TITLE:
Antarctic Cyanobacteria Biodiversity Based on ITS and TrnL Sequencing and Its Ecological Implication
AUTHORS:
Carla Micheli, Rossella Cianchi, Raffaella Paperi, Alessandro Belmonte, Benjamin Pushparaj
KEYWORDS:
Antarctic Cyanobacteria, Biodiversity, ITS, tRNALeu UAA, Secondary Structure
JOURNAL NAME:
Open Journal of Ecology,
Vol.4 No.8,
May
30,
2014
ABSTRACT: Antarctic
cyanobacteria biodiversity was investigated by simultaneous sequencing of the nuclear ribosomal internal transcribed spacer (ITS flanked by partial 16S and 23S), and Chloroplast tRNALeu UAA intron (TrnL),
exploring whether such morphotypes constitute distinct species and explaining
their current distribution. We identified Nostocales, Chrococcales and Oscillatoriales species, collected in different habitats (soil, algal
mats, lake sediments, ice-water) after their growth in cultures. By comparative sequence
analyses available in Genbank, our results proved to be mostly in agreement
with both TrnL and ITS, in the identification of the strains,
particularly for Nostocales. Although
ITS demonstrated more usefully than TrnL
did in identifying Oscillatoriales and Chroococcales, due to the
frequent lack of the intron in these groups, our results lead us to support an
independent phylogenetic dataset of ITS and TrnL (the latter based on
conserved regions) producing not only concordant clusters but also a secondary
structure. Specific assignments of the secondary structure evidenced by different cyanobacteria groups,
especially the D1-D1’ region of ITS and the P6b region of TrnL. For the latter region, the sequences analyzed for Nostoc species could be divided into the two classes previously
identified, on the basis of different heptanucleotide repeats in P6b which were
not foun