COMPARATIVE CHARACTERIZATION OF SOME PARAMETERS OF THE CELL-NUCLEUS IN THE SERIES MYELOMA HYBRIDOMA LYMPHOCYTE

A comparative study of several parameters of the cell nuclei of hybrid oma MLC-1c and its parental cells, myeloma X-63-Ag8.653 cells and Balb /c mouse spleen lymphocytes, was performed. The results of cytogenetic analysis showed that the studied hybridoma and myeloma cell lines are rather stable except that some chromosomal rearrangements were detect ed. By two-dimensional electrophoresis according to the O'Farrell's pr ocedure, it was shown that the similarity between myeloma and hybridom a cells in relative representativeness and reciprocal location of the expressed nuclear proteins was higher than that between these cell lin es and lymphocytes. Probing of the chromatin structure by micrococcal nuclease treatment showed no significant differences in the degree of nuclease resistance between chromatin from myeloma, hybridoma, and lym phoid cells. High levels of Ca2+/Mg2+-dependent endonuclease activity was detected in situ in lymphocyte nuclei and their extracts, while in the same objects in myeloma and hybridoma cells it was not found. How ever, in extracts from myeloma and hybridoma cells nuclei the high amo unts of DNA-binding proteins were found, whereas in mouse spleen lymph ocytes these proteins were undetectable.