Washington, DC   APRIL 9-13, 2011

For the past 11 years, the University of Delaware Howard Hughes Medical Institute’s (HHMI) Undergraduate Science Education program has sent undergraduate students to the Experimental Biology Meetings to present their research. As part of this conference, the American Society for Biochemistry and Molecular Biology sponsored its 15th Undergraduate Poster Competition in which 10 UD students participated. Since 2001, students from the University have received more awards in this competition than students from any other college or university.  Once again, UD students did well. Michael Brister received the first prize in the Proteins and Enzymes category, one of four judging categories. Matthew King received and Honorable Mention.

University of Delaware students who presented posters in the Undergraduate Poster Competition sponsored by ASBMB.

Front Row, left to right: Tejal Naik, Ashley Shay, Jean Huynh, Tori Roop, and Erica Boetefuer.
Back Row,  left to right: Muike Brister, Cory Bovenzi, Bobby Sheehan, Soma Jobbagy, and Matt King.
(Dylan Lowe not present)
Prof. Hal White, Chem & Biochem
Prof. Dave Usher, Biol. Sci.
Prof. Seung Hong, Biol Sci
Prof. Gary Laverty, Biol Sci

Erica Lee Boetefuer
Cory Bovenzi
Michael Angelo Brister
Jean Huynh
Soma Jobbagy
Matthew King
Dylan Lowe
Tejal U Naik
Victoria H. Roop
Ashley Shay
Robert Patrick Sheehan

University of Delaware students and their abstracts.

Erica Lee Boetefuer

Abstract No: 2075
The role of atg18 in signal transduction pathways
during Drosophila development

Erica L. Boetefuer, Erica M. Selva, and David Raden
Department of Biological Sciences

The goal of this research is to clone and characterize two allelic mutations, 8J16 and 9E6. Genetic screens indicated these mutations disrupt Wnt/Wingless (Wg) or Hedgehog (Hh) signaling based upon their embryonic ‘lawn of denticles’ phenotype. Complementation showed 8J16 and 9E6 are autophagy-specific gene 18, atg18, alleles. atg18 plays a role in autophagosome-lysosome fusion for degradation during starvation. In yeast, atg18 negatively regulates endosome-lysosome targeting. Under fed conditions, atg18 mutations should increase endosome-lysosome targeting, as in yeast. In Drosophila, endocytic machinery mutations that block lysosome targeting cause amplified signaling, resulting in mitogenic signaling hyperactivation. This lead to the hypothesis that atg18 mutants would show the reverse; an accumulation of lysosomes at the expense of endosomes and a decrease in Wg signaling. Analysis in Drosophila wing imaginal discs showed no change in endocytic vesicles or Wg signaling in atg188J16 or atg189E6 mutant tissue. To the contrary, Wg signaling was enhanced as measured by the long-range target, Distalless (Dll). Molecular characterization identified atg18 intronic mutations for both alleles. These mutations should not disrupt normal mRNA splicing and RT-PCR revealed no splice variants, supporting this. Future experiments will focus on confirming these mutations are alleles of atg18. EB supported byHHMI undergraduate program.

Day of Presentation: Monday April 11, 2011,
1:05 PM - 2:35 PM, Poster Board Number: B311, Program Number: 747.1

Cory Bovenzi

Abstract No: 1719
Neuronal migration and survival in the developing chick optic tectum

Cory Bovenzi and Deni Galileo
Department of Biological Science

In the developing brain, neurons are born in the ventricular zone and migrate outward via radial glial scaffolds. There also is an early period of widespread programmed cell death (PCD) in the brain, occurring while these neurons are still migrating. In the developing chick optic tectum (OT), we hypothesize there is a relationship between these two processes whereby the cells that die do so because of anoikis: loss of contact with the necessary extracellular matrix produced by radial glia. Specifically, we predict that fibronectin secreted by radial glia interacts with the α8β1 integrin receptors on the neuronal membrane, initiating an intracellular cascade which eventually increases expression of Bcl-2, an anti-apoptotic molecule. Dissociated OT cells were immunostained at different ages and showed a general trend that there is a period (E7.5 through E8) where pro-apoptotic signals such as active Caspase-3 and Bax are present when Bcl-2 is down-regulated. Propidium iodide staining experiments supported immunostaining data, with more fragmented DNA appearing during this same time period. Bcl-2 also was ectopically expressed in the OT using a retroviral vector in hopes to analyze behavior of neurons kept alive artificially. Additionally, OT cells were plated at different densities and cultured to determine whether radial glia contact could suppress neuronal apoptosis and/or increase Bcl-2 levels. CB supported byHHMI undergraduate program.
Day of Presentation: Monday April 11, 2011, 12:25 PM - 1:55 PM, Poster Board Number: B364, Program Number: 753.1 

Michael Angelo Brister
Recipient of an
ASBMB Undergraduate Travel Award.

