ANALYSIS BY SOMATIC-CELL FUSION OF THE PHENOTYPIC PROPERTIES OF A MUTANT EMBRYONAL CARCINOMA CELL-LINE

We have previously reported the isolation of an embryonal carcinoma (E C) cell mutant created via retroviral insertion (1). The mutant (NR1-6 ) is aberrant in respect to morphology, tumorigenicity and response to retinoic acid (RA). In order to determine the dominance/recessive hie rarchy and genetic relationships of these phenotypes, we created hybri d lines from mutant and parental cells. Three hybrid clones (Hyb 1, 2a and 2b), which retain both mutant and parental loci, were analyzed. O ur results indicate that in all parameters - morphology, adhesion, qua litative and quantitative response to RA and tumorigenicity - the hybr ids behave similarly to parental cells. In no case did any of the hybr id lines exhibit a mutant phenotype. The data indicate that the phenot ypes we have studied are genetically interrelated and that the parenta l characteristics are dominant.