A Brassica napus skp1 -like gene promoter drives GUS expression in Arabidopsis thaliana male and female gametophytes

We isolated a gene, BnSKP1γ1 , expressed in rapeseed ( Brassica napus ) microspores, which encodes a protein closely related to the Saccharomyces cerevisiae Skp1p protein previously shown to play a role in cell cycle regulation. Twelve SKP1 -related genes have already been identified in the Arabidopsis thaliana genome. Using a PCR-based strategy, we isolated three other genes. To date, most data available concerning the function of the SKP1 -related genes in plants are indirect. Studies on transgenic A. thaliana plants showthat a 1100-bp BnSKP1γ1 promoter fragment can direct GUS expression in female gametophytes soon after the first haploid mitosis and in male gametophytes from the tetrade stage. No GUS expression can be detected in sporophytic tissues. RT-PCR experiments suggest that this gene is expressed in a similar way in rapeseed. This is the first reported case of a gene exhibiting such an expression pattern in angiosperms.