Cloning,sequence and express pattern analysis of Actin gene from Carica papaya

High quality RNA was extracted from papaya pulp.Then the double-stranded cDNA was obtained through Super SMARTTM PCR cDNA Synthesis Kit.A full-length cDNA clone encoding Actin (Genbank accession number: FJ696416) was amplified by RACE-PCR from papaya.The full length cDNA of CpActin was 1 533 bp with an ORF of 1 134 bp encoding a protein with 377 amino acids.Sequence analysis showed that the amino acid sequence was 98.94%,98.67%,96.29%,94.69% identical with poplar,grape,rice and Arabidopsis thaliana respectively.Phylogenic tree was constructed based on the amino acid sequences of Actin from partial higher species,mammals and fungi using NeighborJoining method.The Actin from papaya and grape had the shortest evolutionary distance.Semi-Quantitative RT-PCR analysis showed that the expression of CpActin at different ripening stages had no notable difference.CpActin could be used as internal control gene in papaya gene expression analysis.