European Ocean Biodiversity Information System

[ report an error in this record ]basket (0): add | show Print this page

Repeated evolution of uniparental reproduction in Sellaphora (Bacillariophyceae)
Poulickova, A; Sato, S; Evans, M; Chepurnov, V.A.; Mann, G (2015). Repeated evolution of uniparental reproduction in Sellaphora (Bacillariophyceae). Eur. J. Phycol. 50(1): 62-79. dx.doi.org/10.1080/09670262.2014.985259
In: European Journal of Phycology. Cambridge University Press/Taylor & Francis: Cambridge. ISSN 0967-0262; e-ISSN 1469-4433
Peer reviewed article  

Available in  Authors 
    Vlaams Instituut voor de Zee: Non-open access 375859 [ request ]

Keywords
    Bacillariophyceae [WoRMS]; Sellaphora C. Mereschkowsky, 1902 [WoRMS]
    Marine/Coastal
Author keywords
    ancestral state reconstruction, autogamy, auxosporulation, cox1, DAPI, diatoms, evolution of automixis, molecular phylogeny, rbcL, Sellaphora pupula agg, uniparental auxosporulation

Authors  Top 
  • Poulickova, A
  • Sato, S
  • Evans, M
  • Chepurnov, V.A.
  • Mann, G

Abstract
    Diatoms possess a remarkable life cycle in which cell size decreases slowly during vegetative cell division and then increases rapidly via special expanding cells called ‘auxospores’, which are usually formed as a result of biparental sexual reproduction. However, auxospores are sometimes produced by single unpaired cells, i.e. uniparentally. We examined the nature of uniparental auxosporulation in Sellaphora and used a two-gene dataset to study phylogenetic relationships between uniparental and biparental Sellaphora demes and species; we tested whether uniparental reproduction has evolved once or repeatedly in the genus. In at least two of the uniparental demes auxosporulation occurred through autogamy (i.e. intra-tetrad mating within an undivided cell). Maximum likelihood phylogenies indicated four lineages of uniparental Sellaphora and significance tests of alternative topologies, in which combinations of uniparental Sellaphora were constrained to be monophyletic, coupled with likelihood reconstruction of ancestral character states, led to rejection of the hypothesis that uniparental auxosporulation evolved only once in the genus. Uniparentally reproducing lineages appear to arise not infrequently in diatoms but do not persist. Two small extranuclear bodies, apparently containing DNA and lying outside the chloroplast (one close to each pole of the cell), were revealed by DAPI staining.

All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors