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Genetics and Genomics

2019

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Full-Text Articles in Animal Sciences

Expression Of Lysine-Mediated Neuropeptide Hormones Controlling Satiety And Appetite In Broiler Chickens, Collins N. Khwatenge, Boniface M. Kimathi, Thyneice Taylor-Bowden, Samuel N. Nahashon Dec 2019

Expression Of Lysine-Mediated Neuropeptide Hormones Controlling Satiety And Appetite In Broiler Chickens, Collins N. Khwatenge, Boniface M. Kimathi, Thyneice Taylor-Bowden, Samuel N. Nahashon

Agricultural and Environmental Sciences Faculty Research

Lysine is the second most limiting amino acid after methionine and is considered the most limiting amino acid for growth in poultry. Lysine requirement for broiler chickens has changed over the years. Leptin and adiponectin represent 2 adipokines that mediate metabolism by eliciting satiety effects whereas ghrelin peptide hormone influences appetite. We hypothesize that this affects growth performance of chicks. This study evaluates the effect of varying dietary lysine homeostasis on performance of broiler chickens through satiety- and appetite-mediating hormones. In 3 replications, 270 one-day-old chicks were reared for 8 wk feeding on diets comprising 0.85, 1.14, and 1.42% lysine …


The Effects Of Foot And Udder Scoring On Cow And Calf Performance, Clayton Lee Mcguire Dec 2019

The Effects Of Foot And Udder Scoring On Cow And Calf Performance, Clayton Lee Mcguire

Graduate Theses and Dissertations

Foot soundness and udder conformation are essential for longevity in beef cattle. The objective of this study was to investigate the effects of foot angle (FA), claw set (CS), teat size (TS) and udder suspension (US) scores on cowherd performance. Data were analyzed for 1,685 observations on Angus-based cows over a four-year period. At weaning FA, CS, TS, and US were evaluated. Scores are based on nine-point scales. A score of one indicates straight pasterns, divergent toes, enlarged bottle shaped teats, and absence of a median suspensory ligament; nine indicates weak pasterns, curled toes, small symmetrical teats, and a tight …


Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford Dec 2019

Estimation Of Genetic Components Related To Infectious Bovine Keratoconjunctivitis Susceptibility In Angus And Angus Derived Cattle Produced In The Southern United States, Eric Oxford

Graduate Theses and Dissertations

The economic impact of infectious bovine keratoconjunctivitis (IBK) has been documented in many parts of the world. Many researchers have observed that prevention of this disease is very difficult given current methodologies. This is primarily due to the multifactorial nature of this disease. The objective of this dissertation was to determine the impact of IBK on calf performance and estimate genetic parameters, heritability and estimated breeding values for IBK susceptibility. Data were analyzed using PROC GLIMMIX of SAS; while genetic parameters were estimated using a linear animal model for both single- and two-traits through MTDFREML. Additional evaluations calculated heritability using …


Investigating Growth Performance And Intestinal Barrier Integrity In Heat-Stressed Modern Broilers And Their Ancestor Jungle Fowl, Travis Tabler Dec 2019

Investigating Growth Performance And Intestinal Barrier Integrity In Heat-Stressed Modern Broilers And Their Ancestor Jungle Fowl, Travis Tabler

Graduate Theses and Dissertations

Heat stress (HS) has a negative effect on poultry production sustainability due to its adverse consequence on bird welfare, health, growth, and mortality. Although modern broilers have greater gut mass and higher energy use efficiency than unselected birds, they are more vulnerable to HS that induces “leaky gut syndrome,” or increased intestinal permeability. The aim of the current study was to determine the effect of HS on growth performance and gut barrier integrity in three modern broiler lines and their ancestor the Jungle Fowl. Four chicken populations including Giant Jungle Fowl (JF), Athens Canadian Random Bred (ACRB), 1995 Arkansas Random …


Molecular Survey Of Helminths Infecting Ground Dwelling Birds In The Grouse Subfamily Tetraoninae, Briana M. Sesmundo Nov 2019

Molecular Survey Of Helminths Infecting Ground Dwelling Birds In The Grouse Subfamily Tetraoninae, Briana M. Sesmundo

