Chapter 10, Problem 23P

On your computer’s browser, view the page accessed by the URL: http://genome.ucsc.edu/cgi-bin/hgGateway

In the Search Term box at the top, type CFTR (for the CFTR gene responsible for cystic fibrosis), then hit “GO.” You will be directed to a window showing the organization of the CFTR gene on human chromosome 7. (If a list appears instead of a picture, click on the first link at the top of the list, and you will be directed to the proper window.) At the top of this window are control buttons that allow you to move your view to the left or right, zoom in (even to the level of the nucleotide sequence), zoom out, or (on the second row) jump to a different chromosomal position. Below these buttons is a diagram, called an idiogram, of the chromosome you are viewing, with a region in red indicating the particular region of the chromosome you are looking at. (You can also click on the idiogram to move around.)

a.	How many exons are in the CFTR gene?
b.	Is the CFTR gene located on the short arm (the p arm) or the long arm (the q arm) of human chromosome 7?
c.	In which direction is the CFTR gene transcribed: toward the centromere, or away from the centromere? Section 10.4 Now zoom out the view by 10×
d.	What are the names of the genes that flank CFTR on either side? Are these genes transcribed from the same strand of chromosome 7 as CFTR, or from the other strand? Now zoom out 100× until the entirety of chromosome 7 is visible.
e.	What is the approximate size of chromosome 7 in Mb?
f.	What is the approximate location of the centromere on human chromosome 7?
g.	What is the significance of the RefSeq genes’ appearing to pile up when you are viewing the whole chromosome?