Simple sequence repeats in bryophyte mitochondrial genomes

Abstract

Simple sequence repeats (SSRs) are thought to be common in plant mitochondrial (mt) genomes, but have yet to be fully described for bryophytes. We screened the mt genomes of two liverworts (Marchantia polymorpha and Pleurozia purpurea), two mosses (Physcomitrella patens and Anomodon rugelii) and two hornworts (Phaeoceros laevis and Nothoceros aenigmaticus), and detected 475 SSRs. Some SSRs are found conserved during the evolution, among which except one exists in both liverworts and mosses, all others are shared only by the two liverworts, mosses or hornworts. SSRs are known as DNA tracts having high mutation rates; however, according to our observations, they still can evolve slowly. The conservativeness of these SSRs suggests that they are under strong selection and could play critical roles in maintaining the gene functions.

• Bryophytes
• evolution
• microsatellites
• mitochondrial genome

Acknowledgements

We sincerely thank Bernard Goffinet (University of Connecticut) and Laura L. Forrest (Royal Botanic Garden Edinburgh, UK) for suggestions and linguistic correction of this article.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

This research was financially supported by the National Natural Science Foundation of China (31170190 and 31370238) and “Project 211” for the East China Normal University. Y.L. is supported by NSF grant (DEB-1240045 to Bernard Goffinet; UCONN) for the postdoctoral position.