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Articles 61 - 90 of 223

Full-Text Articles in Genetics

Temperature Regulation Of Plant Hormone Signaling During Stress And Development, Christian Castroverde, Damaris Dina Jun 2021

Temperature Regulation Of Plant Hormone Signaling During Stress And Development, Christian Castroverde, Damaris Dina

Biology Faculty Publications

Global climate change has broad-ranging impacts on the natural environment and human civilization. Increasing average temperatures along with more frequent heat waves collectively have negative effects on cultivated crops in agricultural sectors and wild species in natural ecosystems. These aberrantly hot temperatures, together with cold stress, represent major abiotic stresses to plants. Molecular and physiological responses to high and low temperatures are intricately linked to the regulation of important plant hormones. In this review, we shall highlight our current understanding of how changing temperatures regulate plant hormone pathways during immunity, stress responses and development. This article will present an overview …


Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker May 2021

Analysis Of Symptom Expressions And Transmission Rates Caused By The Plant Pathogen Phytophthora Ramorum On Native Chaparral Plants From The Genus Arctostaphylos, Bharati Gaonker

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Phytophthora ramorum is the causal agent of Sudden Oak death (SOD), ramorum dieback and ramorum leaf blight which affect both forest environments and nurseries. This oomycete pathogen has had a huge economic impact on the nursery and lumber industry. Forests in California have experienced substantial mortality of oaks affecting the forest dynamics and diversity. Our research investigates four native species and two ornamental cultivars of plants, which belong to the genus Arctostaphylos (manzanita) and are considered to be new hosts for P. ramorum in the chaparral ecosystem of California. Symptom expression and transmission rates were analyzed on Arctostaphylos glauca, …


Understanding The Genetics Of Schizophrenia, Matthew Toohey Apr 2021

Understanding The Genetics Of Schizophrenia, Matthew Toohey

Thinking Matters Symposium

Schizophrenia has been considered heritable for a long time, but only with the advent of new technologies such as whole-genome sequencing and genome-wide association studies can we begin to identify specific molecular causes of schizophrenia. This poster will review some of the genetic variants that research groups have associated with schizophrenia. Current research has indicated that schizophrenia is a polygenic disease and has been linked to many genes. Some of these common risk variants are in protein coding sections of the DNA. These proteins are often linked to neurological development or immune system function. Other variants that have been associated …


Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff Dec 2020

Single-Fluorophore Sensors For Mechanical Force In Living Cells, Sarah Kricheff

Honors Scholar Theses

Mechanotransduction is the process by which a mechanical stimulus is converted to a cellular signal. This process is heavily influential of cell morphology, differentiation, and behavior. However, altered levels of mechanical stimuli are also found in many pathological contexts. For example, cancerous cells have stiffer surrounding tissue than healthy cells, and research suggests that this alters cell behavior and promotes metastasis. Despite these findings, the cellular processes behind these signaling alterations remain widely unknown. Understanding these cascades is critical, as involved proteins can give us a deeper understanding of the role of mechanotransduction, and certain proteins can potentially be targeted …


Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau Nov 2020

Evaluation Of The Xpert Carba-R Nxg Assay For Detection Of Carbapenemase Genes In A Global Challenge Set Of Pseudomonas Aeruginosa Isolates, Fred C. Tenover, Christian M. Gill, Tomefa E. Asempa, Isabella A. Tickler, Caitlin M. Dela Cruz, David P. Nicolau

Biology Faculty Publications

The growing prevalence and diversity of carbapenemase producers among carbapenem-resistant Pseudomonas aeruginosa (CRPA) isolates warrants an expansion of detection capabilities. The purpose of this study was to evaluate the performance of the commercially available Xpert Carba-R (Carba-R) and the research-use-only Xpert Carba-R NxG (Carba-R NxG) in a global collection of P. aeruginosa. The challenge set included 123 P. aeruginosa clinical isolates from 12 countries. Isolates were previously categorized via PCR or whole-genome sequencing. Carbapenemase classes tested include VIM, IMP, NDM, SPM, KPC, and GES. Non-carbapenemase (non-CP)-harboring isolates were also tested (negative control). Isolates were tested using the Carba-R NxG and …


Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan Oct 2020

Herb-Layer Dynamics In An Old-Growth Forest: Vegetation–Environment Relationships And Response To Invasion-Related Perturbations, Taylor M. Buskey, Margaret E. Maloney, Julia I. Chapman, Ryan W. Mcewan

