Correlation between changes in host behaviour and octopamine levels in the tobacco hornworm Manduca sexta parasitized by the gregarious braconid parasitoid wasp Cotesia congregata

1997 ◽  
Vol 200 (1) ◽  
pp. 117-127 ◽  
Author(s):  
S Adamo ◽  
C Linn ◽  
N Beckage

The parasitoid wasp Cotesia congregata lays its eggs within the body of its host, the larval form of the tobacco hornworm Manduca sexta. Host behaviour appeared normal until approximately 8 h prior to the emergence of the parasitoids from their host at which time M. sexta feeding and locomotion declined irreversibly. This change in host behaviour may be to the advantage of the wasp since unparasitized M. sexta presented with wasp pupae ate them. Despite the decline in feeding and locomotion, hosts with emerged parasitoids had normal reflexes and showed no other signs of debilitation. Concomitant with the change in host behaviour, octopamine concentration measured using high-performance liquid chromatography with electrochemical detection (HPLC-ED) increased from 22.2±2.1 pg µl-1 to 143.7±7.8 pg µl-1 in the haemolymph of the host. In unparasitized M. sexta, however, increased octopamine levels were correlated with increased activity. We discuss possible explanations for the co-occurrence of high haemolymph octopamine levels and low behavioural arousal in parasitized M. sexta.

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fiona Li ◽  
Justin W. Hicks ◽  
Lihai Yu ◽  
Lise Desjardin ◽  
Laura Morrison ◽  
...  

Abstract Background In molecular imaging with dynamic PET, the binding and dissociation of a targeted tracer is characterized by kinetics modeling which requires the arterial concentration of the tracer to be measured accurately. Once in the body the radiolabeled parent tracer may be subjected to hydrolysis, demethylation/dealkylation and other biochemical processes, resulting in the production and accumulation of different metabolites in blood which can be labeled with the same PET radionuclide as the parent. Since these radio-metabolites cannot be distinguished by PET scanning from the parent tracer, their contribution to the arterial concentration curve has to be removed for the accurate estimation of kinetic parameters from kinetic analysis of dynamic PET. High-performance liquid chromatography has been used to separate and measure radio-metabolites in blood plasma; however, the method is labor intensive and remains a challenge to implement for each individual patient. The purpose of this study is to develop an alternate technique based on thin layer chromatography (TLC) and a sensitive commercial autoradiography system (Beaver, Ai4R, Nantes, France) to measure radio-metabolites in blood plasma of two targeted tracers—[18F]FAZA and [18F]FEPPA, for imaging hypoxia and inflammation, respectively. Results Radioactivity as low as 17 Bq in 2 µL of pig’s plasma can be detected on the TLC plate using autoradiography. Peaks corresponding to the parent tracer and radio-metabolites could be distinguished in the line profile through each sample (n = 8) in the autoradiographic image. Significant intersubject and intra-subject variability in radio-metabolites production could be observed with both tracers. For [18F]FEPPA, 50% of plasma activity was from radio-metabolites as early as 5-min post injection, while for [18F]FAZA, significant metabolites did not appear until 50-min post. Simulation study investigating the effect of radio-metabolite in the estimation of kinetic parameters indicated that 32–400% parameter error can result without radio-metabolites correction. Conclusion TLC coupled with autoradiography is a good alternative to high-performance liquid chromatography for radio-metabolite correction. The advantages of requiring only small blood samples (~ 100 μL) and of analyzing multiple samples simultaneously, make the method suitable for individual dynamic PET studies.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 2756-2767
Author(s):  
Vijaya Vemani ◽  
Mounika P ◽  
Poulami Das ◽  
Anand Kumar Tengli

