Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels.
BACKGROUND:Reconstructing the history of divergence and gene flow between closely-related organisms has long been a difficult task of evolutionary genetics. Recently, new approaches based on the coalescence theory have been developed to test the existence of gene flow during the process of divergenc...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2009-08-01
|
| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC2715857?pdf=render |
| _version_ | 1818516124097052672 |
|---|---|
| author | Baptiste Faure Didier Jollivet Arnaud Tanguy François Bonhomme Nicolas Bierne |
| author_facet | Baptiste Faure Didier Jollivet Arnaud Tanguy François Bonhomme Nicolas Bierne |
| author_sort | Baptiste Faure |
| collection | DOAJ |
| description | BACKGROUND:Reconstructing the history of divergence and gene flow between closely-related organisms has long been a difficult task of evolutionary genetics. Recently, new approaches based on the coalescence theory have been developed to test the existence of gene flow during the process of divergence. The deep sea is a motivating place to apply these new approaches. Differentiation by adaptation can be driven by the heterogeneity of the hydrothermal environment while populations should not have been strongly perturbed by climatic oscillations, the main cause of geographic isolation at the surface. METHODOLOGY/PRINCIPAL FINDING:Samples of DNA sequences were obtained for seven nuclear loci and a mitochondrial locus in order to conduct a multi-locus analysis of divergence and gene flow between two closely related and hybridizing species of hydrothermal vent mussels, Bathymodiolus azoricus and B. puteoserpentis. The analysis revealed that (i) the two species have started to diverge approximately 0.760 million years ago, (ii) the B. azoricus population size was 2 to 5 time greater than the B. puteoserpentis and the ancestral population and (iii) gene flow between the two species occurred over the complete species range and was mainly asymmetric, at least for the chromosomal regions studied. CONCLUSIONS/SIGNIFICANCE:A long history of gene flow has been detected between the two Bathymodiolus species. However, it proved very difficult to conclusively distinguish secondary introgression from ongoing parapatric differentiation. As powerful as coalescence approaches could be, we are left by the fact that natural populations often deviates from standard assumptions of the underlying model. A more direct observation of the history of recombination at one of the seven loci studied suggests an initial period of allopatric differentiation during which recombination was blocked between lineages. Even in the deep sea, geographic isolation may well be a crucial promoter of speciation. |
| first_indexed | 2024-12-11T00:37:56Z |
| format | Article |
| id | doaj.art-ae5d6cbca08c49ca8923120513bbf6f6 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T00:37:56Z |
| publishDate | 2009-08-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS ONE |
| spelling | doaj.art-ae5d6cbca08c49ca8923120513bbf6f62022-12-22T01:27:04ZengPublic Library of Science (PLoS)PLoS ONE1932-62032009-08-0148e648510.1371/journal.pone.0006485Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels.Baptiste FaureDidier JollivetArnaud TanguyFrançois BonhommeNicolas BierneBACKGROUND:Reconstructing the history of divergence and gene flow between closely-related organisms has long been a difficult task of evolutionary genetics. Recently, new approaches based on the coalescence theory have been developed to test the existence of gene flow during the process of divergence. The deep sea is a motivating place to apply these new approaches. Differentiation by adaptation can be driven by the heterogeneity of the hydrothermal environment while populations should not have been strongly perturbed by climatic oscillations, the main cause of geographic isolation at the surface. METHODOLOGY/PRINCIPAL FINDING:Samples of DNA sequences were obtained for seven nuclear loci and a mitochondrial locus in order to conduct a multi-locus analysis of divergence and gene flow between two closely related and hybridizing species of hydrothermal vent mussels, Bathymodiolus azoricus and B. puteoserpentis. The analysis revealed that (i) the two species have started to diverge approximately 0.760 million years ago, (ii) the B. azoricus population size was 2 to 5 time greater than the B. puteoserpentis and the ancestral population and (iii) gene flow between the two species occurred over the complete species range and was mainly asymmetric, at least for the chromosomal regions studied. CONCLUSIONS/SIGNIFICANCE:A long history of gene flow has been detected between the two Bathymodiolus species. However, it proved very difficult to conclusively distinguish secondary introgression from ongoing parapatric differentiation. As powerful as coalescence approaches could be, we are left by the fact that natural populations often deviates from standard assumptions of the underlying model. A more direct observation of the history of recombination at one of the seven loci studied suggests an initial period of allopatric differentiation during which recombination was blocked between lineages. Even in the deep sea, geographic isolation may well be a crucial promoter of speciation.http://europepmc.org/articles/PMC2715857?pdf=render |
| spellingShingle | Baptiste Faure Didier Jollivet Arnaud Tanguy François Bonhomme Nicolas Bierne Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. PLoS ONE |
| title | Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. |
| title_full | Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. |
| title_fullStr | Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. |
| title_full_unstemmed | Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. |
| title_short | Speciation in the deep sea: multi-locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels. |
| title_sort | speciation in the deep sea multi locus analysis of divergence and gene flow between two hybridizing species of hydrothermal vent mussels |
| url | http://europepmc.org/articles/PMC2715857?pdf=render |
| work_keys_str_mv | AT baptistefaure speciationinthedeepseamultilocusanalysisofdivergenceandgeneflowbetweentwohybridizingspeciesofhydrothermalventmussels AT didierjollivet speciationinthedeepseamultilocusanalysisofdivergenceandgeneflowbetweentwohybridizingspeciesofhydrothermalventmussels AT arnaudtanguy speciationinthedeepseamultilocusanalysisofdivergenceandgeneflowbetweentwohybridizingspeciesofhydrothermalventmussels AT francoisbonhomme speciationinthedeepseamultilocusanalysisofdivergenceandgeneflowbetweentwohybridizingspeciesofhydrothermalventmussels AT nicolasbierne speciationinthedeepseamultilocusanalysisofdivergenceandgeneflowbetweentwohybridizingspeciesofhydrothermalventmussels |