Biology Faculty Publications

Temperate forests of eastern North America are subject to multiple invasions from non-native species that have the potential to drive long-term dynamics in biodiversity. Garlic mustard (Alliaria petiolata (M. Bieb.) Cavara and Grande) is an invasive plant in many deciduous forests, and management efforts often focus on removing this species to initiate native species restoration. Agrilus planipennis Fairmaire (emerald ash borer; Coleoptera: Buprestidae) is a non-native insect pest that has caused substantial loss of ash trees (Fraxinus spp. L.) in North America. Our goal was to understand how the herbaceous layer in an old-growth forest responded to the removal of …


Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler Sep 2020

Does The Presence Of Multiple Β-Lactamases In Gram-Negative Bacilli Impact The Results Of Antimicrobial Susceptibility Tests And Extended-Spectrum Β-Lactamase And Carbapenemase Confirmation Methods?, Fred C. Tenover, Caitlin M. Dela Cruz, Scott Dewell, Victoria M. Le, Isabella A. Tickler

Biology Faculty Publications

Objectives: Many multidrug-resistant Gram-negative bacilli (MDR-GNB) harbour multiple β-lactamases. The aim of this study was to assess the impact of multiple β-lactamase carriage on the accuracy of susceptibility tests and extended-spectrum β-lactamase (ESBL) and carbapenemase confirmation methods.

Methods: A total of 50 MDR-GNB, of which 29 carried multiple β-lactamases, underwent broth microdilution (BMD) and disk diffusion (DD) testing as well as confirmation tests for ESBLs and carbapenemases. Whole-genome sequencing (WGS) was used for β-lactamase gene identification.

Results: Categorical agreement of BMD and DD testing results ranged from 86.5 to 97.7% for 10 β-lactam agents. BMD and DD algorithms for ESBL …


The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan Sep 2020

The Influence Of Riparian Invasion By The Terrestrial Shrub Lonicera Maackii On Aquatic Macroinvertebrates In Temperate Forest Headwater Streams, Michelle N. Little, Kevin W. Custer, Eric B. Borth, Julia I. Chapman, Mitchell J. Kukla, Corey Kuminecz, Margaret E. Maloney, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

The ecology of headwater streams is tightly linked to the riparian zone through organic matter subsidies which are highly susceptible to alteration due to biological invasion. Lonicera maackii is a non-native shrub that is a highly successful invader of headwater stream riparian zones in the American Midwest. We assessed effects on benthic macroinvertebrates across a gradient of invasion intensity from references sites with minimal invasion to a site that had a very heavy invasion. Benthic macroinvertebrates were sampled throughout the year and compositional differences were assessed using Non-metric Multidimensional Scaling ordination, and by comparing the prevalence of sensitive (Ephemeroptera, Plectoptera, …


Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh Jul 2020

Inactivation Of Hippo And Cjun-N-Terminal Kinase (Jnk) Signaling Mitigate Fus Mediated Neurodegeneration In-Vivo, Ankita Sarkar, Abijeet Singh Mehta, Prajakta Deshpande, Madhuri Kango-Singh, Udai Bhan Pandey, Amit Singh

Biology Faculty Publications

Amyotrophic Lateral Sclerosis (ALS), a late-onset neurodegenerative disorder characterized by the loss of motor neurons in the central nervous system, has no known cure to-date. Disease causing mutations in human Fused in Sarcoma (FUS) leads to aggressive and juvenile onset of ALS. FUS is a well-conserved protein across different species, which plays a crucial role in regulating different aspects of RNA metabolism. Targeted misexpression of FUS in Drosophila model recapitulates several interesting phenotypes relevant to ALS including cytoplasmic mislocalization, defects at the neuromuscular junction and motor dysfunction. We screened for the genetic modifiers of human FUS-mediated neurodegenerative phenotype using molecularly …


Using A Novel Cell- Penetrating Peptide Technology To Induce Pluripotency, Laura-Maria Oja May 2020

Using A Novel Cell- Penetrating Peptide Technology To Induce Pluripotency, Laura-Maria Oja

