文档介绍：POGC01 9/11/2001 11:02 AM Page 1
CHAPTER 1
Gene manipulation:
an all-embracing technique
Introduction Sequence analysis
Occasionally technical developments in science Cloning permits the isolation of discrete pieces of a
occur that enable leaps forward in our knowledge genome and their amplification. This in turn enables
and increase the potential for innovation. Molecular the DNA to be sequenced. Analysis of the sequences
biology and biomedical research experienced such of some ically well-characterized genes led to
a revolutionary change in the mid-70s with the the identification of the sequences and structures
development of gene manipulation. Although the which characterize the principal control elements
initial experiments generated much excitement, it is of gene expression, . promoters, ribosome bind-
unlikely that any of the early workers in the field ing sites, etc. As this information built up it became
could have predicted the breadth of applications to possible to scan new DNA sequences and identify
which the technique has been put. Nor could they potential new genes, or open reading frames, because
have envisaged that the methods they developed they were bounded by characteristic motifs. Initially
would spawn an entire prising several this sequence analysis was done manually but to
panies, of varying sizes, in the USA the eye long runs of nucleotides have little meaning
alone. and patterns evade recognition. Fortunately such
The term gene manipulation can be applied to analyses have been facilitated by rapid increases
a variety of sophisticated in vivo ics as well as in the power puters and improvements in soft-
to in vitro techniques. In fact, in most Western ware which have taken place contemporaneously
countries there is a precise legal definition of gene with advances in gene cloning. Now sequences can
manipulation as a result of government legisla- be scanned quickly for a whole series of structural