Phylogeny of Flabellulidae (Amoebozoa: Leptomyxida) inferred from SSU rDNA sequences of the type strain of Flabellula citata Schaeffer, 1926 and newly isolated strains of marine amoebae

Dyková, Iva; Fiala, Ivan; Pecková, Hana; Dvořáková, Helena

doi:10.14411/fp.2008.033

Cited by 9 publications

(2 citation statements)

References 24 publications

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“…Cell fusion is widely reported for Amoebozoa [61,62]. Among the leptomyxids, Leptomyxa reticulata [61], Flabellula baltica [63] and multiple strains of flabellulids [64] are observed to fuse. Subsequently, the cells separate or persist as multinucleate stages.…”

Section: Amoeboid Lineagesmentioning

confidence: 99%

The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms

et al. 2011

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Amoebae are generally assumed to be asexual. We argue that this view is a relict of early classification schemes that lumped all amoebae together inside the 'lower' protozoa, separated from the 'higher' plants, animals and fungi. This artificial classification allowed microbial eukaryotes, including amoebae, to be dismissed as primitive, and implied that the biological rules and theories developed for macroorganisms need not apply to microbes. Eukaryotic diversity is made up of 70þ lineages, most of which are microbial. Plants, animals and fungi are nested among these microbial lineages. Thus, theories on the prevalence and maintenance of sex developed for macro-organisms should in fact apply to microbial eukaryotes, though the theories may need to be refined and generalized (e.g. to account for the variation in sexual strategies and prevalence of facultative sex in natural populations of many microbial eukaryotes). We use a revised phylogenetic framework to assess evidence for sex in several amoeboid lineages that are traditionally considered asexual, and we interpret this evidence in light of theories on the evolution of sex developed for macro-organisms. We emphasize that the limited data available for many lineages coupled with natural variation in microbial life cycles overestimate the extent of asexuality. Mapping sexuality onto the eukaryotic tree of life demonstrates that the majority of amoeboid lineages are, contrary to popular belief, anciently sexual, and that most asexual groups have probably arisen recently and independently. Additionally, several unusual genomic traits are prevalent in amoeboid lineages, including cyclic polyploidy, which may serve as alternative mechanisms to minimize the deleterious effects of asexuality.

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Section: Amoeboid Lineagesmentioning

confidence: 99%

The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms

et al. 2011

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“…Numerous additions have been made to the system of Smirnov et al [15] , generally placing incertae sedis taxa without much modification into the higher-level proposed relationships (eg. [16] , [17] , [18] , [19] , [20] , [21] , [22] ). Subsequent large-scale reconstructions largely corroborated the proposed relationships in the Smirnov et al [15] system [23] , [24] , [25] , [26] .…”

Section: Introductionmentioning

confidence: 99%

Comprehensive Phylogenetic Reconstruction of Amoebozoa Based on Concatenated Analyses of SSU-rDNA and Actin Genes

et al. 2011

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Evolutionary relationships within Amoebozoa have been the subject of controversy for two reasons: 1) paucity of morphological characters in traditional surveys and 2) haphazard taxonomic sampling in modern molecular reconstructions. These along with other factors have prevented the erection of a definitive system that resolves confidently both higher and lower-level relationships. Additionally, the recent recognition that many protosteloid amoebae are in fact scattered throughout the Amoebozoa suggests that phylogenetic reconstructions have been excluding an extensive and integral group of organisms. Here we provide a comprehensive phylogenetic reconstruction based on 139 taxa using molecular information from both SSU-rDNA and actin genes. We provide molecular data for 13 of those taxa, 12 of which had not been previously characterized. We explored the dataset extensively by generating 18 alternative reconstructions that assess the effect of missing data, long-branched taxa, unstable taxa, fast evolving sites and inclusion of environmental sequences. We compared reconstructions with each other as well as against previously published phylogenies. Our analyses show that many of the morphologically established lower-level relationships (defined here as relationships roughly equivalent to Order level or below) are congruent with molecular data. However, the data are insufficient to corroborate or reject the large majority of proposed higher-level relationships (above the Order-level), with the exception of Tubulinea, Archamoebae and Myxogastrea, which are consistently recovered. Moreover, contrary to previous expectations, the inclusion of available environmental sequences does not significantly improve the Amoebozoa reconstruction. This is probably because key amoebozoan taxa are not easily amplified by environmental sequencing methodology due to high rates of molecular evolution and regular occurrence of large indels and introns. Finally, in an effort to facilitate future sampling of key amoebozoan taxa, we provide a novel methodology for genome amplification and cDNA extraction from single or a few cells, a method that is culture-independent and allows both photodocumentation and extraction of multiple genes from natural samples.

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