Genetics and Genomics Commons^™

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.

When Did The Ancestors Of Polynesia Begin To Migrate To Polynesia? The Mtdna Evidence, David Lesniewski

UNLV Theses, Dissertations, Professional Papers, and Capstones

The timing and nature of the migration of the ancestors of the Polynesian people is debated by two competing theories. The "Express Train" and "Slow Boat" theories assert that the migration of the Proto-Polynesian people began around 6,000 years before present (BP) or around 10,000 years BP respectively. Through the use of haplogroups and specific genetic mutations a direct relationship between the Proto-Polynesians and modern Polynesians was attempted to test which of these theories was correct. The ancient skeletal remains from the island of Borneo currently housed at UNLV were used in this study as their dates fall within both …

Inheritance Of Shoulder Spotting In The Tetra, Hyphessobrycon Bentosi Characidae, Jack Frankel

Department of Biology Faculty Publications

The tetra (Hyphessobrycon bentosi) exhibits two phenotypes associated with shoulder spotting. Fish possess ei-ther a prominent black vertical spot located directly behind the operculum (H. b. bentosi,  bentosi  white  tip  tetra) or  lack  this spot (H. b. rosaceus, rosy tetra). Segregation patterns observed from the progenies of ten different crosses suggest that the  inheritance  of  these  phenotypes  is  controlled  by  two  autosomal  loci  acting  in  a complementary  fashion,  with  domi-nance at both loci required for the expression of the spotted phenotype. 

Construction Of A Transgene To Analyze The Function Of The 3’Utr Of The Hdc Gene On Spatial Expression Of Histidine Decarboxylase In Drosophila Melanogaster, Embriette Hyde, Martin G. Burg

Student Summer Scholars Manuscripts

Histamine has been shown to be an important neurotransmitter used in the nervous system of Drosophila melanogaster. Histidine decarboxylase (HDC) is the enzyme that catalyzes the synthesis of histamine. All genetic information necessary for Hdc gene expression has been shown to be present in a 9.4kb genomic DNA fragment. A previous study fused the 5'-UTR of Hdc to the gene encoding eGFP. Microscopic analysis of flies transformed with the pHdc-eGFP transgene showed a weak pattern of eGFP expression in the nervous system as compared to histamine localization, indicating that another genomic region may be necessary for robust Hdc expression. Studies …

Patterning Defects In Silkworm Embryos Analysed Through Cuticle Preparations, Amit Singh, Madhuri Kango-Singh, K. P. Gopinathan

Biology Faculty Publications

The mulberry silkworm, Bombyx mori, a holometabolous lepidopteran insect, has a metameric body plan. Due to its functional adaptation, B. mori presents some unique deviations in its pal/ern from the evolutionarily advanced dipteran insect, Drosophila melanogaster. Previous studies on mutant phenotype analysis in B. mori have been carried out in late stages of larval development. Here we employ, the cuticle preparation approach during embryonic development to study morphological landmarks associated with B. mori, Eri, another race a/silkworm, and pattern defects associated with Ekp mutant of B.mori. The homeotic mutant Ekp, generates ectopic abdominallegs, a feature …

Intradermal Delivery Of Plasmid Vegf(165) By Electroporation Promotes Wound Healing, Bernadette Ferraro, Yolmari Cruz, Domenico Coppola, Richard Heller

Bioelectrics Publications

Skin flaps are extensively used in reconstructive surgeries to repair large defects and deep wounds, but severe ischemia and necrosis often results in loss of the transplanted tissue. Thus, skin flap models are often used to study the biology of healing and necrosis of acute ischemic wounds. Delivery of exogenous vascular endothelial growth factor (VEGF) to areas of ischemia has shown promise for promoting therapeutic angiogenesis, but its expression must be tightly regulated to avoid adverse effects. In this study, plasmid DNA encoding VEGF₁₆₅ (pVEGF) was delivered to the ischemic skin of a rat skin flap model by intradermal …

The Association Of Human Leukocyte Antigen(Hla) Alleles And Type 2 Diabetes Mellitus (T2dm) Among Mexican Americans (Ma), Kantibhai Motiram Patel

