Evolution of sex chromosomes prior to speciation in the dioecious Phoenix species.
Understanding the driving forces and molecular processes underlying dioecy and sex chromosome evolution, leading from hermaphroditism to the occurrence of male and female individuals, is of considerable interest in fundamental and applied research. The genus Phoenix, belonging to the Arecaceae family, consists uniquely of dioecious species. Phylogenetic data suggest that the genus Phoenix has diverged from a hermaphroditic ancestor which is also shared with its closest relatives. We have investigated the cessation of recombination in the sex-determination region within the genus Phoenix as a whole by extending the analysis of P. dactylifera SSR sex-related loci to eight other species within the genus. Phylogenetic analysis of a date palm sex-linked PdMYB1 gene in these species has revealed that sex-linked alleles have not clustered in a species-dependent way but rather in X and Y-allele clusters. Our data show that sex chromosomes evolved from a common autosomal origin before the diversification of the extant dioecious species.
IRD/CIRAD F2F-palm group, UMR DIADE, Centre IRD, Montpellier, France.|Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie, Faculté des sciences de Tunis, Université Tunis El Manar, El Manar, Tunisia.
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Cherif
Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie, Faculté des sciences de Tunis, Université Tunis El Manar, El Manar, Tunisia.
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Zehdi-Azouzi
IRD/CIRAD F2F-palm group, UMR DIADE, Centre IRD, Montpellier, France.
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A
Crabos
IRD/CIRAD F2F-palm group, UMR DIADE, Centre IRD, Montpellier, France.
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Castillo
IRD/CIRAD F2F-palm group, UMR DIADE, Centre IRD, Montpellier, France.
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Chabrillange
Dynadiv, UMR DIADE, Centre IRD, Montpellier, France.
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Pintaud
Laboratoire de Génétique Moléculaire, Immunologie et Biotechnologie, Faculté des sciences de Tunis, Université Tunis El Manar, El Manar, Tunisia.
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Salhi-Hannachi
Institut des Sciences de l'Evolution de Montpellier, Unité Mixte de Recherche 5554 (Université de Montpellier-CNRS-IRD-EPHE), Montpellier, France.|Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
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Glémin
IRD/CIRAD F2F-palm group, UMR DIADE, Centre IRD, Montpellier, France.
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Aberlenc-Bertossi
D028023:Arecaceae / Q000235:genetics*; D032461:Chromosomes, Plant; D019143:Evolution, Molecular; D010802:Phylogeny; D012730:Sex Chromosomes
dioecy; recombination arrest; sex chromosomes; sex-linked gene; speciation