FIG. 4.

Colony PCR showing the presence of two copies of similar genes on the A. evansii genome. Specific primers were derived from the differing intergenic regions of gene cluster types I and II and were used in PCR experiments. Lane 1, colony PCR with primers specific for type I; lane 2, colony PCR with primers specific for type II; lane 3, PCR with a type I subclone and primers specific for type I; lane 4, PCR with a type I subclone and primers specific for type II (negative control); lane 5, PCR with a type II subclone and primers specific for type I (negative control); lane 6, PCR with a type II subclone and primers specific for type II; lane 7, DNA standard. Small amounts of several products were found in negative controls (lanes 4 and 5). These products were of no reproducible size and therefore were considered nonspecific.