Master of Science in Chemical Sciences Theses

Somatic stem cells have been used as a regenerative medicine tool to treat diseases like leukemia for decades, but they are limited in their ability to self-renew and differentiate. A better alternative, induced pluripotent stem cells (iPSCs), has the ability to generate cells from all three germ layers and avoid tissue rejection as well as bypass the ethical concerns related to embryonic stem cells. In 2006, Takahashi and Yamanaka discovered that only four genes were required to induce pluripotency: Oct4, Sox2, Klf4, and c-Myc (OSKM). Since then, pluripotency has been induced with OSKM most effectively by transfection or transduction. However, …


Assessing The Influence Of Riparian Invasion By The Shrub Lonicera Maackii On Terrestrial Subsidies To Headwater Streams, Erin C. Rowekamp, Julia I. Chapman, Ryan Mcewan May 2020

Assessing The Influence Of Riparian Invasion By The Shrub Lonicera Maackii On Terrestrial Subsidies To Headwater Streams, Erin C. Rowekamp, Julia I. Chapman, Ryan Mcewan

Biology Faculty Publications

Invasion of Amur honeysuckle (Lonicera maackii) into riparian areas of headwater streams creates strong potential for alterations of terrestrial subsidies that may drive bottom-up effects on aquatic biota. In this study, we analyzed effects of L. maackii on terrestrial subsidies in stream sites that represented a gradient of invasion intensity in temperate deciduous forests of southwestern Ohio (USA). Leaf litter biomass, terrestrial and aquatic fine woody debris (0.5–9.9 cm diameter) volume and count, and terrestrial and aquatic coarse woody debris (>9.9 cm diameter) volume were analyzed. Based on previous research, we hypothesized that sites with a higher …


An Analysis Of Crispr-Cas Gene Editing In Agriculture, Ashley Laliberte Apr 2020

An Analysis Of Crispr-Cas Gene Editing In Agriculture, Ashley Laliberte

Honors Scholar Theses

The CRISPR-Cas system is a promising form of gene editing, especially for the agriculture industry. The ability to make single-nucleotide edits within a gene of interest, without the need to introduce foreign DNA, is a powerful tool for designing healthier and more efficient crops and food animals. This system provides opportunity for increased nutritional value, decreased food waste, and more economically and environmentally sustainable food production. Though this biotechnology is facing mechanistic limitations due to off-target effects and inefficient homology-directed repair, vast improvements have already been made to improve its efficacy. The CRISPR-Cas system is already the most advanced form …


Assessing Seed Handling Processes To Facilitate A Community-Engaged Approach To Regional Forest Restoration, Meredith Cobb, Michaela J. Woods, Ryan Mcewan Apr 2020

Assessing Seed Handling Processes To Facilitate A Community-Engaged Approach To Regional Forest Restoration, Meredith Cobb, Michaela J. Woods, Ryan Mcewan

Biology Faculty Publications

In the Midwestern United States, there is a strong management impetus toward reforestation to replace trees lost to due to tree mortality and to establish forests on previously cleared properties. Here, we describe a public outreach and volunteer effort that aimed to generate positive, community-engaged restoration outcomes and report on a practical experiment involving seed handling. We obtained tree seeds that were donated by members of the community to local land managers. We evaluated the size of the seeds collected and tested the influence of common stratification media (none, sand and vermiculite) and seed size on germination success of three …


Molecular Differentiation Of Astragalus Species And Varieties From The Western United States: The Chloroplast Dna Bridge Between Evolution And Molecular Systematics, Marwa Neyaz, Daniel Cook, Rebecca Creamer Mar 2020

Molecular Differentiation Of Astragalus Species And Varieties From The Western United States: The Chloroplast Dna Bridge Between Evolution And Molecular Systematics, Marwa Neyaz, Daniel Cook, Rebecca Creamer

Poisonous Plant Research (PPR)

Locoweeds are the most widespread poisonous plant problem in the world and have been reported in the Western United States since the 1800s, causing tremendous losses in livestock. Consumption of locoweeds by grazing animals stimulates the neurological disease, locoism, characterized by weight loss, ataxia, and lack of muscular coordination. The name locoweed is used for Astragalus and Oxytropis species known to contain swainsonine, the toxic principle produced by the plant endophytic fungus Undifilum. Astragalus includes 2,500-3,000 species and many varieties that have almost identical morphological characteristics that overlap among species, leading to improper identification. Therefore, the aim of this study …


