Click
here to close Hello! We notice that
you are using Internet Explorer, which is not supported by Echinobase
and may cause the site to display incorrectly. We suggest using a
current version of Chrome,
FireFox,
or Safari.
PLoS One
2008 Jun 25;36:e2552. doi: 10.1371/journal.pone.0002552.
Show Gene links
Show Anatomy links
Inverse correlation of population similarity and introduction date for invasive ascidians.
Silva N
,
Smith WC
.
???displayArticle.abstract???
The genomes of many marine invertebrates, including the purple sea urchin and the solitary ascidians Ciona intestinalis and Ciona savignyi, show exceptionally high levels of heterozygosity, implying that these populations are highly polymorphic. Analysis of the C. savignyi genome found little evidence to support an elevated mutation rate, but rather points to a large population size contributing to the polymorphism level. In the present study, the relative genetic polymorphism levels in sampled populations of ten different ascidian species were determined using a similarity index generated by AFLP analysis. The goal was to determine the range of polymorphism within the populations of different species, and to uncover factors that may contribute to the high level of polymorphism. We observe that, surprisingly, the levels of polymorphism within these species show a negative correlation with the reported age of invasive populations, and that closely related species show substantially different levels of genetic polymorphism. These findings show exceptions to the assumptions that invasive species start with a low level of genetic polymorphism that increases over time and that closely related species have similar levels of genetic polymorphism.
???displayArticle.pubmedLink???
18575620
???displayArticle.pmcLink???PMC2430530 ???displayArticle.link???PLoS One ???displayArticle.grants???[+]
Figure 1. A map of the Southern California Bight modified from [9].The relative locations of the Santa Barbara Yacht Harbor and Ventura Harbor are shown.
Figure 2. Representative data as displayed by the Genographer program.A. Synthetic gels generated by AFLP for 4 different species from SBYH (C. savignyi, C. intestinalis, Styela plicata, and Botrylloides diegensis). A window with fragments in the range of 75 bp–150 bp is shown. B. Representative scoring of bands in a typical marker in Ciona savignyi (shown in yellow).
Figure 3. Graphical representation of ascidian genetic similarity.The top panel shows the percentage of the total markers for each population that are shared by indicated percent of the individuals sampled. The bottom panel shows the average number of bands per individual for the same data set and in the same species.
Figure 4. Representative resampling of similarity data for two ascidian species.For each species 5 replicates of data from 5, 10 and 40 randomly selected individuals were analyzed by the similarity matrix. The bars for the resampled data show the average of the 5 replicates (±standard deviation).
Figure 5. Plot shows the correlation between the date first reported and the calculated similarity level for the invasive ascidian species within the Southern California Bight.Surprisingly there was a negative correlation between date first recorded and estimated similarity level. It would be assumed that similarity would decrease as a population becomes more established, but this is not the case.
Bensch,
Ten years of AFLP in ecology and evolution: why so few animals?
2005, Pubmed
Bensch,
Ten years of AFLP in ecology and evolution: why so few animals?
2005,
Pubmed
Bonin,
Statistical analysis of amplified fragment length polymorphism data: a toolbox for molecular ecologists and evolutionists.
2007,
Pubmed
Bonin,
Use of amplified fragment length polymorphism (AFLP) markers in surveys of vertebrate diversity.
2005,
Pubmed
Dehal,
The draft genome of Ciona intestinalis: insights into chordate and vertebrate origins.
2002,
Pubmed
Elango,
Variable molecular clocks in hominoids.
2006,
Pubmed
Falush,
Inference of population structure using multilocus genotype data: dominant markers and null alleles.
2007,
Pubmed
Han,
Use of AFLP analyses to assess genetic variation in Morone and Thunnus species.
2002,
Pubmed
Innan,
A method for estimating nucleotide diversity from AFLP data.
1999,
Pubmed
Jiang,
Self- and cross-fertilization in the solitary ascidian Ciona savignyi.
2005,
Pubmed
Lambert,
THE EFFECT OF LIGHT ON THE SPAWNING OF CIONA INTESTINALIS.
1967,
Pubmed
Milkman,
GENETIC AND DEVELOPMENTAL STUDIES ON BOTRYLLUS SCHLOSSERI.
1967,
Pubmed
Small,
Extreme genomic variation in a natural population.
2007,
Pubmed
Sodergren,
The genome of the sea urchin Strongylocentrotus purpuratus.
2006,
Pubmed
,
Echinobase
Stachowicz,
Linking climate change and biological invasions: Ocean warming facilitates nonindigenous species invasions.
2002,
Pubmed
Turon,
Ascidian molecular phylogeny inferred from mtDNA data with emphasis on the Aplousobranchiata.
2004,
Pubmed
Vekemans,
Data from amplified fragment length polymorphism (AFLP) markers show indication of size homoplasy and of a relationship between degree of homoplasy and fragment size.
2002,
Pubmed
Vinson,
Assembly of polymorphic genomes: algorithms and application to Ciona savignyi.
2005,
Pubmed
Vos,
AFLP: a new technique for DNA fingerprinting.
1995,
Pubmed
