxidase and Removal of Bacillus subtilis from the Hemolymph of Acheta domesticus (L.) (Orthoptera: Gryllidae)

Silva, Cleonor C.A. Da

doi:10.1590/s1519-566x2002000300024

Cited by 18 publications

(8 citation statements)

References 15 publications

(24 reference statements)

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“…In our study, resistance to an infection with general microbial pathogen was variable among gammarid populations. However, despite the fact that the ProPO system is known to be involved in defence against bacteria (Da Silva 2002;Sung et al 2004;Hillyer and Christensen 2005), neither PO nor total activity could explain this variation in resistance to the bacterial challenge among G. pulex populations. Such a lack of an association between the activity of the ProPO system and defence against E. coli at the population level suggests that other pathways (not measured in this study) might also be important in crustacean defence against microparasites.…”

Section: Discussionmentioning

confidence: 92%

Variation in immune defence among populations of Gammarus pulex (Crustacea: Amphipoda)

2008

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Despite intensive studies in ecological immunology, few have investigated variation in immune defence among natural populations; in particular, there is a lack of knowledge of the sources of spatial variability in immune defence in the wild. Here we documented variation among twelve populations of the freshwater crustacean Gammarus pulex in the activity of the prophenoloxidase (ProPO) system, which is an important component of invertebrate immunity. We then tested for trade-offs between investment in immune defence and fitness-related traits such as survival and fecundity, as well as for environmental causes of variability (water temperature and conductivity, parasite prevalence). Levels of immune defence differed among populations, with environment partly explaining this population effect, as immune activities were negatively related to water conductivity and acanthocephalan parasite prevalence. There was a strong variation among populations for the maintenance of the ProPO system, while variation in its use was relatively weak. Such a pattern could be partly explained by the relative costs associated with the maintenance and/or the use of the ProPO system. Investment in the ProPO system was negatively correlated to survival, whereas it was positively related to female fecundity and resource storage. However, variation in immunity did not predict resistance to bacterial infection among populations, suggesting that measuring the activity of the ProPO system might not be sufficient to estimate immunocompetence at the population level. These results suggest that investment in immune function is a variable trait, which might be locally optimized as a result of both life history trade-offs and environmental conditions, highlighting the need to combine them in a common framework.

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Section: Discussionmentioning

confidence: 92%

Variation in immune defence among populations of Gammarus pulex (Crustacea: Amphipoda)

2008

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“…Insect phenoloxidase is considered an important mediator in defense reaction against pathogens and parasites. It is present in the hemolymph of most insects as an inactive proenzyme, called prophenoloxidase (Da Silva 2002).…”

Section: Introductionmentioning

confidence: 99%

EFFECT OF FOUR BIOACTIVE COMPOUNDS SEPARATELY AND IN COMBINATION WITH Metarhizium anisopliae ON THE ACTIVITY OF SOME HAEMOLYMPH ENZYMES OF Schistocerca gregaria (FORSKAL).

Farrag¹,

Elfattah²,

Abdelatef³

et al. 2015

Journal of Plant Protection and Pathology

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The effect of Metarhizium anisopliae var.acridum and four bioactive compounds (Neem,L-Glutamic acid,Schinusmolle and abamectin) in sole treatments and in combination with M. anisopliae var.acridum was studied on activity of Lactate Dehydrogenase Trehalase, Phenol oxidase, and Acid Phosphates in 5 th nymphal instar haemolymph of desert locust. Obtained results showed that the integration of M. anisopliae var. acridumand the Four bioactive compounds caused 100 % mortality after six days post treatments, also caused severe reduction in activity of all studied enzymes. M anisopliae var.acridum treatment caused significant reduction in Lactate Dehydrogenase by the second day after treatment, but all treatments caused significant reduction in Lactate Dehydrogenase by 4 th day post treatment except Neem. In case of trehalase all treatments were significantly lower than control treatment except abamectin two days post treatment, but by day four all treatments were lower than control, while in the 6 th day post treatment S. molle, L-Glutamic acid and Neem treatments caused significant increase in Trehales activity. All treatments caused significant increase in Phenol oxidase activity two days post treatment except L-Glutamic acid and abamectin treatment, while after four days Neem and M.var.acridum treatment were still higher than control, but other treatments were significantly lower than control treatment, by the 6 th day post treatment only L-Glutamic acid caused significant increase in Phenol oxidase activity. In the situation of Acid phosphatase activity two days post treatment abamectin , L-Glutamic acid and M. anisopliaevar.acridum + L-Glutamic acid were significantly lower than control, while after four days all treatments were significantly lower than control, after sex days post treatment only M.anisopliaevar.acridum and L-Glutamic acid were lower than control

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“…PO eventually catalyzes the oxidation of tyrosine to produce toxic quinone substances and other short‐lived reaction intermediates that lead to the formation of melanin. Melanin binds to the surface of bacteria and increases the adhesion of hemocytes to bacteria, thus accelerating their removal by nodule formation [4,7].…”

Section: Introductionmentioning

confidence: 99%

Increased bacterial load in shrimp hemolymph in the absence of prophenoloxidase

et al. 2009

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Invertebrates rely on their innate immune responses to protect themselves from pathogens, one of which is melanization of bacteria mediated by the activation of phenoloxidase (PO). Furthermore, invertebrate hemolymph, even that of healthy individuals, has been shown to contain bacterial species. The mechanisms that prevent these bacteria from proliferating and becoming deleterious to the host are, however, poorly understood. Here, we show that knocking down the activity of the inactive precursor of PO [prophenoloxidase (proPO)] by RNA interference resulted in a significant increase in the bacterial load of kuruma shrimp, Marsupenaeus japonicus, even in the absence of a bacterial or viral challenge. Silencing of proPO also led to a sharp increase in shrimp mortality. In addition, the hemolymph of proPO‐depleted shrimp had significantly lower hemocyte counts and PO activity than control samples. Microarray analysis after proPO silencing also showed a decrease in the expression of a few antimicrobial peptides, but no effect on the expression of the genes involved in the clotting system. Treatment with antibiotics prior to and after proPO dsRNA injection, to counteract the loss of proPO, resulted in a significant increase in shrimp survival. Our results therefore show that the absence of proPO renders the shrimp incapable of controlling bacteria present in the hemolymph, and that proPO is therefore essential for its survival.

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Activation of Prophenoloxidase and Removal of Bacillus subtilis from the Hemolymph of Acheta domesticus (L.) (Orthoptera: Gryllidae)

Cited by 18 publications

References 15 publications

Variation in immune defence among populations of Gammarus pulex (Crustacea: Amphipoda)

Variation in immune defence among populations of Gammarus pulex (Crustacea: Amphipoda)

EFFECT OF FOUR BIOACTIVE COMPOUNDS SEPARATELY AND IN COMBINATION WITH Metarhizium anisopliae ON THE ACTIVITY OF SOME HAEMOLYMPH ENZYMES OF Schistocerca gregaria (FORSKAL).

Increased bacterial load in shrimp hemolymph in the absence of prophenoloxidase

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