The second highest chromosome count among vertebrates is observed in cultured sturgeon and is associated with genome plasticity

Abstract

We report the second highest chromosome count among vertebrates in cultured sturgeon (~437) after the schizothoracine cyprinid Ptychobarbus dipogon with ~446 chromosomes. The finding also represents the highest documented chromosome count in Acipenseriformes, and the first report of a functional heptaploid (7n) genome composition in sturgeon. To our knowledge, this study provides the first clear evidence of a maternal origin for spontaneous polyploidization in cultured A. baerii. To date, all available data indicate that spontaneous polyploidization occurs frequently among cultured sturgeons.