Genetics Commons^™

Genetic Diversity In Populations Of Epiphanes Chihuahuaensis (Rotifera: Monogononta) In The Northern Chihuahuan Desert, Diego E. Reyes

Open Access Theses & Dissertations

1. Cryptic speciation in zooplankton is a phenomenon that has been recently gaining much attention. This is due in part to advances in molecular techniques which help in the identification of morphologically indistinct species. Organisms that have been traditionally believed to have cosmopolitan distributions are being found to be composed of cryptic species complexes with high levels of genetic divergence among lineages.

2. Epiphanes chihuahuaensis is a member in the Epiphanes senta species complex. In a previous study by Schröder & Walsh (2007), genetic data, along with morphological and reproductive isolation data were employed to help delineate four species within …

Sirt1 Regulation Of The Heat Shock Response In An Hsf1-Dependent Manner And The Impact Of Caloric Restriction, Rachel Rene Raynes

USF Tampa Graduate Theses and Dissertations

The heat shock response (HSR) is the cell's molecular reaction to protein damaging stress and is critical in the management of denatured proteins. Activation of HSF1, the master transcriptional regulator of the HSR, results in the induction of molecular chaperones called heat shock proteins (HSPs). Transcription of hsp genes is promoted by the hyperphosphorylation of HSF1, while the attenuation of the HSR is regulated by a dual mechanism involving negative feedback inhibition from HSPs and acetylation at a critical lysine residue within the DNA binding domain of HSF1, which results in a loss of affinity for DNA. SIRT1 is a …

A Comprehensive Research Framework For Geographic Parthenogenesis In Whiptail Lizards (Genus Aspidoscelis), Adam Leland

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the most compelling topics in biology has been the ubiquity of sexual reproduction in living organisms. Because the ecological and evolutionary advantages of sex are well founded, those organisms that reproduce asexually remain enigmatic. Parthenogenesis, the clonal reproduction of an all-female species without the need for males, is a relatively common form of asexual reproduction in vertebrates, and has been subject of numerous academic investigations. Many parthenogenic organisms also share aspects of their geographic distributions, such as inhabiting higher latitudes, higher altitudes, islands or island-like habitats, xeric environments, and marginal, disturbed or ecotonal habitats relative to their sexual …

Malnutrition In Sickle Cell Anemia: Implications For Infection, Growth And Maturation, Hyacinth I. Hyacinth, Oluwatoyosi A. Adekeye, Christopher S. Yilgwan

Journal of Social, Behavioral, and Health Sciences

Sickle cell anemia (SCA) is a genetic disease that affects mostly individuals of African and/or Hispanic descent, with the majority of cases in sub-Saharan Africa. Individuals with this disease show slowed growth, delayed sexual maturity, and poor immunologic function. These complications could partly be explained by the state of undernutrition associated with the disease. Proposed mechanism of undernutrition include protein hypermetabolism, decreased dietary intake possibly from interleukin-6-related appetite suppression, increased cardiac energy demand/expenditure, and increased red cell turnover. All the above mechanisms manifest as increased resting energy expenditure. Nutritional intervention utilizing single or multiple nutrient supplementation has led to improved …

Family Matters: An Analysis Of Genetic Relatedness Of Tetraclita Rubescens (The Pink Volcano Barnacle) Over Several Spatial Scales At Monterey And Bodega Bay, California, Kelly N. Chang

Scripps Senior Theses

Inbreeding involves the mating of closely related individuals at a higher frequency than at random; this can decrease the average fitness of populations and individuals by reducing the presence of heterozygotes and augmenting the expression of deleterious genes. Since marine invertebrates exhibit widespread dispersal, their potential for inbreeding is often disregarded. The adult sessile state of barnacles creates the potential for inbreeding as a result of necessary copulation between neighboring individuals. Depending on the degree of mixing that occurs during dispersal, closely related individuals or siblings may settle in close proximity, generating the possibility of kin aggregation and consequent inbreeding. …

Image-Level And Group-Level Models For Drosophila Gene Expression Pattern Annotation, Quian Sun, Sherin Muckatira, Lei Yuan, Shuiwang Ji, Stuart Newfeld, Sudhir Kumar, Jieping Ye

Computer Science Faculty Publications

Background: Drosophila melanogaster has been established as a model organism for investigating the developmental gene interactions. The spatio-temporal gene expression patterns of Drosophila melanogaster can be visualized by in situ hybridization and documented as digital images. Automated and efficient tools for analyzing these expression images will provide biological insights into the gene functions, interactions, and networks. To facilitate pattern recognition and comparison, many web-based resources have been created to conduct comparative analysis based on the body part keywords and the associated images. With the fast accumulation of images from high-throughput techniques, manual inspection of images will impose a serious impediment …

