Essential Cell Biology 5th edition

CHAPTER TEN
10
Analyzing the Structure
and Function of Genes
Since the turn of the century, biologists have amassed an unprecedented
wealth of information about the genes that direct the development and
behavior of living things. Thanks to advances in our ability to rapidly
determine the nucleotide sequence of entire genomes, we now have
access to the complete molecular blueprints for thousands of different
organisms, from the platypus to the plague bacterium, and for thousands
of different people from all over the world.
This information explosion was ignited by technological advances that
allowed the isolation and manipulation of a selected piece of DNA
from among the many millions of nucleotide pairs in a typical chromosome.
Investigators then developed powerful techniques for replicating,
sequencing, and modifying this DNA—and even introducing it into other
organisms that can then be studied in the laboratory.
These technical breakthroughs have had a dramatic impact on all aspects
of cell biology. They have advanced our understanding of the organization
and evolutionary history of complex eukaryotic genomes (as discussed in
Chapter 9) and have led to the discovery of whole new classes of genes,
RNAs, and proteins. They continue to generate new ways of determining
the functions of genes and proteins in living organisms, and they
provide an important set of tools for unraveling the mechanisms—still
poorly understood—by which a complex organism can develop from a
single fertilized egg.
At the same time, our ability to manipulate DNA has had a profound
influence on our understanding and treatment of disease: using these
techniques, we can now detect the mutations in human genes that are
responsible for inherited disorders or that predispose us to a variety of
ISOLATING AND CLONING
DNA MOLECULES
DNA CLONING BY PCR
SEQUENCING DNA
EXPLORING GENE FUNCTION