Abstract
Instability is an intriguing characteristic of many protist genomes, and trypanosomatids are not an exception in this respect. Some regions of trypanosomatid genomes evolve fast. For instance, the trypanosomatid mitochondrial (kinetoplast) genome consists of fairly conserved maxicircle and minicircle molecules that can, nevertheless, possess high nucleotide substitution rates between closely related strains. Recent experiments have demonstrated that rapid laboratory evolution can result in the non-functionality of multiple genes of kinetoplast genomes due to the accumulation of mutations or loss of critical genomic components. An example of a loss of critical components is the reported loss of entire minicircle classes in Leishmania tarentolae during laboratory cultivation, which results in an inability to generate some correctly encoded genes. In the current work, we estimated the evolutionary rates of mitochondrial and nuclear genome regions of multiple natural Leishmania spp. We analyzed synonymous and non-synonymous substitutions and, rather unexpectedly, found that the coding regions of kinetoplast maxicircles are among the most variable regions of both genomes. In addition, we demonstrate that synonymous substitutions greatly predominate among maxicircle coding regions and that most maxicircle genes show signs of purifying selection. These results imply that maxicircles in natural Leishmania populations remain functional despite their high mutation rate.
Original language | English (US) |
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Article number | 384 |
Journal | Tropical Medicine and Infectious Disease |
Volume | 8 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2023 |
Bibliographical note
Funding Information:This research was funded by the Russian Science Foundation, grant number RSF 19-74-10008 to E.S.G. The computational infrastructure used in analysis was purchased using resources provided by the European Regional Funds CZ.02.1.01/16_019/0000759 to V.Y. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.
Publisher Copyright:
© 2023 by the authors.
Keywords
- genome instability
- L. infantum
- L. major
- L. turanica
- leishmania donovani
- SNP
PubMed: MeSH publication types
- Journal Article