18S rRNA data indicate that Aschelminthes are polyphyletic in origin and consist of at least three distinct clades.

Winnepenninckx, Birgitta; Backeljau, Thierry; Mackey, L. Y.; Brooks, James M.; Wächter, Rupert De; Kumar, Sudhir Kumar; Garey, James R.

doi:10.1093/oxfordjournals.molbev.a040287

Cited by 55 publications

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“…This affinity has received broad support from many earlier studies utilizing different sources of phylogenetic information: morphology [15-17], SSU rDNA sequences [18-20], combined analysis of molecular and morphological characters [21,22], and combined analysis of SSU and LSU ribosomal DNA sequences [23]. In contrast to syndermatan monophyly, internal phylogeny within the clade (among Bdelloidea, Monogononta, Seisonidea, and Acanthocephala) has been the subject of relatively vigorous contention [24-27].…”

Section: Introductionmentioning

confidence: 99%

Eurotatorian paraphyly: Revisiting phylogenetic relationships based on the complete mitochondrial genome sequence of Rotaria rotatoria (Bdelloidea: Rotifera: Syndermata)

Min

Park

2009

BMC Genomics

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BackgroundThe Syndermata (Rotifera+Acanthocephala) is one of the best model systems for studying the evolutionary origins and persistence of different life styles because it contains a series of lineage-specific life histories: Monogononta (cyclic parthenogenetic and free-living), Bdelloidea (entirely parthenogenetic and mostly benthic dweller), Seisonidea (exclusively bisexual and epizoic or ectoparasitic), and Acanthocephala (sexual and obligatory endoparasitic). Providing phylogenetic resolution to the question of Eurotatoria (Monogononta and Bdelloidea) monophyly versus paraphyly is a key factor for better understanding the evolution of different life styles, yet this matter is not clearly resolved. In this study, we revisited this issue based on comparative analysis of complete mitochondrial genome information for major groups of the Syndermata.ResultsWe determined the first complete mitochondrial genome sequences (15,319 bp) of a bdelloid rotifer, Rotaria rotatoria. In order to examine the validity of Eurotatoria (Monogononta and Bdelloidea) monophyly/paraphyly, we performed phylogenetic analysis of amino acid sequences for eleven protein-coding genes sampled from a wide variety of bilaterian representatives. The resulting mitochondrial genome trees, inferred using different algorithms, consistently failed to recover Monogononta and Bdelloidea as monophyletic, but instead identified them as a paraphyletic assemblage. Bdelloidea (as represented by R. rotatoria) shares most common ancestry with Acanthocephala (as represented by L. thecatus) rather than with monogonont B. plicatilis, the other representative of Eurotatoria.ConclusionComparisons of inferred amino acid sequence and gene arrangement patterns with those of other metazoan mtDNAs (including those of acanthocephalan L. thecatus and monogonont B. plicatilis) support the hypothesis that Bdelloidea shares most common ancestry with Acanthocephala rather than with Monogononta. From this finding, we suggest that the obligatory asexuality of bdelloideans may have secondarily derived from some other preexisting condition in earlier lineage of rotifers. Providing a more complete assessment of phylogenetic relationships and inferring patterns of evolution of different types of life styles among Syndermata awaits comparisons requiring mitochondrial genome sequencing of Seisonidea.

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Section: Introductionmentioning

confidence: 99%

Eurotatorian paraphyly: Revisiting phylogenetic relationships based on the complete mitochondrial genome sequence of Rotaria rotatoria (Bdelloidea: Rotifera: Syndermata)

Min

Park

2009

BMC Genomics

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“…As mentioned in the Section “ Introduction ,” helminths are known to be polyphyletic [e.g., see Ref. ( 1 – 4 )]. The most well-supported hypothesis suggests that both Nematoda and Platyhelminthes are believed to have multiple origins over evolutionary time.…”

Section: Phylogenetics and Evolution Studiesmentioning

confidence: 99%

“…Helminths are polyphyletic, i.e., they have multiple origins over evolutionary time [e.g., see Ref. ( 1 – 4 )]. They include free-living and parasitic species of Platyhelminthes (flatworms) and Nematoda (roundworms).…”

