Effect of metacestodes of Hymenolepis diminuta on storage and circulating carbohydrates in the intermediate host, Tenebrio molitor

Parasitology ◽  
1994 ◽  
Vol 108 (4) ◽  
pp. 473-478 ◽  
Author(s):  
J. Y. Kearns ◽  
H. Hurd ◽  
A. S. Pullin
Keyword(s):  
Gas Chromatography ◽  
Resource Management ◽  
Intermediate Host ◽  
Post Infection ◽  
Fat Body ◽  
Tenebrio Molitor ◽  
Reproductive Physiology ◽  
Hymenolepis Diminuta ◽  
Carbohydrate Reserves ◽  
Biochemical Studies

SUMMARYThe metamorphosis of oncospheres of the rat tapeworm, Hymenolepis diminuta, to mature metacestodes induces several pathophysiological effects in the intermediate host, Tenebrio molitor (Coleoptera). Previous investigations have failed to elucidate the mechanism responsible for changes in the host reproductive physiology and behaviour. This work forms part of an assessment of the degree to which nutrient resource management may be involved in these interactions. We report that developing metacestodes exert a pronounced effect upon host carbohydrate reserves and also alter circulating carbohydrate titres at some stages post-infection. Biochemical studies of fat body glycogen demonstrated a significant depletion of reserves as early as 3 days post-infection in males and 5 days post-infection in females. Gas chromatography revealed trehalose to be the predominant haemolymph carbohydrate, titres being significantly elevated in male beetles 5 and 9 days post-infection and in females 12 days post-infection. Metacestodes had no effect on glucose concentrations in male or female beetles.

Hymenolepis diminuta: influence of metacestodes on synthesis and secretion of fat body protein and its ovarian sequestration in the intermediate host, Tenebrio molitor

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Hilary Hurd ◽  
C. Arme
Keyword(s):  
Intermediate Host ◽  
Post Infection ◽  
Fat Body ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Body Protein ◽  
Concomitant Reduction ◽  
Fat Bodies

SUMMARYFemale Tenebrio molitor infected with metacestodes of Hymenolepis diminuta exhibit elevated concentrations of female-specific proteins in their haemolymph and the origin of these has been investigated. Following a 4 h in vitro incubation with [14C]leucine, fat bodies from non-infected females secreted 13 times more protein than those from females 12 days post-infection. A comparison of the uptake in vivo of radio-isotope labelled amino acids by ovaries from non-infected and infected beetles of various ages revealed no differences; however, a 51·5% decrease in protein sequestration was detected in females 12 days post-infection. Electrophoresis of homogenates of radio-isotope labelled ovaries demonstrated that the majority of label was associated with vitellin sub-units. It is suggested that the decrease in vitellogenin sequestration associated with infection results in an increase in the haemolymph concentration of these proteins despite a concomitant reduction in their secretion by fat bodies. Both fat body synthesis and ovarian sequestration are under juvenile hormone control and it is proposed that metacestodes of H. diminuta may cause a reduction in the concentration of this hormone in the intermediate host.

Hymenolepis diminuta: metacestode-induced reduction in the synthesis of the yolk protein, vitellogenin, in the fat body of Tenebrio molitor

Parasitology ◽  
1996 ◽  
Vol 112 (4) ◽  
pp. 429-436 ◽  
Author(s):  
T. J. Webb ◽  
H. Hurd
Keyword(s):  
Post Infection ◽  
Fat Body ◽  
Potent Inhibitor ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Vitellogenin Synthesis ◽  
Specific Stage ◽  
Fat Bodies ◽  
Do So

SUMMARYVitellogenin synthesis by the fat body has been monitored using in vitro culture and immunoprecipitation. This system was found to be efficient for measuring vitellogenin production in both non-infected Tenebrio molitor and those infected with Hymenolepis diminuta. In fat bodies from infected beetles, vitellogenin production was decreased by up to 75% (day 24 post-infection) and, at all times investigated, vitellogenin synthesis was significantly below control levels (days 3–30 post-infection). Incubating fat bodies from control insects with isolated metacestodes indicated that this may be a direct effect by the parasite which is developmental stage-specific. Stage II, but not stage III–IV, nor heat-killed parasites could bring about this decrease in vitellogenin. In addition, these effects may be density dependent within the range of 2–20 parasites per fat body; only 2 metacestodes were necessary to cause a significant decrease. Since metacestodes do not take up vitellogenin, nor limit the amount of [14C] leucine available to the fat body for vitellogenin production, it is conceivable that the parasite produces a potent inhibitor of vitellogenin synthesis, or a molecule which induces cells within the fat body to do so.

Hymenolepis diminuta: an investigation of juvenile hormone titre, degradation and supplementation in the intermediate host, Tenebrio molitor

Parasitology ◽  
1990 ◽  
Vol 100 (3) ◽  
pp. 445-452 ◽  
Author(s):  
H. Hurd ◽  
C. Strambi ◽  
N. E. Beckage
Keyword(s):  
Juvenile Hormone ◽  
Intermediate Host ◽  
Topical Application ◽  
Post Infection ◽  
Reproductive Output ◽  
Endocrine System ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta ◽  
Significant Difference ◽  
Female Control

SUMMARYMetacestodes of Hymenolepis diminuta cause a perturbance of vitellogenesis in the intermediate host Tenebrio molitor. The reduction in host reproductive output associated with infection may be due to this pathophysiology. Many of these events are regulated by host juvenile hormone (JH). A comparison of the titre of JH and its rate of degradation in female control and parasitized 15-day-old insects has been made. Haemolymph from female beetles contained 1·27 pMol JH equivalents/100 µl. No significant difference was associated with infection. However, topical application of a JH analogue, methoprene, at the time of infecion or 8 days post-infection reduced the significant accumulation of vitellogenin usually found in the haemolymph of females 12 days or more post-infection. These findings indicate that parasite-induced alteration of host vitellogenesis is not mediated via alteration in JH titres, although observations made after hormone supplementation suggest some form of interaction between the parasite and the host endocrine system.

