Abstract:Objective To clone and analyze the full-length cDNA sequences of cycloartenol synthase gene from Paris polyphyllavar. yunnanensis(PpCAS). MethodsUsing homology cloning and RT-PCR techniques, conserved fragments of PpCAS gene were obtained. RACE technology was usedto obtain 3’ and 5’ end sequences of PpCAS and sequence analysis was done by bioinformatics method. Results The full-length cDNA of PpCAS was 2 309 bp, which contained an open reading frame (ORF) of 2 283 bp. Sequence analysis indicated that PpCAS could encod protein with 760 amino acids, with a predicted relative molecular weight of 8.69 × 104 and an isoelectric point (pI) of 6.54. Sequence analysis and homology modeling suggested that amino acidsequence of PpCAS showed high homology (60%―83%) with CAS of other plants. Conclusion The full-length cDNA sequence of PpCAS is first obtained and it has the typical characteristics of the homologous genes.