The haemoglobin in the condensed chromatin of mature amphibian erythrocytes: a further study

Abstract

The condensed chromatin in mature nucleated erythrocytes is surrounded by nuclear haemo-globin at a concentration about equal to that in the cytoplasm. New measurements employing improved fixation, glutaraldehyde instead of OsO₄, and microspectrophotometnc analyses instead of photographic photometry at one wavelength, show that previously reported values for the content of haemoglobin in the mass of the chromatin in Triturus crutatus, 45–50%, were far too high. In the condensed chromatin of 3 species of amphibia the concentrations of intrachromatin haemoglobin relative to the cytoplasm are 10% (Triturus crutatus), 10% (Necturus maculosa) and 8 % (Amphtuma trtdactylum). It is concluded that haemoglobin is only a minor component of chromatin, and this result is discussed in relation to the condensation of erythrocyte chromatin and observations on its ultrastructure.