In-depth analysis of the genome of Trypanosoma evansi, an etiologic agent of surra
Trypanosoma evansi is the causative agent of the animal trypanosomiasis surra, a disease with serious economic burden worldwide. The availability of the genome of its closely related parasite Trypanosoma brucei allows us to compare their genetic and evolutionarily shared and distinct biological features. The complete genomic sequence of the T. evansi YNB strain was obtained using a combination of genomic and transcriptomic sequencing, de novo assembly, and bioinformatic analysis. The genome size of the T. evansi YNB strain was 35.2 Mb, showing 96.59% similarity in sequence and 88.97% in scaffold alignment with T. brucei. A total of 8,617 protein-coding genes, accounting for 31% of the genome, were predicted. Approximately 1,641 alternative splicing events of 820 genes were identified, with a majority mediated by intron retention, which represented a major difference in post-transcriptional regulation between T. evansi and T. brucei. Disparities in gene copy number of the variant surface glycoprotein, expression site-associated genes, microRNAs, and RNA-binding protein were clearly observed between the two parasites. The results revealed the genomic determinants of T. evansi, which encoded specific biological characteristics that distinguished them from other related trypanosome species.
KeywordsTrypanosoma trypanosomiasis genome annotation function
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We thank Professor Lun Zhaorong from Sun Yat-sen University for providing the Trypanosoma brucei strain. We sincerely appreciate the technical assistance of the technicians at the Key Laboratory of Zoonosis, Shenyang Agriculture University. This study was supported by grants of the National Key Research and Development Program of China (2017YFD0500400 and 2017YFD0501200), the National Natural Science Foundation of China (81420108023 and 81772219), and distinguished scientist grant from Shenyang Agricultural University.
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