ISSN:
0021-9541
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
Hemoglobin has been used in two ways as a tool in the study of cell differentiation. Because of its obvious value as a marker, cells synthesizing hemoglobin have been studied in the process of acquiring this specific function - a property determined by genetic, hormonal, and physiological factors which have been investigated. Alternatively, hemoglobins associated with specific developmental stages have been studied; the molecular relationships of these hemoglobins and the genetic determinants of their structure and of the timing of their appearance in development have been investigated. The following subjects are reviewed: (1) initiation of hemoglobin synthesis, (2) regulation of stem cell differentiation and hemoglobin formation, (3) hemoglobin types in the ontogenesis of erythrocytes, (4) hemoglobin and erythrocyte differentiation, and (5) control of the switch of developmental types of hemoglobin.Experiments bearing on the cytoplasmic control of hemoglobin synthesis in reticulocytes are presented. These experiments indicate that the peptide chains of hemoglobin are differentially released from polysomes: β chains are immediately released as soon as completed, whereas α chains are retained on polysomes after completion and are presumably released upon combination with β chains. Experiments on the accumulation of globin in reticulocytes in the presence of iron-chelating agents indicate that globin is an intermediate in the assembly of hemoglobin and that heme does not play a direct role in the release of hemoglobin chains from polysomes.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcp.1040670414
