Genetics Commons^™

Dorsal Eye Selector Pannier (Pnr) Suppresses The Eye Fate To Define Dorsal Margin Of The Drosophila Eye, Sarah M. Oros, Meghana Tare, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Axial patterning is crucial for organogenesis. During Drosophila eye development, dorso-ventral (DV) axis determination is the first lineage restriction event. The eye primordium begins with a default ventral fate, on which the dorsal eye fate is established by expression of the GATA-1 transcription factor pannier (pnr). Earlier, it was suggested that loss of pnr function induces enlargement in the dorsal eye due to ectopic equator formation. Interestingly, we found that in addition to regulating DV patterning, pnr suppresses the eye fate by downregulating the core retinal determination genes eyes absent (eya), sine oculis (so) and dacshund (dac) to define the …

Physical Interaction Between Vivid And White Collar Complex Regulates Photoadaptation In Neurospora, Chen-Hui H. Chen, Bradley S. Demay, Amy S. Gladfelter, Jay Dunlap, Jennifer J. Loros

Dartmouth Scholarship

Photoadaptation, the ability to attenuate a light response on prolonged light exposure while remaining sensitive to escalating changes in light intensity, is essential for organisms to decipher time information appropriately, yet the underlying molecular mechanisms are poorly understood. In Neurospora crassa, VIVID (VVD), a small LOV domain containing blue-light photoreceptor protein, affects photoadaptation for most if not all light-responsive genes. We report that there is a physical interaction between VVD and the white collar complex (WCC), the primary blue-light photoreceptor and the transcription factor complex that initiates light-regulated transcriptional responses in Neurospora. Using two previously characterized VVD mutants, we show …

Development Of Pyrf-Based Genetic System For Targeted Gene Deletion In Clostridium Thermocellum And Creation Of A Pta Mutant, Shital A. Tripathi, Daniel G. Olson, D. Aaron Argyros, Bethany B. Miller, Trisha F. Barrett, Daniel M. Murphy, Jesse D. Mccool, Anne K. Warner, Vineet B. Rajgarhia, Lee R. Lynd, David A. Hogsett, Nicky C. Caiazza

Dartmouth Scholarship

We report development of a genetic system for making targeted gene knockouts in Clostridium thermocellum, a thermophilic anaerobic bacterium that rapidly solubilizes cellulose. A toxic uracil analog, 5-fluoroorotic acid (5-FOA), was used to select for deletion of the pyrF gene. The ΔpyrF strain is a uracil auxotroph that could be restored to a prototroph via ectopic expression of pyrF from a plasmid, providing a positive genetic selection. Furthermore, 5-FOA was used to select against plasmid-expressed pyrF, creating a negative selection for plasmid loss. This technology was used to delete a gene involved in organic acid production, namely pta, which encodes …

Antibiotic Resistance In Bacillus Subtilis As Affected By Transcriptional Derepression And The Stringent Response, Brandon Eisinger, Ronald E. Yasbin, Eduardo A. Robleto

Undergraduate Research Opportunities Program (UROP)

Bacterial cells under conditions of starvation or prolonged non-lethal selective pressures accumulate mutations in highly transcribed genes. This process is part of cellular programs to increase genetic diversity in conditions of stress, also known as stationary phase or stress-induced mutagenesis. This experiment investigated mutation frequencies for antibiotic resistance as affected by the stringent response. The stringent response is a global cellular process that initiates at the cessation of growth and mediates changes in gene expression that repress synthesis of ribosome components. We used Bacillus subtilis strains that differ in RelA proficiency. The relA gene controls the synthesis of (p)ppGpp, the …

Impact Of Historical Climate Change On The Genetic Structure Of The Great Basin Pocket Mouse, Perognathus Parvus, Ashwitha Francis, Mallory E. Eckstut, Brett R. Riddle

Undergraduate Research Opportunities Program (UROP)

The dynamics of genetic patterns, such as genetic differentiation within and between populations and the geographic distribution of genetic lineages, are often influenced by historical events (such as climatic changes) that have substantially impacted regional biodiversity (the study of phylogeography; Avise, 20001). The magnitude of genetic differentiation among populations is often increased if suitable habitat is reduced, because there is restricted migration among populations. When migration is restricted, the populations may become genetically differentiated from conspecific populations and, over time, may become independent lineages that follow distinctive evolutionary trajectories (Stebbins, 19523; Nevo & Beiles, 19892; Thomas et al., 19984). In …

The Effects Of Growth Hormone In The Inner Ear Of Zebrafish (Danio Rerio) During Hair Cell Regeneration, Chia-Hui Lin

Masters Theses & Specialist Projects

Although deafness is a universal problem, effective treatments have remained elusive. In order to develop potential treatments, an overall understanding of the cellular process of auditory hair cell regeneration, which occurs in fish but not mammals, must be established. A previous microarray analysis and qRT-PCR validation of noise-exposed zebrafish showed that growth hormone (GH) was significantly upregulated during the process of auditory hair cell regeneration. Thus, GH may play an important role during hair cell regeneration. However, cellular effects of exogenous GH in the zebrafish auditory hair cell regeneration have not been examined after noise exposure. To understand the effect …

