Molecular cloning of a myoD-like gene from the parasitic nematode, Trichinella spiralis

The infective larval stage of the nematode Trichinella spiralis is an intracellular parasite of skeletal muscle cells. Infection with T. spiralis results in dedifferentiation of the host cell and the formation of a host/parasite complex. A gene encoding a T. spiralis Helix-Loop-Helix (HLH) protein with homology to the myogenic transcription factor, MyoD, and to the Caenorhabditis elegans protein, CeMyoD, has been identified and partially characterized. The tsmyd-1 gene is expressed constitutively during the muscle-larval and adult stages. A purified recombinant Tsmyd-1 protein, expressed in Escherichia coli, binds to a high affinity mouse MyoD DNA binding site in vitro. The present study describes the first HLH gene to be identified in Trichinella.