构建用于相关基因筛选的微小亚历山大藻产毒株基因组文库

Construction of genomic library of strains producing Alexandrium Minudum algae for the screening of related genes

麻痹性贝毒素(paralytic shellfish poisonings,PSP)严重威胁海产食品质量安全,其主要是由水体中的甲藻代谢产生。利用分子生物学和生物信息学技术构建微小亚历山大藻ATMW02基因组文库,探求与PSP产生相关的基因群。经过与无毒亚历山大藻L35对比筛选,获得ATMW02株系特异性的DNA片段,然后,利用反向PCR扩展该片段的旁侧序列,分析其序列特征和功能,探讨有可能引起藻株致毒的关键酶。通过序列分析获得一段去除了内含子的240 bp大小的核苷酸序列,这条核苷酸序列在终止密码子之外的非编码区突变了三个碱基,并且存在三个非常保守的铜离子结合区。其对应的氨基酸序列翻译的对象是甲硫氨酰氨肽酶(methionine amino peptidase,MAP),氨基酸比对分析,其与芬地亚历山大藻MAP氨基酸序列相似性达到97%。研究结果为深入研究亚历山大藻产毒机制奠定了理论基础,同时,为加强海产品监控和质量安全提供有力的技术支持。

Paralytic shellfish poison（PSP）, which is mainly produced by dinoflagellates of water, is a serious threat to Marine food quality and safety.Alexandrium minutum ATMW02 genomic library was built to search the related gene group in PSP by using molecular biology and bioinformatics technology.After compared with non-toxic Alexandrium L35, a specificity fragments of the DNA in ATMW02 was obtained and the flanking sequences were expanded through reverse PCR. By analyzing the sequence features and functions, the key enzymes were explored that migth cause the poison also obtained a 240 bp nucleotide sequence without intron. This nueleotide sequence mutated three bases outside the termination codon and existed three conservative copper-binding domain, which could be translated into MAP and 97% match with the Alexandium fundyense MAP.The results of this study provided a theoretical foundation for further research on Alexandrium toxin- producing mechanisms.In the meantime ,it could provided technical support to enhance marine food quality and supervision.