Changes induced by Hymenolepis diminuta (Cestoda) in the behaviour of the intermediate host Tenebrio molitor (Coleoptera)

1991 ◽  
Vol 69 (9) ◽  
pp. 2291-2294 ◽  
Author(s):  
Hilary Hurd ◽  
Sharon Fogo
Keyword(s):  
Intermediate Host ◽  
Aggregation Pheromone ◽  
Tenebrio Molitor ◽  
Significant Loss ◽  
Hymenolepis Diminuta ◽  
Male And Female ◽  
Behavioural Changes ◽  
Loss Of Response ◽  
Host Behaviour ◽  
Dose Dependent

Metacestodes of the rat tapeworm, Hymenolepis diminuta, have been shown to induce behavioural changes in the intermediate host Tenebrio molitor (Coleoptera). Male and female beetles, examined 11–12 days postinfection, were shown to exhibit a significant decrease in activity and photophobic behaviour. In addition, a significant loss of response to aggregation pheromone occurred in both sexes. No differences in host behaviour were detected 4–5 days postinfection. It thus appears that behavioural changes are associated with parasite maturity. We were unable to demonstrate a dose-dependent loss of photophobic behaviour.

The effects of Onchocerca lienalis infection on vitellogenesis in the British blackfly, Simulium ornatum

Parasitology ◽  
1994 ◽  
Vol 109 (3) ◽  
pp. 337-343 ◽  
Author(s):  
M. Renshaw ◽  
H. Hurd
Keyword(s):  
Molecular Weight ◽  
Protein Content ◽  
Post Infection ◽  
Fat Body ◽  
Parasite Burden ◽  
Blood Feeding ◽  
Reproductive Physiology ◽  
Filarial Nematode ◽  
Natural Vector ◽  
Approximate Molecular Weight

SummaryWe have previously described the major yolk protein, vitellin, in the British blackfly Simulium ornatum Meigen. Here we demonstrate that vitellogenin, synthesized in the fat body and secreted into the haemolymph, is composed of subunits with the same approximate molecular weight as vitellin, namely 200 and 68 kDa. Simulium ornatum is the natural vector for the cattle filarial nematode Onchocerca lienalis Stiles, which induces host fecundity depletion. A significant reduction in ovarian vitellin content was associated with infection by intrathoracic injection of 20 O. lienalis microfilariae immediately after blood-feeding. Fat body synthesis of vitellogenin was significantly reduced as early as 8 h post-infection in comparison with sham-injected flies. When total haemolymph protein from infected and sham injected flies was compared, titres were significantly depressed 6 h post-infection. However, later in the infection, titres were elevated by 30%, the major component being vitellogenin. The injection of dead microfilariae had no effect. An infection burden of a single parasite caused a significant reduction in ovarian protein content in comparison with shams, but no further significant decrease was observed as the parasite burden was increased from 5 to 20. Possible mechanisms underlying the disturbance of Simulium reproductive physiology are proposed.

Haemolymph from female beetles infected with Hymenolepis diminuta metacestodes retards the development of ovarian follicles in recipient Tenebrio molitor (Coleoptera)

Parasitology ◽  
1997 ◽  
Vol 114 (2) ◽  
pp. 175-179 ◽  
Author(s):  
M. MAJOR ◽  
T. J. WEBB ◽  
H. HURD
Keyword(s):  
Post Infection ◽  
Competitive Inhibition ◽  
Tenebrio Molitor ◽  
Ovarian Follicles ◽  
Hymenolepis Diminuta ◽  
Follicular Epithelium ◽  
Hormone Binding ◽  
Infected Female ◽  
Bona Fide ◽  
Stage 1

Infection with developing metacestodes of the rat tapeworm, Hymenolepis diminuta, is known to retard the accumulation of the yolk protein, vitellin, in the terminal ovarian follicles of the intermediate host, Tenebrio molitor. It is probable that this is the result of competitive inhibition of juvenile hormone binding at a microsomal binding site in the beetle follicular epithelium. Experiments were designed to test the hypothesis that inhibitor molecules were circulating in the haemolymph of infected beetles. Whole haemolymph, collected from male or female beetles at various stages post-infection, was injected into non-infected female recipients 2 days post-emergence. Ovaries were removed 3 days later and the vitellin content of the same sized follicles measured using an ELISA. The vitellin content of follicles from recipients of haemolymph from females infected with metacestodes at stage 1 and stage 3–4 was significantly reduced (24 and 27·9%) compared to sham-infected females. However, haemolymph from females infected with mature metacestodes did not affect the vitellin content. Results were thus comparable to those obtained by monitoring ovarian vitellin levels in female T. molitor with bona fide infections. Haemolymph from infected males did not affect ovarian vitellin content. These results indicate that molecules that can modulate vitellogenesis may be present in the haemolymph of females infected with developing metacestodes but that these factors disappear later in infection.

scholarly journals Efficacy of condensed tannins against larval Hymenolepis diminuta (Cestoda) in vitro and in the intermediate host Tenebrio molitor (Coleoptera) in vivo

2015 ◽  
Vol 207 (1-2) ◽  
pp. 49-55 ◽  
Author(s):  
Suraj Dhakal ◽  
Nicolai V. Meyling ◽  
Andrew R. Williams ◽  
Irene Mueller-Harvey ◽  
Christos Fryganas ◽  
...  
Keyword(s):  
Intermediate Host ◽  
Condensed Tannins ◽  
Tenebrio Molitor ◽  
Hymenolepis Diminuta
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