Candidate Gene Studies In Patients With Autism Spectrum Disorder, Pamela Jackson

All Dissertations

Autism Spectrum Disorder is a grouping of disorders that range from the diagnosis of Asperger Syndrome to Autistic Disorder (formally known as autism). Attention Deficit Disorders and Pervasive Developmental Disorder-Not Otherwise Specified are also a part of this spectrum of disorders. Autism Spectrum Disorder affects one out of every 110 children and has a male to female ratio of 4:1. This has led to the need to identify genes that may be causative for this disorder.
Several genome-wide scans have been conducted and have identified locations in the human genome that may contain causative genes for Autism Spectrum Disorder. One …

Genetic Analysis Of The Function Of The Drosophila Doublesex-Related Factor Dmrt93b, Diana O'Day

Dissertations and Theses (Open Access)

DMRT (Doublesex and Mab-3 related transcription factor) proteins generally associated with sexual differentiation in many organisms share a common DNA binding domain and are often expressed in reproductive tissues. Aside from doublesex, which is a central factor in the regulation of sex determination, Drosophila possesses three different dmrt genes that are of unknown function. Because the association with sexual differentiation and reproduction is not universal and some DMRT proteins have been found to play other developmental roles we chose to further characterize one of these Drosophila genes. We carried out genetic analysis of dmrt93B, which was previously found to be …

Transcriptional Regulation Of The Shigella Flexneri Icsp Promoter: Silencing And Anti-Silencing By H-Ns And Virb, Dustin Harrison

UNLV Theses, Dissertations, Professional Papers, and Capstones

Shigella species are gram-negative intracellular pathogens that cause bacillary dysentery in humans. Many genes required for virulence of Shigella are carried on a large 230 kb plasmid and many of these are under the transcriptional control of the histone-like nucleoid structuring protein (H-NS) and by the major virulence regulator VirB. At the non-permissive temperature of 30⁰C, H-NS represses transcription, while at 37⁰C VirB alleviates this repression. This mechanism of gene regulation has been coined "silencing/anti-silencing" and is commonly found in many important bacterial pathogens including Salmonella spp. and Yersinia spp. The icsP gene, encoded by the Shigella virulence plasmid, is …

Characterizing A Novel Genetic Locus Associated With Familial Co-Occurrence Of Thoracic Aortic Aneurysms And Intracranial Aneurysms, Alexander H. Li

Dissertations and Theses (Open Access)

The Mendelian inheritance of genetic mutations can lead to adult-onset cardiovascular disease. Several genetic loci have been mapped for the familial form of Thoracic Aortic Aneurysms (TAA), and many causal mutations have been identified for this disease. Intracranial Aneurysms (ICA) also show linkage heterogeneity, but no mutations have been identified causing familial ICA alone.

Here, we characterized a large family (TAA288) with an autosomal dominant pattern of inherited aneurysms. It is intriguing that female patients predominantly present with ICA and male patients predominantly with TAA in this family. To identify a causal mutation in this family, a genome-wide linkage analysis …

The Larval Salivary Gland Of Drosophila Melangogaster: A Model System For Temporal And Spatial Steroid Hormone Regulation, Benjamin Constantino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Drosophila melanogaster provides an ideal model organism to test genetic and molecular biological mechanisms within the context of a living animal. For over one hundred years Drosophila continues to produce a boundless extent of informative and important scientific data providing crucial insight into development, disease progression and genetic interactions. A century as a model organism allowed for the development of an abundance of unique genetic and molecular tools allowing researchers to tease apart cellular mechanisms with very little limitation. From the whole adult body to tissue function to molecular networks, if a biological question arises it most likely can be …

Quantitative Trait Loci For Agronomic And End-Use Quality Performance And The Effect Of Soilborne Wheat Mosaic Virus In A Hard Winter Wheat Population In Nebraska, Nicholas A. Crowley

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

To better understand agronomic and end-use quality in wheat (Triticum aestivum L.) we developed a population containing 154 F6:8 recombinant inbred lines (RILs) from the cross TAM107-R7/Arlin. The parental lines and RILs were phenotyped at six environments in Nebraska and differed for resistance to Wheat soilborne mosaic virus (WSBMV), morphological, agronomic, and end-use quality traits. Additionally, a 2300 cM genome-wide linkage map was created for quantitative trait loci (QTL) analysis. Based on our results across multiple environments, the best RILs could be used for cultivar improvement. The population and marker data are publicly available for interested researchers for future research. …

Rna Processing Of Nitrogenase Transcripts In The Cyanobacterium Anabaena Variabilis, Justin Ungerer, Brenda Pratte, Teresa Thiel

Biology Department Faculty Works

Little is known about the regulation of nitrogenase genes in cyanobacteria. Transcription of the nifH1 and vnfH genes, encoding dinitrogenase reductases for the heterocyst-specific Mo-nitrogenase and the alternative V-nitrogenase, respectively, was studied by using a lacZ reporter. Despite evidence for a transcription start site just upstream of nifH1 and vnfH, promoter fragments that included these start sites did not drive the transcription of lacZ and, for nifH1, did not drive the expression of nifHDK1. Further analysis using larger regions upstream of nifH1 indicated that a promoter within nifU1 and a promoter upstream of nifB1 both contributed to expression of nifHDK1, …

