Introduction An understanding of ctenophore biology is critical for reconstructing events that
occurred early in animal evolution. The phylogenetic relationship of ctenophores (comb …

10.7554/eLife.31176.001 Animals have a carefully orchestrated relationship with oxygen.
When exposed to low environmental oxygen concentrations, and during periods of increased …

Porifera are a diverse animal phylum with species performing important ecological roles in
aquatic ecosystems, and have become models for multicellularity and early-animal evolution. …

One central goal of genome biology is to understand how the usage of the genome differs
between organisms. Our knowledge of genome composition, needed for downstream …

The evolutionary origin of metazoan cell types such as neurons and muscles is not known.
Using whole-body single-cell RNA sequencing in a sponge, an animal without nervous …

The genomes of non-bilaterian metazoans are key to understanding the molecular basis of
early animal evolution. However, a full comprehension of how animal-specific traits, such as …

Background The lack of genomic resources can present challenges for studies of non-model
organisms. Transcriptome sequencing offers an attractive method to gather information …

Placozoans are a phylum of nonbilaterian marine animals currently represented by a single
described species, Trichoplax adhaerens, Schulze 1883. Placozoans arguably show the …

Scientific drilling has identified a biosphere in marine sediments 1 , which contain many
uncultivated microbial groups known only by their DNA sequences 2 , 3 – 4 . Recycling of …

Resolving the relationships of animals (Metazoa) is crucial to our understanding of the origin
of key traits such as muscles, guts, and nerves. However, a broadly accepted metazoan …