Honors College Theses

Alaskan grouse and ptarmigan (Galliformes) are important avian game species in Alaska. Interestingly, gallids harbor a fairly diverse helminth fauna, particularly cestodes, which may make birds with high parasite loads more susceptible to predation. Unfortunately, there is limited information available on the helminth fauna of Alaskan gallids, and no molecular surveys. The present study aims to develop baseline data on diversity of intestinal and subcutaneous (filariid) helminth infections in galliforms using morphological and molecular (DNA) approaches. These data can then be used to better understand changes in helminth community structure given current environmental volatility. The intestines, cloaca, liver and kidneys …


Immune Gene Diversity And Populations Structure Of Reticulated Flatwoods Salamander (Ambystoma Bishopi), Steven Tyler Williams Nov 2019

Immune Gene Diversity And Populations Structure Of Reticulated Flatwoods Salamander (Ambystoma Bishopi), Steven Tyler Williams

LSU Master's Theses

Reticulated flatwoods salamander (Ambystoma bishopi) populations began decreasing dramatically in the late 1900s. Contemporary populations are small, isolated, and may be susceptible to inbreeding and reduced adaptive potential because of low genetic variation. Genetic variation at immune genes is especially important as it influences disease susceptibility and adaptation to emerging infectious pathogens, a central conservation concern for declining amphibians. Connectivity between isolated populations is also vital to maintain genetic diversity and avoid inbreeding. I collected tissue samples from across the extant range of this salamander to examine genetic variation and population structure in: immune genes broadly (immunome), the …


Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel Oct 2019

Patterns Of Morphological Plasticity In Metriaclima Zebra And Danio Rerio Suggest Differently Canalized Phenotypes Due To Form-Function Relationships, Dylan Jockel

Masters Theses

In order to ascertain the degree of compatibility in developmental restructuring and behavioral plasticity between two fish species frequently made subject of laboratory research (Metriaclima zebra & Danio rerio), alternative trophic niche exposure experiments utilizing novel three-prong feeding treatments were conducted to obtain morphometric data, which demonstrated both species do bear some degree of plasticity. The results are somewhat complicated by differences in locality of detectable restructuring, which may be due to disparity in the form-function relationship for each species’ lineage. Each is notable in the manner of respective species’ jaw protrusion, as it is driven by anterior …


Dna Fingerprinting Reveals Low Genetic Diversity In Gunnison's Prairie Dog (Cynomys Gunnisoni), Steven E. Travis, C. N. Slobodchikoff, Paul Keim Sep 2019

Dna Fingerprinting Reveals Low Genetic Diversity In Gunnison's Prairie Dog (Cynomys Gunnisoni), Steven E. Travis, C. N. Slobodchikoff, Paul Keim

Con Slobodchikoff, PhD

The use of molecular techniques for the assessment of familial relationships among social species of mammals has become relatively commonplace. However, some species represent poor candidates for such studies due to naturally low levels of genetic diversity, leading to unacceptably large standard errors associated with estimates of relatedness. Here, we report on a preliminary study of genetic diversity within two populations of a social species of ground squirrel, Gunnison's prairie dog (Cynomys gunnisoni) using DNA fingerprinting. We observed low levels of diversity in the form of large mean coefficients of genetic similarity among individuals occupying the same population. …


A Standardized G‐Banded Karyotype For The Raccoon (Procyon Lotor) Compared With The Domestic Cat, Roscoe Stanyon, Francesca Bigoni, Johannes Weinberg, John Hadidian Sep 2019

A Standardized G‐Banded Karyotype For The Raccoon (Procyon Lotor) Compared With The Domestic Cat, Roscoe Stanyon, Francesca Bigoni, Johannes Weinberg, John Hadidian

John Hadidian, PhD

We propose a standardized karyotype for the raccoon (Procyon lotor; 2n = 38, FN 74) and compare it with that of the domestic cat (2n = 38, FN 72). Numerous chromosomes (12) have similar and sometimes identical G-banding and 14 chromosome pairs have remained intact. Other chromosomes apparently differ by Robertsonian translocations and inversions. The conservation of these karyotypes is remarkable considering that the divergence of procyonids and felids predates 50 million years B.P. However, the common diploid number of 38 is not a primitive retention, as sometimes hypothesized. Instead, cats and raccoons converged on this chromosome number by a …


Use Of Probiotic Bacterial Strains And Cell Extracts To Inhibit Acidosis And Liver Abscesses In Cattle, Samodha Charaka Fernand Sep 2019

Use Of Probiotic Bacterial Strains And Cell Extracts To Inhibit Acidosis And Liver Abscesses In Cattle, Samodha Charaka Fernand