Following Tetraploidy In Maize, A Short Deletion Mechanism Removed Genes Preferentially From One Of The Two Homeologs, Margaret R. Woodhouse, James C. Schnable, Brent S. Pedersen, Eric Lyons, Damon Lisch, Shabarinath Subramaniam, Michael Freeling

Department of Agronomy and Horticulture: Faculty Publications

Previous work in Arabidopsis showed that after an ancient tetraploidy event, genes were preferentially removed from one of the two homeologs, a process known as fractionation. The mechanism of fractionation is unknown. We sought to determine whether such preferential, or biased, fractionation exists in maize and, if so, whether a specific mechanism could be implicated in this process. We studied the process of fractionation using two recently sequenced grass species: sorghum and maize. The maize lineage has experienced a tetraploidy since its divergence from sorghum approximately 12 million years ago, and fragments of many knocked-out genes retain enough sequence similarity …

An Initial Map Of Chromosomal Segmental Copy Number Variations In The Chicken, Xiaofei Wang, Samuel N. Nahashon, Tromondae K. Feaster, Ann L. Bohannon-Stewart, Nathaniel Adefope

Agricultural and Environmental Sciences Faculty Research

Background

Chromosomal segmental copy number variation (CNV) has been recently recognized as a very important source of genetic variability. Some CNV loci involve genes or conserved regulatory elements. Compelling evidence indicates that CNVs impact genome functions. The chicken is a very important farm animal species which has also served as a model for biological and biomedical research for hundreds of years. A map of CNVs in chickens could facilitate the identification of chromosomal regions that segregate for important agricultural and disease phenotypes.

Results

Ninety six CNVs were identified in three lines of chickens (Cornish Rock broiler, Leghorn and Rhode Island …

Powerful Snp Set Analysis For Case-Control Genome Wide Association Studies, Michael C. Wu, Peter Kraft, Michael P. Epstein, Deanne M. Taylor, Stephen J. Chanock, David J. Hunter, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

Assessing The Phylogenetic Utility Of Dna Barcoding Using The New Zealand Cicada Genus Kikihia, Megan Ribak

Honors Scholar Theses

DNA Barcoding (Hebert et al. 2003) has the potential to revolutionize the process of identifying and cataloguing biodiversity; however, significant controversy surrounds some of the proposed applications. In the seven years since DNA barcoding was introduced, the Web of Science records more than 600 studies that have weighed the pros and cons of this procedure. Unfortunately, the scientific community has been unable to come to any consensus on what threshold to use to differentiate species or even whether the barcoding region provides enough information to serve as an accurate species identification tool. The purpose of my thesis is to analyze …

A Family-Based Association Study Of Conduct Disorder., Xueqiu Jian

Electronic Theses and Dissertations

Conduct disorder (CD) is a psychiatric syndrome in childhood and adolescence that is one of the most common childhood disorders with continuously increasing prevalence but uncertain pathogenesis. We performed a genome-wide, family-based association study of CD using P2BAT/FBAT software. The data is gathered from Collaborative Study on the Genetics of Alcoholism (COGA) and International Multi-Center ADHD Genetics Project (IMAGE).

Using COGA data, we identified 20 markers which showed suggestive associations (p<10^-3) with CD. Nine of them are located in known genes. Two genes, ADAM10 and CAMK2A, which had been reported associated with Alzheimer's disease (AD), bipolar disorder, …

A Molecular Basis For Craniofacial Laterality In Fishes, Karen Adams

Renée Crown University Honors Thesis Projects - All

Laterality, the preference for development on one side of the body, is essential to the vertebrate body plan. While the vertebrate skeleton usually develops symmetrically, the processes underlying craniofacial laterality are not well understood. Using zebrafish and cichlids as model organisms, this study focuses on the molecular basis of symmetric craniofacial development. Fgf8, Retinoic Acid, and wnt11 were examined to analyze their involvement in regulating craniofacial laterality. Fgf8 is known to play a role in proper jaw development. Because fgf8 and Retinoic Acid interact to achieve laterality of the somites during somitogenesis, the role of Retinoic Acid in regulating …

Xenobiotic Metabolism Genes And Clubfoot, Amy M. Sommer

Dissertations and Theses (Open Access)

Idiopathic or isolated clubfoot is a common orthopedic birth defect that affects approximately 135,000 children worldwide. It is characterized by equinus, varus and adductus deformities of the ankle and foot. Correction of clubfoot involves months of serial manipulations, castings and bracing, with surgical correction needed in forty percent of cases. Multifactorial etiology has been suggested in numerous studies with both environmental and genetic factors playing an etiologic role. Maternal smoking during pregnancy is the only common environmental factor that has consistently been shown to increase the risk for clubfoot. Moreover, a positive family history of clubfoot and maternal smoking increases …