THE 4 CDC25 GENES FROM THE NEMATODE CAENORHABDITIS-ELEGANS

During eukaryotic evolution, multicellular organisms have evolved mult iple members of gene families that may display unique, partially overl apping, or redundant functions during development. More than 75% of th e C. elegans genome has been sequenced, which represents approximately 95% of the coding sequences. This provides a unique opportunity to id entify most, if not all, of the members of a given gene family. We hav e searched the C. elegans genome database for members of a key family of cell cycle regulators, the CDC25 phosphatases, and have identified four genes. The four C. elegans genes represent a larger family within a single organism than has been reported so far in Drosophila, mice a nd humans. An amino acid comparison revealed a high degree of similari ty and identity within the phosphatase domain. This analysis also iden tified an expanded consensus sequence that can be used to discover new members of the CDC25 phosphatase family. However, the four C. elegans sequences display a few novel amino acid substitutions in the residue s surrounding the invariant catalytic motif CX5R. These data demonstra te the value of genome database searching for identifying new members of known gene families, understanding genetic diversity, and for study ing gene structure. (C) 1998 Elsevier Science B.V. All rights reserved .