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Patterns of intron sequence conservation in the genus Tetrahymena

Yichen Zheng / Kristen L. Dimond / Dan Graur / Rebecca A. Zufall
Published Online: 2013-02-27 | DOI: https://doi.org/10.2478/prge-2013-0001

Abstract

Background:

Introns constitute a large fraction of eukaryotic genomes and were once considered neutrally evolving sequences. Recently, however, some introns have been found to harbor sequences that are involved in a variety of regulatory and other functions and show evidence of purifying selection.

Results:

We examine the pattern of sequence divergence among ciliates in the genus Tetrahymena. We find that on average introns are more highly conserved than four-fold degenerate sites. Among introns, we find a correlation between conservation strength and both position rank in the gene as well as size of the coding region; the most conserved introns are found closer to the 5’ end of the largest genes.

Conclusions:

Our results indicate that Tetrahymena introns experience selective constraint, possibly due to harboring regulatory sequences. We advocate for further experimental study of possible intron functions in Tetrahymena.

Keywords: Intron; Evolution; Ciliate; Tetrahymena

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About the article


Received: 2012-08-08

Accepted: 2013-01-14

Published Online: 2013-02-27


Citation Information: Protist Genomics, ISSN (Online) 2299-100X, DOI: https://doi.org/10.2478/prge-2013-0001.

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