Phylogenetic Position of the Giant Anuran Trypanosomes Trypanosoma chattoni, Trypanosoma fallisi, Trypanosoma mega, Trypanosoma neveulemairei, and Trypanosoma ranarum Inferred from 18S rRNA Gene Sequences

2002 ◽  
Vol 88 (3) ◽  
pp. 566 ◽  
Author(s):  
Donald S. Martin ◽  
Andre-Denis G. Wright ◽  
John R. Barta ◽  
Sherwin S. Desser
Keyword(s):  
18S Rrna ◽  
18S Rrna Gene ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Gene Sequences

Effect of Cell Culture on 18S rRNA Gene Sequences in the Cultural Course of Taxus chinensis Cells

2008 ◽  
Vol 63 (1-2) ◽  
pp. 127-132
Author(s):  
Fu Xiang ◽  
Long J. Yu ◽  
Wu Chen ◽  
Zhi Liu
Keyword(s):  
Cell Culture ◽  
Phylogenetic Analysis ◽  
18S Rrna ◽  
Relative Rate ◽  
18S Rrna Gene ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Taxus Chinensis ◽  
Gene Sequences ◽  
Parsimony Method

Cell culture is an effective technology for taxol production. This paper discusses the effect of Taxus cell cultures on the 18S rRNA gene sequences based on the phylogenetic analysis of cultured T. chinensis cells and related species. The phylogenetic tree is reconstructed using the maximum parsimony method and the relative rate test to test the hypothesis of a molecular clock. The phylogenetic analysis indicates that cell culture changes the phylogenetic position of cultured T. chinensis cells. More than that, the 18S rRNA gene of cultured T. chinensis cells has a faster rate of substitution than that of T. chinensis. With T. media as reference, the divergence time of the cultured T. chinensis cells is 7 Ma (million years) more than that of the T. chinensis cells based on the 18S rRNA gene sequences.

18S rRNA Gene Sequences and Supraordinal Classification of the Erysiphales

Mycologia ◽  
1994 ◽  
Vol 86 (2) ◽  
pp. 212 ◽  
Author(s):  
Gregory S. Saenz ◽  
John W. Taylor ◽  
Andrea Gargas
Keyword(s):  
18S Rrna ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Gene Sequences

scholarly journals Revealing the Composition of the Eukaryotic Microbiome of Oyster Spat by CRISPR-Cas Selective Amplicon Sequencing (CCSAS)

2021 ◽  
Author(s):  
Kevin Xu Zhong ◽  
Anna Cho ◽  
Christophe M. Deeg ◽  
Amy M. Chan ◽  
Curtis A. Suttle
Keyword(s):  
18S Rrna ◽  
Amplicon Sequencing ◽  
18S Rrna Gene ◽  
Model Organisms ◽  
Rrna Gene ◽  
Gene Sequences ◽  
Oyster Spat ◽  
Guide Rna ◽  
16S Rna ◽  
Eukaryotic Microbes

Abstract BackgroundThe microbiome affects the health of plants and animals, including humans, and has many biological, ecological and evolutionary consequences. Microbiome studies typically rely on sequencing ribosomal 16S RNA gene fragments, which serve as taxonomic markers for prokaryotic communities; however, for eukaryotic microbes this approach is compromised, because 18S rRNA gene sequences from microbial eukaryotes are swamped by contaminating host rRNA gene sequences. ResultsTo overcome this problem, we developed CRISPR-Cas Selective Amplicon Sequencing (CCSAS), a high-resolution and efficient approach for characterizing eukaryotic microbiomes. CCSAS uses taxon-specific single-guide RNA (sgRNA) to direct Cas9 to cut 18S rRNA gene sequences of the host, while leaving protistan and fungal sequences intact. We validated the specificity of the sgRNA on ten model organisms and an artificially constructed (mock) community of nine protistan and fungal pathogens. The results showed that >96.5% of host rRNA gene amplicons were cleaved, while 18S rRNA gene sequences from protists and fungi were unaffected. When used to assess the eukaryotic microbiome of oyster spat from a hatchery, CCSAS revealed a diverse community of eukaryotic microbes, typically with much less contamination from oyster 18S rRNA gene sequences than other methods using non-metazoan or blocking primers. However, each method revealed taxonomic groups that were not detected using the other methods, showing that a single approach is unlikely to uncover the entire eukaryotic microbiome in complex communities. To facilitate the application of CCSAS, we designed taxon-specific sgRNA for ~16,000 metazoan and plant taxa, making CCSAS widely available for characterizing eukaryotic microbiomes that have largely been neglected. ConclusionCCSAS provides a high-through-put and cost-effective approach for resolving the eukaryotic microbiome of metazoa and plants with minimal contamination from host 18S rRNA gene sequences. Keywords: Eukaryotic microbiome, 18S rRNA gene, Microeukaryote, CRISPR-Cas, Taxon-specific single-guide RNA, gRNA-target-site, CasOligo, CCSAS

scholarly journals A phylogenetic framework for the kingdom Fungi based on 18S rRNA gene sequences

2017 ◽  
Vol 36 ◽  
pp. 33-39 ◽  
Author(s):  
Pablo Yarza ◽  
Pelin Yilmaz ◽  
Katrin Panzer ◽  
Frank Oliver Glöckner ◽  
Marlis Reich
Keyword(s):  
18S Rrna ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
Gene Sequences ◽  
Phylogenetic Framework
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