A catalogue of Bilaterian-specific genes – their function and expression profiles in early development

  title={A catalogue of Bilaterian-specific genes – their function and expression profiles in early development},
  author={Andrea Kraemer-Eis and Luca Ferretti and Philipp H. Schiffer and Peter Heger and Thomas Wiehe},
Bilateria constitute a monophyletic group of organisms comprising about 99% of all living animals. Since their initial radiation about 540Mya they have evolved a plethora of traits and body forms allowing them to conquer almost any habitat on earth. There are only few truly uniting and shared morphological features retained across the phylum. Unsurprisingly, also the genetic toolkit of bilateria is highly diverged. In the light of this divergence we investigated if a set of bilaterian-specific… 



Evolutionary conservation of the eumetazoan gene regulatory landscape.

The results suggest that complex gene regulation originated at least 600 million yr ago, predating the common ancestor of eumetazoans, and Surprisingly, the distribution and abundance of gene regulatory elements relative to these genes are shared between Nematostella and bilaterian model organisms.

Early origin of the bilaterian developmental toolkit

  • D. Erwin
  • Biology
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2009
It is suggested that placozoans and cnidarians represent a depauperate residue of a once more diverse assemblage of early animals, some of which may be represented in the Ediacaran fauna (c. 585–542 Myr ago).

The homeodomain complement of the ctenophore Mnemiopsis leidyi suggests that Ctenophora and Porifera diverged prior to the ParaHoxozoa

The first glimpse of the first sequenced ctenophore genome is provided and it is suggested that Porifera and Ctenophora were the first two extant lineages to diverge from the rest of animals.

Acoel development supports a simple planula-like urbilaterian

It is argued that this animal, with features resembling acoelomorph flatworms, was far simpler morphologically than the protostome–deuterostome ancestor despite possessing a nearly complete eubilaterian genome.

The cnidarian-bilaterian ancestor possessed at least 56 homeoboxes: evidence from the starlet sea anemone, Nematostella vectensis

This work reports the first near-complete set of homeodomains from a basal (diploblastic) animal, Nematostella vectensis, which underwent extensive radiations prior to the evolutionary split between Cnidaria and Bilateria.

Acoel development indicates the independent evolution of the bilaterian mouth and anus

The hypothesis that the bilaterian mouth and anus evolved simultaneously from a common blastoporal opening is contradicted, and it is suggested that a through gut might have evolved independently in different animal lineages.

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.

A genomewide survey of bHLH transcription factors in the coral Acropora digitifera identifies three novel orthologous families, pearl, amber, and peridot

A nearly full set of 70 basic helix-loop-helix (bHLH) transcription factors in this organism is characterized, comparable to 68 bHLH genes in the sea anemone, Nematostella vectensis, and larger than those in most other invertebrate metazoans.

Origin and diversification of the basic helix-loop-helix gene family in metazoans: insights from comparative genomics

The first evolutionary analysis of a whole superfamily of transcription factors, the basic helix-loop-helix (bHLH) proteins, at the scale of the whole metazoan kingdom is reported, suggesting that these features may be extended to other developmental gene families and reflect a general trend in the evolution of the developmental gene repertoires of metazoans.