Abstract No: 1763
The structural characteristics of synthetically glycosylated tau protein sequences

Michael Angelo Brister, Agata Bielska, and Neal Zondlo
Department of Chemistry and Biochemistry

The microtubule-associated protein tau is the primary constituent of neurofibrillary tangles, a pathological hallmark of Alzheimer's Disease. In its diseased state, tau is phosphorylated on over 30 residues, many of which are alternatively modified by O-linked glycosylation by N-acetylglucosamine (O-GlcNAc) in tau's native state. We hypothesized that glycosylation of threonine and serine residues on tau peptides may induce a structural effect different from that of phosphorylation at these locations. We have employed a scheme for the synthesis of glycopeptides incorporating OGlcNAc and isolated the amino acid building block, Fmoc-Thr(β- D-pGlcNAc)-OH. Furthermore, we have developed a functional group to mimic O-GlcNAc modification (pseudo-glycosylation). Peptides from the tau proline-rich domain were synthesized and the conformations were characterized using circular dichroism and NMR for the unmodified, phosphorylated, pseudo-glycosylated, and glycosylated peptides. Phosphorylated sequences exhibitedhigh propensity to form a type II polyproline helix. In  contrast, glycosylated peptides exhibited alternative structures. These findings suggest a structural role for tau modification by OGlcNAc. This project was supported by the Howard Hughes
Medical Institute and the Alzheimer's Association.

Monday April 11, 2011, 1:05 PM - 2:35 PM, Poster Board Number: B93, Program Number: 708.3

First Prize recipient in the Proteins and Enzymes Division

Jean Huynh

Abstract No: 1765
A Role for JAM-A in Ca2+ Homeostasis and Mammalian Sperm Motility

Jean Huynh and Patricia Martin–DeLeon
Department of Biological Sciences

A common cause of male infertility is defective sperm motility (asthenozoospermia) results from the disruption of Ca2+ homeostasis, including the deletion of the Ca2+ influx channel or the major efflux pump, Plasma membrane Ca2+/calmodulin-dependent ATPase isoform 4b/Cl (PMCA4b).  Pmca4 null mouse sperm have elevated calcium, decreased hyperactivated and progressive motility, like Jam-A (Junctional Adhesion Molecule A) null sperm. PMCA4b and JAM-A proteins can associate with PDZ (PSD-95/Dlg/ZO1) domains; Type I and Type II, respectively. PMCA4b can bind to Ca2+/calmodulin-dependent serine kinase (CASK), a Type II. Our lab has hypothesized that each protein interacts with CASK by its PDZ domain for Ca2+ efflux. The goal was to show the potential interactions of these proteins in murine sperm and the role of JAM-A in human sperm motility. In silico analysis revealed a high degree of homology (68- 96%). Immunocytochemistry showed the expression and co-localization of human PMCA4b and CASK on the midpiece and principal piece of the tail, where all three murine proteins reside and on the murine acrosome. Phospho-JAM-A was capacitated and uncapacitated; revealing the presence of the protein on the principal piece and the midpiece of the flagellum. Western analysis and Flow cytometry were used to analyze human JAM-A, showing its presence on the plasma membrane. In a small sample (n=4) of Infertility Clinic patients, Flow cytometry revealed a correlation between low sperm motility (8-16%) and low JAM-A, suggesting that JAM-A may be involved in human subfertility. The interaction of the proteins will be performed using co-immunoprecipitation. The characterization of these proteins and the mechanism of Ca2+ efflux will increase our understanding of factors leading to male infertility/subfertility; improving diagnosis and assisting in reproductive technology. Funded by NIH-COBRE grant #5P20RR015588-07. All animal experiments were conducted in conformance with the FASEB Statement of Principles.

Day of Presentation: Monday April 11, 2011, 1:05 PM - 2:35 PM, Poster Board Number: B304, Program Number: 746.3

Soma Jobbagy
Abstract No: 3881

Characterization of next-generation anti-androgens as

potential prostate cancer therapeutics

Soma Jobbagy1, Robert Allen Sikes2, John Tze-tzun Koh1.

