Multiple GUS expression patterns of a single Arabidopsis gene

Abstract

Ten independent transposant lines with gene or enhancer traps (ET) inserted into the same gene (At2g01170) were identified in Arabidopsis thaliana. Transposon insertions were confirmed for each line. Only three of five ET lines and only one of the five gene trap (GT) lines displayed uidA (GUS) staining. The GUS (beta-glucuronidase) expression patterns of the ET lines were different in all three lines. In the GT line, the GUS expression was restricted to the vascular tissue under all conditions examined. The variation in ET GUS expression suggests that each ET was controlled by different enhancer elements or the different elements of the trapped locus may give rise to different GUS expression patterns. Of five GT lines, three have the GUS gene in the same orientation as the At2g01170 open reading frame, yet only one yielded GUS staining. Regardless of the insertion construct, only those transposants with an insertion at the 3' end of the gene yielded GUS staining. Some transposants displayed a longer root phenotype in the presence of kanamycin that was also observed in 3' insertion sites in At2g01170. Taken together, these data show that insertions in the 5' end of the gene disrupted expression and emphasise the complexity encountered with ET and GT constructs to characterise the expression patterns of genes of interest based solely on GUS expression patterns.