A fish-like invertebrate that can inform origin and innovations of vertebrates

What is it about?

Amphioxus is a invertebrate chordate species, and also the best living proxy for our vertebrate ancestor. We here reconstructed how the extant vertebrate chromosomes originated and evolved from a chromosome configuration similar to that of amphioxus, after two times of whole-genome duplication; and uncovered extraordinary evolutionary stability of how genomes are regulated, and some small-sized micro-chromosomes during the half a billion years of vertebrate divergence.

Featured Image

Photo by Johannes Plenio on Unsplash

Photo by Johannes Plenio on Unsplash

Why is it important?

Only by comparing to a species that are neither vertebrates nor too divergent, one can tell what defines our vertebrates and what is evolutionarily new or unique. Amphioxus is such a proper species that evolves with unusually low tempo, hence harbors much information for our vertebrate ancestor. By comparing the genomes of amphioxus vs. extant representative vertebrate clades, we can trace and reconstruct the steps that lead to the extant divergent vertebrate genomes.