Phylogenetic relationships within the genus Tetrahymena inferred from the cytochrome c oxidase subunit 1 and the small subunit ribosomal RNA genes

Comparative analysis of the mitochondrial cytochromecoxidase subunit I (COI) gene in ciliates (Alveolata, Ciliophora) and evaluation of its suitability as a biodiversity marker

“…The phylogenetic relationships within Tetrahymena correspond to previous studies (Chantangsi et al, 2007;Chantangsi & Lynn, 2008). Based on the initial study of Lynn & Strüder-Kypke (2006) and on the comprehensive study of Chantangsi et al (2007), which both show less than 1% intraspecific divergence and an average of 10% divergence between species in Tetrahymena, we have determined the affiliation of three unknown isolates of Tetrahymena.…”

Tetrahymena in the Laboratory: Strain Resources, Methods for Culture, Maintenance, and Storage

“…Ribosomal RNA based phylogenies of various Tetrahymena species have been developed (Nanney et al, 1989; Preparata et al, 1989). In addition, phylogenetic relationships of many species have been analyzed by bar coding using the cytochrome c oxidase subunit 1 (COX1) (Kher et al, 2011), and the small subunit ribosomal RNA (SSrRNA) genes (Chantangsi et al, 2007; Chantangsi and Lynn, 2008). Phylogenetic relationships have also been examined using comparisons of telomerase RNA (Ye and Romero, 2002).…”

Intraspecific variability in several isolates of Philasterides dicentrarchi (syn. Miamiensis avidus), a scuticociliate parasite of farmed turbot

“…When assessing intraspecific genetic variation, it is important to establish appropriate markers for the organisms under investigation (Gentekaki and Lynn, 2009). For ciliates, nuclear markers such as ITS1, ITS2, and the hypervariable regions of the LSU rRNA are the most commonly used; however, mitochondrial DNA has only rarely been applied as a genetic marker in ciliates (Chantangsi and Lynn, 2008;Barth et al, 2006Barth et al, , 2008Gentekaki and Lynn, 2009;Segade et al, 2009), and ␣-and ␤-tubulin genes have occasionally been used to clarify the phylogenetic position and epigenetic phenomena in ciliates (Fast et al, 2002;Nishi et al, 2005;Robinson and Katz, 2007). In order to identify a variable genetic marker for intraspecific relationships in the P. dicentrarchi isolates, in the present study, PCR primers were developed for the nuclear genes 18S rDNA and ␤-tubulin, and for the mitochondrial Cox1 gene of this scuticociliate.…”

“…Recent research has shown that the 18S rRNA gene is not suitable as a marker for intraspecific variation in ciliates because of its limited variability at this level (Stoeck et al, 2000;Schmidt et al, 2006, Barth et al, 2008. In ciliates the high variation in the Cox1 gene is well known and has been used to study the intraspecific genetic variation in several species of ciliates (Barth et al, 2006;Chantangsi and Lynn, 2008;Gentekaki and Lynn, 2009). However, to date, sequences of other genes such as ␤-tubulin have not been used to study the intraspecific variation in ciliates, but have proven useful for analyzing the intraspecific genetic diversity among several strains of protozoa (Mendoza-León et al, 1995;Chung et al, 2000;Cruz et al, 2006).…”

“…Studies of the intraspecific genetic diversity of ciliates are hampered by the lack of suitable DNA markers (Gentekaki and Lynn, 2009). DNA sequencing of the small subunit of ribosomal RNA (SSUrRNA) and mitochondrial cytochrome oxidase subunit 1 (Cox1) gene has recently been applied to the identification of P. dicentrachi infections (Jung et al, 2005;Rossteuscher et al, 2008), to investigate phylogenetic relations between P.dicentrarchi and other members of the order Philasterida (Paramá et al, 2006;Miao et al, 2008), or within other genera of ciliate parasites (Chantangsi and Lynn, 2008), and used to investigate intraspecific genetic variations in ciliate strains (Barth et al, 2006). Several authors have demonstrated that the polymorphism of the coding region of the ␤-tubulin gene can be used as a molecular marker for identification at the species level (Luis et al, 1998;Yli-Mattila et al, 2004;Belbahri et al, 2008).…”