Figure 12.1 The factory approach to large
scale DNA sequencing.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.1 The factory approach to large
scale DNA sequencing.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.2 Strategies for assembly of a
contiguous genome sequence: (a) the
shotgun approach; (b) the clone contig
approach.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.3 A schematic of the key steps in
the H. influenzae genome sequencing project.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.4 Using oligonucleotide
hybridization to close gaps in the H.
influenzae genome sequence.
Oligonucleotides 2 and 5 both hybridize to the
same l clone, indicating that contigs I and III
are adjacent. The gap between them can be
closed by sequencing the appropriate part of
the l clone.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.5 One problem with the shotgun
approach. An incorrect overlap is made
between two sequences that both terminate
within a repeated element. The result is that
a segment of the DNA molecule is absent
from the DNA sequence.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.6 Chromosome walking.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.7 Building up a clone contig by a
clone fingerprinting technique.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.8 Interspersed repeat element
PCR (IRE–PCR).
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.9 The basis to STS content
mapping.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.10 Typing a restriction site
polymorphism by PCR. In the middle lane the
PCR product gives two bands because it is cut
by treatment with the restriction enzyme. In
the right-hand lane there is just one band
because the template DNA lacks the
restriction site.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.11 Typing an STR by PCR. The PCR
product in the right-hand lane is slightly
longer than that in the middle lane, because
the template DNA from which it is generated
contains an additional CA unit.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.12 Two versions of an SNP.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.13 The principle behind the use of
a mapping reagent. It can be deduced that
markers 1 and 2 are relatively close because
they are present together on four DNA
fragments. In contrast, markers 3 and 4 must
be relatively far apart because they occur
together on just one fragment.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.14 Searching for open reading
frames. (a) Every DNA sequence has six open
reading frames, any one of which could
contain a gene. (b) The typical result of a
search for ORFs in a bacterial genome. The
arrows indicate the directions in which the
genes and spurious ORFs run.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.15 The consensus sequences for
the upstream and downstream exon–intron
boundaries of vertebrate introns. Py =
pyrimidine nucleotide (C or T), N = any
nucleotide. The arrows indicate the boundary
positions.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.16 Homology between two
sequences that share a common ancestor.
The two sequences have acquired mutations
during their evolutionary histories but their
sequence similarities indicate that they are
homologues.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.17 Gene knockout by
recombination between a chromosomal copy
of a gene and a deleted version carried by a
plasmid cloning vector.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.18 Microarray analysis. The
microarray shown here has been hybridized
to two different cDNA preparations, each
labelled with a fluorescent marker. The clones
which hybridize with the cDNAs are identified
by confocal microscopy.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.19 A DNA chip. A real chip would
carry many more oligonucleotides than those
shown here, and each oligonucleotide would
be 20–30 nucleotides in length.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.20 A single gene can give rise to
two proteins, with distinct functions, if the
initial translation product is modified in two
different ways by post-translational
processing.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.
Figure 12.21 Identification of a protein by
two-dimensional electrophoresis followed by
MALDI-TOF mass spectrometry.
Gene Cloning and DNA Analysis by T.A. Brown. © 2006 T.A.
Brown.