Biology Faculty Articles
Document Type
Article
Publication Date
3-2017
Publication Title
BMC Evolutionary Biology
Keywords
Porifera, Tetractinellida, cox1, HGT, VGT, Homing endonuclease gene (HEG), LAGLIDADG, Group I intron, DNA barcoding
ISSN
1471-2148
Volume
17
Issue/No.
82
First Page
1
Last Page
21
Abstract
Background
Mitochondrial introns intermit coding regions of genes and feature characteristic secondary structures and splicing mechanisms. In metazoans, mitochondrial introns have only been detected in sponges, cnidarians, placozoans and one annelid species. Within demosponges, group I and group II introns are present in six families. Based on different insertion sites within the cox1 gene and secondary structures, four types of group I and two types of group II introns are known, which can harbor up to three encoding homing endonuclease genes (HEG) of the LAGLIDADG family (group I) and/or reverse transcriptase (group II). However, only little is known about sponge intron mobility, transmission, and origin due to the lack of a comprehensive dataset. We analyzed the largest dataset on sponge mitochondrial group I introns to date: 95 specimens, from 11 different sponge genera which provided novel insights into the evolution of group I introns.
Results
For the first time group I introns were detected in four genera of the sponge family Scleritodermidae (Scleritoderma, Microscleroderma, Aciculites, Setidium). We demonstrated that group I introns in sponges aggregate in the most conserved regions of cox1. We showed that co-occurrence of two introns in cox1 is unique among metazoans, but not uncommon in sponges. However, this combination always associates an active intron with a degenerating one. Earlier hypotheses of HGT were confirmed and for the first time VGT and secondary losses of introns conclusively demonstrated.
Conclusion
This study validates the subclass Spirophorina (Tetractinellida) as an intron hotspot in sponges. Our analyses confirm that most sponge group I introns probably originated from fungi. DNA barcoding is discussed and the application of alternative primers suggested.
Additional Comments
German Science Foundation grant #: DFG ER 611/3-1, DFG Wo896/15-1; Netherlands Organisation for Scientific Research VENI: 863.14.020
NSUWorks Citation
Schuster, Astrid; Jose V. Lopez; Leontine E. Becking; Michelle Kelly; Shirley A. Pomponi; Gert Wörheide; Dirk Erpenbeck; and Paco Cárdenas. 2017. "Evolution of Group I Introns in Porifera: New Evidence for Intron Mobility and Implications for DNA Barcoding." BMC Evolutionary Biology 17, (82): 1-21. doi:10.1186/s12862-017-0928-9.
ORCID ID
0000-0002-1637-4125
ResearcherID
F-8809-2011
DOI
10.1186/s12862-017-0928-9
Comments
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.