Transcriptomic and genomic identification of spliceosomal genes from .

Diverse splicing types in nuclear and chloroplast genes of protist have been recognized for decades. However, the splicing machinery responsible for processing nuclear precursor messenger RNA introns, including -splicing of the 5' terminal outron and spliced leader (SL) RNA, remains elusive. Here, we identify 166 spliceosomal protein genes and two snRNA genes from . by performing bioinformatics analysis from a combination of next-generation and full-length transcriptomic RNA sequencing (RNAseq) data as well as draft genomic data. With the spliceosomal proteins we identified in hand, the insensitivity of . to some splicing modulators is revealed at the sequence level. The prevalence of SL RNA-mediated -splicing is estimated to be more than 70% from our full-length RNAseq data. Finally, the splicing proteomes between . and its three evolutionary cousins within the same Excavata group are compared. In conclusion, our study characterizes the spliceosomal components in . and provides the molecular basis for further exploration of underlying splicing mechanisms.