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 active chromatin structure. Our previous studies demonstrated that the chicken HMG-17 gene is dispensable for normal growth of the DT40 chicken lymphoid cell line. Here it is shown that the major chicken HMG-14 gene,HMG-14a, is also dispensable and, moreover, that DT40-derived cells lacking both HMG-17 and HMG-14a proteins show no obvious change in phenotype with respect to the parental DT40 cells. Furthermore, no compensatory changes in HMG-14b or histone protein levels were observed in cells lacking both HMG-14a and HMG-17, nor were any alterations detected in such hallmarks of chromatin structure as DNaseI-hypersensitive sites or micrococcal nuclease digestion patterns. It is concluded that the HMG-14a and HMG-17 proteins are not required for normal growth of avian cell linesin vitro, nor for the maintenance of DNaseI-hypersensitive sites in chromatin.