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Meet the Academic Year 2002-2003 IBS-CORE Undergraduate Research Fellows (click on their names or scroll down the page to find out more about their research interests) |
To see the work of past IBSCORE Fellows published in the UM Biology Undergraduate Journal click the BUG. |  |
Erik Berquist, Hometown:
Mercer Island, WA
Research Mentor: Dr. Brooke Martin, U of M Chemistry
Department
Project
Title: Arsenite inhibition of vital citric acid cycle enzymes.
Project
Description:
Chronic
arsenite exposure has been linked to cancer of the lung, skin,
kidney, urinary bladder, and liver. Arsenic is present in surface
and ground water as both arsenate, As(V), and arsenite, As(III),
with As(III) the more toxic oxidation state. The toxicity and
carcinogenicity of arsenite have been ascribed to its ability to
induce oxidative stress. A number of mitochondrial enzymes
contain the putative arsenite reactive lipoic acid essential
cofactor. The enzymes pyruvate dehydrogenase (PDH) and
a-ketoglutarate
dehydrogenase (KGDH), which catalyze the initiating and
rate-determining steps of the energy producing Citric Acid Cycle,
are two of these lipoic acid containing enzymes. In addition to
their energy producing capabilities, these enzymes also play an
important role as antioxidants in minimizing oxidative stress.
The proposed result of arsenite modification of lipoic acid
cofactor would result in a loss of enzyme activity in turn
decreasing energy output, increasing oxidative stress, and
ultimately leading to cell death. To test enzyme inhibition,
classic kinetic studies will be performed on both PDH and KGDH
with varying amounts of arsenite. Binding studies will be
performed using anti-lipoic acid antibodies to determine arsenite
binding of lipoic acid. Further, mass spectroscopy will be
performed on digested enzyme. An increase of the mass of the
lipoic acid containing fragment correlating to the mass of
arsenite indicates arsenite modification.
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Kristin Bott, Hometown:
Boise, ID
Research Mentor: Dr. Paul Spruell
Project Title: The genetic variation and distribution of the Desert
Grassland Whiptail (Cnemidorphorus uniparens) in the San
Simon Valley of Arizona and New Mexico.
Project
Description:
Sexual
reproduction involves more exchange of genetic material than
asexual reproduction. Therefore, asexual populations have a lower
level of genetic variation. The desert grassland whiptail lizard,
Cnemidophorus uniparens, of southeastern Arizona and
southwestern New Mexico, is one of a few asexually-reproducing
vertebrates. This study will look at the genetic variation of
these whiptails in the San Simon Valley of Arizona and New
Mexico. Variation will be studied (1) within sample groups and
(2) among sample group. (A "sample group" is defined as a circle
with radius of the estimated home range of C. uniparens,
about 15 meters.) The geographic spread (distribution) of this
variation will also be studied. Lizards will be caught and
released after a small portion of their tail is clipped and basic
measurements (weight, length) are taken. DNA will be extracted
from these tail clips and analyzed using the Wild Trout/Salmon
Genetics Lab facilities. Analysis will be based on the degree of
similarity of genetic fingerprints within and among sample sites.
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Jessica Elsey,
Hometown: Charleston, SC
Research Mentor:
Dr. Jack
Nunberg
Project Title: Analysis
of Junin Virus fusion through site-directed mutagenesis.
Project Description:
Arenaviruses are a large family of viruses that cause a range of
acute hemorrhagic fever diseases in man. There is no effective
treatment or vaccine for arenavirus infection at the present
date. The study of the methods and structures used by a virus to
gain entry to a host cell can lead to the development of
treatments that will inhibit this first step in the infection
process. Currently there are inhibitors of Human Immunodeficiency
Virus (HIV) disease, or AIDS, in clinical trials due to extensive
study of the structure and methods used by HIV to attach to, and
enter host cells. Arenaviruses and HIV are likely to have
structural similarities when it comes to cell entry. In this
project the structure of cell entry used by Junin virus, a member
of the arenavirus family, will be studied. This will be done by
making mutations of the proteins Junin virus uses for cell
membrane fusion, and then observing whether or not these mutations
effect cell- cell fusion. The more that is understood about the
structure of arenavirus cell entry, the more progress will be made
towards developing effective treatments and inhibitors for this
family of viruses.
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Daisuke Mayuzumi,
Hometown: Gumma, Japan
Research Mentor: Dr.
Stephen Lodmell, U of M Professor
Project
Title:
Mapping of Escherichia coli 16s ribosomal RNA
accessible site by extension of random oligonucleotide libraries
with reverse transcriptase.
Project
Description:
The basic functions of the ribosome include transfer RNA (tRNA)
selection, catalysis of peptidyl transfer, and translocation of
tRNA and messenger RNA (mRNA). The ribosome is a dynamic molecule
on which conformational changes allow decoding of mRNA and tRNA
selection for protein synthesis. Therefore, the elucidation of
structural interactions between mRNA and ribosomal RNA (rRNA) and
proteins is an essential study, as those interactions must play a
key role in translation. Recently, a process for introducing
mutations in mRNA and rRNA, called the instant evolution approach,
has been developed not only to define mRNA-ribosome interactions,
but also to study translation efficiency. It was found that
efficient translation of mRNA species having an altered Shine-Dalgarno
(SD) sequence depends on the presence of specialized ribosome
having an anti-SD (ASD) sequence which is complementary to the
altered Shine-Dalgarno (SD) sequence of the mRNA. Using this
system, mRNA with the coding sequence of chloramphenicol
acethyltransferase (CAT) was selectively translated by specialized
ribosomes.
The Lodmell laboratory
is currently developing a technique to use the specialized ribosome system
used in the instant evolution technique for defining structural
interactions of mRNA and the ribosome. In particular, we will use the
toeprinting technique to study translocation of the ribosome along the
mRNA. However, mRNA including the coding sequence of CAT is too large for
the study, and a shorter mRNA is needed for a rapid and simple method to
investigate the protein synthesis process. Therefore, this proposed
research would focus on making a shorter mRNA on a plasmid using
restriction enzymes, which would shorten the mRNA. This research will help
develop future structural studies of mRNA-ribosome interactions.
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Emily Villegas,
Hometown: Polson, MT
Research Mentor:
Dr. Mary Poss
Project Title: Isolation of a non-domestic cat FIV.
Project Description:
Feline immunodeficiency virus (FIV) is an important
pathogen in both domestic and wild cats. Our lab has obtained several
samples of whole blood from cougars serologically positive for FIV. A
virus from one of these cougars (YM137) was isolated and adapted to a cat
lymphosarcoma cell line (3201). Over a period of several months the number
of cells infected with provirus, and both total and infectious particle
titers were monitored by PCR and plaque assay techniques. The preliminary
results show that the virus has begun to adapt to the cell culture based
on an increase in FIV particles in the supernatant and an increase in
integrated provirus in cells. It was discovered that feline foamy virus (FFV)
was co-isolated with FIV. The initial purpose of this project was to get a
biological clone of YM137-FIV for characterization studies, which requires
that FIV be purified from FFV. Obtaining FIV in a pure culture is
achievable if the viruses don’t co-infect the same cell. Therefore the
goal of this project is to determine whether the viruses can infect the
same cell. This will be accomplished by developing an immunoplaque assay
to determine if individual plaques express FIV and if they contain
proviral DNA by evaluation with polymerase chain reaction (PCR). Electron
microscopy will be used to provide supporting evidence of single virus
infection of susceptible cells.
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