Simakov O, Marlétaz F, Yue JX, O'Connell B, Jenkins J, Brandt A, Calef R, Tung CH, Huang TK, Schmutz J, Satoh N, Yu JK, Putnam NH, Green RE, Rokhsar DS.

Nat Ecol Evol. 2020 Jun;4(6):820-830. doi:10.1038/s41559-020-1156-z

Deeply conserved synteny resolves early events in vertebrate evolution.

Most of the 19 amphioxus (lancelet) chromosomes directly correspond to one of the 17 ancestral chordate linkage groups. Pattern of paralogue elimination show that autotetraploidy was followed by allotetraploidy in bony vertebrates. Vertebrate and amphioxus mini-chromosomes descend from the ancestral linkage groups too.