These authors contributed equally to this work.
DNA BARCODING OF CHLORARACHNIOPHYTES USING NUCLEOMORPH ITS SEQUENCES1
Article first published online: 17 JUN 2010
© 2010 Phycological Society of America
Journal of Phycology
Volume 46, Issue 4, pages 743–750, August 2010
How to Cite
Gile, G. H., Stern, R. F., James, E. R. and Keeling, P. J. (2010), DNA BARCODING OF CHLORARACHNIOPHYTES USING NUCLEOMORPH ITS SEQUENCES. Journal of Phycology, 46: 743–750. doi: 10.1111/j.1529-8817.2010.00851.x
Received 15 May 2009. Accepted 28 April 2010.
- Issue published online: 2 AUG 2010
- Article first published online: 17 JUN 2010
- culture collections;
- internal transcribed spacer;
Chlorarachniophytes are a small group of marine photosynthetic protists. They are best known as examples of an intermediate stage of secondary endosymbiosis: their plastids are derived from green algae and retain a highly reduced nucleus, called a nucleomorph, between the inner and outer pairs of membranes. Chlorarachniophytes can be challenging to identify to the species level, due to their small size, complex life cycles, and the fact that even genus-level diagnostic morphological characters are observable only by EM. Few species have been formally described, and many available culture collection strains remain unnamed. To alleviate this difficulty, we have developed a barcoding system for rapid and accurate identification of chlorarachniophyte species in culture, based on the internal transcribed spacer (ITS) region of the nucleomorph rRNA cistron. Although this is a multicopy locus, encoded in both subtelomeric regions of each chromosome, interlocus variability is low due to gene conversion by homologous recombination in this region. Here, we present barcode sequences for 39 cultured strains of chlorarachniophytes (>80% of currently available strains). Based on barcode data, other published molecular data, and information from culture records, we were able to recommend names for 21 out of the 24 unidentified, partially identified, or misidentified chlorarachniophyte strains in culture. Most strains could be assigned to previously described species, but at least two to as many as five new species may be present among cultured strains.