2007 UCLA Amgen Scholars Program

Student Profiles

Ms. Joy Benavidez

Mr. Sergey Boyarskiy

Ms. Cara Childers

Mr. James Durgin

Ms. Jenny Feng

Mr. Azriel Ghadooshahy

Mr. Daniel Goldstein

Mr. Dmitriy Kolodin

Mr. Martin Krupa

Ms. Erin McDonald

Mr. Kunal Mehta

Mr. Aaron Meyer

Mr. Troy Moore

Ms. Euphemia Mu

Mr. Adeleke Oni

Mr. Richard Rodriguez

Ms. Lauren Sanchez

Ms. Hope Shaffer

Mr. Daniel Sitz

Ms. Emilienne Repak

Ms. Sara Thoi

Ms. Sophia Yang

Ms. Laura Yee

Ms. Jennifer Yeh

Ms. Maggie Zhu

Name: Joy Benavidez
Home University: University of Texas at Brownsville
Class: Senior
Major: Biology
Faculty Mentor: Dr. Daniel Geschwind

As a second year MBRS-RISE scholar at the University of Texas at Brownsville, Joy works in Dr. Luis V. Colom’s Neuroscience lab, where she examines how amyloid beta (Aβ) modifies and influences the function of the septo-hippocampal region in vivo. As an Amgen Scholar at UCLA, Joy is currently working in Dr. Daniel H. Geschwind’s lab studying gene regulation of GABRB3 by the transcription factor FOXP2 in the SY5Y neuronal cell line.

We aim to identify the responsible signaling pathways that render individuals incapable of language acquisition. GABRB3 is one of three genes that contribute to the subunit composition of the inhibitory chloride receptor, GABA A. Initial microarray studies, conducted in Dr. Geschwind’s lab on SY5Y cells overexpressing FOXP2, yielded a significant reduction in GABRB3 expression compared to controls. Mutations in GABRB3 have been implicated in numerous language and developmental disorders, specifically cleft palate and autism. Therefore Joy’s focus is to dissect FOXP2’s role in regulating GABRB3 gene expression.

Joy will clone a luciferase vector containing an inserted GABRB3 promoter, which will then be co-transfected into the SY5Y cells with a vector overexpressing FOXP2. The direct relationship of FOXP2 and GABRB3 will be confirmed by performing chromatin immunoprecipitation (ChIP). Immunohistochemistry and Western blotting will also be performed to examine whether FOXP2 regulation of the transcription of GABRB3 correlates with GABRB3 protein expression.

Joy has recently applied to the MD/PhD program at UCLA and would like to thank Amgen and the Geschwind lab for all of their help and encouragement.

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Name: Sergey Boyarskiy
Home University: UCLA
Class: Junior
Major: Bioengineering
Faculty Mentor: Dr. Frank Laski

As an Amgen Scholar in Dr. Frank Laski’s lab at the department of Molecular, Cellular and Developmental Engineering, Sergey is working on characterizing emperor’s thumb, a novel gene identified in the Laski lab implicated in regulating apoptosis in Drosophilamelanogaster.

Apoptosis, a form of programmed cell death, is a crucial component in the cell cycle. Irregularities in apoptosis play a role in a large number of cancers as well as rheumatoid arthritis. Previous studies in the Laski lab have identified emperor’s thumb’s (et), as a protein deubiquitinase, whose role is somehow related to the regulation of DIAP (Drosophila Inhibitor of Apoptotic Proteins), the only known regulator of cell death. Curiously, et has six possible transcripts, and overexpression of each has revealed that the transcripts fall into two different categories which seem to have juxtaposing effects in terms of regulating apoptosis. Four of the six transcripts induce apoptosis, while the other two inhibit cell death. This summer, Sergey will be identifying the role of et in apoptosis using genetic interactions approach. He will also perform a Northern Blot analysis to identify the RNA transcript of et that is expressed in vivo.

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Name: Cara Childers
Home University: University of Kentucky
Class: Senior
Major: Agricultural Biotechnology
Faculty Mentor: Dr. Geraldine Weinmaster

At the University of Kentucky, Cara works with Dr. Steven Estus, an associate professor in the Department of Physiology. There she examines molecular and cellular mechanisms in neurodegenerative disease, focusing on the effects of single nucleotide polymorphisms in the splicing of the gene UCP2.

