FIG. 6.

Diagram showing the DNA sequence of the minimum rep₂₀₀₉ gene subclone, designated ori₂₀₀₉, that confers a Per phenotype on UC509.9. Nucleotides contained in the direct repeats are shown as uppercase letters. Arrows indicate repeated sequences. Underlined nucleotides indicate positions where random nucleotide substitutions or deletions occurred; nucleotides substituted or deleted at that position are indicated as is the effect that the mutations had on Per. Nucleotide substitutions or deletions that are boxed in the same manner indicate positions where more than one mutation has occurred in one fragment, e.g., three nucleotide substitutions (C-T at position 347, A-T at position 348, and A-G at position 413) and one nucleotide deletion (T- − at position 316) are highlighted with a shaded box. This indicates that these four mutations occur on a single DNA fragment. −, mutation had no effect on Per; +, mutation caused slight loss of Per; ++, mutation caused severe loss of Per; +++, mutation caused complete loss of Per.