Comparative Transcriptome Analysis of a Toxin-Producing Dinoflagellate Alexandrium catenella and Its Non-Toxic Mutant

Marine Drugs

Yong Zhang¹  Shu-Fei Zhang¹  Lin Lin¹ 

[1] State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China;

关键词: marine dinoflagellates;    Alexandrium catenella;    paralytic shellfish toxins;    mutant;    toxin biosynthesis;    transcriptome;    RNA-seq;   

DOI  :  10.3390/md12115698

来源: mdpi

【 摘 要 】

The dinoflagellates and cyanobacteria are two major kingdoms of life producing paralytic shellfish toxins (PSTs), a large group of neurotoxic alkaloids causing paralytic shellfish poisonings around the world. In contrast to the well elucidated PST biosynthetic genes in cyanobacteria, little is known about the dinoflagellates. This study compared transcriptome profiles of a toxin-producing dinoflagellate, Alexandrium catenella (ACHK-T), and its non-toxic mutant form (ACHK-NT) using RNA-seq. All clean reads were assembled de novo into a total of 113,674 unigenes, and 66,812 unigenes were annotated in the known databases. Out of them, 35 genes were found to express differentially between the two strains. The up-regulated genes in ACHK-NT were involved in photosynthesis, carbon fixation and amino acid metabolism processes, indicating that more carbon and energy were utilized for cell growth. Among the down-regulated genes, expression of a unigene assigned to the long isoform of sxtA, the initiator of toxin biosynthesis in cyanobacteria, was significantly depressed, suggesting that this long transcript of sxtA might be directly involved in toxin biosynthesis and its depression resulted in the loss of the ability to synthesize PSTs in ACHK-NT. In addition, 101 putative homologs of 12 cyanobacterial sxt genes were identified, and the sxtO and sxtZ genes were identified in dinoflagellates for the first time. The findings of this study should shed light on the biosynthesis of PSTs in the dinoflagellates.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.