Inactivation of the alpha-actinin gene in Dictyostelium.

alpha-Actinin-negative transformants of Dictyostelium have been obtained by transforming cells with a transformation vector carrying part of the alpha-actinin gene in either sense or antisense orientation. The transformants did not produce detectable alpha-actinin anymore and contained an altered RNA lacking the 3' part of the coding sequences. The deficiency in alpha-actinin was due to an integration of the transformation vector into the gene, since it could be detected by Southern blot analysis in the endogenous gene.