亚历山大藻钙调蛋白基因的克隆鉴定及对细胞生长和热胁迫的表达分析

In this paper, calmodulin gene of the HAB species Alexandrium catenella was isolated, and its transcription profile with respect to grow rate and heat stress was investigated. A full cDNA sequence of cam gene was obtained. It consisted of 597 nucleotides (nt), comprising 25 nt of the 5′ untranslated region (UTR), 122 nt of the 3′ UTR, and an open reading frame (ORF) of 450 nt, encoding 149 amino acid residues. The deduced CaM was highly conserved compared with CaM of other organisms. By implementing quantitative PCR, the relationship between transcription level of cam and growth rate of Alexandrium catenella was investigated. The results showed that cam expression level had a similar trend with the cell growth rate through the whole growing stage. The cam transcription was increased more than 8 fold in abundance from lag phase to the exponential phase, and obviously decreased from exponential phase to stationary/decline phase. Additionally, response of cam gene to heat stress was studied. Relative expression level of cam exhibited a significant decline trend with time during the heat shock experiment. All the results suggested that cam play an important role within process that the cells response to environmental stress and growth.