In Dr. Geraldine Weinmaster’s laboratory, Cara is examining the requirements of furin processing in the Notch1 protein. The laboratory previously developed a mouse model system using homologous recombination to generate knock-in mice with a deleted furin cleavage sequence in the Notch1 gene (N1 ∆FC). To study the phenotype of N1 ∆FC mutant mice, heterozygous mice carrying the targeted allele have been crossed to obtain a congenic N1 ∆FC line. These mutant mice have been found to have enhanced survival compared to other Notch signaling pathway mutants, but have vascular defects that resemble a loss in Notch-signaling. The proposed experiments will analyze embryonic vascular defects and biochemical properties exhibited by mice defective in furin cleavage of Notch1. Using immunohistochemistry and in situ hybridization, Cara looks to analyze the expression and gene products of Notch1 and other downstream genes, such as HRT2 and Snail. These experiments should provide insights into the requirements of Notch1 furin processing for normal embryonic development.

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Name: James Durgin
Home University: Pennsylvania State
Class: Senior
Major: Physics
Faculty Mentor: Dr. Frank Pajonk

At Pennsylvania State University James works with Professor Andrew Webb by designing, building, and testing radiofrequency coils for MRI imaging of small animals. At UCLA, he is investigating the effects of proteasome inhibiting drugs on radiosensitivity with Dr. Frank Pajonk.

Proteasome inhibiting drugs are a new class of drugs that are used clinically to treat multiple myeloma. However, proteasome inhibitors have been shown to reduce cancer mass in other types of cancer as well. The purpose of his research is to better understand the effect of two proteasome inhibiting drugs, PS-341 and NPI0052, on gliomas. This will involve testing the ability of the drugs to pass through the blood-brain barrier, determining toxic levels of the drug, and examining any radiosensitivity, since these drugs may be used in combination with radiation therapy. Much of the work will involve testing cell lines with different concentrations of both drugs and then exposing the treated cells to varying levels of radiation. Overall, the results of his work should provide a better understanding of how each drug interacts with a variety of glioma cell lines when exposed to radiation. This information, along with toxicity levels and the ability to cross the blood-brain barrier, should be useful to physicians as they prescribe PS-341 and NPI002 as treatment options.

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Name: Ni (Jenny) Feng
Home University: UCLA
Class: Senior
Major: Biology
Faculty Mentor: Dr. Barney Schlinger

Ni Feng is working with Dr. Barney Schlinger in the Physiological Sciences Department to investigate the effects of hormones on avian courtship behavior. Under Dr. Schlingers mentorship, Ni has been studying the androgen control of the complex courtship behavior of the Golden-collared Manakin (Manacus vitellinus), a tropical bird found in Panama. Male manakins create loud snapping sounds by rapidly and forcefully contracting their wings to attract females.

As a URTSP scholar and Amgen Scholar, Ni has investigated the role of testosterone and its androgen metabolites in stimulating the male manakin display . The sexually dimorphic morphology of the wing muscles and the higher accumulation of testosterone by male motor neurons in the spinal cord suggest that androgens acting on male wing muscles may be responsible for the male-specific display. The conversion of testosterone into its active androgenic metabolite 5α-dihydroxytestosterone (5α-DHT) by 5α-reductase is crucial for its function in target tissues . 5α-DHT is a more potent androgen than testosterone because it binds to androgen receptors with a higher affinity. Ni has quantified 5α- and 5β-reductase activities in two limb muscles of male and female manakins as well as in the zebra finch (Taenopygia guttata), a non-wingsnapping bird, to look for sex, muscle, and species differences in androgen sensitivity . Since the actions of testosterone metabolites ultimately lie in the interaction with steroid receptors, Ni is currently using real time PCR to measure androgen receptor mRNA levels in manakin and zebra finch limb muscles.

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Name: Azriel Ghadooshahy
Home University : UCLA
Class: Senior
Major: Cybernetics
Faculty Mentor: Dr. Dean Buonomano

As an Amgen Scholar in Dr. Dean Buonomano’s lab in the UCLA Neurobiology department, Azriel is studying in vitro neural network dynamics in a mouse model of Fragile X.

Fragile X is an X-linked null mutation of the FMR1 gene in humans which confers severe cognitive and learning disabilities. Fragile X causes altered dendritic spine morphology and faulty regulation of the metabotropic glutamate receptors in the cortex. This enhances mGluR-mediated long term depression and compromise mGluR-mediated long term potentiation, both of which are important for learning and contribute to emergent neural network properties.

