Accepted_test

Orthonectida is a small, rare, and in many aspects enigmatic group of organisms with a unique life cycle and a highly simplified adult free-living stage parasitizing various marine invertebrates. Several studies have shown that parasitism can lead to a dramatic reduction of the body plan, morphological structures and also affects organisms at the genomic level. In previous studies were shown that Orthonectida has extremely compact genomes due to the significant reduction of gene number, intergenic regions, intron length, and repetitive elements. As a result, gene density in these species much higher than in other metazoans and genes suggested might be possess operon-like gene organization. In this study we sequenced I. linei transcriptome and compared the experimentally determined polycistronic transcripts with computational analysis of intergenic distances in the I. linei genome.