The single-copy actin gene of Phytophthora megasperma encodes a protein considerably diverged from any other known actin.

This paper reports the cloning and sequencing of a Phytophthora megasperma actin gene. Sequence analysis revealed that the gene does not contain introns and encodes a putative actin protein remarkably diverged from any other known actins. Genomic Southern analysis indicates that there is a single actin gene per haploid genome, which is actively transcribed in vivo, as revealed by S1 mapping of the transcripts. The transcripts are heterogeneous in size because they have different 3' termini, none of which contains the conventional AATAAA polyadenylation signal.