A clinically relevant mouse model carrying an analogous FMR mutation is being used to determine whether or not Fragile X causes altered neural dynamics in cortical networks relative to wild-type littermate controls. Our focus is on spontaneous (non-evoked) dynamics. We are also studying development of network dynamics over time in vitro as well as intrinsic excitability of neurons. The current objective is to establish whether or not FMR-Knockout mice exhibit altered dynamics relative to littermate controls. This study will contribute to a deeper understanding the disease as well as guide potential treatment options.

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Name: Dan Goldstein
Home University: Emory University
Class: Senior
Major: Chemistry
Faculty Mentor: Dr. Caius Radu

As part of the Amgen Scholars program at UCLA, Dan is working in the lab of Dr. Caius Radu, exploring the relationship between 18F-FDG (2-fluoro-2-deoxy-D-glucose) uptake and cellular metabolism.

Positron Emission Tomography (PET) scans can be used to visualize different types of cancer. When radioactive probes such as positron-emitting radionuclides are injected into humans, high energy (511 keV) gamma rays are emitted. PET produces a 3-dimensional whole-body image representative of the biological properties of the PET probe. However, certain types of cancer display different properties when imaged by FDG, an analog of glucose, which is often upregulated in response to cancer. Therefore, Dan is currently working to analyze the relationship between cancer lines that exhibit a high versus low rate of FDG uptake in order to find a relationship between PET imaging and the various stages in the metabolic pathways of Glycolsis and the Krebs cycle. This should ultimately allow physicians to better diagnose and understand the specific type of cancer a person is experiencing, and eventually lead to the development of more specific probes for the diagnosis and treatment of cancer.

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Name: Dmitriy Kolodin
Home University: UCSB
Class: Senior
Major: Microbiology with an emphasis on Biotechnology
Faculty Mentor: Dr. Harold Monbouquette

For the last two years, Dmitriy has been working on directed evolution of silicatein in Dr. Dan Morse’s lab as part of the Research Internship in Science and Engineering (RISE) at UCSB. The project involves evolving silicatein, an enzyme that catalyzes the condensation of silica in Tethya aurantia sponges, in order to produce a new and more efficient way for producing titanium dioxide and cadmium sulfide at ambient temperature and pressure.

At UCLA, Dmitriy’s work in the Monbouquette lab focuses on elucidating the biochemical pathway for synthesizing archaeal membrane lipids, which consist of two diether lipids that are linked through their isoprenoid hydrocarbon tails to form tetraehter lipids that span the entire membrane. This tetraether lipid structure provides the archaeal membrane with the needed stability to survive in extreme conditions. The ability to synthesize these tetraether lipids would provide a potential novel approach for drug delivery due to the high stability that has been displayed by these membranes. Dmitriy’s project involves cloning two of the enzymes involved in the biosynthetic pathway from the genome of Archaeoglobus fulgidus and engineering E. coli to be able to express these enzymes. This project will not only confirm whether these enzymes are involved in key steps in the pathway, but will help progress the engineering of E. coli for mass production of archaeal tetraether lipids.

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Name: Martin Krupa
Home University: UCSD
Class: Senior
Major: Bioinformatics
Faculty Mentor: Samson Chow

As a Chancellor’s Research Scholar, Martin has worked in Senyon Choe’s Structural Biology Laboratory at The Salk Institute on crystallization of GFP-tagged E. coli membrane proteins. He is currently working in Samson Chow’s lab in the Department of Molecular and Medical Pharmacology at UCLA on the characterization of XMRV, a novel gammaretrovirus associated with prostate cancer.

Xenotropic MLV-related virus (XMRV) was discovered in tumors of prostate cancer patients homozygous for a reduced activity variant of RNase L, an endoribonuclease that degrades single stranded RNA and a downstream target in the interferon antiviral response. XMRV ’s role in tumorigenesis, however, has not yet been defined and a casual mechanism describing its oncogenic potential remains unknown. Because XMRV cannot infect murine cells, part of Martin’s research focuses on engineering a recombinant clone of XMRV that can infect murine cells. This involves substituting XMRV’s envelope polyprotein (env) region with the env region of Moloney-MLV to create an amphotropic virus with murine receptors (aXMRV). In some cases, proteins encoded by the env region can directly cause cancer, as with erythroleukemia induced by the Friend virus. The long term goal of Martin’s research is to determine the oncogenicity of XMRV’s env region. His current work focuses on constructing a high titer aXMRV, and then comparing its replication kinetics in cultured mouse cells to WT-XMRV in human cells.