Open Access Theses & Dissertations

The epidemic of type 2 diabetes mellitus (T2DM) is ranked as a major public health priority across the United States and especially in the El Paso, Texas region. The risk for the development of T2DM is greater in minority groups, particularly among Mexican Americans (MA) who comprise approximately 78% of El Paso's population. The growing incidence of T2DM in this group is typically attributed to increase in weight (obesity). The incidence of diabetes may also be influenced by genetic factors that are unique to this group. Several earlier studies have identified genetic markers for type 1 diabetes mellitus (T1DM). These …

Dna Before Proteins? Recent Discoveries In Nucleic Acid Catalysis Strengthen The Case, Aaron Steven Burton, Niles Lehman

Chemistry Faculty Publications and Presentations

An RNA-DNA World could arise from an all-RNA system with the development of as few as three ribozymes— a DNA-dependent RNA polymerase, an RNA-dependent DNA polymerase, and a catalyst for the production of DNA nucleotides. A significant objection to DNA preceding proteins is that RNA has not been shown to catalyze the production of DNA. However, RNA- and DNAzymes have been recently discovered that catalyze chemical reactions capable of forming deoxyribose, such as mixed aldol condensation of 5’-glyceryl- and 3’- glycoaldehyde-terminated DNA strands. Thus, the only remaining obstacles to RNA-catalyzed in vitro DNA synthesis are alterations of substrate and template …

Multiple Imputation To Correct For Measurement Error In Admixture Estimates In Genetic Structured Association Testing, Miguel A. Padilla, Jamin Divers, Laura K. Vaughan, David B. Allison, Hemant K. Tiwari

Psychology Faculty Publications

Objectives: Structured association tests ( SAT), like any statistical model, assumes that all variables are measured without error. Measurement error can bias parameter estimates and confound residual variance in linear models. It has been shown that admixture estimates can be contaminated with measurement error causing SAT models to suffer from the same afflictions. Multiple imputation (MI) is presented as a viable tool for correcting measurement error problems in SAT linear models with emphasis on correcting measurement error contaminated admixture estimates. Methods: Several MI methods are presented and compared, via simulation, in terms of controlling Type I error rates for both …

Choosing The Right Path: Enhancement Of Biologically Relevant Sets Of Genes Or Proteins Using Pathway Structure, Reuben Thomas, Julia M. Gohlke, Geffrey F. Stopper, Frederick M. Parham, Christopher J. Portier

Biology Faculty Publications

A method is proposed that finds enriched pathways relevant to a studied condition using the measured molecular data and also the structural information of the pathway viewed as a network of nodes and edges. Tests are performed using simulated data and genomic data sets and the method is compared to two existing approaches. The analysis provided demonstrates the method proposed is very competitive with the current approaches and also provides biologically relevant results.

Site Directed Mutagensis Of Bacteriophage Hk639 And Identification Of Its Integration Site, Madhuri Jonnalagadda

Masters Theses & Specialist Projects

Bacteriophages affect bacterial evolution, pathogenesis and global nutrient cycling. They are also the most numerous and diverse group of biological entities on the planet [1, 2, 3, 4, 5, 6]. Members of the Lambda phage family share a similar genetic organization and control early gene expression by suppressing transcription, a process known as antitermination. Transcription antitermination in Lambda is mediated by a phage-encoded protein whereas in lambdoid phage HK022, antitermination is mediated by a phage-encoded RNA molecules. Recent results suggest that another bacteriophage called HK639 also appears to use RNA-mediated antitermination. To characterize this newly identified phage we generated site …

Comparison Of Electrically Mediated And Liposome-Complexed Plasmid Dna Delivery To The Skin, Loree C. Heller, Mark J. Jaroszeski, Domenico Coppola, Richard Heller

Bioelectrics Publications

BACKGROUND: Electroporation is an established technique for enhancing plasmid delivery to many tissues in vivo, including the skin. We have previously demonstrated efficient delivery of plasmid DNA to the skin utilizing a custom-built four-plate electrode. The experiments described here further evaluate cutaneous plasmid delivery using in vivo electroporation. Plasmid expression levels are compared to those after liposome mediated delivery.

METHODS: Enhanced electrically-mediated delivery, and less extensively, liposome complexed delivery, of a plasmid encoding the reporter luciferase was tested in rodent skin. Expression kinetics and tissue damage were explored as well as testing in a second rodent model.