A Positive Feedback Loop Of Hippo- And C-Jun-Amino-Terminal Kinase Signaling Pathways Regulates Amyloid-Beta-Mediated Neurodegeneration, Madison Irwin, Meghana Tare, Aditi Singh, Oorvashi Roy Puli, Neha Gogia, Matthew Riccetti, Prajakta Deshpande, Madhuri Kango-Singh, Amit Singh Mar 2020

A Positive Feedback Loop Of Hippo- And C-Jun-Amino-Terminal Kinase Signaling Pathways Regulates Amyloid-Beta-Mediated Neurodegeneration, Madison Irwin, Meghana Tare, Aditi Singh, Oorvashi Roy Puli, Neha Gogia, Matthew Riccetti, Prajakta Deshpande, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300) is an age-related disorder that affects millions of people. One of the underlying causes of AD is generation of hydrophobic amyloid-beta 42 (Aβ42) peptides that accumulate to form amyloid plaques. These plaques induce oxidative stress and aberrant signaling, which result in the death of neurons and other pathologies linked to neurodegeneration. We have developed a Drosophila eye model of AD by targeted misexpression of human Aβ42 in the differentiating retinal neurons, where an accumulation of Aβ42 triggers a characteristic neurodegenerative phenotype. In a forward deficiency screen to look for genetic modifiers, we identified a molecularly …


Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong Jan 2020

Spatial And Temporal Genetic Structure Of Winter-Run Steelhead (Oncorhynchus Mykiss) Returning To The Mad River, California, Steven R. Fong

Cal Poly Humboldt theses and projects

Distinct populations of steelhead in the wild are in decline. The propagation of steelhead in hatcheries has been used to boost population numbers for recreational fisheries and for use in conservation. However, hatchery breeding practices of steelhead can result in changes in genetic structure. I investigated the genetic structure of winter-run steelhead (Oncorhynchus mykiss) returning to the Mad River, California, where a hatchery has been used enhance production for recreational fisheries since 1971. Genetic variability in Mad River steelhead was evaluated using 96 single nucleotide polymorphisms (SNPs) among 4203 individuals, including the Mad River and nearby locations, and …


Optimization And Validation Of The Neurolux Wireless Optoelectronics System For Optogenetics, Karis Courey, Su Hyun Lee Ph.D., Adam Smith Ph.D., Nicholas Cilz Ph.D., Sarah K. Williams Avram Ph.D., Adi Cymerblit-Sabba Ph.D., June Song, Nicholas Leipzig Ph.D., W. Scott Young M.D., Ph.D. Jan 2020

Optimization And Validation Of The Neurolux Wireless Optoelectronics System For Optogenetics, Karis Courey, Su Hyun Lee Ph.D., Adam Smith Ph.D., Nicholas Cilz Ph.D., Sarah K. Williams Avram Ph.D., Adi Cymerblit-Sabba Ph.D., June Song, Nicholas Leipzig Ph.D., W. Scott Young M.D., Ph.D.

Williams Honors College, Honors Research Projects

Utilizing light and genetic engineering, optogenetics permits the manipulation of events within cells via light using the light-sensitive properties of single-component microbial opsins. Microbial opsins are activated by a light source, such as lasers, light-emitting diodes, and incandescent sources that deliver light to the region of interest either directly or indirectly, such as through fiberoptics. In classical in vivo optogenetics, the wiring of optic fibers necessitates tethering of animals by the optic fiber to the light source. The novel NeuroLux wireless optoelectronic system for optogenetics circumvents issues pertaining to classical optogenetics by utilizing near-field power transfer via magnetic coil antennae …


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 …


Acute Systemic Inflammatory Response To Lipopolysaccharide Stimulation In Pigs Divergently Selected For Residual Feed Intake, Haibo Liu, Kristina M. Feye, Yet T. Nguyen, Anoosh Rakhshandeh, Crystal L. Loving, Jack C. M. Sekkers, Nicholas K. Gabler, Christopher K. Tuggle Oct 2019

Acute Systemic Inflammatory Response To Lipopolysaccharide Stimulation In Pigs Divergently Selected For Residual Feed Intake, Haibo Liu, Kristina M. Feye, Yet T. Nguyen, Anoosh Rakhshandeh, Crystal L. Loving, Jack C. M. Sekkers, Nicholas K. Gabler, Christopher K. Tuggle

Mathematics & Statistics Faculty Publications

Background: It is unclear whether improving feed efficiency by selection for low residual feed intake (RFI) compromises pigs’ immunocompetence. Here, we aimed at investigating whether pig lines divergently selected for RFI had different inflammatory responses to lipopolysaccharide (LPS) exposure, regarding to clinical presentations and transcriptomic changes in peripheral blood cells.

