Author:
Herrmann Jennifer A.,Koprowska Agata,Winters Tesa J.,Villanueva Nancy,Nikityuk Victoria D.,Pek Feini,Reis Elizabeth M.,Dominguez Constancia Z.,Davis Daniel,McPherson Eric,Rocco Staci R.,Recendez Cynthia,Difuntorum Shyla M.,Faeth Kelly,Lopez Mario D.,Awwad Habeeba M.,Ghobashy Rola A.,Cappiello Lauren,Neidle Ellen L.,Quiñones-Soto Semarhy,Reams Andrew B.
Abstract
AbstractThe controversial theory of adaptive amplification states gene amplification mutations are induced by selective environments where they are enriched due to the stress caused by growth restriction on unadapted cells. We tested this theory with three independent assays using an Acinetobacter baylyi model system that exclusively selects for cat gene amplification mutants. Our results demonstrate all cat gene amplification mutant colonies arise through a multistep process. While the late steps occur during selection exposure, these mutants derive from low-level amplification mutant cells that form before growth-inhibiting selection is imposed. During selection, these partial mutants undergo multiple secondary steps generating higher amplification over several days to multiple weeks to eventually form visible high-copy amplification colonies. Based on these findings, amplification in this Acinetobacter system can be explained by a natural selection process that does not require a stress response. These findings have fundamental implications to understanding the role of growth-limiting selective environments on cancer development.
Publisher
Cold Spring Harbor Laboratory