Department of Animal Science: Faculty Publications

Disclosed are methods of using probiotic bacterial strains Aneurinibacillus migulanus, Aneurinibacillus aneurinilyti cus and / or extracts thereof for inhibiting the growth of Streptococcus bovis , Fusobacterium necrophorum , and Acranobacterium ( Actinomyces ) pyogenes . These bacterial strains and / or their extracts can be used in cattle to treat acidosis and / or liver abscesses , as well as inhibit foot rot, among other infections and conditions caused by Strepto coccus bovis and / or Fusobacterium necrophorum and / or Acranobacterium (Actinomyces) pyogenes. Compositions for use in these methods are also provided.


Rescue And Reestablishment Of Chicken Models For Spontaneously Occurring Hashimoto’S Thyroiditis And Systemic Sclerosis/Scleroderma, Joseph Zolton Hiltz Aug 2019

Rescue And Reestablishment Of Chicken Models For Spontaneously Occurring Hashimoto’S Thyroiditis And Systemic Sclerosis/Scleroderma, Joseph Zolton Hiltz

Graduate Theses and Dissertations

The loss of biodiversity is a topic gaining popularity both in the political and scientific forums. Nearly 30 years ago researchers and politicians congregated in Rio de Janeiro (1992) to attend the first Earth Summit. It was the first meeting of its kind discussing the tangible pressing consequences of biodiversity loss as well as the potential long term ramifications. Many of the countries represented at this summit implemented short and long term plans in order to accurately measure losses of biodiversity as well as establishing organizations to help diagnose and remedy the current problems at hand. These new organizations and …


Work-Type Influences Perceived Livestock Herding Success In Australian Working Kelpies, Jonathan B. Early, Elizabeth R. Arnott, Lisa J. Mascord, Diane Van Rooy, Paul Mcgreevy, Claire M. Wade Jul 2019

Work-Type Influences Perceived Livestock Herding Success In Australian Working Kelpies, Jonathan B. Early, Elizabeth R. Arnott, Lisa J. Mascord, Diane Van Rooy, Paul Mcgreevy, Claire M. Wade

Paul McGreevy, PhD

Background

Working dog handlers and breeders have very different behavioural requirements in the animals that they employ for managing livestock. The Australian Working Kelpie breed may be used in several working contexts, notably yards, paddocks and a combination of both. The working context influences the skillsets required and gives rise to three corresponding work-types: Yard, Paddock and Utility Kelpies. In particular, dogs used for working stock in the confines of yards and trucks interact with stock more forcefully than those mustering in larger areas (paddocks) where they can herd stock effectively from a greater distance. This article explores owner assessments …


Gene Expression Profiling In Salmonella Choleraesuis-Infected Porcine Lung Using A Long Oligonucleotide Microarray, Shu-Hong Zhao, Daniel Kuhar, Joan K. Lunney, Harry Dawson, Catherine Guidry, Jolita J. Uthe, Shawn M. D. Bearson, Justin Recknor, Dan Nettleton, Christopher K. Tuggle Jul 2019

Gene Expression Profiling In Salmonella Choleraesuis-Infected Porcine Lung Using A Long Oligonucleotide Microarray, Shu-Hong Zhao, Daniel Kuhar, Joan K. Lunney, Harry Dawson, Catherine Guidry, Jolita J. Uthe, Shawn M. D. Bearson, Justin Recknor, Dan Nettleton, Christopher K. Tuggle

Dan Nettleton

Understanding the transcriptional response to pathogenic bacterial infection within food animals is of fundamental and applied interest. To determine the transcriptional response to Salmonella enterica serovar Choleraesuis (SC) infection, a 13,297-oligonucleotide swine array was used to analyze RNA from control, 24-h postinoculation (hpi), and 48-hpi porcine lung tissue from pigs infected with SC. In total, 57 genes showed differential expression (p < 0.001; false discovery rate = 12%). Quantitative real-time PCR (qRT-PCR) of 61 genes was used to confirm the microarray results and to identify pathways responding to infection. Of the 33 genes identified by microarray analysis as differentially expressed, 23 were confirmed by qRT-PCR results. A novel finding was that two transglutaminase family genes (TGM1 and TGM3) showed dramatic increases in expression postinoculation; combined with several other apoptotic genes, they indicated the induction of apoptotic pathways during SC infection. A predominant T helper 1-type immune response occurred during infection, with interferon …


