ธิติมา แผ่นยาใหญ่. Analysis of Oligonucleotide Triplets for Classification of Cyanobacteria. Master's Degree(Bioinformatics). King Mongkut's University of Technology Thonburi. KMUTT Library. : King Mongkut's University of Technology Thonburi, 2009.
Analysis of Oligonucleotide Triplets for Classification of Cyanobacteria
Abstract:
Cyanobacteria or blue-green algae have diverse morphology and habitats. The algae are
extensively used in products such as human health, animal feed, pharmaceuticals and
cosmetics due to the presence of high proportion of proteins, polysaccharides, vitamins
and essential fatty acids. In spite of their widely uses, their classification still poses
questions among researchers. Murata et al. (1992) proposed a new classification based
on the position and number of double bond in fatty acid produced by the bacteria. This
work attempted to investigate the relation between the patterns of the double bond and
the nucleotide patterns in 16s rRNA. Among the II organisms used in the study, 13
oligonucleotide triplets (31.7%) showed similar classification as Murata's. Anabaena
(group2) was, however, always clustered with Gloeobaeter violaeeus PCC 7421, which
contradicted to Murata's results. In another part of the work, the ratios of
oligonucleotide triplets among 4 genes (16s rRNA, epeA, epeB and desC) from four
cynobacteria species were calculated and used as similarity indices among the bacteria.
The results revealed that there were two types of useful oligonucleotide triplets: the first
type could divided the 4 groups of bacteria (based on Murata's results) equally into 2
sets, while the other type of oligonucleotide triplets separated one from the rest three
groups. Combination of two triplets from the first type or the first and the second type
could be used to divide the bacteria into 4 groups as Murata's classification.