Gene transfer. Ways that bacteria can acquire new genetic info Transformation Taking up of “naked DNA” from solution Transduction Transfer of DNA one to cell to another by a virus Conjugation “Mating”: transfer of DNA from one bacterium to another by direct contact. Transformation.
Griffith combined heat killed, virulent cells with live, harmless mutants. The living cells took up the DNA from solution, changed into capsule-producing, virulent bacteria.
DNA must be homologous, so transformation
only occurs between a few, close relatives.
More common, but still requires close relative.
A mutation is an inheritable change in DNA.
This means an alteration in a basepair or
in the order of the basepairs.
Mutations may affect a single basepair,
(point mutation) where they may
change the sequence in an RNA or
protein, or not (silent mutation).
During protein synthesis, bases are read
3 at a time (codon); when the first base
is read, the “reading frame” is established.
If the frame is altered at some point the bases will NOT be in
the right places, and the information will be garbled.
First, expose cells to mutagen, then spread onto defined medium containing many amino acids and other nutrients. Replica plate onto medium with same composition except NO SERINE.