Microarray Gene Expression Profiles Of Fasting Induced Changes In Liver And Adipose Tissues Of Pigs Expressing The Melanocortin-4 Receptor D298n Variant, Sender Lkhagvadorj, Long Qu, Weiguo Cai, Oliver P. Coutoure, C. Richard Barb, Gary J. Hausman, Dan Nettleton, Lloyd L. Anderson, Jack C. M. Dekkers, Christopher K. Tuggle Jul 2019

Microarray Gene Expression Profiles Of Fasting Induced Changes In Liver And Adipose Tissues Of Pigs Expressing The Melanocortin-4 Receptor D298n Variant, Sender Lkhagvadorj, Long Qu, Weiguo Cai, Oliver P. Coutoure, C. Richard Barb, Gary J. Hausman, Dan Nettleton, Lloyd L. Anderson, Jack C. M. Dekkers, Christopher K. Tuggle

Dan Nettleton

Transcriptional profiling coupled with blood metabolite analyses were used to identify porcine genes and pathways that respond to a fasting treatment or to a D298N missense mutation in the melanocortin-4 receptor (MC4R) gene. Gilts (12 homozygous for D298 and 12 homozygous for N298) were either fed ad libitum or fasted for 3 days. Fasting decreased body weight, backfat, and serum urea concentration and increased serum nonesterified fatty acid. In response to fasting, 7,029 genes in fat and 1,831 genes in liver were differentially expressed (DE). MC4R genotype did not significantly affect gene expression, body weight, backfat depth, or any measured …


Unique Genome-Wide Transcriptome Profiles Of Chicken Macrophages Exposed To Salmonella-Derived Endotoxin, Ceren Ciraci, Christopher K. Tuggle, Michael J. Wannemeuhler, Dan Nettleton, Susan J. Lamont Jul 2019

Unique Genome-Wide Transcriptome Profiles Of Chicken Macrophages Exposed To Salmonella-Derived Endotoxin, Ceren Ciraci, Christopher K. Tuggle, Michael J. Wannemeuhler, Dan Nettleton, Susan J. Lamont

Dan Nettleton

Background: Macrophages play essential roles in both innate and adaptive immune responses. Bacteria require endotoxin, a complex lipopolysaccharide, for outer membrane permeability and the host interprets endotoxin as a signal to initiate an innate immune response. The focus of this study is kinetic and global transcriptional analysis of the chicken macrophage response to in vitro stimulation with endotoxin from Salmonella typhimurium-798.

Results: The 38535-probeset Affymetrix GeneChip Chicken Genome array was used to profile transcriptional response to endotoxin 1, 2, 4, and 8 hours post stimulation (hps). Using a maximum FDR (False Discovery Rate) of 0.05 to declare genes as differentially …


Postnatal Nutrient Repartitioning Due To Adaptive Developmental Programming, Robert J. Posont, Dustin T. Yates Jul 2019

Postnatal Nutrient Repartitioning Due To Adaptive Developmental Programming, Robert J. Posont, Dustin T. Yates

Department of Animal Science: Faculty Publications

The consequences of prenatal stress on lifelong metabolic function and health was first proposed by David Barker and Nicholas Hales with the publication of their Thrifty Phenotype Hypothesis in the early 1990s.1,2 Subsequent studies in humans and animals have further demonstrated that stress-induced adaptive fetal programming leads to tissue-specific changes in metabolic function and growth capacity.3,4 Developmental adaptations to the intrauterine nutrient restriction that accompanies most maternofetal stressors target regulatory pathways for nutrient utilization in non-essential tissues such as skeletal muscle.4-6 This aids intrauterine survival by re-appropriating nutrients to support neural, cardiac, and endocrine tissue function but reduces metabolic efficiency …


Computational Integration Of Structural And Functional Genomics Data Across Species To Develop Information On The Porcine Inflammatory Gene Regulatory Pathway, C. K. Tuggle, Y. F. Wang, O. P. Couture, L. Qu, J. J. Uthe, D. Kuhar, J. K. Lunney, D. Nettleton, J. C. Dekkers, S. M. D. Bearson Jun 2019

Computational Integration Of Structural And Functional Genomics Data Across Species To Develop Information On The Porcine Inflammatory Gene Regulatory Pathway, C. K. Tuggle, Y. F. Wang, O. P. Couture, L. Qu, J. J. Uthe, D. Kuhar, J. K. Lunney, D. Nettleton, J. C. Dekkers, S. M. D. Bearson

