Week Number: 17
Seminar Date: Friday 1st December
Time: 12pm – 1pm
Module: Cell Biology S5030
Dry Practical Pre-Lab
We are going to go through the lab practical and the resources available to you. This
practical has a lot of elements. A lot of the marks received will be obtained outside of the
practical. The lab experience should give you experience with microscopy.
This lab is worth 25% of your final grade. This will take place on Tuesday 5th December.
You will have the Christmas break to do your write up, it will be due on the 16th of January
2024.
The topic: We are looking at what happens to cells when they receive a signal to change
shape. We will be using baker’s yeast, a non-pathogenic yeast.
Overview:
A cell changes shape when cells mate. Yeast cells come in two different mating types, A-
Type and Alpha type. They are genetically identical apart from one small change in the
genome that tells the cells to do different tasks:
1. Release a mating pheromone (chemicals secreted to attract something).
2. Allows receptor expression for those pheromones. Pheromones are secreted outside
of the cell. The mating site of the cell will have a receptor on the outside for the
pheromone from the opposite mating type to dock. The cell will detect the
pheromone, leading to a change in shape.
This change in shape is called a mating projection, when the mating factor is detected, there
will be a bulge on the side of the cell causing the cell to change form. The mating projections
fuse together the two mating types to become one, they do this because a mating type and
alpha mating type form a haploid. Once bound they will form a diploid.
We are interested in this process because it is an example of a shape change in response to
a signal. We want to understand what is happening in the cell that leads to the shape
change. If we look at the right-hand panel on the slide, we have our yeast cell which shows
the mating projection (sensed from the mate). The mating projection is sensed by the mate
and causes it to look for it and fuse with it. The green dots are the vesicles required to
change the shape of the cell and actin fibers (important for transporting material in the cell).
We want to understand how the projection of pheromone leads to changes in the cell.
Before coming to the practical you need to look at 3 resources:
1) Review article on the process of yeast mating.
2) Review 2 videos covering the mating process.
These are available on Moodle. You need these to answer the questions in your write up.
1
Seminar Date: Friday 1st December
Time: 12pm – 1pm
Module: Cell Biology S5030
Dry Practical Pre-Lab
We are going to go through the lab practical and the resources available to you. This
practical has a lot of elements. A lot of the marks received will be obtained outside of the
practical. The lab experience should give you experience with microscopy.
This lab is worth 25% of your final grade. This will take place on Tuesday 5th December.
You will have the Christmas break to do your write up, it will be due on the 16th of January
2024.
The topic: We are looking at what happens to cells when they receive a signal to change
shape. We will be using baker’s yeast, a non-pathogenic yeast.
Overview:
A cell changes shape when cells mate. Yeast cells come in two different mating types, A-
Type and Alpha type. They are genetically identical apart from one small change in the
genome that tells the cells to do different tasks:
1. Release a mating pheromone (chemicals secreted to attract something).
2. Allows receptor expression for those pheromones. Pheromones are secreted outside
of the cell. The mating site of the cell will have a receptor on the outside for the
pheromone from the opposite mating type to dock. The cell will detect the
pheromone, leading to a change in shape.
This change in shape is called a mating projection, when the mating factor is detected, there
will be a bulge on the side of the cell causing the cell to change form. The mating projections
fuse together the two mating types to become one, they do this because a mating type and
alpha mating type form a haploid. Once bound they will form a diploid.
We are interested in this process because it is an example of a shape change in response to
a signal. We want to understand what is happening in the cell that leads to the shape
change. If we look at the right-hand panel on the slide, we have our yeast cell which shows
the mating projection (sensed from the mate). The mating projection is sensed by the mate
and causes it to look for it and fuse with it. The green dots are the vesicles required to
change the shape of the cell and actin fibers (important for transporting material in the cell).
We want to understand how the projection of pheromone leads to changes in the cell.
Before coming to the practical you need to look at 3 resources:
1) Review article on the process of yeast mating.
2) Review 2 videos covering the mating process.
These are available on Moodle. You need these to answer the questions in your write up.
1
