Draft macronucleus genome of Euplotes crassus ciliate

Abstract

Basic bioinformatics analysis has been performed on the draft macronucleus genome and transcriptome of the Euplotes crassus ciliate. More than a quarter of E. crassus genes contain several exons. Among introns, a large fraction of tiny introns was revealed with the length of 20–30 nucleotides. We determined 63 cases of alternative splicing and found 14 introns with nonstandard splicing sites. About 2000 of hypothesized genes in E. crassus have no homologues with other ciliates but in the majority of them a considerable similarity is observed with bacterial genes that can be due to contamination while ciliate sample preparation. Comparison of the genomes of E. crassus and other ciliates evidences the expansion of the same gene families, which are responsible for the vitality of free-living heterotrophic organisms.