Dan Nettleton

We are investigating the porcine gut immune response to infection through gene expression profiling. Porcine Affymetrix GeneChip data was obtained from RNA prepared from mesenteric lymph node of swine infected with either Salmonella enterica serovar Typhimurium (ST) or S. Choleraesuis (SC) for 0, 8, 24, 48 or 504 hours post-inoculation (hpi). In total, 2,365 genes with statistical evidence for differential expression (DE; p < 0.01, q < 0.26, fold-change> 2) between at least two time-points were identified. Comparative Gene Ontology analyses revealed that a high proportion of annotated DE genes in both infections are involved in immune and defence responses. Hierarchical clustering of expression patterns and …


Post-Weaning Blood Transcriptomic Differences Between Yorkshire Pigs Divergently Selected For Residual Feed Intake, Haibo Liu, Yet T. Nguyen, Dan Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle Jun 2019

Post-Weaning Blood Transcriptomic Differences Between Yorkshire Pigs Divergently Selected For Residual Feed Intake, Haibo Liu, Yet T. Nguyen, Dan Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle

Dan Nettleton

Background: Improving feed efficiency (FE) of pigs by genetic selection is of economic and environmental significance. An increasingly accepted measure of feed efficiency is residual feed intake (RFI). Currently, the molecular mechanisms underlying RFI are largely unknown. Additionally, to incorporate RFI into animal breeding programs, feed intake must be recorded on individual pigs, which is costly and time-consuming. Thus, convenient and predictive biomarkers for RFI that can be measured at an early age are greatly desired. In this study, we aimed to explore whether differences exist in the global gene expression profiles of peripheral blood of 35 to 42 day-old …


Identification Of Differentially Expressed Gene Categories In Microarray Studies Using Nonparametric Multivariate Analysis, Dan Nettleton, Justin Recknor, James M. Reecy Jun 2019

Identification Of Differentially Expressed Gene Categories In Microarray Studies Using Nonparametric Multivariate Analysis, Dan Nettleton, Justin Recknor, James M. Reecy

Dan Nettleton

The field of microarray data analysis is shifting emphasis from methods for identifying differentially expressed genes to methods for identifying differentially expressed gene categories. The latter approaches utilize a priori information about genes to group genes into categories and enhance the interpretation of experiments aimed at identifying expression differences across treatments. While almost all of the existing approaches for identifying differentially expressed gene categories are practically useful, they suffer from a variety of drawbacks. Perhaps most notably, many popular tools are based exclusively on gene-specific statistics that cannot detect many types of multivariate expression change. We have developed a nonparametric …


Differentially Expressed Genes In Blood From Young Pigs Between Two Swine Lines Divergently Selected For Feed Efficiency: Potential Biomarkers For Improving Feed Efficiency, Haibo Liu, Yet T. Nguyen, Daniel S. Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle Jun 2019

Differentially Expressed Genes In Blood From Young Pigs Between Two Swine Lines Divergently Selected For Feed Efficiency: Potential Biomarkers For Improving Feed Efficiency, Haibo Liu, Yet T. Nguyen, Daniel S. Nettleton, Jack C. M. Dekkers, Christopher K. Tuggle

Dan Nettleton

The goal of this study was to find potential gene expression biomarkers in blood of piglets that can be used to predict pigs’ future feed efficiency. Using RNA-seq technology, we found 453 genes were differentially expressed (false discovery rate (FDR) ≤ 0.05) in the blood of two Yorkshire lines of pigs divergently selected for feed efficiency (FE) based on residual feed intake (RFI). Genes involved in several biosynthetic processes were overrepresented among genes more highly expressed in the low RFI line compared to the high RFI line. Weighted gene co-expression network analysis (WGCNA) also revealed genes involved in some of …


Beef Production Systems In The Nebraska Sandhills, Mckay Erickson Jun 2019

Beef Production Systems In The Nebraska Sandhills, Mckay Erickson

Department of Animal Science: Dissertations, Theses, and Student Research

Four studies were conducted to determine the effectiveness of improving production systems of beef cattle in the Sandhills region of Nebraska. These studies were to determine impacts of modified estrus synchronization protocols, genomic testing heifer calves for longevity, and evaluation of 2 differing calving systems (March or May) for improving biological outcome and improved production. Experiment 1 utilized 180 yearling heifers to determine the effectiveness of a second dose of prostaglandin F(PGF) with those females not expressing estrus after an initial 14 d MGA-PG estrus synchronization protocol. The treatment of PGF did increase estrus expression, but did not …


