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Proceedings of the Royal Society B: Biological Sciences logoLink to Proceedings of the Royal Society B: Biological Sciences
. 2000 Oct 22;267(1457):2057–2063. doi: 10.1098/rspb.2000.1249

The control of morph development in the parasitic nematode Strongyloides ratti.

S C Harvey 1, A W Gemmill 1, A F Read 1, M E Viney 1
PMCID: PMC1690777  PMID: 11416909

Abstract

The parasitic nematode Strongyloides ratti has a complex life cycle. The progeny of the parasitic females can develop into three distinct morphs, namely directly developing infective third-stage larvae (iL3s), free-living adult males and free-living adult females. We have analysed of the effect of host immune status (an intra-host factor), environmental temperature (an extra-host factor) and their interaction on the proportion of larvae that develop into these three morphs. The results are consistent with the developmental decision of larvae being controlled by at least two discrete developmental switches. One is a sex-determination event that is affected by host immune status and the other is a switch between alternative female morphs that is affected by both host immune status and environmental temperature. These findings clarify the basis of the life cycle of S. ratti and demonstrate how such complex life cycles can result from a combination of simple developmental switches.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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