Results: LPS injection induced acute systemic inflammation in both the low-RFI and high-RFI line (n = 8 per line). At 4 h post injection (hpi), the low-RFI line had a significantly lower (p= 0.0075) mean rectal temperature compared to the high-RFI line. However, no significant differences in complete blood count …


Eugenics In The 21st Century, Jessica Linn Chin Sep 2019

Eugenics In The 21st Century, Jessica Linn Chin

Dissertations, Theses, and Capstone Projects

Eugenics is the science of enhancing the human population through the management of breeding and hereditary traits. This thesis explores the history of eugenics and shows how eugenic practices continue in the 21st century with advancements in technology and positive eugenic goals that can result in adverse effects on the human body and society. When Sir Francis Galton coined the term eugenics in 1883, he intended to improve British society with the use of positive eugenics. Galton used positive eugenics to encourage people with good mental and physical qualities to produce more children. He avoided negative eugenics, which involved …


Total Rna Extraction From Transgenic Flies Misexpressing Foreign Genes To Perform Next Generation Rna Sequencing, Abijeet Singh Mehta, Agustin Luz-Madrigal, Jian-Liang Li, Panagiotis A. Tsonis, Amit Singh Aug 2019

Total Rna Extraction From Transgenic Flies Misexpressing Foreign Genes To Perform Next Generation Rna Sequencing, Abijeet Singh Mehta, Agustin Luz-Madrigal, Jian-Liang Li, Panagiotis A. Tsonis, Amit Singh

Biology Faculty Publications

Due to absence of transgenic approaches in Notopthalmus Viridescens (newt), and conservation of genetic machinery across species, we generated transgenic Drosophila melanogaster to misexpress unique genes from newt. Novel newt genes cloned, and inserted at attP site in Drosophila were misexpressed ubiquitously using tubulin Gal-4. Sample (total RNA) for RNA sequencing was collected at 3rd instar larval stage during which major developmental events takes place in Drosophila. Total RNA was extracted, and purified using RNA clean and ConcentratorTM. RNA quality was quantitated by calculating absorbance at 260 nm (A260) and 280 nm (A280) wavelengths using Nanodrop 2000 spectrophotometer. Good quality …


Comparative Transcriptomic Analysis And Structure Prediction Of Novel Newt Proteins, Abijeet Singh Mehta, Agustin Luz-Madrigal, Jian-Liang Li, Panagiotis A. Tsonis, Amit Singh Aug 2019

Comparative Transcriptomic Analysis And Structure Prediction Of Novel Newt Proteins, Abijeet Singh Mehta, Agustin Luz-Madrigal, Jian-Liang Li, Panagiotis A. Tsonis, Amit Singh

Biology Faculty Publications

Notophthalmus viridescens (Red-spotted Newt) possess amazing capabilities to regenerate their organs and other tissues. Previously, using a de novo assembly of the newt transcriptome combined with proteomic validation, our group identified a novel family of five protein members expressed in adult tissues during regeneration in Notophthalmus viridescens. The presence of a putative signal peptide suggests that all these proteins are secretory in nature. Here we employed iterative threading assembly refinement (I-TASSER) server to generate three-dimensional structure of these novel Newt proteins and predicted their function. Our data suggests that these proteins could act as ion transporters, and be involved …


Assessing The Efficacy Of Seedling Planting As A Forest Restoration Technique In Temperate Hardwood Forests Impacted By Invasive Species, Michaela J. Woods, Meredith Cobb, Katie Hickle Aug 2019

Assessing The Efficacy Of Seedling Planting As A Forest Restoration Technique In Temperate Hardwood Forests Impacted By Invasive Species, Michaela J. Woods, Meredith Cobb, Katie Hickle

Biology Faculty Publications

The emerald ash borer (Agrilus planipennis Fairmaire; EAB) is an invasive insect that causes mortality of trees in the genus Fraxinus, creating canopy gaps that may facilitate invasion by exotic plants. Planting native tree seedlings under EAB-infested Fraxinus may accelerate succession and preclude invasive plant expansion; however, the effectiveness of this approach has not been experimentally tested. We assessed understory seedling planting of Quercus rubra, Carya laciniosa, and Juglans cinerea in EAB-infested forests, where the invasive shrub Lonicera maackii (Amur honeysuckle) was removed. We tested whether the use of plastic tree shelters (“tree tubes”) or planting season (fall versus spring) …