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Name: Erin McDonald
Home University: UCLA
Class: Senior
Major: Microbiology, Immunology and Molecular Genetics
Faculty Mentor: Dr. Robert Gunsalus

Erin is using her bioinformatics approach to studying signal transduction pathways in methanogenic and syntrophic bacteria. She is undertaking a comparative analysis of the mechanisms of other well-studied organisms’ specific responses that have already been deduced. These well known models can be used to uncover similar pathways, show adaptations of classical pathways and explain novel signal transduction pathways in the methanogens and syntrophs. To dissect the control mechanisms she is purifying transcriptional regulators of these pathways from Methanosarcina acetivorans to deduce possible mechanistic features. These regulators will be sequenced and their function in signaling transduction pathways inferred. Her experiments will establish a better understanding of the role of methanogens and syntrophs in the global carbon cycle. Syntrophy between the syntrophs and methanogens is extremely important, as it involves the cooperative degradation of a carbon compound to create a reaction with favorable energy production. Erin hopes her research will allow her lab to characterize and understand key energy steps in the production of methane gas and hydrogen gas and their part in reverse electron flow. She hopes such information will promote understanding of the global carbon cycle’s role in our ever-changing environment.

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Name: Kunal Mehta
Home University: UCLA
Class: Senior
Major: Bioengineering
Faculty Mentor: Dr. Jacob J. Schmidt

Kunal’s work centers on controlling the electrophoretically driven translocation of single-stranded DNA through a biological nanopore to enable rapid single-molecule DNA sequencing. Although previous work has shown that protein nanopores can discriminate among different nucleotides in single-stranded DNA, true single-molecule sequencing has not yet been realized. The salient obstacle is that the speed of translocation is too fast to enable amperometric detection of individual nucleotides. We are investigating two approaches to slow the rate of translocation: by opposing the electrophoretic driving force with an externally applied magnetic force, and by hybridizing short DNA oligonucleotides to hinder movement through the nanopore. Our preliminary experiments using the pore protein alpha Hemolysin have been encouraging; we have measured distinct current magnitudes that may suggest dynamic single-molecule discrimination between adenine and cytosine nucleotides as they travel through the pore. Ultimately, we hope that this work will establish the feasibility of nanopore DNA sequencing and provide insight into the physics of the trapped ssDNA-nanopore assembly. 

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Name: Aaron Meyer
Home University : UCLA
Class: Junior
Major: Chemistry
Faculty Mentor: Dr. Daniel Kamei

Aaron Meyer has worked with Dr. Daniel Kamei for one year in the Department of Bioengineering, examining the use of novel two-phase surfactant systems in order to concentrate diagnostically significant biomarkers. More specifically, he is attempting to selectively concentrate nucleic acids by exploiting their charge.

In recent publications, researchers have noted the presence of unique nucleic and proteinaceous markers in the saliva and urine of patients with certain disorders such as oral squamous cell carcinoma and bladder cancer. The ability to identify these markers allows for the detection of the corresponding disorders, and early detection typically results in a much higher survival rate, even beyond the promises of currently experimental treatments. However, the tested fluids contain a wide array of molecules, very few of which are significant. Ideally, nascent disorders would be detected through regular screening; however, current detection methods require expensive equipment and special training, precluding their use in a clinical setting. Using the methods Aaron is investigating, the ability to selectively concentrate these markers might be increased, thus significantly increasing the sensitivity of current tests. The nature of surfactant systems additionally allows for their use in a clinical environment for screening purposes in cheaper, easier to use, and more environmentally friendly forms.

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Name: Troy Moore
Home University: UCSD
Class: Senior
Major: Pharmacological Chemistry
Faculty Mentor: Dr. Craig Merlic

While at UCSD, Troy works with Michael Sailor on the characterization of poly-NiPAM/porous silica composites. He further studied the release profiles of these composites by thermally triggering the collapse of the composites, thereby releasing loaded proteins. In Dr. Craig Merlic’s lab, Troy is working on the development of substrates for organometallic catalyzed coupling reactions. These substrates will be used to study novel and more efficient synthetic routes to target molecules.

