Discrimination of closely related species in tintinnid ciliates: New insights on crypticity and polymorphism in the genus helicostomella

This study focuses on the utility of molecular markers for the discrimination of closely related species in tintinnid ciliates. We analyzed the ecologically important genus Helicostomella by sequencing part of the large-subunit rDNA (LSU rDNA) and the 5.8S rDNA combined with the internally transcrib...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Santoferrara, Luciana F., Alder, Viviana A.
Publicado: 2015
Materias:
Closely related species
Cryptic species
DNA barcoding
Molecular markers
Polymorphic species
Tintinnid ciliate
Ciliophora
Helicostomella
Tintinnida
Tintinnopsis
protozoal DNA
ribosomal spacer DNA
ribosome DNA
ribosome RNA
RNA 5.8S
RNA, ribosomal, 26S
sea water
Atlantic Ocean
chemistry
ciliate
classification
cluster analysis
cytology
DNA sequence
genetic variability
genetics
microscopy
molecular genetics
parasitology
phylogeny
Cluster Analysis
DNA, Protozoan
DNA, Ribosomal
DNA, Ribosomal Spacer
Genetic Variation
Microscopy
Molecular Sequence Data
Phylogeny
RNA, Ribosomal
RNA, Ribosomal, 5.8S
Seawater
Sequence Analysis, DNA
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14344610_v166_n1_p78_Santoferrara
http://hdl.handle.net/20.500.12110/paper_14344610_v166_n1_p78_Santoferrara
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:This study focuses on the utility of molecular markers for the discrimination of closely related species in tintinnid ciliates. We analyzed the ecologically important genus Helicostomella by sequencing part of the large-subunit rDNA (LSU rDNA) and the 5.8S rDNA combined with the internally transcribed spacer regions 1 and 2 (5.8S rDNA-ITS) from forty-five individuals collected in NW and SW Atlantic waters and after culturing. Although all described Helicostomella species represent a continuum of morphologies, forms with shorter or longer loricae would correspond to different species according to previous molecular data. Here we observed that long forms show both crypticity (i.e. two almost identical long forms with different DNA sequences) and polymorphism (i.e. some long forms develop significantly shorter loricae after culturing). Reviewing all available tintinnid sequences, we found that 1) three Helicostomella clusters are consistent with different species from a molecular perspective, although these clusters are neither clearly differentiated by their loricae nor unambiguously linked to described species, 2) Helicostomella is closely related (probably to the family or genus level) to four ". Tintinnopsis-like" morphospecies, and 3) if considered separately, neither LSU rDNA nor 5.8S rDNA-ITS completely discriminate closely related species, thus supporting the use of multi-gene barcodes for tintinnids. © 2014 Elsevier GmbH.

Ejemplares similares