Collagen IV is a primordial extracellular matrix component associated with the transition to animal multicellularity, and enabled the formation and evolution of epithelial tissues.

Even though the ctenophore Mnemiopsis leidyi develops polarized epithelial tissues, polarization is not mediated by the conserved mechanisms polarizing bilaterian and cnidarian epithelial cells.

Sponges and ctenophores lack hypoxia-inducible factors, suggesting that the metazoan last common ancestor could have lived aerobically under severe hypoxia and did not need to regulate its transcription in response to oxygen availability.

The animal phylogeny of glutamate receptors indicates that vertebrate types do not account for all receptor classes originated during evolution, neither are they the pinnacle of a linear evolutive process.

Evolutionary reconstruction of the ecdysis pathway shows that its major elements are present in the majority of metazoans, providing evidence that they originated much earlier than currently assumed.

Advanced orthology clustering of bilaterian and non-bilaterian sequences identifies 157 bilaterian-specific genes which are linked to key morphological features of this animal group.

Protein coding genes strongly support a sister group relationship between Placozoa and Cnidaria to the exclusion of Bilateria, contradicting previous phylogenies, which have likely been misled by pervasive compositional heterogeneity.

An in silico analysis of gap junction proteins supports the hypothesis that connexins replaced the primordial innexins in chordate gap junctions due to an evolutionary bottleneck.

The analysis of 20 coral genomic datasets provides unprecedented insights into what makes reef-building corals unique, including the evolution of novel gene families involved in biomineralization, signaling and stress responses that have led to their evolutionary success throughout the Phanerozoic Eon.

Expression patterns and biophysical properties of acid-sensing ion channels in numerous bilaterian animals offer insight into the deployment of ion channels by the evolving nervous system in complex animals.