Map-based Cloning: Jumping-Linking
- Chromosome walks can be interrupted if a segment of the region to be walked through
is non-clonable (for example if it is toxic to the host cell).
- Chromosome walks can be detoured in many directions if one of
the clone end probes (filled box) is a repeated sequence.
- The jumping-linking strategy was invented to overcome the problems
of unclonable segments and repeated sequences and to enable larger
regions of the genome to be scanned.
- Use is made of a restriction enzyme that recognizes few sites in the DNA (large thick bars) and an
enzyme that cuts frequently (small thin bars).
- The jumping library contains clones in which the two double digestion fragments at
either end of a large fragment are cloned in the same plasmid
in the library (segments connected by dotted lines).
- The linking library consists of plasmids containing the fragments
generated by the frequent cutter that also contain a recognition
site for the rare cutter.
- The two libraries are used in alternation to hop down the molecular
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This is page 413 of Molecular Genetics by Ulrich Melcher, ©1997, 1998
E-mail inquiries to U. Melcher------------Last Updated: 22 October, 1998