The Ribosome and Its Role in Early Development.

The cells of any given multicellular organism arise from a single fertilized egg by mitotic divisions. This implies that every cell has the same chromosomal content and thus the same genetic information. Such an assumption was verified by Gurdon (1962) who transplanted nuclei from single somatic cells of the frog into enucleated frog eggs, allowed them to develop and obtained normal adult frogs. If all cells have the same genetic information and the ability to express this information under appropriate conditions, how do cells differentiate and specialize?Mirsky (1964) observed that as much as 70-80% of the DNA of the thymus nuclei could be removed with DNAase with no obvious effect on the amount of RNA synthesized. Me concluded that the DNA removed must have been "repressed" or inactive in RNA synthesis. With few exceptions, all cells of an organism contain the same genetic information, yet much of the information remains untranslated into proteins or enzymes (Market. J 964). This is one of the key concepts of the theory of differential gene activity. During the course of development, genes are selectively activated and repressed to effect the patterns of RNA synthesis necessary for the development and differentiation of an adult organism.

Level thesis:degree_level

Thesis

Year

1971

Author dc:creator

• Roberts, Janice Williamson

• Multicellular organism
• Adult frogs
• Enucleated frog eggs
• DNA
• RNA synthesis

Repository record dc:identifier

https://digitalcommons.library.uab.edu/etd-collection/7120

OAI identifier oai:identifier

oai:digitalcommons.library.uab.edu:etd-collection-8112