A deletion mutation, designated 9, fails to complement mutants 1, 3, 5, 7, and 8. Wild-type recombinants are observed from mutant 9 and mutations 3, 5, and 8; however, no wild-type recombinants are observed between mutant 9 and mutants 1 and 7. Another deletion mutation, 10, fails to complement mutants 1, 4, 5, 6, 8, and 9. Mutant 10 forms wild-type recombinants with mutants 1, 5, and 6, but not with mutants 4 and 8. Mutant 9 and mutant 10 both form wild-type recombinants. Additional gene mapping information identifies mutants 2 and 3 as the flanking genes in this group of genes.
a) Assuming these mutations (2 and 3) are on opposite ends of the gene map, determine the order of these mutations (1-8) in the region of the chromosome.
b) How many genes are represented by these mutations? Identify the mutants for each complementation group.
c) In each coinfection above that is identified as a failure to complement (-), scientists see evidence of recombination producing wild-type growth. How do the scientists distinguish between wild-type growth resulting from complementation and wild-type growth that is due to recombination?