Sunday, April 29, 2007

Cloning and characterization of a novel Ä12-fatty acid desaturase gene from Sapium sebiferum

Bei Niu, Ying Xu, Lin Tang, Fang Yan, Shen-hua Wang, and Fang Chen. School of Life Sciences, Sichuan University, 24 South Section 1, 1st Ring Road, Chengdu, China

A new full-length cDNA (Ssd12) was cloned from Sapium sebiferum using RT-PCR and RACE methods. The cloned cDNA was confirmed to encode a Δ12-fatty acid desaturase (Δ12-FAD) by the accumulation of C18:2 and C16:2 in Saccharomyces cerevisiae transformants. Ssd12 contained a 1145 bp open reading frame encoding 381 amino acid residues. The amino acid sequence showed a much higher match with other microsomal Δ12-FAD amino acid sequences than with chloroplast Δ12-FAD amino acid sequences. Genomic Southern blot analysis and real time PCR suggested that Ssd12 had at least two copies and was expressed constitutively in roots, leaves, stems, and seeds.