[Molecular analysis of certain derivatives of mutants with the unstable white-starka allele]

Molecular analysis of several mutations of the white locus was performed. The mutations were obtained as a result of mutagenesis in the unstable white-starka locus described previously. A large insert (approximately 15 kb in length) downstream of the first exon of the white gene was shown to be partly excised. Simultaneous excisions of various regions from the natural regulatory region of the white locus were also observed. Restriction enzyme analysis showed that the observed mutations and reversions resulted from large deletions from the regulatory gene region. Southern and Northern blot hybridization showed the presence of unknown regulatory regions within and outside the insert.