In the preservation of normal physiological functions, the building blocks of the body called amino acids play a crucial role. A number of valuable and nutritional phytoconstituents are contained in fruit juices, such as vitamins, minerals, microelements, organic acids, antioxidants, flavonoids, amino acids and other components. Due to the growing population and demand, the quality of fruit juices is decreasing. One of the unethical and harmful practices called adulteration or food fraudulence has been adopted by most food and beverage industries. The amino acids which is one of the most important phytochemicals of fruit and fruit juices which affects the organoleptic properties like color, odor, and taste of juices and also helps in authenticity process from governing bodies by providing total amino acid content. Consequently, the main aim of the present review work is to provide information regarding the importance of amino acids, how they are adulterated, the potential analytical approach to detected amino acids and which methods are generally accepted method by the food industries. According to the literature review, we presume that reverse phased high-performance liquid chromatography with pre-column derivatization was the most adopted method for quality checking due to its advantages over other old and recent analytical approaches like simple, rapid, cost-effective nature, less / no sample matrix effect with high sensitivity, accuracy, and precision.


2018 ◽  
Vol 92 (15) ◽  
Author(s):  
Germain Chevignon ◽  
Georges Periquet ◽  
Gabor Gyapay ◽  
Nathalie Vega-Czarny ◽  
Karine Musset ◽  
...  

ABSTRACT Polydnaviruses (PDVs) are essential for the parasitism success of tens of thousands of species of parasitoid wasps. PDVs are present in wasp genomes as proviruses, which serve as the template for the production of double-stranded circular viral DNA carrying virulence genes that are injected into lepidopteran hosts. PDV circles do not contain genes coding for particle production, thereby impeding viral replication in caterpillar hosts during parasitism. Here, we investigated the fate of PDV circles of Cotesia congregata bracovirus during parasitism of the tobacco hornworm, Manduca sexta, by the wasp Cotesia congregata. Sequences sharing similarities with host integration motifs (HIMs) of Microplitis demolitor bracovirus (MdBV) circles involved in integration into DNA could be identified in 12 CcBV circles, which encode PTP and VANK gene families involved in host immune disruption. A PCR approach performed on a subset of these circles indicated that they persisted in parasitized M. sexta hemocytes as linear forms, possibly integrated in host DNA. Furthermore, by using a primer extension capture method based on these HIMs and high-throughput sequencing, we could show that 8 out of 9 circles tested were integrated in M. sexta hemocyte genomic DNA and that integration had occurred specifically using the HIM, indicating that an HIM-mediated specific mechanism was involved in their integration. Investigation of BV circle insertion sites at the genome scale revealed that certain genomic regions appeared to be enriched in BV insertions, but no specific M. sexta target site could be identified. IMPORTANCE The identification of a specific and efficient integration mechanism shared by several bracovirus species opens the question of its role in braconid parasitoid wasp parasitism success. Indeed, results obtained here show massive integration of bracovirus DNA in somatic immune cells at each parasitism event of a caterpillar host. Given that bracoviruses do not replicate in infected cells, integration of viral sequences in host DNA might allow the production of PTP and VANK virulence proteins within newly dividing cells of caterpillar hosts that continue to develop during parasitism. Furthermore, this integration process could serve as a basis to understand how PDVs mediate the recently identified gene flux between parasitoid wasps and Lepidoptera and the frequency of these horizontal transfer events in nature.


1995 ◽  
Vol 269 (6) ◽  
pp. R1321-R1326 ◽  
Author(s):  
S. A. Davies ◽  
G. R. Huesmann ◽  
S. H. Maddrell ◽  
M. J. O'Donnell ◽  
N. J. Skaer ◽  
...  

