Send to:

Choose Destination
See comment in PubMed Commons below
Mol Biochem Parasitol. 2005 Feb;139(2):213-23.

daf-7 and the development of Strongyloides ratti and Parastrongyloides trichosuri.

Author information

  • 1School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK.


daf-7 is a key ligand in one of the three pathways that control dauer larva development in Caenorhabditis elegans. Given the similarities between dauer larvae of free-living nematodes and third stage infective larvae of animal parasitic nematodes, we hypothesised that daf-7 may be involved in the development of these infective larvae. To investigate this, we cloned daf-7 orthologues from Strongyloides ratti and Parastrongyloides trichosuri and analysed their RNA level by semi-quantitative RT-PCR during the S. ratti and P. trichosuri life cycles and in a range of in vitro and in vivo conditions. We found that, in both species, the RNA level of daf-7 was low in free-living stages but peaked in the infective L3 (iL3) stage with little or no expression in the parasitic stages. This contrasts with the daf-7 RNA level in C. elegans, which peaks in L1, decreases thereafter, and is absent in dauer larvae. The RNA level of daf-7 in infective larvae was reduced by larval penetration of host skin or development in the host, but not by a shift to the body temperature of the host.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk