Heterogeneous Rates of Molecular Evolution Among Cryptic Species of the Ciliate Morphospecies Chilodonella uncinata

Authors

Laura A. Katz, Smith CollegeFollow
Jennifer DeBerardinis, Smith College
Meaghan S. Hall, Smith College
Alexandra M. Kovner, Smith College
Micah Dunthorn, University of Massachusetts Amherst
Spencer V. Muse, NC State University

Document Type

Article

Publication Date

12-1-2011

Publication Title

Journal of Molecular Evolution

Abstract

While molecular analyses have provided insight into the phylogeny of ciliates, the few studies assessing intraspecific variation have largely relied on just a single locus [e.g., nuclear small subunit rDNA (nSSUrDNA) or mitochondrial cytochrome oxidase I]. In this study, we characterize the diversity of several nuclear protein-coding genes plus both nSSU-rDNA and mitochondrial small subunit rDNA (mtSSU-rDNA) of five isolates of the ciliate morphospecies Chilodonella uncinata. Although these isolates have nearly identical nSSU-rDNA sequences, they differ by up to 8.0% in mtSSU-rDNA. Comparative analyses of all loci, including b-tubulin paralogs, indicate a lack of recombination between strains, demonstrating that the morphospecies C. uncinata consists of multiple cryptic species. Further, there is considerable variation in substitution rates among loci as some protein-coding domains are nearly identical between isolates, while others differ by up to 13.2% at the amino acid level. Combining insights on macronuclear variation among isolates, the focus of this study, with published data from the micronucleus of two of these isolates, indicates that C. uncinata lineages are able to maintain both highly divergent and highly conserved genes within a rapidly evolving germline genome.

Keywords

Ciliate, Cryptic species, Genome architecture, Molecular evolution

Volume

73

Issue

5-6

First Page

266

Last Page

272

DOI

10.1007/s00239-011-9468-x

ISSN

00222844

Rights

© Springer Science+Business Media, LLC 2012.

Comments

Peer reviewed accepted manuscript.

Recommended Citation

Katz, Laura A.; DeBerardinis, Jennifer; Hall, Meaghan S.; Kovner, Alexandra M.; Dunthorn, Micah; and Muse, Spencer V., "Heterogeneous Rates of Molecular Evolution Among Cryptic Species of the Ciliate Morphospecies Chilodonella uncinata" (2011). Biological Sciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/bio_facpubs/119