1Chemistry and Biochemistry, 2Biological Sciences

Anti-androgens are the gold standard of care for treatment of advanced prostate cancer (PCa). The purpose of this study was to
characterize novel anti-androgens PLM1, PLM6, and PAN52 designed and synthesized in the Koh laboratory. PLM6 and PAN52  but not PLM1 are thought to have unique mechanisms of action based on their ability to evade progression to anti-androgen resistance in vitro. Western blot analysis of nuclear fractions showed correlation between prevention of AR nuclear translocation and progression of anti-androgen resistance in prostate cancer cell lines. Some differences in localization effects were also observed between LNCaP and CWR22Rv1 PCa models that may reflect AR mutants present in these cell lines. The compound PLM6 and PAN52 found to down-regulate the androgen receptor (AR) in PCa cell lines. These compounds thus appear to hold promise as therapy for advanced prostate cancer.  This work funded by the Beckman Foundation and the National Institutes of Health 5R01DK054257

Day of Presentation: Tuesday April 12, 2011,1:05 PM - 2:35 PM, Poster Board Number: B429,Program Number: 968.2

Matthew King
Abstract No: 1765

Fibronectin in the Ocular Lens

Matthew R. King, Yan Wang, and Melina K. Duncan
Department of Biological Sciences

Although once thought to be either absent or non-essential to the lens, the recent finding that fibronectin (FN) knock-out zebra fish develop cataract has sparked interest into FN’s role in lens biology.  FN is a common protein in extra cellular matrices (ECM’s) and its splice variants are associated with a wound healing response. Immunofluorescent staining revealed that that FN concentrations progressively increase as the back of the posterior capsule is approached ant that it is localized to the center portion of the posterior capsule and the outermost front portion of the anterior capsule contain FN.  RT-PCR investigation revealed FN mRNA in both lens cell types (epithelial and fiber cells).  Additional RT-PCR analysis into the two major splice variants of FN (EDA and EDB) showed that epithelial cells have a higher amount of EDB FN than fiber cells.  Inversely, fiber cells displayed EDA FN while epithelial cells did not. When comparing this finding with my immunofluorescent finding that only EDA exists in the posterior capsule, it can be speculated that EDA FN is produced by the fiber cells.  Though posterior capsular FN appears to have cellular origins the location of the anterior capsular FN suggests extraneous origins.  It is important to understand the distribution of the two variants in normal lenses in order to see how this distribution might change in wound healing responses such as post cataract surgery clouding. MRK supported by HHMI undergraduate program. MRK supported by HHMI undergraduate program.

Sunday April 10, 2011, 12:25 PM - 1:55 PM, Poster Board Number: B283, Program Number: 555.4

Honorable Mention Poster

Dylan Lowe

Abstract No: 1299
Effect of Perlecan/Hspg2 Endoplasmic Reticulum Retention
on Cellular Stress During Cartilage Development

Dylan A. Lowe, Padma P. Srinivasan, and Catherine Kirn-Safran
Biological Sciences

Perlecan/Hspg2 (PLN) is a scaffolding proteoglycan functioning mainly in the extracellular matrix as a modulator of growth factor bioavailability. PLN gene loss-of-function mutation results in severe skeletal defects and embryonic death. In this study, we use a viable hypomorph mouse model in which PLN expression is reduced. Adult PLN hypomorph mice display a short stature, early osteoarthritis, and altered bone properties. These defects are likely the result of aberrant PLN expression during embryogenesis. Immunostaining of newborn cryosections revealed an absence of columnar organization and severe reduction of PLN secretion in the cartilage matrix of hypomorph versus control bones. Furthermore, the majority of PLN in the hypomorphs co-localized with a strong signal for BiP, an endoplasmic reticulum (ER) chaperone involved in the early steps of the unfolding protein response (UPR). Interestingly, the retention of PLN in the ER was accompanied by increased deposition of another proteoglycan, aggrecan, in the cartilage matrix. Our data suggest that reduced PLN secretion during bone formation induces abnormal patterning that may be partially compensated by increased secretion of other matrix components. Ongoing work further investigates how the UPR and other cellular mechanisms contribute to the abnormal phenotype in PLN hypomorphs. Supported by NIH P20-RR016458. DAL. DAL supported by HHMI undergraduate program.