Traditional organometallic coupling reactions often involve costly and toxic catalysts and substrates. Furthermore, the substrates for these reactions usually contain asymmetric terminal ends, making them difficult to synthesize. Troy is working on substrates and reactions to address these problems. He is synthesizing two similar coupling substrates from p-toluenesulfonamide. First, he is synthesizing an N,N-pentyne and subsequently an N,N-propyne (both with the alkyne functionality at the terminal end). Following this, these molecules are made into functional coupling substrates by stereoselective hydroboration. The synthetic route to these substrates is much simpler than traditional coupling substrates due to their symmetry. Troy will work up and purify an adequate quantity of these molecules so that they can be used to study two specific coupling reactions. First, a Pd(II)-catalyzed alkyne insertion will be explored on an E,E-hydroborated substrate, which would be immediately useful in the formation of fused ring systems in macrocyclic systems via Diels-Alder reactions. Second, a Pd(II)-catalyzed coupling will be attempted on a Z,Z-hydroborated substrate, which if possible, will allow for the coupling of much smaller and more strained ring systems. The development of Pd(II)-catalyzed methods of these reactions should reduce the cost and difficulty in many useful organic syntheses while allowing for many new synthetic possibilities.

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Name: Euphemia Mu
Home University: Princeton
Class: Junior
Major: Molecular Biology
Faculty: Dr. Anna Wu and Dr. Eric Lepin

Euphemia previously researched at the University of Pennsylvania in a human clinical phase II study of curcumin and the chemoprevention of colon cancer. Also, she has worked at Clark University, where she studied Nerve Growth Factor and Alzheimer’s disease.

As an Amgen Scholar, Euphemia works under Dr. Anna Wu and Dr. Eric Lepin in the Department of Molecular & Medical Pharmacology. This summer, Euphemia’s project aims to engineer antibody fragments that will image xenografts overexpressing ErbB3 in vivo.

The ErbB family of four epidermal growth factor receptors regulates normal developmental, proliferation, and apoptotic processes. High levels of ErbB are often found on the surfaces of breast and prostate cancer cells. Euphemia will focus on the most prevalent and potent ErbB receptor pairing in cancers, the ErbB2/ErbB3 heterodimer. Currently, ErbB2 is the target of such drugs as Iressa and Herceptin. The properties of ErbB3, however, are still unclear. Euphemia will identify optimal human single-chain variable fragments (ScFvs), which retain only the variable portion of antibodies, which will bind specifically to ErbB3. From these ScFvs, she will construct ScFv dimmers or diabodies, for in vivo targeting and imaging to delineate precise factors that result in ErbB2/ErbB3 heterodimer overexpression. Her work will lay the foundation for technology that will allow for the diagnosis of the stage and prognosis of cancer.

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Name: Adeleke Oni
Home University: Xavier University
Class: Senior
Major: Chemical Science
Faculty Mentor: Dr. Michael E. Jung

At Xavier University, Adeleke Oni works with Dr. Richard J. Mullins, with plans of completing the total synthesis of +(-) Kalkitoxin. At UCLA, Adeleke is currently working in the lab of Dr. Michael E. Jung in the Department of Chemistry and Biochemistry. He is developing new methodologies and applying these new techniques to complete the total synthesis of natural products using synthetic organic chemistry. Specifically, he will discover if 1,3-cyclopentadiene will undergo a Diels-Alder reaction in high yield with 2,3-Furandione, 5-phenyl-.

Adeleke’s synthesis begins with reacting acetophenone with tert -Butyldimethylsilyl trifluoromethanesulfonate and triethyl amine. The product will result in a TBDMS group that can react with oxalyl chloride to form the desired dieneophile, 2,3-Furandione, 5-phenyl-. The best diene needed to react with the dieneophile must be in the cis arrangement in order to produce the final product, a cis-hydroxy acid. This is the most important and difficult reaction in the synthesis. To make the selected diene, 1,3-cyclopentadiene, he will first have to break open Dicyclopentadiene molecules using a retro Diels-Alder method. After completion of the Diels-Alder reaction, Adeleke will finally be able to perform a reduction reaction with sodium periodate to obtain his final goal of producing a cis-hydroxy acid via the Diels-Alder reaction. In future studies, similar methodologies will be examined to aid in producing larger and therefore more complicated compounds

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Name: Richard Brooks Rodriguez
Home University: UCLA
Class: Senior and a second year Departmental Scholar
pursuing a M.S. in Organic Chemistry
Major: Chemistry
Faculty Mentor: Dr. Miguel A. Garcia-Garibay

Richard previously worked on community education projects at the Center for the Study of Latino Health and Culture at the David Geffen School of Medicine. He currently works with Dr. Garcia-Garibay in the Chemistry and Biochemistry Department, and has worked there for over one year. Richard is a current AMGEN Scholar, Organic Chemistry TA, and he spent the last summer as a CNSI Fellow.