Utilizing An Electronic Feeder To Measure Mineral And Energy Supplement Intake In Beef Heifers Grazing Native Range, Kacie L. Mccarthy, Sarah R. Underdahl, Michael Undi, Stephanie Becker, Carl R. Dahlen Jun 2019

Utilizing An Electronic Feeder To Measure Mineral And Energy Supplement Intake In Beef Heifers Grazing Native Range, Kacie L. Mccarthy, Sarah R. Underdahl, Michael Undi, Stephanie Becker, Carl R. Dahlen

Department of Animal Science: Faculty Publications

Introduction

Grasslands in the Northern Plains provide the primary forage source for ruminants throughout much of the year (Schauer et al., 2004). Supplementation practices are often necessary to maintain production and offset forage nutritive decline throughout the grazing season (Schauer et al., 2004; Cline et al., 2009). Typically, to maintain a targeted production level, energy and protein supplementations are used for grazing livestock (Caton and Dhuyvetter, 1997). For developing heifers consuming low-quality forages, inclusion of energy ingredients into supplements may be beneficial for growth and reproductive performance (Schillo et al., 1992; Ciccioli et al., 2005; Cappellozza et al., 2014). In …


Effect Of Cooled Perches On The Efficacy Of An Induced Molt In White Leghorn Laying Hens Previously Exposed To Heat Stress, J Y. Hu, P Y. Hester, Y Xiong, R S. Gates, M M. Makagon, H W. Cheng May 2019

Effect Of Cooled Perches On The Efficacy Of An Induced Molt In White Leghorn Laying Hens Previously Exposed To Heat Stress, J Y. Hu, P Y. Hester, Y Xiong, R S. Gates, M M. Makagon, H W. Cheng

Department of Animal Science: Faculty Publications

This study examined the effect of water chilled perches on hen production and physiological responses to induced molt during elevated temperatures. A total of 288White Leghorns at 82 wk of age were housed in 36 cages of 6 banks. Each bank was assigned to 1 of 3 treatments: cooled perches, air perches, and no perches. The hens were subjected to 2 heat episodes during their first laying cycle at week 21 to 35 and week 73 to 80, respectively. The hens were subjected to a 28 D nonfasted molting regimen starting at 85 wk of age. Cyclic heat of 32◦C …


Hiding In The Lianas Of The Tree Of Life: Molecular Phylogenetics And Species Delimitation Reveal Considerable Cryptic Diversity Of New World Vine Snakes, Robert C. Jadin, Christopher Blair, Michael J. Jowers, Anthony Carmona, John C. Murphy May 2019

Hiding In The Lianas Of The Tree Of Life: Molecular Phylogenetics And Species Delimitation Reveal Considerable Cryptic Diversity Of New World Vine Snakes, Robert C. Jadin, Christopher Blair, Michael J. Jowers, Anthony Carmona, John C. Murphy

Publications and Research

The Brown Vine Snake, Oxybelis aeneus, is considered a single species despite the fact its distribution covers an estimated 10% of the Earth’s land surface, inhabiting a variety of ecosystems throughout North, Central, and South America and is distributed across numerous biogeographic barriers. Here we assemble a multilocus molecular dataset (i.e. cyt b, ND4, cmos, PRLR) derived from Middle American populations to examine for the first time the evolutionary history of Oxybelis and test for evidence of cryptic lineages using Bayesian and maximum likelihood criteria. Our divergence time estimates suggest that Oxybelis diverged from its sister genus, Leptophis …


X-Inactivation And Epigenetics, Serena Weston Apr 2019

X-Inactivation And Epigenetics, Serena Weston

Thinking Matters Symposium Archive

To prevent abnormal development caused by expressing both X chromosomes, female mammals inactivate one of their X chromosomes using an epigenetic process called dosage compensation. This literature review examines how X chromosome inactivation (XCI) occurs during the formation and development of an embryo. This condensation of DNA is marked by histone tail modifications, DNA methylation, and the arrival of structural proteins resulting in extraordinarily stable heterochromatin. X-inactivation is regulated in cis by the X-inactivation center (Xic) that contains the Xist gene and its antisense gene, Tsix. On one X chromosome, Xist RNA is expressed and coats the center of the …


