Stepwise Evolution of Essential Centromere Function in a Drosophila Neogene

Essential Novelty The evolution of essential function for newly originated genes presents a conundrum, in that prior to the gene's origin either the essential function was absent or else performed by another gene or set of genes. In order to better understand how new genes acquire essential function, Ross et al. (p. 1211 ) investigated the origin of the Drosophila gene Umbrea. Umbrea became an essential protein in certain Drosophila species through the gain of localization at the centromere and a role in chromosome segregation.