Reference "Bronze-2 gene of maize: reconstruction of a wild-type allele and analysis of transcription and splicing"

Reference ID

7219

Title

Bronze-2 gene of maize: reconstruction of a wild-type allele and analysis of transcription and splicing

Source

The Plant cell, 1990, vol. 2, pp. 1039-1049

Authors (3)

Nash-J	Luehrsen-K-R
Walbot-V

Abstract

The maize Bronze-2 (Bz2) gene, whose product acts late in the anthocyanin
biosynthetic pathway, has been cloned and its transcript has been mapped. We
have developed a general procedure for reconstructing wild-type alleles from
transposable element-induced mutants. An existing transposon-containing clone,
bz2::mu1 [McLaughlin, M., and Walbot, V. (1987). Genetics 117, 771-776], was
modified by replacing the region of bz2::mu1 containing the transposon with the
corresponding polymerase chain reaction-amplified sequence from the progenitor
allele that has no Mu insertion. Particle gun delivery of the reconstructed Bz2
gene to embryonic scutellar tissue lacking a functional Bz2 gene complemented
the bz2 mutant phenotype, as demonstrated by the production of purple spots.
Having cloned the wild-type allele, we then analyzed the Bz2 transcript, whose
features include an 82-nucleotide 5'-untranslated leader, one small intron (78
base pairs) within the coding region, and multiple polyadenylation sites. Four
Mutator transposon insertions that eliminate gene function were mapped within
the 850-nucleotide transcription unit. We found that variable levels of
unspliced Bz2 RNA are present in purple husk tissue; this finding may indicate
that the expression of Bz2 is regulated in part at the level of transcript
processing.