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Page Items
* The Problem
* The Method
* The Investigation
* Personal Investigation page
Research Assistant Wanted

Brother Gregory wants you to help him find the number genes in various yeast metabolic pathways. In this investigation you will be provided with sets of yeast mutants, all of which have been damaged in various genes that control a specific metabolic pathway.

You will then use these haploid yeast mutants in mating reactions that produce diploid cells, by analyzing whether or not the diploid can make a substance for itself, you will be able to find out the number of genes in a particular metabolic pathway.

Assistants

You are to become Brother Gregory's research assistant. You must carry out the experiment, gather data, analyze your results and give Brother Gregory the answer you have found.

First, print out your personal investigation page (below) and find out how many genes (steps in a pathway) are in the sets of mutants you are supposed to investigate. Carry out the experiment, gather and record your data, analyze your results and write down the appropriate numbers on your personal investigation page.

This is important. Bring your completed investigation page to the examination, if it is required on your topic schedule.



Page Items
* Research Assistants
* The Method
* The Investigation
* Personal Investigation page
The Problem

Sets of unknown haploid yeast mutants have been provided for you. You must use the the phenomenon called complemenation analysis, and mate each mutant with each other mutant in the set to find out if the two mutant genes are complementary or not.

From this information, you should be able to work out how many different genes there are in your assigned metabloic pathways.

Metabolic Pathways and
Complementation Analysis



Page Items
* Research Assistants
* The Problem
* The Investigation
* Personal Investigation page
The Method

In these investigations you observe what happens when two different haploid yeast mutants are mated together to form a diploid cell (with two copies of each gene).

If both these haploid mutants are damaged in the same gene, then the resulting diploid cell will also still be damaged in this function. It will not be able to make any working copies of the protein coded for by this gene(s) and will still not be able to grow if the missing product is not present.

Before you begin, take this opportunity to read about how the mutants are prepared and how haploid yeast cells are mated (fused) together to form a diploid.

How to mate yeast and form diploids



Page Items
* Research Assistants
* The Problem
* The Method
* Personal Investigation page

Start the Investigation

In this investigation you have been assigned four different sets of mutants. These will have a "set number" (i.e. #1 -or- #4 -or- #9, etc.). These are the numbers you have been assigned on your personal investigation page. These are the sets of mutants you must investigate.

Each set of mutants also has a "batch number" (i.e. [3476] -or- [5623] -or- [8745], etc.). These numbers reference the "batch" or "kind" of mutants being investigated. You do not need these numbers to find the correct answers in these investigations.

Each set of mutants comes in two forms; a-mating type and alpha-mating type, and both are numbered 1 -to- 9.

The a-mating type mutants will be placed as vertical streaks on your mating and analysis petri dishes, while the alpha-mating type mutants will be placed as horizontal streaks on your mating and analysis petri dishes.

In your experiments, you will see the results of mating these sets of mutants together, and by looking at the intersections of the vertical and horizontal streaks, you will be able to see if any diploids formed that can grow on the selective media.

Mate yeast together and find How Many Genes

Print out your
personal investigation page

Page Items
* Research Assistants
* The Problem
* The Method
* The Investigation
Carefully enter your Seat Number or PCIN number
(e.g.
MM34, or MA56, or WA41)
in the box below, click, and print out the page that appears.

Find the answers to the questions, write your answers on the investigation page, and bring the completed assignment to the designated exam for grading purposes.

Personal Investigation Page

Enter your seat number or PCIN number here: -


Science@a Distance
© 2002, Professor John Blamire