Early origin of the bilaterian developmental toolkit

@article{Erwin2009EarlyOO,
  title={Early origin of the bilaterian developmental toolkit},
  author={Douglas H. Erwin},
  journal={Philosophical Transactions of the Royal Society B: Biological Sciences},
  year={2009},
  volume={364},
  pages={2253 - 2261}
}
  • D. Erwin
  • Published 12 August 2009
  • Biology
  • Philosophical Transactions of the Royal Society B: Biological Sciences
Whole-genome sequences from the choanoflagellate Monosiga brevicollis, the placozoan Trichoplax adhaerens and the cnidarian Nematostella vectensis have confirmed results from comparative evolutionary developmental studies that much of the developmental toolkit once thought to be characteristic of bilaterians appeared much earlier in the evolution of animals. The diversity of transcription factors and signalling pathway genes in animals with a limited number of cell types and a restricted… 

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References

SHOWING 1-10 OF 107 REFERENCES

The Trichoplax genome and the nature of placozoans

Despite the apparent cellular and organismal simplicity of Trichoplax, its genome encodes a rich array of transcription factor and signalling pathway genes that are typically associated with diverse cell types and developmental processes in eumetazoans, motivating further searches for cryptic cellular complexity and/or as yet unobserved life history stages.

The genome of the choanoflagellate Monosiga brevicollis and the origin of metazoans

It is shown that the physical linkages among protein domains often differ between M. brevicollis and metazoans, suggesting that abundant domain shuffling followed the separation of the choanoflagellate and metazoan lineages.

Developmental expression of transcription factor genes in a demosponge: insights into the origin of metazoan multicellularity

It is demonstrated that members of a range of transcription factor gene classes are expressed during the development of the demosponge Reniera, including ANTP, Pax, POU, LIM‐HD, Sox, nuclear receptor, Fox (forkhead), T‐box, Mef2, and Ets genes.

Sea Anemone Genome Reveals Ancestral Eumetazoan Gene Repertoire and Genomic Organization

A comparative analysis of the draft genome of an emerging cnidarian model, the starlet sea anemone Nematostella vectensis, suggests that gene “inventions” along the lineage leading to animals were likely already well integrated with preexisting eukaryotic genes in the eumetazoan progenitor.

Molecular genetic insights into deuterostome evolution from the direct-developing hemichordate Saccoglossus kowalevskii

  • C. Lowe
  • Biology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2008
Developmental genetic data are providing a unique insight into early deuterostome evolution, revealing a complexity of genetic regulation previously attributed only to vertebrates, and morphological, palaeontological and molecular datasets should all be considered carefully when speculating about ancestral deuterstome features.

The unicellular ancestry of animal development.

  • N. King
  • Biology
    Developmental cell
  • 2004

Cnidarian milestones in metazoan evolution.

It is suggested that paedomorphic events in descendants of this ancestor led to the array of diversity seen in the main extant animal phyla and can provide an integrative test of hypotheses of homologies and independent evidence of the evolutionary relationships among extant taxa.

Acoel flatworms: earliest extant bilaterian Metazoans, not members of Platyhelminthes.

Sequence data of 18S ribosomal DNA genes from non-fast evolving species of acoels and other metazoans reveal that this group does not belong to the Platyhelminthes but represents the extant members of the earliest divergent Bilateria, an interpretation that is supported by recent studies on the embryonic cleavage pattern and nervous system of acOels.

The phylogenetic distribution of metazoan microRNAs: insights into evolutionary complexity and constraint.

The continuous acquisition and fixation of miRNAs in various animal groups strongly correlates both with the hierarchy of metazoan relationships and with the non-random origination of meetazoan morphological innovations through geologic time.

A simple plan — cnidarians and the origins of developmental mechanisms

Cnidarian sequencing projects are showing that the common metazoan ancestor was more genetically complex than was previously assumed, and molecular genetic approaches are blurring the developmental divide between cnidarians and bilateral animals.
...