Genotypic diversity and differentiation among populations of two benthic freshwater diatoms as revealed by microsatellites.
Mol Ecol
; 24(17): 4433-48, 2015 Sep.
Article
em En
| MEDLINE
| ID: mdl-26227512
ABSTRACT
Given their large population sizes and presumed high dispersal capacity, protists are expected to exhibit homogeneous population structure over large spatial scales. On the other hand, the fragmented and short-lived nature of the lentic freshwater habitats that many protists inhabit promotes strong population differentiation. We used microsatellites in two benthic freshwater diatoms, Eunotia bilunaris 'robust' and Sellaphora capitata, sampled from within a pond and connected ponds, through isolated ponds from the same region to western Europe to determine the spatial scale at which differentiation appears. Because periods of low genotypic diversity contribute to population differentiation, we also assessed genotypic diversity. While genotypic diversity was very high to maximal in most samples of both species, some had a markedly lower diversity, with up to half (Eunotia) and over 90% (Sellaphora) of the strains having the same multilocus genotype. Population differentiation showed an isolation-by-distance pattern with very low standardized FST values between samples from the same or connected ponds but high values between isolated ponds, even when situated in the same region. Partial rbcL sequences in Eunotia were consistent with this pattern as isolated ponds in the same region could differ widely in haplotype composition. Populations identified by Structure corresponded to the source ponds, confirming that 'pond' is the main factor structuring these populations. We conclude that freshwater benthic diatom populations are highly fragmented on a regional scale, reflecting either less dispersal than is often assumed or reduced establishment success of immigrants, so that dispersal does not translate into gene flow.
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Texto completo:
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Variação Genética
/
Diatomáceas
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Genética Populacional
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Genótipo
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Europa
Idioma:
En
Revista:
Mol Ecol
Assunto da revista:
BIOLOGIA MOLECULAR
/
SAUDE AMBIENTAL
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Bélgica