Abomasal nematode species differ in their in vitro response to exsheathment triggers

Bekelaar, Kiliana; Waghorn, T.S.; Tavendale, Michael H.; McKenzie, Catherine; Leathwick, Dave M.

doi:10.1007/s00436-018-6183-1

Cited by 8 publications

(12 citation statements)

References 16 publications

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“…The infective larval stages of these species respond robustly to a diverse array of host and environmental sensory cues, including CO 2 (Gang and Hallem, 2016 ; Bryant and Hallem, 2018 ). In addition, many parasitic nematodes may rely on sensory cues inside the host body, including CO 2 , to re-initiate development upon host entry, direct somatic migration and establish a successful infection (Hawdon and Schad, 1990 , 1992 ; Hawdon et al ., 1992 ; Bekelaar et al ., 2018 , 2019 ).…”

Section: Responses Of Mammalian-parasitic Nematodes To Co 2mentioning

confidence: 99%

“…In addition to being a robust behavioural cue for parasitic nematodes, CO 2 is also an important regulator of their development and physiology. For example, CO 2 stimulates exsheathment and activation (exit from the developmentally arrested iL3 stage) in passively ingested ruminant parasites such as Haemonchus contortus (Rogers and Sommerville, 1960 ; Taylor and Whitlock, 1960 ; Sommerville, 1964 ; Bekelaar et al ., 2018 , 2019 ). However, the requirement for CO 2 during exsheathment varies across species.…”

Section: Responses Of Mammalian-parasitic Nematodes To Co 2mentioning

confidence: 99%

“…For instance, parasitic nematodes may encounter high CO 2 concentrations released from potential hosts as a byproduct of respiration or from the host feces within which they develop (Byrnes et al ., 1997 ; Buszewski et al ., 2007 ; Carrillo and Hallem, 2015 ). CO 2 concentrations are also high in specific tissues such as the venous bloodstream, lungs and intestine (Jensen and Jorgensen, 1994 ; Rotbart et al ., 2017 ), suggesting CO 2 may be an important intra-host cue for parasitic nematodes (Hawdon and Schad, 1990 ; Bekelaar et al ., 2018 , 2019 ). Moreover, many free-living nematodes are found in rotting vegetation, where CO 2 levels are often high (Burg and Burg, 1965 ; Felix and Duveau, 2012 ).…”

Section: Introductionmentioning

confidence: 99%

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The role of carbon dioxide in nematode behaviour and physiology

Banerjee

Hallem

2019

Parasitology

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Carbon dioxide (CO2) is an important sensory cue for many animals, including both parasitic and free-living nematodes. Many nematodes show context-dependent, experience-dependent and/or life-stage-dependent behavioural responses to CO2, suggesting that CO2 plays crucial roles throughout the nematode life cycle in multiple ethological contexts. Nematodes also show a wide range of physiological responses to CO2. Here, we review the diverse responses of parasitic and free-living nematodes to CO2. We also discuss the molecular, cellular and neural circuit mechanisms that mediate CO2 detection in nematodes, and that drive context-dependent and experience-dependent responses of nematodes to CO2.

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Section: Responses Of Mammalian-parasitic Nematodes To Co 2mentioning

confidence: 99%

Section: Responses Of Mammalian-parasitic Nematodes To Co 2mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The role of carbon dioxide in nematode behaviour and physiology

Banerjee

Hallem

2019

Parasitology

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“…These findings further support the notion that heat shock is more crucial as a biological factor for inducing exsheathment, than temperature itself . A follow up study tested this hypothesis using rumen fluid as a medium combined with CO2 and heat shock (Bekelaar et al, 2019). The results yielded >80% exsheathment in under 4 hours for H. contortus (Bekelaar et al, 2019).…”

Section: Effects Of High Temperature Incubation and Heat Shock On L3 mentioning

confidence: 99%

“…A follow up study tested this hypothesis using rumen fluid as a medium combined with CO2 and heat shock (Bekelaar et al, 2019). The results yielded >80% exsheathment in under 4 hours for H. contortus (Bekelaar et al, 2019). Future work should focus on exploring the specific biological pathways triggered by heat shock, as well as additional host or environmental factors that may influence the rate of exsheathment when the magnitude of heat shock is smaller .…”

Section: Effects Of High Temperature Incubation and Heat Shock On L3 mentioning

confidence: 99%

The Effect of Season Upon the Life Cycle of Haemonchus Contortus in Experimentally Infected Lambs

Brummett¹

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This project was developed to study the life cycle of the most pathogenic gastrointestinal nematode (GIN) affecting small ruminants, Haemonchus contortus. The main goal of the study was to test the effects that the environment and the age of the adult worm have on the resulting egg's ability to hatch in vitro and the larvae's ability to undergo exsheathment both artificially in vitro as well as in vivo within the rumen. A secondary study objective was to compare the results from the two exsheathment assays in order to see how well they correlate. This study was designed to run in a series of cycles according to the start of each season (cycles denoted as: Fall 1, Winter, Spring, Summer and Fall 2). Each cycle began with the infection of two genetically related donor lambs with H. contortus larvae (L3). Larvae and eggs were harvested from the donor lambs for 4-6 months (increasing worm ages) for each cycle and were subjected to in vitro egg hatch and in vitro and in vivo exsheathment assays, respectively. Eggs were incubated in a well plate at 26°C and after 24 hours of incubation, hatchability of eggs was assessed under the microscope. For the in vitro exsheathment assay, larvae were bubbled with CO2 for 15 minutes and incubated at 37°C for 18 hours and were then observed under the microscope to determine percent live exsheathment, as well as viability. For the in vivo assay, larvae were added to a containment capsule and suspended in the rumen of four fistulated ewes for 8 hours, recovered and examined under the microscope to determine percent live exsheathment, as well as viability. Data collected from the two exsheathment assays were statistically compared to one another according to seasonal effects and age of worm effects. v PREFACE This thesis has been prepared using the Manuscript Format. Chapter I contains a literature review, while Chapter II contains a manuscript that will be submitted for publication. Chapter III covers a summary of future research directions. vi TABLE OF CONTENTS

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