Use of an RFLP as a co-dominant genetic marker for a recessive trait
In the pedigree,
birth of individual II-2 with the recessive phenotype
indicates that the parents must both be heterozygotes: the other
unaffected sibs seek genetic counseling to determine if they may
be carriers. The genetic tests shows that two (II-3 &
II-4) are carriers, and that one of the two children of
the latter (III-2) is
also a carrier.
Suppose this same experiment were done by amplifying the 5kb
region by PCR, and the
products are cut with the restriction enzyme and separated by
electrophoresis, and that the mutation occurs 2.5 kb from the middle restriction site and
0.5 kb from the right-hand restriction site. How many bands would you expect to see in the heterozygote? Draw the expected gel
result. Is this result the
same or different than the previous homework assignment?