In article <9111191406.AA19426 at genbank.bio.net> NAGEL at EGFRCUVX.bitnet ("MUHAMMAD W. HEGAZY") writes:
>Can anybody explain in details the theory of using RFLPs in determining
>the genetic variation between 2 organisms giving an example of a simple
>Mendelian trait like plant height ??
I'm rusty on it, but in my understanding, restriction enzymes are
applied to DNA. Each enzyme recognizes a certain codon sequence, and
cleaves the DNA at that point. If a codon sequence which is normally
at a given point is not there, this results in the absence of two
smaller fragments and the presence of one larger one, thus
"Restriction Fragment Length Polymorphism". The correlation of an RFLP
with a genetic trait indicates that DNA involved in the expression of
that trait lies near the cleavage point at which the RFLP occurs: the
RFLP or perhaps the cleavage point is a marker for the trait. Genes
involved in Huntington's Disease and other diseases have been found in
this way.