RESULTS: Experiments …

Identifying The Cis-Acting Sugar Response Elements That Facilitate Glucose Signaling In Arabidopsis Thaliana, Frank Barretta, Jr.

All Theses

Identifying the initial sugar sensing and response activating mechanisms in plants has been difficult due to the dual functions of sugars as nutrients and as signaling molecules. In this study, we have examined transcript expression and promoter features of different genes encoding proteins for actin remodeling that have been implicated as targets of plant glucose signaling. Using Reverse Transcription PCR analysis, we confirmed that expression of two actin-associated genes, actin depolymerizing factor 9 (ADF9) and actin related protein 8 (ARP8), are repressed following a short-term glucose treatment of Arabidopsis thaliana seedlings. Glucose did not repress the expression of other ADF …

Evolutionary Genetics Of Tetrodotoxin (Ttx) Resistance In Snakes: Tracking A Feeding Adaptation From Populations Through Clades, Chris R. Feldman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Understanding the nature of adaptive evolution has been the recent focus of research detailing the genetic basis of adaptation and theoretical work describing the mechanics of adaptive evolution. Nevertheless, key questions regarding the process of adaptive evolution remain. Ultimately, a detailed description of the ecological context, evolutionary history, and genetic basis of adaptations is required to advance our understanding of adaptive evolution. To address some of the contemporary issues surrounding adaptive evolution, I examine phenotypic and genotypic changes in a snake feeding adaptation.

Adaptations can arise through fixation of novel mutations or recruitment of existing variation. Some populations of the …

The Genetics Of Colonization In Two Amphibian Species After The 1980 Eruption Of Mount St. Helens, Kristin Ann Bakkegard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The genetics of colonization is understudied in salamanders but has large conservation implications as new habitats are formed or restored to their previous condition. The 1980 eruption of Mount St. Helens provided a natural experiment to study the genetic effects of a large infrequent environmental disturbance on two species of salamander, Taricha granulosa (Rough-skinned newt) and Ambystoma gracile (Northwestern salamander). Both these species breed in ponds, and are thought to exhibit high breeding site fidelity and low vagility. I designated three treatments based on the effects of the eruption: new ponds (created by the eruption, immigrants only), recovery lakes (in …

Monogenic Control Of Sex-Limited Colouration In The Honey Gourami, Trichogaster Chuna, Jack Frankel

Department of Biology Faculty Publications

Of the numerous subtropical and tropical freshwater speciesof  fish,  labyrinth  fish  are  among  the  most  varied  in  bodymarkings and colouration patterns. Four taxonomic families(Belontiidae, Anabantidae, Helostomatidae, and Osphrone-midae)  of  the  suborder  Anabantoidei  comprise  the  ‘tradi-tional’  labyrinth  fishes,  a  group  of  about  80  African  andSoutheast Asian species (Linke 1991).  These Anabantoidsare popular with aquarists due to their interesting reproduc-tive behaviours, with males of most species brooding eggs intheir mouths or in floating bubble nests (Vevers 1980; Linke1991; Axelrod and Vorderwinkler 1995; Mills 2000).  Theyhave also been the focus of genetic, environmental, and mor-phological studies (Sommer 1982; Gosline 1985; Klinkhardtet  al.  1995; …

A Cell Biology Laboratory Exercise To Study Sub-Cellular Organelles In Drosophila, Meghana Tare, Amit Singh

Biology Faculty Publications

The fast-changing scenario of undergraduate education puts emphasis on introducing students to hands-on techniques as part of their laboratory courses. In order to cater to large numbers of students and the time constraints involved with undergraduate level laboratory courses, there is a need for development of experiments that are cost effective and can be completed in a defined time frame. We have devised a laboratory exercise for teaching cell biology using the Drosophila melanogaster model. Drosophila can be reared in a short period of time in a cost effective manner. We used Drosophila tissue to study the sub-cellular organization of …

Ecotypic Variation In Elymus Elymoides Subspecies Brevifolius Race C In The Northern Intermountain West, Matthew C. Parsons

