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Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments

BACKGROUND: Dispersal ability, population genetic structure and species divergence in marine nematodes are still poorly understood, especially in remote areas such as the Southern Ocean. We investigated genetic differentiation of species and populations of the free-living endobenthic nematode genera...

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Autores principales: Hauquier, Freija, Leliaert, Frederik, Rigaux, Annelien, Derycke, Sofie, Vanreusel, Ann
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5450352/
https://www.ncbi.nlm.nih.gov/pubmed/28558672
http://dx.doi.org/10.1186/s12862-017-0968-1
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author Hauquier, Freija
Leliaert, Frederik
Rigaux, Annelien
Derycke, Sofie
Vanreusel, Ann
author_facet Hauquier, Freija
Leliaert, Frederik
Rigaux, Annelien
Derycke, Sofie
Vanreusel, Ann
author_sort Hauquier, Freija
collection PubMed
description BACKGROUND: Dispersal ability, population genetic structure and species divergence in marine nematodes are still poorly understood, especially in remote areas such as the Southern Ocean. We investigated genetic differentiation of species and populations of the free-living endobenthic nematode genera Sabatieria and Desmodora using nuclear 18S rDNA, internal transcribed spacer (ITS) rDNA, and mitochondrial cytochrome oxidase I (COI) gene sequences. Specimens were collected at continental shelf depths (200–500 m) near the Antarctic Peninsula, Scotia Arc and eastern side of the Weddell Sea. The two nematode genera co-occurred at all sampled locations, but with different vertical distribution in the sediment. A combination of phylogenetic (GMYC, Bayesian Inference, Maximum Likelihood) and population genetic (AMOVA) analyses were used for species delimitation and assessment of gene flow between sampling locations. RESULTS: Sequence analyses resulted in the delimitation of four divergent species lineages in Sabatieria, two of which could not be discriminated morphologically and most likely constitute cryptic species. Two species were recognised in Desmodora, one of which showed large intraspecific morphological variation. Both genera comprised species that were restricted to one side of the Weddell Sea and species that were widely spread across it. Population genetic structuring was highly significant and more pronounced in the deeper sediment-dwelling Sabatieria species, which are generally less prone to resuspension and passive dispersal in the water column than surface Desmodora species. CONCLUSIONS: Our results indicate that gene flow is restricted at large geographic distance in the Southern Ocean, which casts doubt on the efficiency of the Weddell gyre and Antarctic Circumpolar Current in facilitating circum-Antarctic nematode species distributions. We also show that genetic structuring and cryptic speciation can be very different in nematode species isolated from the same geographic area, but with different habitat preferences (surface versus deeper sediment layers). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-017-0968-1) contains supplementary material, which is available to authorized users.
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spelling pubmed-54503522017-06-01 Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments Hauquier, Freija Leliaert, Frederik Rigaux, Annelien Derycke, Sofie Vanreusel, Ann BMC Evol Biol Research Article BACKGROUND: Dispersal ability, population genetic structure and species divergence in marine nematodes are still poorly understood, especially in remote areas such as the Southern Ocean. We investigated genetic differentiation of species and populations of the free-living endobenthic nematode genera Sabatieria and Desmodora using nuclear 18S rDNA, internal transcribed spacer (ITS) rDNA, and mitochondrial cytochrome oxidase I (COI) gene sequences. Specimens were collected at continental shelf depths (200–500 m) near the Antarctic Peninsula, Scotia Arc and eastern side of the Weddell Sea. The two nematode genera co-occurred at all sampled locations, but with different vertical distribution in the sediment. A combination of phylogenetic (GMYC, Bayesian Inference, Maximum Likelihood) and population genetic (AMOVA) analyses were used for species delimitation and assessment of gene flow between sampling locations. RESULTS: Sequence analyses resulted in the delimitation of four divergent species lineages in Sabatieria, two of which could not be discriminated morphologically and most likely constitute cryptic species. Two species were recognised in Desmodora, one of which showed large intraspecific morphological variation. Both genera comprised species that were restricted to one side of the Weddell Sea and species that were widely spread across it. Population genetic structuring was highly significant and more pronounced in the deeper sediment-dwelling Sabatieria species, which are generally less prone to resuspension and passive dispersal in the water column than surface Desmodora species. CONCLUSIONS: Our results indicate that gene flow is restricted at large geographic distance in the Southern Ocean, which casts doubt on the efficiency of the Weddell gyre and Antarctic Circumpolar Current in facilitating circum-Antarctic nematode species distributions. We also show that genetic structuring and cryptic speciation can be very different in nematode species isolated from the same geographic area, but with different habitat preferences (surface versus deeper sediment layers). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12862-017-0968-1) contains supplementary material, which is available to authorized users. BioMed Central 2017-05-30 /pmc/articles/PMC5450352/ /pubmed/28558672 http://dx.doi.org/10.1186/s12862-017-0968-1 Text en © The Author(s). 2017 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research Article
Hauquier, Freija
Leliaert, Frederik
Rigaux, Annelien
Derycke, Sofie
Vanreusel, Ann
Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title_full Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title_fullStr Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title_full_unstemmed Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title_short Distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in Antarctic sediments
title_sort distinct genetic differentiation and species diversification within two marine nematodes with different habitat preference in antarctic sediments
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5450352/
https://www.ncbi.nlm.nih.gov/pubmed/28558672
http://dx.doi.org/10.1186/s12862-017-0968-1
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