抄録
A polyubiquitin gene (McUBI1) promoter region including its 5' UTR together with its first intron was isolated from the genomic DNA of M. crystallinum using a primer walking protocol. A 726 bp intron was found immediately 5' to the translation initiation codon in the second exon. To establish this McUBI1 promoter as a native and constitutive promoter, we have improved a transient expression assay based on particle bombardment and the dual-luciferase reporter technique, which should facilitate investigations into the regulation of McUBI1 gene in vivo. An intronless 2.58 kb promoter fragment was fused with the firefly luciferase and Renilla luciferase reporter gene. These chimeric gene constructs were introduced into leaves of M. crystallinum by particle bombardment for transient assay. We observed high expression level from the intronless promoter in M. crystallinum which is more stable than that from CaMV35S promoter. We will investigate the effect of existence of intron on expression level in M. crystallinum.
