14
FRIEDHELM HILDEBRANDT
The following principles apply to replication of genomic DNA (Figure
8A):
• Replication is semi-conservative, i.e. each newly formed double strand
consists of one newly synthesized daughter strand and one original parent strand which has served as a template for base pairing in replication
(Figure 8A).
• Replication starts when a multi-enzyme complex, that contains a DNA
polymerase (e.g. DNA-Pol. 111 in prokaryotes) binds to double-stranded
DNA and opens up the double strand. DNA-Polymerases (Figure SB) use
the nucleotide sequence of the original ("parent") strand as the template
A
Exons
mRNA
Genes
•
Avoragc distance between
Gene complexes
polymorphic sites
Chromesoma fragme nts
recombined durJ ng meiosis
•
=
Average distance
Chromosomes
between genas
Total huma~ 1
genome slze
B
Allele·specllic oligonucleotlde
Ollgonueleotide ligatlon
Soquenelng
Donaturi ng gradient.gel electrophOresis and RNase A techniQue
Polyacrylamide gel electrophoresis
Polymerase chain reaction
Agarosegel electrophoresis
Molecular cloning
Pulsod fielet gradient gel eleclrophoresls
Genetic link.age
Chromosomal in silu
hybridization
10 1
107
109 3X109
Nucleolides
0.1
10
1 00
1 000 3000
Centimorgans
Fig. 7. Diagnostic techniques and the human genome. (A) The ranges of sizes of informational units of the humangenomein nucleotides or centiMorgans. (B) The size ranges over
which various diagnostic techniques are useful. (Modified from [7].)