A cardioacceleratory peptide, CAP2b, identified originally in the lepidopteran Manduca sexta, stimulates fluid secretion by Malpighian tubules of the dipteran Drosophila melanogaster. High-performance liquid chromatography analyses of adult D. melanogaster reveal the presence of a CAP2b-like peptide, that coelutes with M. sexta CAP2b and synthetic CAP2b and that has CAP2b-like effects on the M. sexta heart. CAP2b accelerates fluid secretion in tubules stimulated by adenosine 3',5'-cyclic monophosphate (cAMP) but has no effect on tubules stimulated by guanosine 3',5'-cyclic monophosphate (cGMP), implying that it acts through the latter pathway. By contrast, the action of leucokinin is additive to both cAMP and cGMP but not to thapsigargin, suggesting that leucokinin acts by the elevation of intracellular calcium. CAP2b stimulation elevates tubule cGMP levels but not those of cAMP. By contrast, leucokinin has no effect on levels of either cyclic nucleotide. Both CAP2b and cGMP increase transepithelial potential difference, suggesting that stimulation of vacuolar-adenosinetriphosphatase action underlies the corresponding increases in fluid secretion. Overall, the results show that a Drosophila CAP2b-related peptide acts to stimulate fluid secretion by Malpighian tubules through the cGMP-signaling pathway.


2005 ◽  
Vol 51 (5) ◽  
pp. 505-512 ◽  
Author(s):  
Kevin E. Amaya ◽  
Sassan Asgari ◽  
Richard Jung ◽  
Melissa Hongskula ◽  
Nancy E. Beckage

Author(s):  
J. I. Bungudu ◽  
Lorrie M. Murphy

Metformin hydrochloride is an anti-hyperglycaemic drug that is widely prescribed in the management of noninsulin diabetes mellitus (NIDDM). However, metformin does not undergo complete metabolism in the body thereby excreting significant amount through urine and eventual discharged into the water bodies. Therefore, this work investigates the possibility bio-sorption of metformin by Fucus spiralis seaweed. High performance liquid chromatography (HPLC) and FITR was used for quantifying metformin biosorption. The result shows that Fucus spiralis is a potential biosbent for metformin removal in aqueous solution. The highest removal was up to 74% at 50 µg/mL. It can be mentioned here that this study is the first of it kind in testing seaweed for metformin biosorption. In conclusion, biomass (Fucus spiralis) was tested for its efficiency in metformin removal in aqueous solution. Adsorption studies revealed that F. spiralis can be used as potential adsorbent for metformin uptake. Very limited literature investigates the application of seaweeds species for pharmaceutical remediation. Remediation of waste and surface water using readily available adsorbent such as seaweed will be useful as it relates to human health and environmental contamination. HPLC was used in this study but other spectroscopic technique such as UV/vis could be explored to ascertain the optimized method. Further studies would be needed to test other algal species for metformin bio sorption.


2021 ◽  
Author(s):  
Deidra J. Jacobsen

AbstractCo-evolutionary interactions between plants and herbivores have led to a range of plant defenses that minimize insect damage and a suite of counter-adaptations that allow herbivores to feed on defended plants. Consumption of plant secondary compounds results in herbivore growth and developmental costs but can be beneficial if eating these secondary compounds results in deterrence or harm to natural enemies.To test the role of secondary compounds on herbivore fitness in the context of natural enemies, I combined field measurements of the prevalence of a parasitoid wasp (Cotesia congregata) with detailed measurements of the costs of plant secondary compounds on growth, immune, and fitness traits across developmental stages in the herbivore Manduca sexta. When M. sexta larvae consume defended plants, Cotesia congregata are known to have reduced success. However, this anti-enemy benefit to the M. sexta host must be considered in relationship to parasitoid abundance and the type and strength of the fitness costs M. sexta incurs feeding on plant secondary compounds.I found that Cotesia congregata parasitoids exert large negative selective pressures, killing 31-57% of M. sexta larvae in the field. Manduca sexta developed fastest during the instars most at risk for parasitoid oviposition but growth was slowed by consumption of plant secondary compounds (nicotine and rutin). These negative size effects at the larval stage carried over to influence adult traits associated with flight and mating but there were no immune, survival, or fecundity costs of consuming plant defensive compounds as larvae.Synthesis. These results suggest that the developmental costs experienced by M. sexta herbivores consuming defensive compounds may be outweighed by a survival benefit in the face of abundant enemy pressures.


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