Evidence for correlation between mutability of an unstable anthocyanin-governing locus and abundance of anthocyanin.

The pal-rec gene of Antirrhinum majus suppresses anthocyanin except in those cell lines where pal-rec has mutated to Pal, so that anthocyanin-coloured flecks appear on whitish petals. Antirrhinum majus families of very high and very low anthocyanin content (Dark and Pale) were obtained and crossed with two pal-rec pal-rec lines, one with consistently high and the other consistently low mutability. Mutable offspring from Dark parents tended to show higher mutability than those from Pale parents in crosses with either mutable line, providing evidence for an association between intense pigmentation and high mutability. Such an association is discussed in the context of relationship between precursor availability for conversion by a gene product and initiation of activity of that gene.