Genetic counseling has not been discussed in this chapter, but it is a service provided by trained professional counselors who also have detailed knowledge of medical genetics, as described in Application Chapter A. Genetic counselors provide details about gene mutations and have knowledge of most of the details of diseases associated with genetic abnormalities. With regard to genetic testing to identify one's personal risk of cancer, what are the three or four topics you think are most important to be able to discuss with a genetic counselor?

Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions. There are two types of Lynch syndrome. What are they?

Go to the website http://www.ncbi.nlm.nih.gov/omim and enter 'Lynch syndrome' in the Search box at the top of the page. From the list of options given, select '#120435—Lynch Syndrome.' Use the information you retrieve to answer the following questions. Provide a brief summary of the normal functions of the protein products of these genes.

You have identified a recessive mutation that alters bristle patterning in Drosophila and have used recombinant DNA technology to identify a genomic clone that you believe harbors the gene. How would you demonstrate that your gene is on the genomic clone?

The CBF genes of Arabidopsis are induced by exposure of the plants to low temperature. How would you examine the temporal and spatial patterns of expression after induction by low temperature?

The CBF genes of Arabidopsis are induced by exposure of the plants to low temperature. Can you design a method that would reveal these changes in gene expression in a way that a farmer could recognize them by observing plants growing in the field?

When the S. cerevisiae genome was sequenced and surveyed for possible genes, only about 40% of those genes had been previously identified in forward genetic screens. This left about 60% of predicted genes with no known function, leading some to dub the genes fun (function unknown) genes. As an approach to understanding the function of a certain fun gene, you wish to create a loss-of-function allele. How will you accomplish this?