A1 Refereed original research article in a scientific journal
Is polyploidy a persevering accident or an adaptive evolutionary pattern? The case of the brine shrimp Artemia
Authors: Maniatsi S, Baxevanis AD, Kappas I, Deligiannidis P, Triantafyllidis A, Papakostas S, Bougiouklis D, Abatzopoulos TJ
Publisher: ACADEMIC PRESS INC ELSEVIER SCIENCE
Publication year: 2011
Journal: Molecular Phylogenetics and Evolution
Journal name in source: MOLECULAR PHYLOGENETICS AND EVOLUTION
Journal acronym: MOL PHYLOGENET EVOL
Number in series: 2
Volume: 58
Issue: 2
First page : 353
Last page: 364
Number of pages: 12
ISSN: 1055-7903
DOI: https://doi.org/10.1016/j.ympev.2010.11.029
Abstract
Asexual organisms are confronted with substantial drawbacks, both immediate and delayed, threatening their evolutionary persistence. Yet, genetic associations with asexuality may refresh the gene pool promoting adaptation of clonal lineages; polyploidy is one of them. Parthenogenesis itself and/or polyploidy are responsible for the maintenance and spread of clones in Artemia, a sexual-asexual genus of halophilic anostracans. We applied flow cytometry, microsatellite genotyping, and mtDNA sequencing to 23 asexual populations. Artemia parthenogens have evolved multiple times either through hybridization or spontaneously. Nine out of 23 populations contained clones of mixed ploidy (2n, 3n, 4n). Most clones were diploid (20/31) while two and nine clones were triploid and tetraploid, respectively. Apomictic triploids and tetraploids formed two distinct groups of low genetic diversity compared with the more divergent automictic diploids. Polyploidy is also polyphyletic in Artemia, with triploids and tetraploids having independent origins from different sexual ancestors. We discern a pattern of geographical parthenogenesis with all clonal groups being more widespread than their closest sexuals. In favour of a specialist model, asexual diploids are restricted to single locations and are strikingly segregated from generalist triploids and tetraploids occupying a variety of sites. This is a rare pattern of mixed life-history strategies within an asexual complex. (C) 2010 Elsevier Inc. All rights reserved.
Asexual organisms are confronted with substantial drawbacks, both immediate and delayed, threatening their evolutionary persistence. Yet, genetic associations with asexuality may refresh the gene pool promoting adaptation of clonal lineages; polyploidy is one of them. Parthenogenesis itself and/or polyploidy are responsible for the maintenance and spread of clones in Artemia, a sexual-asexual genus of halophilic anostracans. We applied flow cytometry, microsatellite genotyping, and mtDNA sequencing to 23 asexual populations. Artemia parthenogens have evolved multiple times either through hybridization or spontaneously. Nine out of 23 populations contained clones of mixed ploidy (2n, 3n, 4n). Most clones were diploid (20/31) while two and nine clones were triploid and tetraploid, respectively. Apomictic triploids and tetraploids formed two distinct groups of low genetic diversity compared with the more divergent automictic diploids. Polyploidy is also polyphyletic in Artemia, with triploids and tetraploids having independent origins from different sexual ancestors. We discern a pattern of geographical parthenogenesis with all clonal groups being more widespread than their closest sexuals. In favour of a specialist model, asexual diploids are restricted to single locations and are strikingly segregated from generalist triploids and tetraploids occupying a variety of sites. This is a rare pattern of mixed life-history strategies within an asexual complex. (C) 2010 Elsevier Inc. All rights reserved.
UTU Research Portal