Differential salt fractionation of active and inactive genomic domains in chicken erythrocyte.

We have utilized the Sanders salt fractionation technique (Sanders, M. M. (1978) J. Cell Biol. 79, 97-109) to analyze the products of micrococcal nuclease digestion of adult chicken erythrocyte nuclei. By dot-blot hybridization with specific gene probes, it is found that nucleosomes from the globin gene domain, including a region extending to about 10 kilobase pairs 5' to the beta p gene are selectively enriched in the fractions eluted at low salt. In contrast, a single copy sequence located at about 10 kilobase pairs 5' to the beta p gene was concentrated in the less salt-soluble fractions. The vitellogenin and ovalbumin genes, which are never expressed in erythroid tissues, are also concentrated in the less salt-soluble fractions. Some more generally expressed genes (histone H4, thymidine kinase) appear to be more uniformly distributed. The low salt fractions are depleted in H1/H5, enriched in high mobility group 14 and 17, and contain somewhat more highly acetylated histones.