Presentation: Sunday April 10, 2011,12:30 PM - 2:00 PM, Poster Board Number: C65, Program Number: 492.9

Tejal U Naik

Abstract No: 5569
Development of a Peptide Nucleic Acid Based siRNA Delivery System

Tejal U. Naik and Millicent O. Sullivan
Department of Biological Sciences and Chemical Engineerng

Small interfering RNA (siRNA) is a double stranded RNA molecule that plays a major role in gene silencing by catalyzing the degradation of complementary mRNA, and thus inhibiting expression.  The ability to harness siRNA for therapeutic benefit can have a widespread impact on a variety of diseases ranging from cancer to HIV/AIDS.  However, the efficacy of such treatments is limited due to the many extracellular and intracellular barriers associated with siRNA delivery.  One approach to delivery, involving siRNA-functionalized surfaces, can improve the cellular response and specificity by enabling tunable release and creating a locally-concentrated microenvironment. In this work, we lay the groundwork for the development of a peptide nucleic acid (PNA)-based surface-mediated siRNA delivery system.  PNAs are nucleic acid analogs that hybridize with complementary DNA or RNA sequences, enabling the direct attachment of various macromolecules such as peptides.  Conjugation of targeting and protective moieties can potentially enhance the delivery of siRNA.  To begin development of this delivery system, we completed two tasks.  First, a cell transfection model utilizing stably transfected B16FO mouse melanoma cells (producing green fluorescent protein [GFP]) was established.  Anti-GFP siRNA was designed and its efficacy was evaluated via flow cytometry and fluorescence microscopy.  Optimization of cell seeding density, siRNA concentration, use of antibiotics, and time of transfections was accomplished, effectively demonstrating gene silencing capability.  Our second task was to prepare molecular conjugates for PNA-based siRNA modifications.  siRNA-PNA-peptide conjugates were assembled and purified through Reverse Phase High Performance Liquid Chromatography (RP-HPLC).  Future development of this delivery system will include linkage of the conjugates to surfaces via the PNA-peptide tethers, and exploration of the delivery system in B16FO cells.

Presentation: Tuesday April 12, 2011, 1:05 PM - 2:35 PM, Poster Board Number: B75,  Program Number: 903.4

Best Thematic Poster Award for the RNA category for the second year in a row.

Victoria H. Roop

Abstract No. 7103

Mutation in the βB2-crystallin gene leads to cataracts, epithelial mesenchymal transition, and upregulation of integrins

Victoria H. Roop, Fahmy Mamuya, Melinda K. Duncan
Biological Sciences

The most abundant protein in the lens fiber cells is βB2-crystallin (Crybb2). Mutations in the Crybb2 gene have been shown to cause cataracts in both mice and humans. A twelve nucleotide deletion in the lens epithelial cells, known as the Crybb2Phil mutation, leads to epithelial mesenchymal transition (EMT) during development. However, the mechanism behind this phenotype is poorly understood.  The aim of this project is to understand the causes and effects of mutations in βB2-crystallin. Tissues obtained from Crybb2Phil mutant adult mice were immunostained with αV, α2, α3, α5, α6, β1 integrin subunits, and phospo-SMAD3. Compared to the wild type lens, β1, αV, and α5 were upregulated in the Crybb2Phil mutant. However, no changes were seen in α2, α3, and α6 integrin subunits. Phospho-SMAD3 and smooth muscle actin (SMA) levels were also upregulated in Crybb2Phil mice. Upregulation of SMA signifies that the Crybb2phil mice undergo EMT during development. Furthermore, over expression of β1 and αV integrin along with SMAD3 in these mutants suggest that the TGFβ-SMAD interacting pathway may be involved. This project is funded by National Eye Institute grant EY015279. VR is a Charles Peter White Scholar.

Presentation: Tuesday April 12, 2011, 12:25 PM - 1:55 PM, Poster Board No: B110 Program Number: 909.10

Ashley Shay

Recipient of an
ASBMB Undergraduate Travel Award.

Abstract No: 575
Hypoplastic Left Heart Syndrome: Molecular Consequences of Transcription Factor Mutations

Ashley Shay1, Susan Kirwin2, Vicky Funanage2
1BiologicalSciences, University of Delaware, Newark, DE,
2Biomedical Research, Nemours, Wilmington, DE.

