Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it>
<p>Abstract</p> <p>Background</p> <p>Comparative phylogeography recently performed on the mitochondrial <it>cytochrome oxidase I </it>(<it>mtCOI</it>) gene from seven deep-sea vent species suggested that the East Pacific Rise fauna has undergone...
Main Authors: | , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
BMC
2010-07-01
|
Series: | BMC Evolutionary Biology |
Online Access: | http://www.biomedcentral.com/1471-2148/10/220 |
id |
doaj-9bfa970fa7874b10abdfb09b9e531418 |
---|---|
record_format |
Article |
spelling |
doaj-9bfa970fa7874b10abdfb09b9e5314182021-09-02T07:57:57ZengBMCBMC Evolutionary Biology1471-21482010-07-0110122010.1186/1471-2148-10-220Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it>Plouviez SophieLe Guen DominiqueLecompte OdileLallier François HJollivet Didier<p>Abstract</p> <p>Background</p> <p>Comparative phylogeography recently performed on the mitochondrial <it>cytochrome oxidase I </it>(<it>mtCOI</it>) gene from seven deep-sea vent species suggested that the East Pacific Rise fauna has undergone a vicariant event with the emergence of a north/south physical barrier at the Equator 1-2 Mya. Within this specialised fauna, the tube-dwelling polychaete <it>Alvinella pompejana </it>showed reciprocal monophyly at <it>mtCOI </it>on each side of the Equator (9°50'N/7°25'S), suggesting potential, ongoing allopatric speciation. However, the development of a barrier to gene flow is a long and complex process. Secondary contact between previously isolated populations can occur when physical isolation has not persisted long enough to result in reproductive isolation between genetically divergent lineages, potentially leading to hybridisation and subsequent allelic introgression. The present study evaluates the strength of the equatorial barrier to gene flow and tests for potential secondary contact zones between <it>A. pompejana </it>populations by comparing the <it>mtCOI </it>gene with nuclear genes.</p> <p>Results</p> <p>Allozyme frequencies and the analysis of nucleotide polymorphisms at three nuclear loci confirmed the north/south genetic differentiation of <it>Alvinella pompejana </it>populations along the East Pacific Rise. Migration was oriented north-to-south with a moderate allelic introgression between the two geographic groups over a narrow geographic range just south of the barrier. Multilocus analysis also indicated that southern populations have undergone demographic expansion as previously suggested by a multispecies approach. A strong shift in allozyme frequencies together with a high level of divergence between alleles and a low number of 'hybrid' individuals were observed between the northern and southern groups using the <it>phosphoglucomutase </it>gene. In contrast, the <it>S-adenosylhomocysteine hydrolase </it>gene exhibited reduced diversity and a lack of population differentiation possibly due to a selective sweep or hitch-hiking.</p> <p>Conclusions</p> <p>The equatorial barrier leading to the separation of East Pacific Rise vent fauna into two distinct geographic groups is still permeable to migration, with a probable north-to-south migration route for <it>A. pompejana</it>. This separation also coincides with demographic expansion in the southern East Pacific Rise. Our results suggest that allopatry resulting from ridge offsetting is a common mechanism of speciation for deep-sea hydrothermal vent organisms.</p> http://www.biomedcentral.com/1471-2148/10/220 |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Plouviez Sophie Le Guen Dominique Lecompte Odile Lallier François H Jollivet Didier |
spellingShingle |
Plouviez Sophie Le Guen Dominique Lecompte Odile Lallier François H Jollivet Didier Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> BMC Evolutionary Biology |
author_facet |
Plouviez Sophie Le Guen Dominique Lecompte Odile Lallier François H Jollivet Didier |
author_sort |
Plouviez Sophie |
title |
Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> |
title_short |
Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> |
title_full |
Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> |
title_fullStr |
Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> |
title_full_unstemmed |
Determining gene flow and the influence of selection across the equatorial barrier of the East Pacific Rise in the tube-dwelling polychaete <it>Alvinella pompejana</it> |
title_sort |
determining gene flow and the influence of selection across the equatorial barrier of the east pacific rise in the tube-dwelling polychaete <it>alvinella pompejana</it> |
publisher |
BMC |
series |
BMC Evolutionary Biology |
issn |
1471-2148 |
publishDate |
2010-07-01 |
description |
<p>Abstract</p> <p>Background</p> <p>Comparative phylogeography recently performed on the mitochondrial <it>cytochrome oxidase I </it>(<it>mtCOI</it>) gene from seven deep-sea vent species suggested that the East Pacific Rise fauna has undergone a vicariant event with the emergence of a north/south physical barrier at the Equator 1-2 Mya. Within this specialised fauna, the tube-dwelling polychaete <it>Alvinella pompejana </it>showed reciprocal monophyly at <it>mtCOI </it>on each side of the Equator (9°50'N/7°25'S), suggesting potential, ongoing allopatric speciation. However, the development of a barrier to gene flow is a long and complex process. Secondary contact between previously isolated populations can occur when physical isolation has not persisted long enough to result in reproductive isolation between genetically divergent lineages, potentially leading to hybridisation and subsequent allelic introgression. The present study evaluates the strength of the equatorial barrier to gene flow and tests for potential secondary contact zones between <it>A. pompejana </it>populations by comparing the <it>mtCOI </it>gene with nuclear genes.</p> <p>Results</p> <p>Allozyme frequencies and the analysis of nucleotide polymorphisms at three nuclear loci confirmed the north/south genetic differentiation of <it>Alvinella pompejana </it>populations along the East Pacific Rise. Migration was oriented north-to-south with a moderate allelic introgression between the two geographic groups over a narrow geographic range just south of the barrier. Multilocus analysis also indicated that southern populations have undergone demographic expansion as previously suggested by a multispecies approach. A strong shift in allozyme frequencies together with a high level of divergence between alleles and a low number of 'hybrid' individuals were observed between the northern and southern groups using the <it>phosphoglucomutase </it>gene. In contrast, the <it>S-adenosylhomocysteine hydrolase </it>gene exhibited reduced diversity and a lack of population differentiation possibly due to a selective sweep or hitch-hiking.</p> <p>Conclusions</p> <p>The equatorial barrier leading to the separation of East Pacific Rise vent fauna into two distinct geographic groups is still permeable to migration, with a probable north-to-south migration route for <it>A. pompejana</it>. This separation also coincides with demographic expansion in the southern East Pacific Rise. Our results suggest that allopatry resulting from ridge offsetting is a common mechanism of speciation for deep-sea hydrothermal vent organisms.</p> |
url |
http://www.biomedcentral.com/1471-2148/10/220 |
work_keys_str_mv |
AT plouviezsophie determininggeneflowandtheinfluenceofselectionacrosstheequatorialbarrieroftheeastpacificriseinthetubedwellingpolychaeteitalvinellapompejanait AT leguendominique determininggeneflowandtheinfluenceofselectionacrosstheequatorialbarrieroftheeastpacificriseinthetubedwellingpolychaeteitalvinellapompejanait AT lecompteodile determininggeneflowandtheinfluenceofselectionacrosstheequatorialbarrieroftheeastpacificriseinthetubedwellingpolychaeteitalvinellapompejanait AT lallierfrancoish determininggeneflowandtheinfluenceofselectionacrosstheequatorialbarrieroftheeastpacificriseinthetubedwellingpolychaeteitalvinellapompejanait AT jollivetdidier determininggeneflowandtheinfluenceofselectionacrosstheequatorialbarrieroftheeastpacificriseinthetubedwellingpolychaeteitalvinellapompejanait |
_version_ |
1721178104029773824 |