Phenoloxidase activity of reproductive gland and its role in stabilization of egg envelopes ofAchatina fulica(Pulmonata: Stylommatophora)

1985 ◽  
Vol 8 (2) ◽  
pp. 73-81 ◽  
Author(s):  
R. Kalyani ◽  
K. Nellaiappan ◽  
K. Ramalingam
Keyword(s):  
Phenoloxidase Activity ◽  
Egg Envelopes ◽  
Reproductive Gland

scholarly journals Effect of Honey and Syrup Diets Enriched with 1,3-1,6 β-Glucans on Honeybee Survival Rate and Phenoloxidase Activity (Apis mellifera L. 1758)

2021 ◽  
Vol 8 (7) ◽  
pp. 130
Author(s):  
Simona Sagona ◽  
Baldassare Fronte ◽  
Francesca Coppola ◽  
Elena Tafi ◽  
Matteo Giusti ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Survival Rate ◽  
Significant Variation ◽  
Innate Immune ◽  
Control Group ◽  
Phenoloxidase Activity ◽  
Immune Modulators ◽  
Negative Effect ◽  
Potential Negative Effect ◽  
Combined Action

β-glucans can activate the animal innate immune system by acting as immune-modulators and inducing various stimulatory effects. The aim of this study was to investigate the effect of 1,3-1,6 β-glucans administered orally for 96 h on Apis mellifera workers (newly emerged and nurse bees). β-glucans were included in honey and syrup. Survival rate and phenoloxidase activity were measured. In both newly emerged and nurse bees, β-glucans supplementation did not affect survival rate (p > 0.05). Conversely, phenoloxidase activity was higher in both newly emerged bees (p = 0.048) and nurse bees (p = 0.014) fed with a honey diet enriched with β-glucans compared to those fed with only honey. In both the newly emerged and nurse bees, no statistical differences in phenoloxidase activity were recorded between the group fed with a syrup-based diet enriched with β-glucans and the control group (p > 0.05). The absence of significant variation in survival suggests that the potential negative effect of β-glucans in healthy bees could be mitigated by their metabolism. Conversely, the inclusion of β-glucans in a honey-based diet determined an increase of phenoloxidase activity, suggesting that the effect of β-glucan inclusion in the diet of healthy bees on phenoloxidase activity could be linked to the type of base-diet. Further investigations on β-glucans metabolism in bees, on molecular mechanism of phenoloxidase activation by 1,3-1,6 β-glucans, and relative thresholds are desirable. Moreover, investigation on the combined action of honey and β-glucans on phenoloxidase activity are needed.

scholarly journals Thioester-Containing Protein-4 Regulates the Drosophila Immune Signaling and Function against the Pathogen Photorhabdus

2016 ◽  
Vol 9 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Upasana Shokal ◽  
Ioannis Eleftherianos
Keyword(s):  
Immune Response ◽  
Photorhabdus Luminescens ◽  
Human Pathogen ◽  
Loss Of Function ◽  
Phenoloxidase Activity ◽  
Microbial Infections ◽  
Immune Pathways ◽  
And Function ◽  
Important Progress

Despite important progress in identifying the molecules that participate in the immune response of Drosophila melanogaster to microbial infections, the involvement of thioester-containing proteins (TEPs) in the antibacterial immunity of the fly is not fully clarified. Previous studies mostly focused on identifying the function of TEP2, TEP3 and TEP6 molecules in the D. melanogaster immune system. Here, we investigated the role of TEP4 in the regulation and function of D. melanogaster host defense against 2 virulent pathogens from the genus Photorhabdus, i.e. the insect pathogenic bacterium Photorhabdus luminescens and the emerging human pathogen P. asymbiotica. We demonstrate that Tep4 is strongly upregulated in adult flies following the injection of Photorhabdus bacteria. We also show that Tep4 loss-of-function mutants are resistant to P. luminescens but not to P. asymbiotica infection. In addition, we find that inactivation of Tep4 results in the upregulation of the Toll and Imd immune pathways, and the downregulation of the Jak/Stat and Jnk pathways upon Photorhabdus infection. We document that loss of Tep4 promotes melanization and phenoloxidase activity in the mutant flies infected with Photorhabdus. Together, these findings generate novel insights into the immune role of TEP4 as a regulator and effector of the D. melanogaster antibacterial immune response.

