[Cloning and analysis of psaB cDNA of Dunaliella salina].

One pair of degenerate primer was designed according to conserved motifs of the psaB (A2 subunit of photosystem I) of Chlamydomonas reinhardtii, Chlamydomonas moewusii, Chlorella vulgaris and Mesostigma viride, and a total RNA of Dunaliella salina (D. salina) was extracted with TRIzol reagent. A cDNA fragment, about 1.8kb in length, from green algal D. salina was obtained through RT-PCR method. The resulting PCR product was cloned into T-vector and screened to determine its sequence. Homologous analysis of the deduced amino acid sequence was performed by BLAST and subsequeqtly compared with GenBank data. The obtained cDNA sequence was 1815 bp long, which encodes 605 amino acids (GenBank accession number: AY820754). The sequence shared high homologue with the following psaB: Chlamydomonas reinhardtii 92%, Chlamydomonas moewusii 91%, Chlorella vulgaris 86%, Mesostigma viride 85%, Physcomitrella patens subsp. Patens 85% and Nephroselmis olivacea 84%. It can be concluded that the cloned sequence is psaB cDNA fragment from D. salina.