Regulation of lipid storage in
Saccharomyces
cerevisiae
Shaelie Harper
McDonough-Stukey Lab
A Little History
• How do cells “know” when they have
made enough lipid?
• Previously, Cheryl Jacobs had isolated
a mutant (114) we believe is defective
at sensing lipid amounts
• My work this summer was to begin
characterization of the mutant
Growth Phenotype
(clumpy vs. normal)
• Within a tetrad, it can vary what strains are
clumpy and which aren’t
• If the ratio is 2:2 within a tetrad, this means
there is only 1 mutation
Clumpy
Normal
Gas Chromatography data
•To the top is a picture of the
GC at Hope College
•To the left is an example of
the data collected by the GC
•Each Peak represents a
different fatty acid, and its
relative amount present in
each cell
Data Tables
•By creating data
tables, it is easier
to make
comparisons and
conclusions for
each individual
strain
Fatty acid Amount and Composition
Whole cell FA composition
Comparison of whole cell FA quantity
FA amount (normalized
total GC peak area)
50
Percent of total FA
sup114
40
diploid
w303-1a
30
20
10
0
10:0
12:0
14:0
16:0
16:1
FA species
18:0
18:1
26:0
16000
14000
12000
10000
8000
6000
4000
2000
0
1A
1B
1C
1D
Strain
•These charts are compiled after analyzing the
data from the GC and organizing it onto
spreadsheets (shown on the previous slide), so
we can compare different strains
Result summary
Tetrad
1
2
3
4
6
7
8
Spore
FA
Amount
Clumpy
Growth
A
Wt
NC
B
Wt
NC
C
+++
C
D
+++
C
A
NC
B
C
C
C
D
NC
A
C
B
Wt
NC
C
+++
C
D
NC
A
NC
B
C
C
NC
D
C
A
NC
B
C
C
C
D
NC
A
NC
B
C
C
C
D
NC
A
Wt
NC
B
+++
C
C
+++
C
D
wt
NC
•Clumpy Growth is
inherited in a single
gene manner (2:2
inheritance)
•Preliminary results
indicate that elevated
fatty acid amount is
correlated to growth
habit, and is a single
gene mutation
Conclusions
• By examining inheritance patterns we are
able to see
– Clumpy growth habit is correlated to
elevated FA amount
– Elevated FA amount is a recessive single
gene trait
Credits
• REACH
• Dr. McDonough and Dr. Stukey
• Rachel Van Kempen
• Caitlin Rice