In experiments of disaggregation and re-aggregation of embryonic cells, there sometimes arise complexes in which differently differentiated tissues are present in chaotic arrangement, having no relation, or only a slight relation, to the arrangement of the same tissues in a normal individual. We have referred to such complexes as teratomas (Fig. 454). The term "teratoma," however, was originally coined to [...]
In this article we will discuss about:- 1. Introduction to the Action of Genes in Differentiation 2. Signals to Genes in Differentiation 3. Recognition of Genes by Signal Molecules 4. Control of Genes at the Transcription Stage 5. Post-Transcriptional Control of Gene Expression 6. Further Possibilities 7. Relation of Differentiation to Mitosis and a Few Others. Contents: Introduction to the [...]
In this article, the changing pattern of processes of differentiation will be shown in examples taken from the development of living organisms. Hemoglobins: How specific genes change their activity during development is illustrated by the composition of hemoglobins in man. The hemoglobin in adult humans is in the form of composite molecules consisting of four units (polypeptides), two of which [...]