Schlegel R A, Haye K R, Litwack A H, Phelps B M
Biochim Biophys Acta. 1980 Feb 29;606(2):316-30. doi: 10.1016/0005-2787(80)90041-6.
Morris [1] has suggested that the difference in nucleosome repeat length between chicken liver (200 base pairs) and mature chicken erythrocytes (212 base pairs) may be due to the presence of histone H5 which is found in chicken erythroid cells but not in other tissues. Levels of H5 increase during erythroid maturation in the adult chicken. To determine what influence H5 might have on repeat length, erythroid populations at various stages of maturation were isolated, and repeat lengths and levels of H5 were determined. Bone marrow cells from anemic chickens were cultured in vitro to permit non-cycling erythroblasts to mature and thus increase in density. Less dense cycling basophilic erythroblasts were then isolated by buoyant density centrifugation. This erythroblasts were then isolated by buoyant density centrifugation. This population has a repeat length of 205 base pairs and an H5 content roughly two-thirds that of mature erythrocytes, which have a repeat length of 212 base pairs. A population intermediate in maturation, consisting of cells of the anemic pheripheral blood, has a repeat length of 218 base pairs, and the predominant cell type in this population has an H5 content greater than that of mature erythrocytes. Therefore, changes in histone H5 content are reflected by the nucleosome repeat length during erythroid maturation.
莫里斯[1]提出，鸡肝（200个碱基对）和成熟鸡红细胞（212个碱基对）之间核小体重复长度的差异可能是由于组蛋白H5的存在，这种蛋白存在于鸡红细胞中，但在其他组织中不存在。成年鸡红细胞成熟过程中H5水平会升高。为了确定H5可能对重复长度有何种影响，分离了不同成熟阶段的红细胞群体，并测定了重复长度和H5水平。对贫血鸡的骨髓细胞进行体外培养，以使非循环的成红细胞成熟，从而使其密度增加。然后通过浮力密度离心法分离密度较低的循环嗜碱性成红细胞。接着通过浮力密度离心法分离这些成红细胞。该群体的重复长度为205个碱基对，H5含量约为成熟红细胞的三分之二，成熟红细胞的重复长度为212个碱基对。一个成熟程度处于中间的群体，由贫血外周血中的细胞组成，其重复长度为218个碱基对，该群体中的主要细胞类型的H5含量高于成熟红细胞。因此，在红细胞成熟过程中，组蛋白H5含量的变化通过核小体重复长度得以体现。