Section: Introductionmentioning

confidence: 99%

Helminths and Cancers From the Evolutionary Perspective

2018

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Helminths include free-living and parasitic Platyhelminthes and Nematoda which infect millions of people worldwide. Some Platyhelminthes species of blood flukes (Schistosoma haematobium, Schistosoma japonicum, and Schistosoma mansoni) and liver flukes (Clonorchis sinensis and Opisthorchis viverrini) are known to be involved in human cancers. Other helminths are likely to be carcinogenic. Our main goals are to summarize the current knowledge of human cancers caused by Platyhelminthes, point out some helminth and human biomarkers identified so far, and highlight the potential contributions of phylogenetics and molecular evolution to cancer research. Human cancers caused by helminth infection include cholangiocarcinoma, colorectal hepatocellular carcinoma, squamous cell carcinoma, and urinary bladder cancer. Chronic inflammation is proposed as a common pathway for cancer initiation and development. Furthermore, different bacteria present in gastric, colorectal, and urogenital microbiomes might be responsible for enlarging inflammatory and fibrotic responses in cancers. Studies have suggested that different biomarkers are involved in helminth infection and human cancer development; although, the detailed mechanisms remain under debate. Different helminth proteins have been studied by different approaches. However, their evolutionary relationships remain unsolved. Here, we illustrate the strengths of homology identification and function prediction of uncharacterized proteins from genome sequencing projects based on an evolutionary framework. Together, these approaches may help identifying new biomarkers for disease diagnostics and intervention measures. This work has potential applications in the field of phylomedicine (evolutionary medicine) and may contribute to parasite and cancer research.

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“…Hyman [5] and Ruppert [6] regarded the group as a class within Aschelminthes. Today Gastrotricha is considered a phylum [7], which based on molecular data, most likely has a basal position in the Platyzoa within Lophotrochozoa [e.g. 8]–[11].…”

Section: Introductionmentioning

confidence: 99%

Phylogeny of Thaumastodermatidae (Gastrotricha: Macrodasyida) Inferred from Nuclear and Mitochondrial Sequence Data

et al. 2011

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BackgroundPhylogenetic relationships within Gastrotricha are poorly known. Attempts to shed light on this subject using morphological traits have led to hypotheses lacking satisfactory statistical support; it seemed therefore that a different approach was needed.Methodology/Principal FindingsIn this paper we attempt to elucidate the relationships within the taxonomically vast family Thaumastodermatidae (Macrodasyida) using molecular sequence data. The study includes representatives of all the extant genera of the family and for the first time uses a multi-gene approach to infer evolutionary liaisons within Gastrotricha. The final data set comprises sequences of three genes (18S, 28S rDNA and COI mtDNA) from 41 species, including 29 thaumastodermatids, 11 non-thaumastodermatid macrodasyidans and a single chaetonotidan. Molecular data was analyzed as a combined set of 3 genes and as individual genes, using Bayesian and maximum likelihood approaches. Two different outgroups were used: Xenotrichula intermedia (Chaetonotida) and members of the putative basal Dactylopodola (Macrodasyida). Thaumastodermatidae and all other sampled macrodasyidan families were found monophyletic except for Cephalodasyidae. Within Thaumastodermatidae Diplodasyinae and Thaumastodermatinae are monophyletic and so are most genera. Oregodasys turns out to be the most basal group within Thaumastodermatinae in analyses of the concatenated data set as well as in analyses of the nuclear genes. Thaumastoderma appears as the sister taxon to the remaining species. Surprisingly, Tetranchyroderma is non-monophyletic in our analyses as one group of species clusters with Ptychostomella while another appears as the sister group of Pseudostomella.Conclusions/SignificanceResults in general agree with the current classification; however, a revision of the more derived thaumastodermatid taxa seems necessary. We also found that the ostensible COI sequences from several species do not conform to the general invertebrate or any other published mitochondrial genetic code; they may be mitochondrially derived nuclear genes (numts), or one or more modifications of the mitochondrial genetic code within Gastrotricha.

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18S rRNA data indicate that Aschelminthes are polyphyletic in origin and consist of at least three distinct clades.

Cited by 55 publications

References 0 publications

Eurotatorian paraphyly: Revisiting phylogenetic relationships based on the complete mitochondrial genome sequence of Rotaria rotatoria (Bdelloidea: Rotifera: Syndermata)

Eurotatorian paraphyly: Revisiting phylogenetic relationships based on the complete mitochondrial genome sequence of Rotaria rotatoria (Bdelloidea: Rotifera: Syndermata)

Helminths and Cancers From the Evolutionary Perspective

Phylogeny of Thaumastodermatidae (Gastrotricha: Macrodasyida) Inferred from Nuclear and Mitochondrial Sequence Data

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