&CHAPTER 6

Molecular Genetics of Gene Expression

MARIA GALLO

Agronomy Department, Cancer/Genetics Research Complex, University of Florida, Gainesville, Florida

ALISON K. FLYNN

Veterinary Medical Center, University of Florida, Gainesville, Florida

6.0. CHAPTER SUMMARY AND OBJECTIVES

6.0.1 Summary

Along the information pipeline from DNA (a gene) to the production of a protein, there are

many steps where gene expression can be controlled. In eukaryotes, such as plants,

transcriptional control is considered the major form of gene regulation. Because of its

importance, transcriptional regulation has been the best studied and probably the most

manipulated. However, it is becoming clearer each day that posttranscriptional mechanisms

of gene regulation are critical because levels of transcription are not always well correlated

with functional protein levels. Additionally, as the area of proteomics advances, and as we

move from genetically engineering plants to improve their performance or enhance their

utility in a traditional agricultural setting, to using plants as biofactories to produce proteins,

posttranslational regulation will gain in importance.

6.0.2 Discussion Questions

1. What are the differences between DNA and RNA?


2. Describe the main parts of a gene and their functions.


3. How important arecis-regulatory elements andtrans-acting factors in gene regulation?


4. What are the control points that can regulate gene expression?

6.1 The gene

6.1.1 DNA Coding for a Protein via the Gene

From Chapter 2, we saw that there are several definitions of a gene. In this chapter,gene

means a specific segment of DNA, including its regulatory regions, that code for a protein.

Plant Biotechnology and Genetics: Principles, Techniques and Applications, Edited by C. Neal Stewart, Jr.

Copyright#2008 John Wiley & Sons, Inc.

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