Strongyloides stercoralis age-1: A Potential Regulator of Infective Larval Development in a Parasitic Nematode

Stoltzfus, Jonathan D.; Massey, Holman C.; Nolan, Thomas J.; Griffith, Sandra D.; Lok, James B.

doi:10.1371/journal.pone.0038587

Cited by 45 publications

(91 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The transgenic lines were screened for the roller phenotype and GFP expression. GFP expression driven by the Ce-age-1 promoter was detected in amphidial neurons and the intestine, consistent with previous reports for S. stercoralis [30]. GFP expression driven by the Hcage-1 promoter was detected in the entire intestine at L1 and L2 stages, but concentrated in the anterior intestine of the L3 stage (Figure 5c-f).…”

Section: Transcriptional Profiles In H Contortus and Localization Osupporting

confidence: 91%

“…Recently, components of insulinlike signalling have been identified in parasitic nematodes, including A. caninum [37,38], H. contortus [39,40] and S. stercoralis [30,41,42,57], suggesting that similar signalling is utilized by both free-living and parasitic nematodes. In the present study, two PI3K genes were identified in H. contortus using available data [33], including a Hc-age-1 encoding a p110 catalytic subunit and a Hc-aap-1 encoding a p50/p55-like regulatory subunit, consistent with those in C. elegans and S. stercoralis [12,13,30].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Exploring the role of two interacting phosphoinositide 3-kinases of Haemonchus contortus

Gasser

Lok

et al. 2014

Parasites & Vectors

View full text Add to dashboard Cite

Background: Phosphoinositide 3-kinases (PI3Ks) are relatively conserved and important intracellular lipid kinases involved in signalling and other biological pathways. In the free-living nematode Caenorhabditis elegans, the heterodimeric form of PI3K consists of catalytic (AGE-1) and regulatory (AAP-1) subunits. These subunits are key components of the insulin-like signalling pathway and play roles in the regulation of the entry into and exit from dauer. Although, in parasitic nematodes, similar components are proposed to regulate the transition from free-living or arrested stages to parasitic larvae, nothing is known about PI3Ks in relation to the transition of third-stage larvae (L3s) to parasitism in Haemonchus contortus.

show abstract

Section: Transcriptional Profiles In H Contortus and Localization Osupporting

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Exploring the role of two interacting phosphoinositide 3-kinases of Haemonchus contortus

Gasser

Lok

et al. 2014

Parasites & Vectors

View full text Add to dashboard Cite

show abstract

“…Using overlap extension PCR (Nelson and Fitch, 2011; Stoltzfus et al, 2012a), two constructs designated pL-CG2 and pL-HG2 (Fig. 1) fusing either the Ce-daf-2 or Hc-daf-2 promoter to the gfp coding sequence and the Ce-unc-54 terminator ( t ), were assembled in two steps.…”

Section: Methodsmentioning

confidence: 99%

Hc-daf-2 encodes an insulin-like receptor kinase in the barber’s pole worm, Haemonchus contortus, and restores partial dauer regulation

