Algae. 2011; 26(3): 229-235.
Spliced leader sequences detected in EST data of the dinoflagellates Cochlodinium polykrikoides and Prorocentrum minimum
Ruoyu Guo1 and Jang-Seu Ki1,*
1Department of Green Life Science, Sangmyung University, Seoul 110-743, Korea
Spliced leader (SL) trans-splicing is a mRNA processing mechanism in dinoflagellate nuclear genes. Although studies have identified a short, conserved dinoflagellate SL (dinoSL) sequence (22-nt) in their nuclear-encoded transcripts, whether the majority of nuclear-coded transcripts in dinoflagellates have the dinoSL sequence remains doubtful. In this study, we investigated dinoSL-containing gene transcripts using 454 pyrosequencing data (Cochlodinium polykrikoides, 93 K sequence reads, 31 Mb; Prorocentrum minimum, 773 K sequence reads, 291 Mb). After making comparisons and performing local BLAST searches, we identified dinoSL for one C. polykrikoides gene transcript and eight P. minimum gene transcripts. This showed transcripts containing the dinoSL sequence were markedly fewer in number than the total expressed sequence tag (EST) transcripts. In addition, we found no direct evidence to prove that most dinoflagellate nuclear-coded transcripts have this dinoSL sequence.
Keywords : Cochlodinium polykrikoides; expressed sequence tag; Prorocentrum minimum; spliced leader sequence;