image of the database obtained on this date.) The default gap penalty and nucleotide match score were used. The nucleotide mismatch penalty, -q, parameter was set to À1 rather than the default. The results of any BLAST query with an expect value <0.0001 were returned in tabular format from the blastall program. The information about each return (bit score, expect value, mismatches, length of match) was placed in the Return{hash key}{info} hash using the SubSeq identity as the hash key for further analysis.