 

 



| This slide illustrates one
  reason why Ctbp2 should be considered a high priority positional candidate
  gene that may modulate the expression level of App.  Ctbp2 is a strong cis QTL in some brain regions (here the
  data are taken from the striatum). 
  If Ctbp2 contains variants that modulate its own expression then these
  expression differences may produce many downstream effects. Of course, we now
  want to know much more about the known biology of Ctbp2. What kind of gene is
  it? To begin to answer that question we can use a number of resources listed
  in the LINKS page. | |
| Notes: | |
| 1. The App QTL is bimodal. Perhaps there are actually two causal factors
  in this region--one close to 123 Mb and the other close to 127 Mb. | |
| 2. The precision of QTL
  mapping depends on several factors, including the effect size and
  interactions among QTLs modulating a trait, the number of genetic individuals
  that are studied, and the distribution of recombinations in the study
  population.  In the case above,
  the QTL(s) are likely to be confined to the interval from 120 to 132 Mb. The
  bootstrap test (yellow bars shown in some of the previous slides) can be
  usual for estimating the consistency of QTL peaks. |