Studies of these females show that the XIST locus on their tiny ring X chromosomes is either not present or not expressed .
studies of these females show that the xist locus on their tiny ring x chromosomes is either not present or not expressed .
O O O B-multi_cell O O O B-DNA_domain_or_region I-DNA_domain_or_region O O B-DNA_molecule I-DNA_molecule B-DNA_molecule I-DNA_molecule O O O O O O O O