Male Determining Gene Nix May Bring An End To Transmission Of Diseases Through Mosquitoes, Mohammed Mahdi Apr 2019

Male Determining Gene Nix May Bring An End To Transmission Of Diseases Through Mosquitoes, Mohammed Mahdi

Thinking Matters Symposium Archive

Female mosquitoes take blood from humans to gain protein needed to produce eggs, and in the process they can transmit viruses, such as Zika, Dengue, and chikungunya, or parasites, such as malaria. Male mosquitoes do not transmit diseases. This literature review will examine what is known about how sex is determined in mosquitoes and how this can be used to manipulate the females that spread diseases to humans. Using CRISPR Cas9, the lab of Zhijian Tu removed the Nix gene from mosquito embryos; all of these were feminized. Ectopic overexpression of Nix gene product in mosquito embryos caused even genetically …


Population Viability And Connectivity Of The Federally Threatened Eastern Indigo Snake In Central Peninsular Florida, Javan Bauder Mar 2019

Population Viability And Connectivity Of The Federally Threatened Eastern Indigo Snake In Central Peninsular Florida, Javan Bauder

Doctoral Dissertations

Understanding the factors influencing the likelihood of persistence of real-world populations requires both an accurate understanding of the traits and behaviors of individuals within those populations (e.g., movement, habitat selection, survival, fecundity, dispersal) but also an understanding of how those traits and behaviors are influenced by landscape features. The federally threatened eastern indigo snake (EIS, Drymarchon couperi) has declined throughout its range primarily due to anthropogenically-induced habitat loss and fragmentation making spatially-explicit assessments of population viability and connectivity essential for understanding its current status and directing future conservation efforts. The primary goal of my dissertation was to understand how …


Blood Mercury Levels Of Zebra Finches Are Heritable: Implications For The Evolution Of Mercury Resistance, Kenton A. Buck, Claire W. Varian-Ramos, Daniel A. Cristol, John P. Swaddle Mar 2019

Blood Mercury Levels Of Zebra Finches Are Heritable: Implications For The Evolution Of Mercury Resistance, Kenton A. Buck, Claire W. Varian-Ramos, Daniel A. Cristol, John P. Swaddle

Daniel Cristol

Mercury is a ubiquitous metal contaminant that negatively impacts reproduction of wildlife and has many other sub-lethal effects. Songbirds are sensitive bioindicators of mercury toxicity and may suffer population declines as a result of mercury pollution. Current predictions of mercury accumulation and biomagnification often overlook possible genetic variation in mercury uptake and elimination within species and the potential for evolution in affected populations. We conducted a study of dietary mercury exposure in a model songbird species, maintaining a breeding population of zebra finches (Taeniopygia guttata) on standardized diets ranging from 0.0–2.4 μg/g methylmercury. We applied a quantitative genetics …


Substantial Red Wolf Genetic Ancestry Persists In Wild Canids Of Southwestern Louisiana, Jennifer R. Adams, John J. Cox, Lisette P. Waits Mar 2019

Substantial Red Wolf Genetic Ancestry Persists In Wild Canids Of Southwestern Louisiana, Jennifer R. Adams, John J. Cox, Lisette P. Waits

Forestry and Natural Resources Faculty Publications

Concerns over red wolf (Canis rufus) extinction caused by hybridization with coyotes (C. latrans) led to the capture and removal of remnant wild wolves from southwestern Louisiana and southeastern Texas, United States, during the 1970s. Here we show that despite decades of unmitigated hybridization, and declaration of endangered red wolves as functionally extinct in the wild, red wolf mitochondrial or nuclear DNA ancestry persists in ∼55% of contemporary wild canids sampled in southwestern Louisiana. Surprisingly, one individual had 78–100% red wolf ancestry, which is within the range for 75% red wolf, red wolf backcross, or putative …


Crispr-Mediated Gene Editing: Scientific And Ethical Issues, Jarrod Bailey Mar 2019

Crispr-Mediated Gene Editing: Scientific And Ethical Issues, Jarrod Bailey

Genetics Collection

There remains substantial evidence to warrant great concern over the poor efficiency and specificity of clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genetic modification (GM), despite relatively minor improvements compared to other GM methods. These issues cause persistent, adverse, ethical, and scientific consequences for GM animals, which may never be sufficiently resolvable.