Variability in Secondary Structure of 18S Ribosomal RNA as Topological Marker for Identification of Paramecium species

Journal Article

Shakoori, Farah R. Shakoori,1 Fareeda Tasneem,1 K. Al-Ghanim,2 S. Mahboob,2 F. Al-Misned,2 Nusrat Jahan,3 and Abdul Rauf . 2014

• نوع عمل المنشور: RIBOTYPING; SSrRNA; SECONDARY STRUCTURE OF 18SrRNA; Paramecium spp; PHYLOGENETIC RELATIONSHIP OF CILIATES
• رابط المنشور على الويب: Journal of Cellular Biochemistry
• الوسوم: RIBOTYPING; SSrRNA; SECONDARY STRUCTURE OF 18SrRNA; Paramecium spp; PHYLOGENETIC RELATIONSHIP OF CIL
• المجلة \ الصحيفة: Journal of Cellular Biochemistry
• رقم العدد: 12
• رقم الإصدار السنوي: 115
• الصفحات: 2077–2088

مستخلص المنشور

Besides cytological and molecular applications, Paramecium is being used in water quality assessment and for determination of saprobic
levels. An unambiguous identification of these unicellular eukaryotes is not only essential, but its ecological diversity must also be explored in
the local environment. 18SrRNA genes of all the strains of Paramecium species isolated from waste water were amplified, cloned and
sequenced. Phylogenetic comparison of the nucleotide sequences of these strains with 23 closely related Paramecium species from GenBank
Database enabled identification of Paramecium multimicronucleatum and Paramecium jenningsi. Some isolates did not show significant close
association with other Paramecium species, and because of their unique position in the phylogenetic tree, they were considered new to the
field. In the present report, these isolates are being designated as Paramecium caudatum pakistanicus. In this article, secondary structure of
18SrRNA has also been analyzed as an additional and perhaps more reliable topological marker for species discrimination and for determining
possible phylogenetic relationship between the ciliate species. On the basis of comparison of secondary structure of 18SrRNA of various
isolated Paramacium strains, and among Paramecium caudatum pakistanicus, Tetrahymena thermophila, Drosophila melanogaster, and
Homo sapiens, it can be deduced that variable regions are more helpful in differentiating the species at interspecific level rather than at
intraspecific level. It was concluded that V3 was the least variable region in all the organisms, V2 and V7 were the longest expansion segments
of D. melanogaster and there was continuous mutational bias towards G.C base pairing in H. sapiens. J. Cell. Biochem. 115: 2077–2088,
2014. © 2014 Wiley Periodicals, Inc.