|Cui, X - IOWA STATE UNIVERSITY|
|Hsia, A - IOWA STATE UNIVERSITY|
|Schnable, P - IOWA STATE UNIVERSITY|
Submitted to: Maize Genetics Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: February 26, 1998
Publication Date: N/A
Technical Abstract: Some Mu-induced alleles condition a mutant phenotype only in the presence of Mutator activity (Martienssen et al., 1990). The inability of these alleles to exhibit a mutant phenotype in Mu-inactive stocks is termed "Mu suppression". Two of six Mu-tagged rf2 alleles (rf2-m9390 and rf2-m8110) are Mu-suppressible. Both can be reactivated via crosses to Mu-active lines. The rf2-m9390 allele contains a Mu1 insertion in the 5' UTR of the rf2 gene, 104-bp upstream of the translation start codon. Suppressed plants homozygous for rf2-m9390 accumulate rf2 mRNA at a level indistinguishable from that of wild-type plants. However, these transcripts are not derived from the native transcription initiation site. The rf2-m8110 allele contains a Mu7 insertion in the 3' UTR of the rf2 gene, 36-bp downstream of the stop codon. In suppressed plants, rf2 mRNA accumulates at a slightly lower level than in wild-type plants. 3' RACE analysis has revealed several lpolyadenylation sites within the terminal inverted repeats of Mu7. Hence, this allele reveals an apparently novel mechanism for Mu-suppression.