Keywords: 
• forest tree breeding /
• Cunninghamia lanceolata /
• CesA gene /
• cloning /
• sequence analysis /
• expression analysis

Abstract: In this study, two full-length cDNAs encoding cellulose synthase （CESA） were isolated from Chinese fir （Cunninghamia lanceolata） using RT-PCR and RACE technology, and their sequence lengths were 3 235 bp and 3 876 bp, respectively. They were named ClCesA1 and ClCesA2, and the corresponding GenBank accession numbers were JQ844574 and JQ844575 respectively. The encoded proteins are composed of 992 and 1 092 amino acids, with theoretical molecular weight of 111 845.3 and 123 105.7 D, whose isoelectric points are 6.04 and 6.65, respectively. Amino acid sequences contain typical motifs of plant CESA proteins: a ring finger domain, two class specific regions CSRI and CSRII, two conserved regions CRI and CRII, cellulose synthase substrate binding domain D, D, D, QVLRW, and eight transmembrane regions. The expression analysis showed that ClCesA1 and ClCesA2 genes exhibited the high transcript abundance in stem, the corresponding expression levels in mature xylem were higher than that in cortex. The two genes had the lower expression levels in root and leaf. The further expression analysis was conducted using the dwarf Chinese fir with the specific wood properties. The results showed that the expression levels of ClCesA1 and ClCesA2 in the xylem of normal fir were about 2-12 times than that of the dwarf. Two ClCesA genes may be play important roles in the wood formation of Chinese fir. ［Ch, 5 fig. 19 ref.］