Sequence Analysis Of The Ren1 Genomic Region From The Grapevine ‘Kishmish Vatkana’, Dani Joseph Aug 2019

Sequence Analysis Of The Ren1 Genomic Region From The Grapevine ‘Kishmish Vatkana’, Dani Joseph

Graduate Theses/Dissertations

The REN1 region of the grapevine ‘Kishmish Vatkana’ was mapped as the locus that confers resistance to the economically important disease, grape powdery mildew. The purpose of this work was to extend the nucleotide sequence information of this region. By sequencing a heretofore unknown bacterial artificial chromosome clone, the sequence information of this region was extended by 46,890 nucleotides. Sequencing was performed using the third-generation sequencing method, named Oxford Nanopore Technology (ONT). In order to improve the accuracy of the sequence data, a modified ONT library preparation method was developed. ONT sequencing of a library prepared with the modified protocol …


Emergence Of Oxacillin Resistance In Stealth Methicillin-Resistant Staphylococcus Aureus Due To Meca Sequence Instability, Richard V. Goering, Erin A. Swartzendriber, Anne E. Obradovich, Isabella A. Tickler, Fred C. Tenover Jul 2019

Emergence Of Oxacillin Resistance In Stealth Methicillin-Resistant Staphylococcus Aureus Due To Meca Sequence Instability, Richard V. Goering, Erin A. Swartzendriber, Anne E. Obradovich, Isabella A. Tickler, Fred C. Tenover

Biology Faculty Publications

Staphylococcus aureus strains that possess a mecA gene but are phenotypically susceptible to oxacillin and cefoxitin (OS-MRSA) have been recognized for over a decade and are a challenge for diagnostic laboratories. The mechanisms underlying the discrepancy vary from isolate to isolate. We characterized seven OS-MRSA clinical isolates of six different spa types from six different states by whole-genome sequencing to identify the nucleotide sequence changes leading to the OS-MRSA phenotype. The results demonstrated that oxacillin susceptibility was associated with mutations in regions of nucleotide repeats within mecA. Subinhibitory antibiotic exposure selected for secondary mecA mutations that restored oxacillin resistance. …


Hippo Signaling In Cancer: Lessons From Drosophila Models, Kirti Snigdha, Karishma Sanjay Gangwani, Gauri Vijay Lapalikar, Amit Singh, Madhuri Kango-Singh May 2019

Hippo Signaling In Cancer: Lessons From Drosophila Models, Kirti Snigdha, Karishma Sanjay Gangwani, Gauri Vijay Lapalikar, Amit Singh, Madhuri Kango-Singh

Biology Faculty Publications

Hippo pathway was initially identified through genetic screens for genes regulating organ size in fruitflies. Recent studies have highlighted the role of Hippo signaling as a key regulator of homeostasis, and in tumorigenesis. Hippo pathway is comprised of genes that act as tumor suppressor genes like hippo (hpo) and warts (wts), and oncogenes like yorkie (yki). YAP and TAZ are two related mammalian homologs of Drosophila Yki that act as effectors of the Hippo pathway. Hippo signaling deficiency can cause YAP- or TAZ-dependent oncogene addiction for cancer cells. YAP and TAZ are often activated …


Streptococcus Agalactiae Strains With Chromosomal Deletions Evade Detection With Molecular Methods, Isabella A. Tickler, Fred C. Tenover, Scott Dewell, Victoria M. Le, Rachel N. Blackman, Richard V. Goering, Amy E. Rogers, Heather Piwonka, Brittney D. Jung-Hynes, Derrick J. Chen, Michael J. Loeffelholz, Devasena Gnanashanmugam, Ellen Jo Baron Apr 2019

Streptococcus Agalactiae Strains With Chromosomal Deletions Evade Detection With Molecular Methods, Isabella A. Tickler, Fred C. Tenover, Scott Dewell, Victoria M. Le, Rachel N. Blackman, Richard V. Goering, Amy E. Rogers, Heather Piwonka, Brittney D. Jung-Hynes, Derrick J. Chen, Michael J. Loeffelholz, Devasena Gnanashanmugam, Ellen Jo Baron