Lok

Gasser

et al. 2014

International Journal for Parasitology

Self Cite

View full text Add to dashboard Cite

Infective L3s (iL3s) of parasitic nematodes share common behavioural, morphological and developmental characteristics with the developmentally arrested (dauer) larvae of the free-living nematode Caenorhabditis elegans. It is proposed that similar molecular mechanisms regulate entry into or exit from the dauer stage in C. elegans, and the transition from free-living to parasitic forms of parasitic nematodes. In C elegans, one of the key factors regulating the dauer transition is the insulin-like receptor (designated Ce-DAF-2) encoded by the gene Ce-daf-2. However, nothing is known about DAF-2 homologues in most parasitic nematodes. Here, using a PCR-based approach, we identified and characterised a gene (Hc-daf-2) and its inferred product (Hc-DAF-2) in Haemonchus contortus (a socioeconomically important parasitic nematode of ruminants). The sequence of Hc-DAF-2 displays significant sequence homology to insulin receptors (IR) in both vertebrates and invertebrates, and contains conserved structural domains. A sequence encoding an important proteolytic motif (RKRR) identified in the predicted peptide sequence of Hc-DAF-2 is consistent with that of the human IR, suggesting that it is involved in the formation of the IR complex. The Hc-daf-2 gene was transcribed in all life stages of H. contortus, with a significant up-regulation in the iL3 compared with other stages. To compare patterns of expression between Hc-daf-2 and Ce-daf-2, reporter constructs fusing the Ce-daf-2 or Hc-daf-2 promoter to sequence encoding GFP were microinjected into the N2 strain of C. elegans, and transgenic lines were established and examined. Both genes showed similar patterns of expression in amphidial (head) neurons, which relate to sensation and signal transduction. Further study by heterologous genetic complementation in a daf-2-deficient strain of C. elegans (CB1370) showed partial rescue of function by Hc-daf-2. Taken together, these findings provide a first insight into the roles of Hc-daf-2/Hc-DAF-2 in the biology and development of H. contortus, particularly in the transition to parasitism.

show abstract

“…18 Similarly, the development of infective larvae has been shown to be controlled by similar molecular genetic mechanisms such as Caenorhabditis elegans (via the AGE-1 region) in S. stercoralis via a structural homologue of the AGE-1 region called Ss-AGE-1. 19 Therefore, a chemical agent is likely to be involved in the mediation of differentiation of S. stercoralis larvae.…”

Section: Strongyloides' Life Cyclementioning

confidence: 99%

Human strongyloidiasis: identifying knowledge gaps, with emphasis on environmental control

Taylor

Garrard

O’Donahoo

et al. 2014

RRTM

View full text Add to dashboard Cite

Strongyloides is a human parasitic nematode that is poorly understood outside a clinical context. This article identifies gaps within the literature, with particular emphasis on gaps that are hindering environmental control of Strongyloides. The prevalence and distribution of Strongyloides is unclear. An estimate of 100-370 million people infected worldwide has been proposed; however, inaccuracy of diagnosis, unreliability of prevalence mapping, and the fact that strongyloidiasis remains a neglected disease suggest that the higher figure of more than 300 million cases is likely to be a more accurate estimate. The complexity of Strongyloides life cycle means that laboratory cultures cannot be maintained outside of a host. This currently limits the range of laboratory-based research, which is vital to controlling Strongyloides through environmental alteration or treatment. Successful clinical treatment with antihelminthic drugs has meant that controlling Strongyloides through environmental control, rather than clinical intervention, has been largely overlooked. These control measures may encompass alteration of the soil environment through physical means, such as desiccation or removal of nutrients, or through chemical or biological agents. Repeated antihelminthic treatment of individuals with recurrent strongyloidiasis has not been observed to result in the selection of resistant strains; however, this has not been explicitly demonstrated, and relying on such assumptions in the longterm may prove to be shortsighted. It is ultimately naive to assume that continued administration of antihelminthics will be without any negative long-term effects. In Australia, strongyloidiasis primarily affects Indigenous communities, including communities from arid central Australia. This suggests that the range of Strongyloides extends beyond the reported tropical/subtropical boundary. Localized conditions that might result in this extended boundary include accumulation of moisture within housing because of malfunctioning health hardware inside and outside the house and the presence of dog fecal matter inside or outside housing areas.

show abstract

Strongyloides stercoralis age-1: A Potential Regulator of Infective Larval Development in a Parasitic Nematode

Cited by 45 publications

References 78 publications

Exploring the role of two interacting phosphoinositide 3-kinases of Haemonchus contortus

Exploring the role of two interacting phosphoinositide 3-kinases of Haemonchus contortus

Hc-daf-2 encodes an insulin-like receptor kinase in the barber’s pole worm, Haemonchus contortus, and restores partial dauer regulation

Human strongyloidiasis: identifying knowledge gaps, with emphasis on environmental control

Contact Info

Product

Resources

About