Two new species of Dulcicalothrix (Nostocales, Cyanobacteria) from India and erection of Brunnivagina gen. nov., with observations on the problem of using multiple ribosomal operons in cyanobacterial taxonomy.

Autor: Saraf A; Collection of Cyanobacteria, Institut Pasteur, Université Paris Cité, Paris, France.; Department of Biological Sciences, Ramniranjan Jhunjhunwala College of Arts, Science and Commerce, Mumbai, India., Singh P; Department of Botany, Banaras Hindu University, Varanasi, India., Kumar N; Department of Botany, Banaras Hindu University, Varanasi, India., Pal S; Department of Botany, Banaras Hindu University, Varanasi, India., Johansen JR; Department of Biology, John Carroll University, University Heights, Ohio, USA.; Department of Botany, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
Jazyk: angličtina
Zdroj: Journal of phycology [J Phycol] 2024 Oct; Vol. 60 (5), pp. 1139-1160. Date of Electronic Publication: 2024 Aug 08.
DOI: 10.1111/jpy.13488
Abstrakt: Two new species of Dulcicalothrix, D. adhikaryi sp. nov. and D. iyengarii sp. nov., were discovered in India and are characterized and described in accordance with the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN). As a result of phylogenetic analysis, Calothrix elsteri is reassigned to Brunnivagina gen. nov. During comparison with all Dulcicalothrix for which sequence data were available, we observed that the genus has six ribosomal operons in three orthologous types. Each of the three orthologs could be identified based upon indels occurring in the D1-D1' helix sequence in the ITS rRNA region between the 16S and 23S rRNA genes, and in these three types, there were operons containing ITS rRNA regions with and without tRNA genes. Examination of complete genomes in Dulcicalothrix revealed that, at least in the three strains for which complete genomes are available, there are five ribosomal operons, two with tRNA genes and three with no tRNA genes in the ITS rRNA region. Internal transcribed spacer rRNA regions have been consistently used to differentiate species, both on the basis of secondary structure and percent dissimilarity. Our findings call into question the use of ITS rRNA regions to differentiate species in the absence of efforts to obtain multiple operons of the ITS rRNA region through cloning or targeted PCR amplicons. The ITS rRNA region data for Dulcicalothrix is woefully incomplete, but we provide herein a means for dealing with incomplete data using the polyphasic approach to analyze diverse molecular character sets. Caution is urged in using ITS rRNA data, but a way forward through the complexity is also proposed.
(© 2024 The Author(s). Journal of Phycology published by Wiley Periodicals LLC on behalf of Phycological Society of America.)
Databáze: MEDLINE
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