2. Lead: An Environmental Health
Concern
The Problem: damages brain, nervous
system, and reproductive system, especially in
young children
The Source: leaded gasoline, lead based
paints, industrial settings, batteries
Neurophysical effects of lead, such as
decrease in IQ levels, are known but
molecular mechanisms behind these effects
are not
3. Purpose
Gene human expected To analyze differential
Name gene regulation
(yeast) expression of 10 genes
Heat shock HSP10 HSPE1 up predisposed to lead
proteins
HSPA5
exposure using yeast as a
KAR2 up
model organism
DED81 NARS up
MES1 MARS up
tRNA
charging TYS1 YARS up
WRS1 WARS up
THS1 TARS up
Amino-acid BAT2 BCAT1 up
biosynthesis
SHM2 SHMT2 up
Anion
Channel VDAC3
POR1 down
4. Methods
Lead environment added to yeast culture in varying
concentrations from 0-1000µM Pb
RNA extraction and confirmation
UV visible spectrophotometry to quanfity RNA
cDNA synthesis using reverse transcriptase
Primer design using software provided by Operon
Narrow range of annealing temperature, melting
temperature, and a GC content between 40-60%
PCR and gel electrophoresis to qualitatively analyze
differential gene expression
5. TDH1
1 kb
.5 kb
.2 kb
.1 kb
0 µM 100 µM 500µM 1000 µM Negative
Pb Pb Pb Pb Control
TDH1 is a housekeeping gene that should exhibit constant
expression and whose gene product is around 100 bp. Since
constant expression is observed, differential gene expression in all
subsequent genes is because of lead-exposure, not error in
standardization.
6. HSP10 DED81
1 kb
.5 kb
.2 kb
.1 kb
0 µM 100 µM 500µM 1000 µM Neg. 0 µM 100 µM 500µM 1000 µM Neg.
Pb Pb Pb Pb Control Pb Pb Pb Pb Control
HSP10 is slightly upregulated as expected and the gene product was
around 200 bp as expected. The intensity of the bands is higher in lead-
exposed yeast than the control, which exhibits baseline expression.
DED81 (between 100-200 bp) is also upregulated as expected until the
1000µM sample, where a decrease in expression is observed, most
HSP10 DED81
probably because at such a high concentration of lead, there is a decrease
in cell viability.
7. Conclusions
HSP10 and DED81 are mostly regulated as
expected but DED81 needs to be re-tested at
lower concentrations of lead
Differential gene expression in yeast models gene
expression of respective homologues in human
genome
Elucidates the molecular mechanisms behind the
neurophysical effects of lead in humans
Relevance in determining the appropriate
therapies targeting response pathways affected
by exposure to lead in humans
8. Future research
PCR reactions for primers of 8 other genes associated
with lead-exposure in other studies
Protein level- analyze differential expression of the
protein products of these genes using western blot
