Many vertebrate species have similar sets of protein-coding genes, though they can exhibit very different phenotypes, and, in Science, a team of researchers recounts its comparison of organ transcriptomes, with a particular focus on alternative splicing patterns, from a number of vertebrate species. The team notes that there are significant differences in alternative splicing patterns between diverged species. In particular, it reports that organs from primate species have higher cassette exon alternative splicing than organs from non-primate species have. "Our work offers conclusive evidence that the reassortment of splicing code features can account for the majority of [alternative splicing] differences between vertebrate species," the team writes.
Also in Science, investigators from Massachusetts Institute of Technology examine conservation of alternative splicing among species. They sequenced complementary DNA from nine tissues from mouse, rat, rhesus macaque, cow, and chicken. They generated more than 16 billion reads and more than 1 trillion bases that they then mapped to the species' respective genomes to create a map showing splice junctions and isoforms. "We find that while tissue-specific gene expression programs are largely conserved, alternative splicing is well conserved in only a subset of tissues and is frequently lineage-specific," they write.