Biology Faculty Publications

Surveillance of circulating microbial populations is critical for monitoring the performance of a molecular diagnostic test. In this study, we characterized 31 isolates of Streptococcus agalactiae (group B Streptococcus [GBS]) from several geographic locations in the United States and Ireland that contain deletions in or adjacent to the region of the chromosome that encodes the hemolysin gene cfb, the region targeted by the Xpert GBS and GBS LB assays. PCR-negative, culture-positive isolates were recognized during verification studies of the Xpert GBS assay in 12 laboratories between 2012 and 2018. Whole-genome sequencing of 15 GBS isolates from 11 laboratories revealed …


Unified Methods For Feature Selection In Large-Scale Genomic Studies With Censored Survival Outcomes, Lauren Spirko-Burns, Karthik Devarajan Mar 2019

Unified Methods For Feature Selection In Large-Scale Genomic Studies With Censored Survival Outcomes, Lauren Spirko-Burns, Karthik Devarajan

COBRA Preprint Series

One of the major goals in large-scale genomic studies is to identify genes with a prognostic impact on time-to-event outcomes which provide insight into the disease's process. With rapid developments in high-throughput genomic technologies in the past two decades, the scientific community is able to monitor the expression levels of tens of thousands of genes and proteins resulting in enormous data sets where the number of genomic features is far greater than the number of subjects. Methods based on univariate Cox regression are often used to select genomic features related to survival outcome; however, the Cox model assumes proportional hazards …


Supervised Dimension Reduction For Large-Scale "Omics" Data With Censored Survival Outcomes Under Possible Non-Proportional Hazards, Lauren Spirko-Burns, Karthik Devarajan Mar 2019

Supervised Dimension Reduction For Large-Scale "Omics" Data With Censored Survival Outcomes Under Possible Non-Proportional Hazards, Lauren Spirko-Burns, Karthik Devarajan

COBRA Preprint Series

The past two decades have witnessed significant advances in high-throughput ``omics" technologies such as genomics, proteomics, metabolomics, transcriptomics and radiomics. These technologies have enabled simultaneous measurement of the expression levels of tens of thousands of features from individual patient samples and have generated enormous amounts of data that require analysis and interpretation. One specific area of interest has been in studying the relationship between these features and patient outcomes, such as overall and recurrence-free survival, with the goal of developing a predictive ``omics" profile. Large-scale studies often suffer from the presence of a large fraction of censored observations and potential …


Diversity Of Resistance Mechanisms In Carbapenem-Resistant Enterobacteriaceae At A Health Care System In Northern California, From 2013 To 2016, Fiona Senchyna, Rajiv L. Gaur, Johanna Sandlund, Cynthia Truong, Guillaume Tremintin, Dietmar Kültz, Carlos A. Gomez, Fiona B. Tamburini, Tessa Andermann, Ami Bhatt, Isabella A. Tickler, Nancy Watz, Indre Budvytiene, Gongyi Shi, Fred C. Tenover, Niaz Banaei Mar 2019

Diversity Of Resistance Mechanisms In Carbapenem-Resistant Enterobacteriaceae At A Health Care System In Northern California, From 2013 To 2016, Fiona Senchyna, Rajiv L. Gaur, Johanna Sandlund, Cynthia Truong, Guillaume Tremintin, Dietmar Kültz, Carlos A. Gomez, Fiona B. Tamburini, Tessa Andermann, Ami Bhatt, Isabella A. Tickler, Nancy Watz, Indre Budvytiene, Gongyi Shi, Fred C. Tenover, Niaz Banaei

Biology Faculty Publications

The mechanism of resistance in carbapenem-resistant Enterobacteriaceae (CRE) has therapeutic implications. We comprehensively characterized emerging mechanisms of resistance in CRE between 2013 and 2016 at a health system in Northern California. A total of 38.7% (24/62) of CRE isolates were carbapenemase gene-positive, comprising 25.0% (6/24) blaOXA-48 like, 20.8% (5/24) blaKPC, 20.8% (5/24) blaNDM, 20.8% (5/24) blaSME, 8.3% (2/24) blaIMP, and 4.2% (1/24) blaVIM. Between carbapenemases and porin loss, the resistance mechanism was identified in 95.2% (59/62) of CRE isolates. Isolates expressing blaKPC were 100% susceptible to ceftazidime–avibactam, meropenem–vaborbactam, …