Evolution of group I introns in Porifera: new evidence for intron mobility and implications for DNA barcoding

BMC Evolutionary Biology

Research Article

Astrid Schuster¹  Dirk Erpenbeck²  Gert Wörheide³  Paco Cárdenas⁴  Jose V. Lopez⁵  Shirley A. Pomponi⁶  Leontine E. Becking⁷  Michelle Kelly⁸ 

[1] Department of Earth- & Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, Munich, Germany;Department of Earth- & Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, Munich, Germany;GeoBio-CenterLMU, Ludwig-Maximilians-Universität München, Richard-Wagner Str. 10, 80333, Munich, Germany;Department of Earth- & Environmental Sciences, Palaeontology and Geobiology, Ludwig-Maximilians-Universität München, Richard-Wagner-Str. 10, 80333, Munich, Germany;SNSB - Bavarian State Collections of Palaeontology and Geology, Richard-Wagner Str. 10, 80333, Munich, Germany;GeoBio-CenterLMU, Ludwig-Maximilians-Universität München, Richard-Wagner Str. 10, 80333, Munich, Germany;Department of Medicinal Chemistry, Division of Pharmacognosy, BioMedical Center, Uppsala University, Husargatan 3, 75123, Uppsala, Sweden;Halmos College of Natural Sciences and Oceanography, Nova Southeastern University, 33004, Dania Beach, FL, USA;Harbor Branch Oceanographic Institute-Florida Atlantic University, 5600 U.S. 1 North, 34946, Ft Pierce, FL, USA;Marine Animal Ecology, Wageningen University & Research Centre, P.O. Box 3700, AH, Wageningen, The Netherlands;Naturalis Biodiversity Center, Marine Zoology Department, PO Box 9517, RA, 2300, Leiden, The Netherlands;National Centre for Aquatic Biodiversity and Biosecurity, National Institute of Water and Atmospheric Research, P.O. Box 109–695, Newmarket, Auckland, New Zealand;

关键词: Porifera;    Tetractinellida;    cox1;    HGT;    VGT;    homing endonuclease gene (HEG);    LAGLIDADG;    group I intron;    DNA barcoding;   

DOI  :  10.1186/s12862-017-0928-9

 received in 2016-09-15, accepted in 2017-02-28,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundMitochondrial 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.ResultsFor 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.ConclusionThis 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.

【 授权许可】

CC BY   
© The Author(s). 2017