NEITHER HMG-14A NOR HMG-17 GENE-FUNCTION IS REQUIRED FOR GROWTH OF CHICKEN DT40 CELLS OR MAINTENANCE OF DNASEI-HYPERSENSITIVE SITES

HMG-14 and HMG-17 form a family of ubiquitous non-histone chromosomal proteins and have been reported to bind preferentially to regions of a ctive chromatin structure. Our previous studies demonstrated that the chicken HMG-17 gene is dispensable for normal growth of the DT40 chick en lymphoid cell line, Here it is shown that the major chicken HMG-14 gene, HMG-14a, is also dispensable and, moreover, that DT40-derived ce lls lacking both HMG-17 and HMG-14a proteins show no obvious change in phenotype with respect to the parental DT40 cells, Furthermore, no co mpensatory changes in HMG-14b or histone protein levels were observed in cells lacking both HMG-14a and HMG-17, nor were any alterations det ected in such hallmarks of chromatin structure as DNasel-hypersensitiv e sites or micrococcal nuclease digestion patterns, It is concluded th at the HMG-14a and HMG-17 proteins are not required for normal growth of avian cell lines in vitro, nor for the maintenance of DNasel-hypers ensitive sites in chromatin.