Effect of the endoparasitoidCampoletis chlorideae on phenoloxidase activity inHelicoverpa armigera hemolymph

2001 ◽  
Vol 46 (21) ◽  
pp. 1797-1800 ◽  
Author(s):  
Lihong Yin ◽  
Chenzhu Wang ◽  
Junde Qin
Keyword(s):  
Phenoloxidase Activity

scholarly journals Humoral and Haemocytic Responses ofLitopenaeus vannameito Cd Exposure

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Juan C. Bautista-Covarrubias ◽  
Germán J. Velarde-Montes ◽  
Domenico Voltolina ◽  
Luz M. García-de la Parra ◽  
Martín F. Soto-Jiménez ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
Initial Response ◽  
White Shrimp ◽  
Control Treatment ◽  
Clotting Time ◽  
Metal Concentrations ◽  
Phenoloxidase Activity ◽  
Cd Exposure

White shrimp,Litopenaeus vannamei, subadults were exposed to four dilutions of the 96 h cadmium LC50reported for postlarvae (PL12) of this species, and the effects were evaluated after 5, 48, and 96 h of exposure. While treatments did not affect survival and hemolymph clotting time increased with time, but not as a response to Cd exposure, the intensity of other responses was related to concentration, to time of exposure, and to their interaction. Hemocyanin decreased with time in all metal concentrations but increased in the control treatment, and an almost similar trend was observed with hemocyte numbers. As an initial response, phenoloxidase activity decreased with all metal concentrations, but it increased later to values similar or higher than the control treatment.

scholarly journals Phospholipase A2Inhibitors Synthesized by Two Entomopathogenic Bacteria, Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata

2012 ◽  
Vol 78 (11) ◽  
pp. 3816-3823 ◽  
Author(s):  
Samyeol Seo ◽  
Sunghong Lee ◽  
Yongpyo Hong ◽  
Yonggyun Kim
Keyword(s):  
Immune Responses ◽  
Diamondback Moth ◽  
Culture Broth ◽  
Xenorhabdus Nematophila ◽  
Phenoloxidase Activity ◽  
Bacterial Metabolites ◽  
Content Type ◽  
Entomopathogenic Bacteria ◽  
Inhibitory Activities ◽  
Photorhabdus Temperata

ABSTRACTThe entomopathogenic bacteriaXenorhabdus nematophilaandPhotorhabdus temperatasubsp.temperatasuppress insect immune responses by inhibiting the catalytic activity of phospholipase A2(PLA2), which results in preventing biosynthesis of immune-mediating eicosanoids. This study identified PLA2inhibitors derived from culture broths of these two bacteria. BothX. nematophilaandP. temperatasubsp.temperataculture broths possessed significant PLA2-inhibitory activities. Fractionation of these bacterial metabolites in the culture broths using organic solvent and subsequent chromatography purified seven potent PLA2inhibitors, three of which (benzylideneacetone [BZA], proline-tyrosine [PY], and acetylated phenylalanine-glycine-valine [FGV]) were reported in a previous study. Four other compounds (indole, oxindole,cis-cyclo-PY, andp-hydroxyphenyl propionic acid) were identified and shown to significantly inhibit PLA2.X. nematophilaculture broth contained these seven compounds, whileP. temperatasubsp.temperataculture broth contained three compounds (BZA, acetylated FGV, andcis-cyclo-PY). BZA was detected in the largest amount among these PLA2compounds in both bacterial culture broths. All seven bacterial metabolites also showed significant inhibitory activities against immune responses, such as phenoloxidase activity and hemocytic nodulation; BZA was the most potent. Finally, this study characterized these seven compounds for their insecticidal activities against the diamondback moth,Plutella xylostella. Even though these compounds showed relatively low toxicities to larvae, they significantly enhanced the pathogenicity ofBacillus thuringiensis. This study reports bacterial-origin PLA2inhibitors, which would be applicable for developing novel insecticides.

Nitrite Stress on Density of Hemocyte and Phenoloxidase Activity in Hemolymph of Charybdis japonica

2013 ◽  
Vol 295-298 ◽  
pp. 82-86
Author(s):  
Xing Hong Xu ◽  
Li Zhou ◽  
Yan Qing Liu ◽  
Bin Lun Yan
Keyword(s):  
Day Treatment ◽  
Exposed Group ◽  
Control Group ◽  
Phenoloxidase Activity ◽  
Charybdis Japonica

In order to discuss the effects of nitrite on the density of hemocyte (DHC) and phenoloxidase (PO) activity in hemolymph of Charybdis japonica, the crabs were exposed to six nitrite-N groups (0, 2.0, 4.0, 6.0, 8.0 and 10.0 mg L-1 ambient nitrite-N concentrations). The DHC and PO activity was examined on days 1, 3, 5, 10 and 15 following the stress. Results showed that the two indexes appeared to have a decline trend after an initial ascent. After 1 day treatment, the DHC of five treatments were higher than that of the control group respectively, while the PO activity of 8.0 and 10.0 mg L-1 nitrite-N exposed group decreased compared with control. With time elapsed, the DHC of lower concentration nitrite-N exposed group increased faster, while the PO activity of higher concentration nitrite-N exposed group rised faster than other treatments. After 15-day stress, all parameters tested were lower than those of control group barring the DHC of 2.0 and 4.0 mg L-1 nitrite-N exposed group and the PO activity of 2.0, 4.0, and 6.0 mg L-1 nitrite-N exposed group.

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