AGGREGATION INDEPENDENT OF N-CADHERIN AND NEURAL CELL-ADHESION MOLECULE ON QUAIL MYOBLASTS TRANSFORMED WITH TEMPERATURE-SENSITIVE ROUS-SARCOMA VIRUS

Quail myoblasts transformed with the temperature-sensitive mutant of R ous sarcoma virus (QM-RSV cells) differentiate temperature-sensitively . At 41 degrees C, the cells begin to fuse after about 15-18 h and for m multinucleated myotubes, whereas, at 35.5 degrees C, the cells proli ferate. Tyrosine-phosphorylation relates to this temperature-sensitive differentiation. In the course of the investigation of QM-RSV cells, when QM-RSV cells were dissociated with EDTA and shaken in DMEM, the a ggregation activity was detected. This activity was expressed on the c ells cultured at 41 degrees C, but not at 35.5 degrees C. For detailed characterization of the aggregation, cells from which cadherin and/or neural cell adhesion molecule (NCAM) were removed by trypsin treatmen t were used. It was then observed that temperature-sensitive and calci um-dependent aggregation activity was expressed on the cells treated w ith trypsin and EDTA (TE-cells), although the TE-cells did not retain either aggregation molecule. The aggregation activity began to be expr essed at 2-4h after temperature shift and increased with the different iation. The expression of the activity related to the tyrosine-phospho rylation of some protein. The aggregation of TE-cells was completely i nhibited by D(+)-mannose, D(+)-glucose, and N-acetyl-D-glucosamine, bu t D(+)-galactose did nor affect the aggregation. Thus, the present res ults suggest that the aggregation of mannose specific C-type animal le ctin recognized on TE-cells relates to the early stage of the differen tiation of QM-RSV cells.