The Garcia-Garibay Group works towards the synthesis and study of dynamic crystalline materials. Currently, Richard is working towards the development of a dynamic crystalline material which can possibly be switched between two states of solid state dynamics. Previously, Richard synthesized a diarylethene photoswitch and is now currently synthesizing a molecular rotor that will be combined with the diarylethene in the convergent synthesis of a photochemically reactive molecular dirotor. Currently, chemists are powerless in predicting the crystal structure of large organic molecules such as the one Richard is synthesizing. Therefore, the photochemical reactivity of this compound can not be predicted in the solid state as it depends on the crystal structure. Richard’s research will answer this and other questions regarding the solid state dynamics of a diarylethene based molecular dirotor following the completion of its synthesis.

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Name: Lauren Sanchez
Home University: UCLA
Class: Senior (4 th Year)
Major: Molecular, Cell, and Developmental Biology
Faculty Mentor: Dr. Luisa Iruela-Arispe

For the past three years, Lauren has worked under the guidance of Dr. Luisa Iruela-Arispe in the Department of MCDB. Lauren has participated in URSP as a Van Trees Scholar, and is completing her undergraduate honors thesis in fall 2007.

Progestins, synthetic forms of the female hormone progesterone, are widely used by women in both contraceptives and hormone replacement therapy (HRT). Progesterone as a hormonal supplement was once thought to be beneficial to women’s cardiovascular health. However, recent studies have demonstrated that women using an HRT regimen of estrogen and progesterone are at a greater risk for developing heart disease than women using estrogen only. Preliminary studies done by the Arispe Lab have suggested a link between expression of the progesterone receptor (PR) and vascular permeability, which may contribute to the development of heart disease. In contribution to this study, Lauren is generating a reporter mouse model, in which the reporter gene lacZ has been substituted for the PR gene. Using the PRLacZ model, she will characterize wild-type patterns of PR expression in the vasculature of female mice of varying ages. Lauren has also begun characterization of vascular PR expression in another mouse model, the PRCre/Rosa, as associated by lacZ and antibody staining. The PRCre/Rosa (provided by Dr. John Lydon, Baylor College of Medicine), identifies both populations of cells that once expressed PR and their derivatives. Findings from the PRCre/Rosa mice will help direct study of the PRLacZ mouse.

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Name: Hope Shaffer
Home University: Calvin College
Class: Senior
Major: Double majoring in Biotechnology
and Classical Civilization
Faculty Mentor: Dr. Kent Hill

Hope has previously worked with genetic characterization of the lacrimal glands of Sjogren’s syndrome models and the effect of mDia1 on neurite outgrowth in the department of molecular biology at Calvin College. She is currently working with Dr. Kent Hill in the MIMG department of UCLA on two projects. The first project examines the role a specific flagellar protein of the African trypanosome, LC1, on motility, and the second project analyzes the specific domains of another flagellar protein, trypanin, that are required for activity and localization.

The dynein light chain 1 (LC1) is required for directional flagellar beat in African trypanosomes. Mutant trypanosomes lacking the LC1 protein exhibit reverse flagellar beat and backwards motion, as well as failed separation after cytokinesis. While it is believed that these defects are a result of the loss of motility seen following LC1 deletion, it is possible that the presence of the protein itself is essential for correct flagellar beat, directional motility, and proper separation during cytokinesis. In order to determine if motility or the protein itself is essential to trypanosomes, Hope plans to create two different LC1 mutants that will remove all activity of the protein while allowing for proper transcription, folding, and presence of LC1.

Knockdown mutants of trypanin produce trypanosomes that are unable to complete cytokinesis in the bloodstream, which results in the formation of large amorphous clumps of joined, non-viable trypanosomes. Because loss of trypanin is so devastating to trypanosomes and little is known about the protein itself, it is important to characterize functional domains of trypanin in order to identify trypanin-associated proteins. Hope’s approach has been to express trypanin protein fragments to analyze the effects in vivo. Her current focus is to identify protein domains sufficient for localization as well as domains that lead to lethal phenotypes similar to those in trypanin mutants.