Contour Extraction Of Drosophila Embryos Using Active Contours In Scale Space, Soujanya Siddavaram Ananta

Masters Theses & Specialist Projects

Contour extraction of Drosophila embryos is an important step to build a computational system for pattern matching of embryonic images which aids in the discovery of genes. Automatic contour extraction of embryos is challenging due to several image variations such as size, shape, orientation and neigh- boring embryos such as touching and non-touching embryos. In this thesis, we introduce a framework for contour extraction based on the connected components in the gaussian scale space of an embryonic image. The active contour model is applied on the images to refine embryo contours. Data cleaning methods are applied to smooth the jaggy …

Review Of "Fifty Animals That Changed The Course Of History" By E. Chaline, John B. Jenkins

Biology Faculty Works

No abstract provided.

Identifying Genetic Variants And Characterizing Their Role In Clubfoot, Katelyn S. Weymouth

Dissertations and Theses (Open Access)

Clubfoot is a common, complex birth defect affecting 4,000 newborns in the United States and 135,000 world-wide each year. The clubfoot deformity is characterized by inward and rigid downward displacement of one or both feet, along with persistent calf muscle hypoplasia. Despite strong evidence for a genetic liability, there is a limited understanding of the genetic and environmental factors contributing to the etiology of clubfoot. The studies described in this dissertation were performed to identify variants and/or genes associated with clubfoot. Genome-wide linkage scan performed on ten multiplex clubfoot families identified seven new chromosomal regions that provide new areas to …

Genetic Analysis Of The Hippo Pathway In Mouse Liver, Li Lu

Dissertations and Theses (Open Access)

Cancer therapy and tumor treatment remain unsolved puzzles. Genetic screening for tumor suppressor genes in Drosophila revealed the Hippo-signaling pathway as a kinase cascade consisting of five core components. Disrupting the pathway by deleting the main component genes breaks the balance of cell proliferation and apoptosis and results in epithelial tissue tumorigenesis. The pathway is therefore believed to be a tumor suppressor pathway. However, a corresponding role in mammals is yet to be determined. Our lab began to investigate the tumor suppression function of the potent mammalian Hippo pathway by putting floxed alleles into the mouse genome flanking the functional-domain-expressing …

The Role Of The Arched Helicases In Exosome-Mediated Function, A. Alejandra Klauer

Dissertations and Theses (Open Access)

RNA processing and degradation are two important functions that control gene expression and promote RNA fidelity in the cell. A major ribonuclease complex, called the exosome, is involved in both of these processes. The exosome is composed of ten essential proteins with only one catalytically active subunit, called Rrp44. While the same ten essential subunits make up both the nuclear and cytoplasmic exosome, there are nuclear and cytoplasmic exosome cofactors that promote specific exosome functions in each of the cell compartments. To date, it is unclear how the exosome distinguishes between RNA substrates. We hypothesize that compartment specific cofactors may …

Tet1: A Unique Dna Demethylase For Maintenance Of Dna Methylation Pattern, Chunlei Jin

Dissertations and Theses (Open Access)

DNA methylation at the C5 position of cytosine (5-methylcytosine, 5mC) is a crucial epigenetic modification of the genome and has been implicated in numerous cellular processes in mammals, including embryonic development, transcription, X chromosome inactivation, genomic imprinting and chromatin structure. Like histone modifications, DNA methylation is also dynamic and reversible. However, in contrast to well defined DNA methyltransferases, the enzymes responsible for erasing DNA methylation still remain to be studied. The ten-eleven translocation family proteins (TET1/2/3) were recently identified as Fe(II)/2-oxoglutarate (2OG)-dependent 5mC dioxygenases, which consecutively convert 5mC into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine and 5-carboxylcytosine both in vitro and in mammalian …

A Genetic, Transgenic, And Transcriptomic Analysis Of Larval Salivary Gland Physiology In Drosophila Melanogaster, Elana A. Paladino

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cholesterol is the precursor to a unique class of lipophilic signaling molecules called steroid hormones that initiate the development of sexual characteristics, reactions to stress, and maintenance of metabolism, among many other functions. Although much progress has been made in understanding the function of these signaling hormones, we do not fully understand how a single steroid can cause many distinct, tissue-specific responses. Drosophila melanogaster is an effective model for understanding steroid hormone action because of its simplicity. The steroid molting hormone 20-hydroxyecdysone (hereafter, 20E) is the primary active steroid in Drosophila and mediates not only larval molts and the emergence …

Septin Phosphorylation And Coiled-Coil Domains Function In Cell And Septin Ring Morphology In The Filamentous Fungus Ashbya Gossypii, Rebecca A. Meseroll, Patricia Occhipinti, Amy S. Gladfelter

