The Toxic Dinoflagellate Karenia brevis Encodes Novel Type I-like Polyketide Synthases Containing Discrete Catalytic Domains

Growth- and nutrient-dependent gene expression in the toxigenic marine dinoflagellate Alexandrium minutum

“…In analogy to the situation in trypanosomes, the phenomenon of mRNA transsplicing in dinoflagellates has been suggested to be associated with post-transcriptional control of gene expression (Bachvaroff and Place, 2008;Monroe and Van Dolah, 2008). Our data on the percentages of differentially expressed A. minutum sequences that contain the typical transsplicing-associated spliced leader (SL) sequence suggests that this mechanism in dinoflagellates is not associated with a lack of regulation at the transcriptional level.…”

“…Genomic studies on dinoflagellates, however, are complicated by profound doubts as to what extent methods and concepts developed in model organisms, including other protists, are applicable to dinoflagellates (Bachvaroff and Place, 2008;Monroe and Van Dolah, 2008; Moreno Díaz de la Espina et al, 2005). Dinoflagellates arguably contain the most unusual eukaryotic genetic machinery known.…”

“…Both regulation of mRNA abundances (Hosoi-Tanabe et al, 2005;Okamoto and Hastings, 2003;Taroncher-Oldenburg and Anderson, 2000;Toulza et al, 2010) and a high prevalence of translational regulation Lidie, 2007;Rossini et al, 2003) have been reported in dinoflagellates. The discovery of spliced-leader transsplicing (Lidie and Van Dolah, 2007;Slamovits and Keeling, 2008;Zhang et al, 2007) and of single-domain transcripts apparently derived from multi-domain genes led to the suggestion of trypanosome-like mechanisms of spliced-leader-associated constitutive translational gene regulation in dinoflagellates (Monroe and Van Dolah, 2008). In analogy to trypanosomes, highly expressed dinoflagellate genes were proposed to be constitutively transcribed and regulated during mRNA processing by a mechanism involving trans-splicing (Bachvaroff and Place, 2008).…”

Current Knowledge and Recent Advances in Marine Dinoflagellate Transcriptomic Research

“…Microarray analysis in K. brevis showed that expression of PKSs genes did not change over the diel cycle despite evidence that toxin production is specific to certain diel phases or cell cycle stages in dinoflagellates [56]. The role of PKSs in toxin production of dinoflagellates needs to be further investigated, as several PKS genes found in dinoflagellates may potentially function as fatty acid synthases (FAS) [72,73]. In A. catenella strain ACT03, expression levels of two genes, S-adenosyl-homocysteine hydrolase (SAHH) and S-adenosylmethionine synthetase (SAM-S), which are involved in methylation and cell cycle progression, were speculated to correlate with toxin expression in A. catenella [30].…”

Genomic characterisation of the ichthyotoxic prymnesiophyteChrysochromulina polylepis,and the expression of polyketide synthase genes in synchronized cultures

“…Nevertheless, the presence of at least one PKS gene in the toxic dinoflagellate Karenia brevis was proven by the same author (Snyder et al, 2003). To circumvent the problems associated with the use of degenerate primers for PCR approaches, Monroe & van Dolah (2008) managed to isolate full-length sequences of single catalytic domains from PKS genes from the same organism, by screening cDNA libraries. They claim that the sequence is most similar to type I modular PKS, but that the structure is most similar to type II (for review see Hertweck et al, 2007).…”