MAMMALIAN CELL GENETICS I. SELECTION AND CHARACTERIZATION OF MUTATIONS AUXOTROPHIC FOR L-GLUTAMINE OR RESISTANT TO 8-AZAGUANINE IN CHINESE HAMSTER CELLS <i>IN VITRO</i>

Abstract

IOCHEMICAL mutants in somatic cell cultures have been obtained either by establishing cell cultures from mutants known in the whole organism that are also expressed at the cellular level or by means of various techniques to isolate clones of cells that have developed phenotypes different from those of the parental culture.The present report describes the isolation and cytogenetic characterization of two genetic variants, viz., L-glutamine (gln) auxotrophy and 8-azaguanine (azg) resistance that had arisen spontaneously in the population of an established cell line of Chinese hamster.By the use of cell fusion technique, we showed that both mutations were recessive.Preliminary results of this work have been previously summarized (CHU, MERRIAM, and BRIMER 1967;CHU and BRIMER 1968).