Chapter 9, Problem 38P

On your computer’s browser, view the page accessed by the URL: http://genome.ucsc.edu/cgi-bin/hgGateway In the gene box at the top, type “CFTR” (for the CFTR gene responsible for cystic fibrosis), then “sub- mit”. You will be directed to a window showing the organization of the CFTR gene on human chromo- some 7. (If a list appears instead of a picture, click on the first link in 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 but- tons is a diagram, called an ideogram, of the chromo- some 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 ideogram to move around.)

a.	How many exons are in the CFTR gene?
b.	In which exon (s) is (are) the 5’ UTR? The 3’ UTR?
c.	In which direction is the CFTR gene tranScribed: toward the centromere, or away from the centromere?
d.	Is the CFTR gene located on the short arm (the p arm) or the long arm (the q arm) of human chromosome 7?

Now zoom out the view by $10\times$.

e.	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 twice more at $10\times$ until the entirety of Chromosome 7 is visible.

f.	What is the approximate size of chromosome 7 in Mb?
g.	What is the approximate location of the centromere on human chromosome 7?
h.	What is the significance of the Refseq genes’ appearing to pile up when you are viewing the whole chromosome?