Figure 3. The system can be used to determine the timing of recombination.
In crosses of strains carrying different mutants of hH1::GFP (3′GFP and 5′GFP) as alleles, chromosomes in most asci will not fluoresce (1 in A, B & C). However, occasionally recombination will generate a wild-type GFP allele and fluorescence will become visible (2 in A, B & C). If recombination occurs with normal timing, fluorescence should be observed in young asci (A) and in all subsequent stages. Where the timing of recombination is abnormal, fluorescence will be restricted to a later stage (B & C). With this assay, recombination can also be detected in asci lacking a full complement of spores (C).
