EXPRESSION OF CHIMERIC GENES IN CAENORHABDITIS-ELEGANS

We have shown the expression of transformed genes in the nematode Caenorhabditis elegans using a new gene fusion system. Vectors consisting of the flanking regions of a collagen gene (col-1) or a major sperm protein gene of C. elegans fused to the Escherichia coli uidA gene,encoding .beta.-glucuronidase, were microinjected into worms and found to be propagated as high-copy extrachromosomal tandem arrays. We have detected .beta.-glucuronidase activity in transformed lines, and have shown that the activity is dependent upon the correct reading frame of the construction and on the presence of the worm sequences. The enzyme activity was shown to be encoded by the chimeric .beta.-glucuronidase gene by co-segregation analysis and by inactivation with specific antisera. Expression is at a very low level, and seems to be constitutive. We have used histochemical techniques to visualize the enzyme activity in embryos.