Differential chromatin structure within a tandem array 100 kb upstream of the maize b1 locus is associated with paramutation.

ABSTRACT: Recombination mapping defined a 6-kb region, 100 kb upstream of the transcription start site, that is required for B-I enhancer activity and paramutation-a stable, heritable change in transcription caused by allele interactions in maize (Zea mays). In this region, B-I and B' (the only b1 alleles that participate in paramutation) have seven tandem repeats of an 853-bp sequence otherwise unique in the genome; other alleles have one. Examination of recombinant alleles with different numbers of tandem repeats indicates that the repeats are required for both paramutation and enhancer function. The 6-kb region is identical in B-I and B', showing that epigenetic mechanisms mediate the stable silencing associated with paramutation. This is the first endogenous gene for which sequences required for

SUBMITTER: Stam M 

PROVIDER: S-EPMC186425 | biostudies-literature | 2002 Aug

REPOSITORIES: biostudies-literature