Common Structural Patterns in the Maxicircle Divergent Region of Trypanosomatidae.

Evgeny S Gerasimov,Yulia A Rudenskaya,Ksenia A Zamyatnina,Alexander A Kolesnikov,Nadezda S Matveeva,Natalya Kraeva,Vyacheslav Yurchenko

doi:10.3390/pathogens9020100

Abstract

Maxicircles of all kinetoplastid flagellates are functional analogs of mitochondrial genome of other eukaryotes. They consist of two distinct parts, called the coding region and the divergent region (DR). The DR is composed of highly repetitive sequences and, as such, remains the least explored segment of a trypanosomatid genome. It is extremely difficult to sequence and assemble, that is why very few full length maxicircle sequences were available until now. Using PacBio data, we assembled 17 complete maxicircles from different species of trypanosomatids. Here we present their large-scale comparative analysis and describe common patterns of DR organization in trypanosomatids.

Highlights

Trypanosomatids are unicellular parasitic organisms with a single large mitochondrion per cell [1,2]
The shortest sequence in this study of 23,201 bp belongs to Trypanosoma brucei (Lister 427), while the longest one of 47,384 bp is from T. cruzi (Dm28c)
The shortest coding region (CR) sequences were documented in Trypanosoma spp., where cryptogenes undergo the most extensive RNA editing [4,5], while the longest CR sequences were in monoxenous trypanosomatids, whose cryptogenes have reduced editing domains [37,38,39]

Summary

Introduction

Trypanosomatids are unicellular parasitic organisms with a single large mitochondrion per cell [1,2]. Mitochondrial DNA of trypanosomatids is a network of concatenated circular molecules of two types: maxicircles and minicircles [3]. There are thousands of minicircles present in a single mitochondrion [6,7,8]. Maxicircles are much larger (25–50 kbps) and present in up to 100 copies [9]. Mitochondrial genes are compactly located in the so-called coding region (CR) of a maxicircle, which is typically about 16 kbps, and demonstrate high level of synteny between species [18,19,20,21]. The rest of maxicircle’s molecule is termed the divergent region (DR), sometimes called the variable region [22,23,24,25]

Methods

Results

Discussion

Conclusion