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Name: Daniel Sitz
Home University : UCLA
Class: Junior
Major: Molecular, Cell, and Developmental Biology
Faculty Mentor: Dr. Jeffrey H. Miller

Daniel previously worked for the Undergraduate Research Consortium in Functional Genomics where he worked on cell lineage tracing and decoding the role of genes in Drosophila eye development through reverse genetics. As a new member in the lab of Dr. Jeffrey H. Miller, in the department of Microbiology, Immunology, and Molecular Genetics, Daniel examines antibiotic sensitivity in E. coli. The lab is currently screening the Escherichia coli knockout collection for sensitivity to several classes of antibiotics. The objective of this work is to find target genes that, when deleted increase E. coli’s sensitivity to antibiotics. With the discovery of target genes the lab hopes to later collaborate with other labs to find small molecule inhibitors that can be co-administered with an antibiotic to overcome current resistance. In addition to achieving a direct application the lab also expects to learn more about the mechanisms in which antibiotics function and the cells defenses against them.

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Name: Emilienne Repak
Home University: MIT
Class: Junior
Major: Biological Engineering
Faculty Mentor: Dr. Douglas Black

Emilienne has worked in the Fee lab at MIT as a UROP student in Brain and Cognitive Sciences. She has also worked as a summer intern in the Jefferson University Farber Institute for Neuroscience. At UCLA, she is in Dr. Douglas Black’s laboratory studying the role of alternative gene splicing in neuronal development.

Specifically she is investigating potential splicing regulators of Numb, a protein that plays a critical role in neuronal cell fate determination. Numb has four alternative splicing patterns. The different alternatively spliced Numb proteins have been shown to induce either cell proliferation or differentiation. Recent work within the Black lab has led researchers to suspect that a family of regulators known as the Fox proteins may be responsible for the alternative splicing patterns exhibited by Numb. Using knock-out mice as well as P19 and N2A cell lines, the laboratory is currently probing the role of the various Fox proteins in changes of Numb splicing during cell differentiation. Emilienne is looking at the dependence of Numb alternative splicing on Fox regulation in vivo in the mouse. She has also utilized specific siRNAs to selectively inhibit one of several critical neuronal splicing regulators in vitro. She is analyzing the differences between Numb RNA transcripts produced under these various conditions.

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Name: Van Sara Thoi
Home University: UCSD
Class: Senior
Major: Chemistry
Faculty Mentor: Dr. Richard B. Kaner

Van Sara Thoi is a 4th year chemistry student at UC San Diego. She works with Professor Seth M. Cohen on synthesizing metal organic frameworks using metal dipyrrinato complexes and terephthalic acid derivatives. At UCLA, Sara is working with Dr. Richard B. Kaner in the Department of Chemistry and Biochemistry on conducting polymer composites as a chemical sensor for mercury vapor at low concentrations. Conducting polymers have drawn much attention because their conductivity can be readily controlled through various doping processes. These polymers are utilized in various electronic and optical applications. In addition, recent discoveries have shown that nanostructured polymers enhance their performances and allow for greater sensitivity and versatility. Sara is interested in the activity of nanofibrillar polyaniline, polythiophene, and polypyrrole composites for mercury detection. The second part of her research delves into why polypyrrole composites performs better than polythiophene and polyaniline composites. This research involves understanding the electronics of the polymers and examining hard-soft acid-base chemistry.

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Name: Sophia Yang
Home University: UCLA
Class: Junior
Major: Chemistry with a Physical Chemistry Concentration
Faculty Mentor: Dr. Yung-Ya Lin

Sophia has been working with Dr. Yung-Ya Lin’s group in the Department of Chemistry and Biochemistry since her freshman year. She is currently studying the spin dynamics occurring within magnetic resonance imaging (MRI) experiments in order to develop new techniques with better contrast.

While MRI is a preferred tool for imaging biological systems because of its noninvasive nature, it severely lacks in obtaining sufficient contrast for distinguishing between different tissue types. This is especially significant for the early detection of diseases such as cancer, and has consequently limited MRI’s feasibility. External contrast enhancing agents such as superparamagnetic iron oxide (SPIO) nanoparticles have been developed, but since they give negative contrast, it is still difficult to detect them apart from areas void of signal. Dr. Lin’s group focuses on a feedback field resulting from the interaction between the nuclear spins and the receiver coil, a phenomenon known as Radiation Damping. Recently, they have been able to modify a magnet which is able to alter the strength and phase of this magnetic field, thus adding another line to the pulse sequence. This summer, Sophia will be testing to find the optimal parameters for using a feedback field enhanced pulse to image an SPIO solution. With the ability to change the phase, it is possible that this new methodology may be able to obtain positive contrast, one of the most sought after goals in MRI research.

