18. Molecular Genetic Tools

You have identified an enhancer trap line (see Figure 14.17) generated by P element transposition in Drosophila in which the marker gene from the enhancer trap is specifically expressed in the wing imaginal disc.

How would you show that the expression pattern of the enhancer trap line reflects the endogenous gene expression pattern of the adjacent gene?

A family consisting of a mother (I-1), a father (I-2), and three children (II-1, II-2, and II-3) are genotyped by PCR for a region of an autosome containing repeats of a 10-bp sequence. The mother carries 16 repeats on one chromosome and 21 on the homologous chromosome. The father carries repeat numbers of 18 and 26.

Identify all the possible genotypes of children of this couple by specifying PCR fragment lengths in each genotype.

A family consisting of a mother (I-1), a father (I-2), and three children (II-1, II-2, and II-3) are genotyped by PCR for a region of an autosome containing repeats of a 10-bp sequence. The mother carries 16 repeats on one chromosome and 21 on the homologous chromosome. The father carries repeat numbers of 18 and 26.

What genetic term best describes the pattern of inheritance of this DNA marker? Explain your choice.

Suppose you have a 1-kb segment of cloned DNA that is suspected to contain a eukaryotic promoter including a TATA box, a CAAT box, and an upstream GC-rich sequence. The clone also contains a gene whose transcript is readily detectable. Your laboratory supervisor asks you to outline an experiment that will (1) determine if eukaryotic transcription factors (TF) bind to the fragment and, if so, (2) identify where on the fragment the transcription factors bind. All necessary reagents, equipment, and experimental know-how are available in the laboratory. Your assignment is to propose techniques to be used to address the two items your supervisor has listed and to describe the kind of results that would indicate binding of TF to the DNA and the location of the binding. (Hint: The techniques and general results are discussed in this chapter.)

In a dideoxy DNA sequencing experiment, four separate reactions are carried out to provide the replicated material for DNA sequencing gels. Reaction products are usually run in gel lanes labeled A, T, C, and G.

How does PCR play a role in dideoxy DNA sequencing?

In a dideoxy DNA sequencing experiment, four separate reactions are carried out to provide the replicated material for DNA sequencing gels. Reaction products are usually run in gel lanes labeled A, T, C, and G.

Why is incorporation of a dideoxynucleotide during DNA sequencing identified as a 'replication-terminating' event?

In a dideoxy DNA sequencing experiment, four separate reactions are carried out to provide the replicated material for DNA sequencing gels. Reaction products are usually run in gel lanes labeled A, T, C, and G.

Identify the nucleotides used in the dideoxy DNA sequencing reaction that produces molecules for the A lane of the sequencing gel.

Using an illustration style and labeling similar to that in Problem 29, draw the electrophoresis gel containing dideoxy sequencing fragments for the DNA template strand 3'-AGACGATAGCAT-5'.