Reliable amplification of actin genes facilitates deep-level phylogeny

The gene for actin as a highly conserved and functionally essential genetic element is developing into a major tool for phylogenetic analysis within a broad organismic range. We therefore propose a set of universally applicab le primers that allow reliable amplification of actin genes. For primer con struction the amino acid sequences of 57 actin genes comprising fungi, anim als, plants and protists were analysed, aligned and used for the definition of six well-conserved regions which are suitable as priming sites in PCR a mplification experiments. Ten primers were designed for specific in vitro a mplification of actin gene fragments from a wide range of microorganisms. T he corresponding gene fragments provide a strong basis to isolate nearly co mplete actin genes for further molecular characterization and for establish ing phylogenies based on actin gene trees.