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Little information is available on the extent of local adaptation for many native grass species. This is the case for squirreltail (Elymus section Sitanion), despite this group's prevalence and importance in rangeland restoration efforts. I evaluated 32 populations of E. elymoides ssp. brevifolius race C, a phylogenetic subdivision of bottlebrush squirreltail (E. elymoides) centered in the northern Intermountain West, for phenotypic variables and neutral genetic markers to measure their association with geographical origin. Phenotypic traits were measured in common field and greenhouse environments, and genetic diversity was assessed using Amplified Fragment Length Polymorphism. Three factors were extracted from the phenotypic …

Phenotypic Plasticity And The Post-Modern Synthesis: Integrating Evo-Devo And Quantitative Genetics In Theoretical And Empirical Studies, Alison G. Scoville

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mainstream evolutionary biology lacks a mature theory of phenotype. Following from the Modern Synthesis, researchers tend to assume an unrealistically simple mapping of genotype to phenotype, or else trust that the complexities of developmental architecture can be adequately captured by measuring trait variances and covariances. In contrast, the growing field of evolutionary developmental biology (evo-devo) explicitly examines the relationship between developmental architecture and evolutionary change, but lacks a rigorous quantitative and predictive framework. In my dissertation, I strive to integrate quantitative genetics and evo-devo, using both theoretical and empirical studies of plasticity. My first paper explores the effect of realistic …

Utilizing Multiplex Ligation-Dependent Probe Amplification To Detect Novel X-Linked Microduplications Which Cause Intellectual Disability, Dianne Cohn

All Dissertations

ABSTRACT
A number of conditions related to X-linked intellectual disabilities (XLID) are in part due to microduplications that are not visible cytogenetically. With the focus on Rho, Ras and Rab genes, a family of genes known to be associated with intellectual disabilities, were screened for dosage aberrations (Leeuwen, F. N. 1997), (Ng, E. L. 2008), (Gissen, P. 2007), (Gurkan, C. 2005). Cohorts of intellectually disabled ID individuals were explored with new technologies. These new technologies include comparative genomic hybridization (CGH), multiplex ligation dependent probe amplification (MLPA) and quantitative PCR (qPCR) (Madrigal, I. 2007), (Hermsen, M. A. 2005), (Morey, J. S. …

Functional Characterization Of Hexokinase-Like 1 (Hkl1) From Arabidopsis Thaliana, Abhijit Karve

All Dissertations

Arabidopsis hexokinase1 (AtHXK1) is a moonlighting protein with roles in both glucose signaling and catalysis. In this study, we first cloned and characterized the six HXK related genes from Arabidopsis. Three of the six encoded proteins were shown not to phosphorylate hexoses and thus, are designated as hexokinase-like (HKL) proteins. Though they are only 50% identical to HXK1, the amino acid sequences of HKL1 and HKL2 both have well conserved glucose binding domains and other recognized structural elements. The possible basis for their lack of catalytic activity was further probed by site-directed mutagenesis and ultimately was attributed to a suite …

Evolution Acts On Enhancer Organization To Fine-Tune Gradient Threshold Readouts, Justin Crocker, Yoichiro Tamori, Albert Erives

Dartmouth Scholarship

The elucidation of principles governing evolution of gene regulatory sequence is critical to the study of metazoan diversification. We are therefore exploring the structure and organizational constraints of regulatory sequences by studying functionally equivalent cis-regulatory modules (CRMs) that have been evolving in parallel across several loci. Such an independent dataset allows a multi-locus study that is not hampered by nonfunctional or constrained homology. The neurogenic ectoderm enhancers (NEEs) of Drosophila melanogaster are one such class of coordinately regulated CRMs. The NEEs share a common organization of binding sites and as a set would be useful to study the relationship …

Ovarian Development In Mice Requires The Gata4-Fog2 Transcription Complex, Nikolay L. Manuylov, Fatima O. Smagulova, Lyndsay Leach, Sergei G. Tevosian

Dartmouth Scholarship

We have demonstrated previously that mammalian sexual differentiation requires both the GATA4 and FOG2 transcriptional regulators to assemble the functioning testis. Here we have determined that the sexual development of female mice is profoundly affected by the loss of GATA4-FOG2 interaction. We have also identified the Dkk1 gene, which encodes a secreted inhibitor of canonical beta-catenin signaling, as a target of GATA4-FOG2 repression in the developing ovary. The tissue-specific ablation of the beta-catenin gene in the gonads disrupts female development. In Gata4(ki/ki); Dkk1(-/-) or Fog2(-/-); Dkk1(-/-) embryos, the normal ovarian gene expression pattern is partially restored. Control of ovarian development …

