Genetic and molecular analysis of the Spm-dependent a-m2 alleles of the maize a locus.

摘要: The Suppressor-mutator (Spm) transposable element family of maize consists the fully functional standard Spm (Spm-s) and many mutant elements. Insertion an in or near a gene can markedly alter its expression, some cases bringing under control mechanisms that regulate expression element. To gain insight into such mechanisms, as well to enlarge our understanding element's genetic organization, we have analyzed derivatives unique insertion at locus which is co-expressed co-regulated with We describe properties structure 9 strains (collectively designated a-m2 alleles) selected by McClintock from original allele for heritable changes affecting either gene. Most mutations are intra-element deletions within 8.3-kb element; both function controls alleles internally deleted, transposition-defective elements ends contain target sequences mediate Spm's ability activate argue reflect operation element-encoded positive regulatory mechanism, negative mechanism affects element, but appears not be mediated product.