Identification, genetic variation, and structural analysis of 18S rRNA of Theileria orientalis and Theileria velifera-like isolates from Myanmar

• Published in: Parasitology international Vol. 82; p. 102299
• Main Authors: Bawm, Saw, Sagara, Rumi, Kakisaka, Keita, Thu, May June, Hmoon, Myint Myint, Htun, Lat Lat, Win, Mar Mar, Nonaka, Nariaki, Nakao, Ryo, Suzuki, Hitoshi, Katakura, Ken
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-06-2021
• Subjects: 18S rRNA; Genetic variation; Myanmar; Secondary structure; Theileria orientalis; Theileria velifera; Myanmar; Theileria velifera; Secondary structure; Genetic variation; 18S rRNA; Theileria orientalis
• DOI: 10.1016/j.parint.2021.102299
• EISSN: 1873-0329
• ISSN: 1383-5769

Ribosomal RNA genes have been widely used for the identification and phylogenetic analysis of various organisms, including parasitic protozoa. Here, we report nine near full-length Theileria orientalis 18S rRNA gene sequences from cattle from different areas of Myanmar. Phylogenetic analysis of the 18S rRNA genes revealed a considerably close genetic relationship among T. orientalis isolates from Australia, China, Japan, Korea, Myanmar, and Pakistan. We also obtained four Theileria velifera-like (Theileria cf. velifera) 18S rRNA gene sequences from two cattle and two water buffaloes from the northernmost area of Myanmar. The phylogenetic analysis of T. cf. velifera isolates from Myanmar along with T. velifera and T. cf. velifera isolates from African countries suggested an evolutionary lineage of greater complexity in T. velifera-related parasites. DNA alignment analysis indicated the presence of 51 and 55 nucleotide variation positions within the 18S rRNA genes from 15 T. orientalis and 11 T. velifera-related isolates, respectively. Alignment entropy analysis of the 18S rRNA sequences indicated that both T. orientalis and T. velifera-related isolates had three hyper variable regions, corresponding to V2, V4, and V7 regions in eukaryotes. The degree of variation was prominent in the V2 in T. orientalis and V4 in T. velifera-related isolates. The secondary structure analysis of the 18S rRNA predicted using minimum free energy algorism revealed that the structure of V4 region differed most significantly between T. orientalis and T. velifera. These results provide novel insights into common structures, variations and functions of small subunit rRNA in Theileria species.
Phylogenetic analysis and nucleotide variable positions in the predicted secondary structure of 18S rRNA sequences of Theileria orientalis and Theileria velifera isolates. [Display omitted]
•Molecular detection of Theileria velifera-like isolates from cattle and buffaloes in Myanmar.•Monophyletic lineage of T. orientalis parasites among Asian countries.•Greater complexity in evolutionary lineage of T. velifera-related parasites.•Comparison of 18S rRNA secondary structures between T. orientalis and T. velifera.•Analysis of variable regions in 18S rRNA of T. orientalis and T. velifera.