The Stallion's Mane: The Next Generation Of Horses In Mongolia, Amanda Hund

Independent Study Project (ISP) Collection

Horses play a central role in Mongolian history and culture, yet there has been little academic research on breeding methods, either traditional or modern in Mongolia. The goal of good horse breeding is to maintain and improve the quality of the breed. By looking at the traditional breeding, we gain a better understanding of what Mongolian culture values in their horses and what they are hoping to pass on to the next generation. We can also learn how this information is passed on in an oral tradition from generation to generation of horse trainers and herders. In traditional Mongolian horse …

Gene Expression And Phenotype Response Of Drosophila Melanogaster To Selection., Kenneth W. Mcdonald

Electronic Theses and Dissertations

The evolution of phenotypic plasticity is currently a topic of paramount interest in a diverse field of sub-disciplines. Salience is placed by all fields in describing the interaction of selection and phenotypic plasticity and the consequence of this interaction more broadly on evolution. Lacking in the discussion is substantial empirical description of genotype/phenotype interactions that by definition constitute the plastic response to novel and stressful environments. Here, I present empirical observations that bring the interaction of genotype and phenotype into focus. Drosophila melanogaster populations subjected to selection for tolerance to low food or high alcohol conditions each exhibited an enhancement …

Investigation Of Gene And Protein Expression Based On Honey Bee (Apis Mellifera) Aging, Flight Experience, And Behavior, Azucena A. Benito, G. E. Mancinelli, A. Ammons, Michelle M. Elekonich

Undergraduate Research Opportunities Program (UROP)

Honeybees undergo a process of adult behavioral development, spending their first 2-3 weeks working inside the constant environment of the hive. At about 3 weeks of age workers leave the hive as foragers who gather pollen and nectar. Previous research found that bees show an enormous decline in immunity as a result of their transition from regular hive jobs to more difficult foraging activities. Foragers can be forced to go back into hive-tasks, thus becoming “reverted nurses” which may also allow a reversal of immunosenescence. Understanding how this happens could prove to be useful because if there is flexibility in …

Expression Of Thor Does Not Increase Desiccation Resistance In Drosophila Melanogaster, Robert L. Kobey, Deborah K. Hoshizaki, Allen G. Gibbs

Undergraduate Research Opportunities Program (UROP)

Using microarray analysis of Drosophila melanogaster, the Gibbs lab has identified several hundred candidate genes that may be involved in desiccation resistance. One of these genes is Thor, an important downstream target of the TOR/insulin signaling pathway. Preliminary results confirm that Thor plays a role in desiccation resistance. Further research will be needed to verify these results and understand the mechanism by which Thor increases desiccation resistance. This research will also serve as a proof-of-principle for testing microarray-derived hypotheses.

A previous microarray analysis found evidence that down-regulation of protein synthesis might be a cellular response to desiccation through the up-regulation …

Construction Of A Thif Genetic Disruption In Bacillus Subtilis, Kathleen Bradley, Christine Pybus, Ronald Yasbin, Eduardo Robleto

Undergraduate Research Opportunities Program (UROP)

The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the thiF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Kathleen will first construct a non-polar thiF genetic …

Constructing An Argf- Strain Of Bacillus Subtilis, Allison Faucher, Christine Pybus, Ronald E. Yasbin, Eduardo A. Robleto

Undergraduate Research Opportunities Program (UROP)

The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the argF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Allison will first construct a non-polar argF genetic …

The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Shigella flexneri is a pathogenic bacterium that causes severe dysentery in humans commonly known as shigellosis. Shigella encodes an outer membrane protease called IcsP. The regulation of icsP expression is under direct control of a transcriptional factor called VirB, which controls the expression of many virulence genes in Shigella. Previous work has shown through deletion analysis of the icsP promoter region that sequences as far as 1368 base pairs upstream of the transcription starting site are important for the regulation of the icsP gene by VirB. However, it is still unclear whether VirB activation requires sequences within the icsP promoter …