Decoding cyanobacterial phylogeny and molecular evolution using an evonumeric approach
- 423 Downloads
Forty-one heterocystous cyanobacteria strains representing 12 cyanobacterial genera collected from all across India were assessed in phylogenetic and evolutionary perspectives. The structural gene 16S ribosomal RNA (rRNA) and the functional genes nifD and psbA were selected as molecular chronometers in this study. The phylogenetic analyses demonstrated the monophyly of heterocystous cyanobacteria with significant intermixing, along with establishing the polyphyly of Stigonematales, strongly supporting the need for re-amendments in cyanobacterial taxonomy and systematics. Molecular trends obtained did not clearly reflect the phenotypic affiliations, thus advocating for genetic characterizations using more molecular markers. Large-scale evonumeric extrapolations of gene sequence data of all the three molecular markers was performed to assess the evolutionary pace of heterocystous cyanobacteria on the basis of nucleotide diversity, recombination frequencies, and the DNA divergence between the sampled taxa. The obtained results tilted the evolutionary pace in favor of the less complex Nostocales thus indicating that possibly the simple non-branched forms are more flexible and adaptive for evolutionary diversifications as compared to the more complex and branched ones. This study hence represents a unique blend of molecular phylogeny with evogenomic sequence analyses for understanding the genetic diversity, phylogeny, and evolutionary pace within the heterocystous cyanobacteria.
KeywordsPhylogeny Heterocystous cyanobacteria Evolutionary pace Evonumeric approach Evonumeric simulation
We are thankful to the CSIR, DST, and UGC, New Delhi, for providing financial support in the form of project. Prashant Singh is also thankful to CSIR, New Delhi, for their financial support in the form of SRF. The Head, Department of Botany, Banaras Hindu University, Varanasi, India, is gratefully acknowledged for providing laboratory facilities.
Conflict of interest
The authors declare that they have no conflict of interest.
- Desikachary TV (1959) Cyanophyta, part I and II. Indian Council of Agricultural Research, New DelhiGoogle Scholar
- Druga B, Weker M, Sesarman A, Hegedus A, Coma C, Sicora C, Dragos N (2013) Molecular characterization of microcystin-producing cyanobacteria from Romanian fresh waters. Eur J Phycol 48:287–294Google Scholar
- Kenyon CK (2003) Phylogenetic analysis of the heterocystous cyanobacteria as assessed by 16S and 23S rRNA. Thesis submitted to the Miami University, Oxford. pp 1–51Google Scholar
- Komárek J, Anagnostidis K (1989) Modern approach to the classification system of cyanophytes for Nostocales. Arch Hydrobiol Suppl 82:247–345Google Scholar
- Litvaitis MK (2002) A molecular test of cyanobacterial phylogeny: inferences from constraint analyses. Hydrobiologia 468:135–145Google Scholar
- Mollenhauer D (1988) Nostoc species in the field. Arch Hydrobiol Suppl 80:315–326Google Scholar
- Nei M, Kumar S (2000) Molecular evolution and phylogenetics. Oxford University Press, New YorkGoogle Scholar
- Rzhetsky A, Nei M (1992) A simple method for estimating and testing minimum evolution trees. Mol Biol Evol 9:945–967Google Scholar
- Stuken A, Rucker J, Endrulat T, Preussel K, Hemm M, Nixdorf B, Karsten U, Wiedner C (2006) Distribution of three alien cyanobacterial species (Nostocales) in northeast Germany Cylindrospermopsis raciborskii, Anabaena bergii and Aphanizomenon aphanizomenoides. Phycologia 45:696–703CrossRefGoogle Scholar
- Woese CR (1987) Bacterial evolution. Microbial Rev 51:221–271Google Scholar