rbradbur at hardy.u.washington.edu (Robert Bradbury) writes:
>Now, looking at the "Parameters of the Human Genome", NE Morton, PNAS 88:7474-6
>we can see the X chromosome is 5.1% of the genome. Assuming that we have
>100,000 genes and that one in 10 are "active" in a cell, we must have 500
>active genes on the X chromosome. Going back to my 2.2*10^-5 mutation rate
>we get 1 in 100 cells with a broken X-chromosome gene.
Two qualifiers:
Don't forget, not all genes on the X are unpaired with the Y. A region
called the "pseudoautosomal" region contains paired genes. Most of these
genes escape X-inactivation. Also, a few genes which do pair are not
X-inactivated, so in 1/2 the population those genes have extra copies.
Keith Robison
Harvard University
Program in Biochemistry, Molecular, Cellular, and Developmental Biology
robison at ribo.harvard.edu
