Lab 8: Complementation 3, DNA Sequencing & Bioinformatics

After doing some mutagenesis of a wild type strain of yeast, various mutants were found defective in histidine production.  This image shows the results from a histidine complementation assay like you have done. Mutant strain 1, “A” mating type, is the vertical streak. Mutants alpha 2-5 are alpha mating types and are the horizontal streaks. All strains have a single mutation and the mutation is recessive to the wild type allele. After doing the mating and growing on a YPD plate (left), the yeast were transferred to a SD plate (right). What can you conclude just from these results?  Select the best answer.

 

Strain 2, 3, and 5 all have mutations in the same gene

Strains 1 and 4 are in different complementation groups

Strains 2, 3, and 5 are in the same complementation group

Strains 1 and 4 are in the same complementation group

Strains 1 and 4 are in the same complementation group

In this pre-lab, you will practice using some of the bioinformatics tools that you will use during the post-lab assignment. We will focus on the apolipoprotein E gene (Gene name = APOE), which encodes a protein involved in the metabolism of fats.  

Use the instructions provided in lecture to answer the question below. 

The APOE gene is located on the ["short", "long"]  arm of chromosome ["19", "16"]. 

According to the NCBI gene home page, APOE has ["4", "6"]  exons

long

19

6

You perform a Sanger DNA sequencing reaction with dNTPs, DNA polymerase, buffer as outline on bCourses and the following DNA template, primer and ddNTPs: Based upon the template and the primer pick the corresponding expected electrophoretogram.

B

The wildtype and mutant sequences below are coding sequences from the middle of an open reading frame:

What type of mutation results from the nucleotide exchange indicated by the red letter:

Missense

Nonsense

Silent

Loss of Function

Silent

Find the closest neighboring gene to human LDLR that is encoded by the same strand of this chromosome. Hint: if the genes are on the same strand, then the arrows of the two genes should be facing the same direction. If you put your cursor over the gene arrow, it will give you the full name of the DNA region. You are looking for a gene that encodes for a protein, not a microRNA, pseudogene or enhancer.

Click on the name of that gene to open up its gene page. What kind of enzymatic activity does the protein have that this gene encodes for?

 

synthesis of proteins

 ATPase

 protease

 Lactase

 ATPase

You analyze capillary electrophoresis of a Sanger DNA sequencing reaction. Over the entire 800 nucleotide long reaction no yellow bands can be visualized. Which one of the following answers describes this sequencing reaction most accurately?

  

dCTP were accidentally not added when setting up the reaction

 

ddCTP were accidentally not added when setting up the reaction

 

ddGTP were accidentally not added when setting up the reaction

 

dGTP were accidentally not added when setting up the reaction

ddGTP were accidentally not added when setting up the reaction

How many steps of the histidine biosynthesis pathway are represented based on the data shown below? 

 

Two steps

Three steps

One step

Two or three steps

Three steps