Skip to main content

IMIS

A new integrated search interface will become available in the next phase of marineinfo.org.
For the time being, please use IMIS to search available data

 

[ report an error in this record ]basket (0): add | show Print this page

Natural hybrids in Pseudo-nitzschia pungens: genetic and morphological evidence
Casteleyn, G. (2009). Natural hybrids in Pseudo-nitzschia pungens: genetic and morphological evidence, in: Casteleyn, G. Species structure and biogeography of Pseudo-nitzschia pungens = Soortstructuur en biogeografie van Pseudo-nitzschia pungens. pp. 65-84
In: Casteleyn, G. (2009). Species structure and biogeography of Pseudo-nitzschia pungens = Soortstructuur en biogeografie van Pseudo-nitzschia pungens. PhD Thesis. Universiteit Gent; Vakgroep Biologie, Onderzoeksgroep Protistologie en Aquatische Ecologie: Gent. 201 pp., more

Available in  Author 

Keywords
    Algae > Diatoms
    Pseudo-nitzschia pungens (Grunow ex Cleve) G.R.Hasle, 1993 [WoRMS]
    Marine/Coastal

Author  Top 

Abstract
    Hybridization between genetically distinguishable taxa provides opportunities for investigating speciation. While hybridization is a common phenomenon in various macro-organisms, natural hybridization among micro-eukaryotes is barely studied. Here we used a nuclear and a chloroplast molecular marker and morphology to demonstrate the presence of natural hybrids between two genetically and morphologically distinct varieties of the marine planktonic diatom Pseudo-nitzschia pungens (vars.pungen and cingulata) in a contact zone in the northeast Pacific. Cloning and sequencing of the rDNA internal transcribed spacer region revealed strains containing ribotypes from both varieties, indicating hybridization. Both varieties were found to also have different chloroplast-encoded rbcL sequences. Hybrid strains were either hetero- or homoplastidial, as demonstrated by denaturing gradient gel electrophoresis, which is in accordance with expectations based on the mode of chloroplast inheritance in Pseudo-nitzschia. While most hybrids are probably first generation, there are also indications for further hybridization. Morphologically, the hybrids resembled var. pungens for most characters rather than having an intermediate morphology. Further research should focus on the hybridization frequency, by assessing the spatial and temporal extent of the contact zone, and hybrid fitness, to determine the amount of gene flow between the two varieties and its evolutionary consequences.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Author