Hypoplastic Left Heart Syndrome (HLHS; MIM #241550) is a condition of congenital malformations of the left side of the heart. The left ventricle is typically underdeveloped and insufficient at supporting systemic circulation. The mitral valve may be improperly formed or closed completely and the aorta can be abnormally narrow. These abnormalities affect the heart’s ability at pumping oxygenated blood to the body. Normally, the foramen ovale and patent ductus close at birth to permit blood to be oxygenated by the pulmonary circulation. However, in HLHS, the blood is pumped through the right ventricle pumping blood both to the lungs (via the pulmonary artery) and out to the body. Surgical intervention is required in order to correct these malformations. HLHS has been found to be more prevalent in males than females and 10% of patients are diagnosed with other birth defects. To date, it has been theorized that there is a genetic cause for HLHS; however, no known monogenic cause has been determined. Current research is investigating changes in genes known to be involved in cardiac development: TBX5, NKX2.5, GJA1, GATA4, Hand1 and Hand2. TBX5 has been linked to Holt-Oram Syndrome, which is a heart-limb disease that has similar cardiac defects to HLHS. DNA from patients with HLHS will be analyzed to determine whether a genomic mutation is a cause of the cardiac defect. These results will be compared within a cohort of HLHS patients to determine if there is a genetic basis for their abnormal cardiovascular development.

Presentation: Monday April 11, 2011, 1:05 PM - 2:35 PM,Poster Board Number: B43,  Program Number: 698.16

Robert Patrick Sheehan
Abstract No. 4095.
Heterochromatin is retained during lens fiber cell differentiation

Robert Patrick Sheehan and Melinda K Duncan
Department of Biological Sciences,

The lens of the eye contains both epithelial and fiber cells, with fibers cells deriving from the equatorial epithelium. When these cells differentiate, the nucleus and cellular organelles are broken down to facilitate transparency. However, small fragments of DNA can remain in fully mature lens fiber cells, although their structureis unknown. We found that histone H3, trimethylated on Lysine 9, as well as 5-Methylcytosine, which are both associated with compact heterochromatin, co-localize with these DNA fragments. In contrast, the DNA remnants are not associated with either histone H3 Lysine 9 acetylation or histone H4 lysine 8 acetylation, which are predominant in the more accessible euchromatin. This data suggests that the DNA fragments persisting in mature lens fiber cells are entirely composed of heterochromatin, likely because their highly compacted state prevented access of the nucleases responsible for DNA degradation during lens fiber cell differentiation. This led to the further hypothesis, which is currently being tested, that these fragments predominantly contain transcriptionally silent genes, which are likely to be found in heterochromatin. Supported by Howard Hughes Medical Institute and the National Eye Institute.

Presentation: Tuesday, April 12, 12:25-1:55pm. Poster Board Number B53, Program Number 896.7

After the Awards Ceremony on Sunday,
April 10, the UD group gathered outside the hall for a photo with Dr. Kathleen Cornelly who was one  of the organizers of the event. Left to right: Dr. Cornelly, Dr. Usher, Mike Brister, Tejal Naik, Cory Bovenzi, Bobby Sheehan, Soma Jobbagy (back), Ashley Shay (front), Matt King (back),l Jean Huynh (front) Tori Roop, Erica Boetefuer, and Dr. Seung Hong. (not shown: Dr. Hal White, Gary Laverty, and Dylan Lowe). Dylan Lowe particpated in the Anatomy Undergraduate Poster session.

Matt King and Mike Brister
with their award plaques.

Erica Boetefuer and Mike Brister
putting up Erica's poster.

Tori Roop posing as a Knockout mouse.

The Washington Convention Center
where EB2011 was held.

Half of the Convention Center's
huge ventor and poster display floor.

The ASBMB Undergraduate Poster Competition

Dinner on the town.

Hashbrowns an Bobby and Van's

Link to UDaily article.

The trip to the Experimental Biology 2011 Meetings in Washington, DC was organized by the University of Delaware HHMI Undergraduate Science Education Program with additional support from travel grants from the American Society for Biochemistry and Molecular Biology Arnold and Mabel Beckman Scholars Program, and the Women Scholars Program. The HHMI Undergradaute Science Education Program, the Arnold and Mabel Beckman Scholars Program, Charles Peter White Fund, Undergraduate Research Program, NIH, and NSF, supported research by the students. 

website for last year's meeting in Anaheim.

Return to  University of Delaware HHMI Home Page
Created 13 February 2011,  last revised  24 April 2011 by Hal White [halwhite at udel.edu]
Copyright  2011 Harold B. White, Department of Chemistry and Biochemistry, University of Delaware