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Name: Laura Yee
Home University: UCLA
Class: Senior
Major: Molecular, Cell and Developmental Biology
Faculty Mentor: Alvaro Sagasti

Laura Yee has been conducting research in Alvaro Sagasti’s lab since the spring of 2006. The Sagasti lab studies the development of peripheral sensory neurons in zebrafish, particularly the intricate arbors of trigeminal neurons, which innervate the head and sense touch, temperature, and pain. Laura’s project explores possible differences between trigeminal neurons in the head, and their counterpart in the body, Rohon-Beard neurons. Trigeminal and Rohon-Beard neurons both sense stimuli from the environment, causing zebrafish embryos to rapidly turn away from potential threats. However, trigeminal neurons elicit stronger turns, whereas Rohon-Beard neurons elicit weaker turns. Laura is investigating whether fundamental differences in the hardwiring of trigeminal and Rohon-Beard neurons to interneurons in the CNS mediate the different strengths of escape behavior. She employs a variety of techniques to study this neural circuit, including behavioral assays, 2-photon laser ablation, calcium imaging, and in vivo imaging of trigeminal and Rohon-Beard neurons.

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Name: Jennifer Yeh
Home University: MIT
Class: Junior
Major: Chemical and Biological Engineering
Faculty Mentor: Dr. Hong Wu

In Dr. Sangeeta Bhatia’s lab at MIT Health Sciences and Technology, Jennifer studies the effects of cell-cell interactions and environmental factors on hepatocyte function with the goal of developing an in vitro hepatic tissue model for pharmaceutical drug development. As a UCLA Amgen Scholar in Dr. Hong Wu’s lab in the Molecular and Medical Pharmacology Department, Jennifer is studying self-renewable leukemic stem cells and associated molecular and genetic alterations in a Pten-deficient murine leukemia model.

Deletion of the Pten tumor suppressor gene causes defects in hematopoietic stem cell self-renewal and myeloproliferative disorder followed by T-cell acute lymphoblastic leukemia (T-ALL). Dr. Wu’s lab has shown that TCRα/δ-c-Myc translocation and β-catenin accumulation are required for the transformation of T-cell progenitors into leukemic stem cells (LSCs) in this murine model. Jennifer aims to determine alterations of the Notch1 pathway associated with T-cell leukemia in this model. The Notch1 signaling pathway, involved in hematopoietic stem cell self-renewal during embryonic development and hematopoietic progenitor signaling, is altered in T-ALL. The PEST domain of Notch1 has a high frequency of mutation in both human and murine T-ALL. Jennifer will screen for mutations in the PEST domain in the TCRα/δ-c-My model of T cell leukemia. She will also determine the altered expression of Fbxw7, a negative regulator of Notch1, and Hes1, a downstream target of Notch1 signaling, in bone marrow and thymus cells isolated from mice in blast crisis, the final stage of leukemia. Finally, Jennifer’s work towards in vivo, non-invasive imaging mouse model for LSCs will help her lab compare and observe the effects of different therapeutic treatments on LSCs.

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Name: Maggie Zhu
Home University : UCLA
Class: Junior
Major: Molecular, Cell and Developmental Biology
Faculty Mentor: Dr. Eric Vilain

The research of the Vilain laboratory focuses on the molecular basis of sex determination in mammals. Maggie is currently studying Wnt4, a signaling molecule involved in female sex determination.

In early fetal development, gonad is morphologically indistinguishable in male and female. In male, the expression of Sry directs gonad to follow the testicular pathway. In female, Wnt4 is involved in the ovarian pathway; however, the molecular mechanism of Wnt4 action is unknown in this context. Previous experiments showed that cell migration from the mesonephros into the developing gonad, a critical feature of testicular development, is repressed by Wnt4. In cell culture, Wnt4 re-localizes β-catenin, a cell adhesion molecule, to the cell membrane and cell-cell expression adhesion is increased. As adhesion prevents cell migration, Maggie hypothesized that Wnt4 re-localizes β-catenin to the cell membrane in the developing ovary to inhibit male-like cell migration. To test this hypothesis, Maggie will perform immunohistochemistry to localize b -catenin in both wild type (WT) and Wnt4 knock-out (KO) mouse embryonic gonads. She expects to see b -catenin localizing with cell-cell adhesion markers on the cell membrane in WT ovaries, but not in WT testes or Wnt4 KO ovaries. Maggie’s project will contribute to the establishment of molecular mechanism of mammalian female sex determination, and it will ultimately help the rapid diagnosis and management of atypical genital formation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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