Evolution of a new chromosomal lineage in a laboratory population of Drosophila through centric fission

Structural rearrangements of chromosomes have played a decisive role in the karyotypic evolution of species. It is also known that inversions, translo cations, fusions, fissions, heterochromatin variations and other chromosoma l changes occur as transient events in natural populations. Herein we repor t the occurrence of a rare event of centric fission of a metacentric chromo some in a laboratory population of Drosophila, called Cytorace 1. This cent ric fission has been fixed in a sub-population of Cytorace 1, resulting in a new chromosomal lineage called Fissioncytorace-1.