Dartmouth Scholarship

Septins are a class of GTP-binding proteins conserved throughout many eukaryotes. Individual septin subunits associate with one another and assemble into heteromeric complexes that form filaments and higher-order structures in vivo. The mechanisms underlying the assembly and maintenance of higher-order structures in cells remain poorly understood. Septins in several organisms have been shown to be phosphorylated, although precisely how septin phosphorylation may be contributing to the formation of high-order septin structures is unknown. Four of the five septins expressed in the filamentous fungus, Ashbya gossypii, are phosphorylated, and we demonstrate here the diverse roles of these phosphorylation sites …

Intsormil- Centa’S New Bmr Sorghum Varieties Create A Surge In Dairy Production, René Clará Valencia

INTSORMIL Scientific Publications

Scientists from the INTSORMIL-CENTA project based at the National Center for Agricultural Technology and Forestry (CENTA) of El Salvador have worked for five years to develop varieties of sorghum for grain and forage that are highly nutritious to cattle. Using the gene bmr-12, received from Dr. Gebisa Ejeta of Purdue University, they combined commercial varieties CENTA S-2, S-3 CENTA, CENTA RCV and VG 146 and were able to form new varieties containing this same gene. The first generation created 76 new varieties.

Scribble Acts In The Drosophila Fat-Hippo Pathway To Regulate Warts Activity, Shilpi Verghese, Indrayani Waghmare, Hailey Kwon, Katelin Hanes, Madhuri Kango-Singh

Biology Faculty Publications

Epithelial cells are the major cell-type for all organs in multicellular organisms. In order to achieve correct organ size, epithelial tissues need mechanisms that limit their proliferation, and protect tissues from damage caused by defective epithelial cells. Recently, the Hippo signaling pathway has emerged as a major mechanism that orchestrates epithelial development. Hippo signaling is required for cells to stop proliferation as in the absence of Hippo signaling tissues continue to proliferate and produce overgrown organs or tumors. Studies in Drosophila have led the way in providing a framework for how Hippo alters the pattern of gene transcription in target …

Freq-Seq: A Rapid, Cost-Effective, Sequencing-Based Method To Determine Allele Frequencies Directly From Mixed Populations, Lon Chubiz, Ming-Chun Lee, Nigel Delaney, Christopher Marx

Biology Department Faculty Works

No abstract provided.

Serotonin System Gene Polymorphisms Are Associated With Impulsivity In A Context Dependent Manner, Scott F. Stoltenberg, Christa C. Christ, Krista B. Highland

Department of Psychology: Faculty Publications

Impulsivity is a risk factor for adverse outcomes and characterizes several psychiatric disorders and risk for suicide. There is strong evidence that genetic variation influences individual differences in impulsivity, but the details are not yet understood. There is growing interest in better understanding the context dependency of genetic effects that is reflected in studies examining gender specificity, gene × environment interaction and epistasis (gene-gene interaction). In a cross-sectional study we examined whether polymorphisms in six serotonin system candidate genes and the experience of early life trauma (age 0–12) were associated with individual differences in impulsivity in a nonclinical sample of …

Phylogenetics Links Monster Larva To Deep-Sea Shrimp., Heather D Bracken-Grissom, Darryl L Felder, Nicole L Vollmer, Joel W Martin, Keith A Crandall

Computational Biology Institute

Mid-water plankton collections commonly include bizarre and mysterious developmental stages that differ conspicuously from their adult counterparts in morphology and habitat. Unaware of the existence of planktonic larval stages, early zoologists often misidentified these unique morphologies as independent adult lineages. Many such mistakes have since been corrected by collecting larvae, raising them in the lab, and identifying the adult forms. However, challenges arise when the larva is remarkably rare in nature and relatively inaccessible due to its changing habitats over the course of ontogeny. The mid-water marine species Cerataspis monstrosa (Gray 1828) is an armored crustacean larva whose adult identity …

Organellar Signaling Expands Plant Phenotypic Variation And Increases The Potential For Breeding The Epigenome, Roberto De La Rosa Santamaria

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

MUTS HOMOLOGUE 1 (MSH1) is a nuclear gene unique to plants that functions in mitochondria and plastids, where it confers genome stability. Phenotypic effects of MSH1 down- regulation were studied in sorghum inbreed line Tx430 and Arabidopsis ecotype Columbia-0, with the hypothesis that RNAi suppression of MSH1 triggers retrograde signaling from organelles to the nucleus, alters the epigenome, and derives heritable phenotypic variation suitable for artificial selection. An array of morphological traits and metabolic pathways was detected, including leaf variegation, male sterility and dwarfism, associated with altered gibberellic acid metabolism, higher levels of reactive oxygen species (ROS), and decreased synthesis …