Genetic Structures Commons^™

Using Genetically Diverse Mice To Examine The Effects Of Environmental Enrichment Of The Transcriptome, Michael Richard Leonardo

Theses, Dissertations and Capstones

Environmental impoverishment is a model of early life stress with direct consequences across a wide range of neurological and physiological conditions. Neuron morphology and density as well as anxiety disorders and addiction have shown to have significant relationships with environmental impoverishment models. Conversely, environmental enrichment confers therapeutic benefits that are protective across these conditions. There is an observed spectrum of resistance or vulnerability to the effects of housing conditions across populations, indicating genetics as an influential factor. Understanding this interaction is critical for deepening our knowledge of how genes and environment interact in ways that confer resistance or vulnerability, and …

Improved Allele Frequencies In Gnomad Through Local Ancestry Inference, Pragati Kore, Michael W Wilson, Grace Tiao, Katherine Chao, Philip W Darnowsky, Nicholas A Watts, Jessica Honorato Mauer, Samantha M Baxter, Genome Aggregation Database Consortium, Heidi L Rehm, Mark J Daly, Konrad J Karczewski, Elizabeth G Atkinson

Faculty, Staff and Students Publications

The Genome Aggregation Database (gnomAD) is a foundational resource for allele frequency data, widely used in genomic research and clinical interpretation. However, traditional estimates rely on individual-level genetic ancestry groupings that may obscure variation in recently admixed populations. To improve resolution, we applied local ancestry inference (LAI) to over 27 million variants in two admixed groups: Admixed American (n = 7612) and African/African American (n = 20,250), deriving ancestry-specific allele frequencies. We show that 78.5% and 85.1% of variants in these groups, respectively, exhibit at least a twofold difference in ancestry-specific frequencies. Moreover, 81.49% of variants with LAI information would …

Dominant Negative Atp5f1a Variants Disrupt Oxidative Phosphorylation Causing Neurological Disorders, Sara M Fielder, Marisa W Friederich, Daniella H Hock, Jessie R Zhang, Liana M Valin, Jill A Rosenfeld, Kevin T A Booth, Natasha J Brown, Rocio Rius, Tanavi Sharma, Liana N Semcesen, Kim C Worley, Lindsay C Burrage, Kayla Treat, Tara Samson, Sarah Govert, Sara Dacunha, Weimin Yuan, Jian Chen, Jacob Lesinski, Hieu Hoang, Stephanie A Morrison, Farah A Ladha, Roxanne A Van Hove, Cole R Michel, Richard Reisdorph, Eric Tycksen, Dustin Baldridge, Gary A Silverman, Claudia Soler-Alfonso, Erin Conboy, Francesco Vetrini, Lisa Emrick, William J Craigen, Undiagnosed Diseases Network, Stephen M Sykes, David A Stroud, Johan L K Van Hove, Tim Schedl, Stephen C Pak

Faculty, Staff and Students Publications

ATP5F1A encodes the α-subunit of complex V of the respiratory chain, which is responsible for mitochondrial ATP synthesis. We describe 6 probands with heterozygous de novo missense ATP5F1A variants that presented with developmental delay, intellectual disability, and movement disorders. All variants were located at the contact points between the α- and β-subunits. Functional studies in C. elegans revealed that the variants were damaging via a dominant negative genetic mechanism. Biochemical and proteomics studies of proband-derived cells showed a marked reduction in complex V abundance and activity. Mitochondrial physiology studies revealed increased oxygen consumption, yet decreased mitochondrial membrane potential and ATP …

Variants In Bsn, Encoding The Presynaptic Protein Bassoon, Result In A Distinct Neurodevelopmental Disorder With A Broad Phenotypic Range, Stacy G Guzman, Sarah M Ruggiero, Shiva Ganesan, Colin A Ellis, Alicia G Harrison, Katie R Sullivan, Zornitza Stark, Natasha J Brown, Sajel L Kana, Anabelle Tuttle, Jair Tenorio, Pablo Lapunzina, Julián Nevado, Marie T Mcdonald, Courtney Jensen, Patricia G Wheeler, Lila Stange, Jennifer Morrison, Boris Keren, Solveig Heide, Meg W Keating, Kameryn M Butler, Mike A Lyons, Shailly Jain, Mehdi Yeganeh, Michelle L Thompson, Molly Schroeder, Hoanh Nguyen, Jorge Granadillo, Kari M Johnston, Chaya N Murali, Katie Bosanko, T Andrew Burrow, Chop Birth Defects Biorepository, Penn Medicine Biobank, Syreeta Morgan, Deborah J Watson, Hakon Hakonarson, Ingo Helbig

Faculty, Staff and Students Publications

Disease-causing variants in synaptic function genes are a common cause of neurodevelopmental disorders (NDDs) and epilepsy. Here, we describe 14 individuals with de novo disruptive variants in BSN, which encodes the presynaptic protein Bassoon. To expand the phenotypic spectrum, we identified 15 additional individuals with protein-truncating variants (PTVs) from large biobanks. Clinical features were standardized using the Human Phenotype Ontology (HPO) across all 29 individuals, which revealed common clinical characteristics including epilepsy (13/29, 45%), febrile seizures (7/29, 25%), generalized tonic-clonic seizures (5/29, 17%), and focal-onset seizures (3/29, 10%). Behavioral phenotypes were present in almost half of all individuals (14/29, 48%), …

2024 Lifetime Achievement Award: Biology Unbalanced: Genes, Gene Dosage, And Disease Susceptibility, James R Lupski

Faculty, Staff and Students Publications

This article is based on the address given by the author at the 2024 meeting of The American Society of Human Genetics (ASHG) in Denver, CO. A video of the original address can be found at the ASHG website.

Design And Implementation Of An Action Plan For Justice, Equity, Diversity, And Inclusion Within The Clinical Genome Resource, Alice B Popejoy, Deborah I Ritter, Danielle Azzariti, Jonathan S Berg, Joanna E Bulkley, Mildred Cho, Claudia Gonzaga-Jauregui, Teri E Klein, Daphne O Martschenko, Akinyemi Oni-Orisan, Erin M Ramos, Heidi L Rehm, Erin R Riggs, Matthew W Wright, Michael Yudell, Sharon E Plon, Joannella Morales

Faculty, Staff and Students Publications

How might members of a large, multi-institutional research and resource consortium foster justice, equity, diversity, and inclusion as central to its mission, goals, governance, and culture? These four principles, often referred to as JEDI, can be aspirational-but to be operationalized, they must be supported by concrete actions, investments, and a persistent long-term commitment to the principles themselves, which often requires self-reflection and course correction. We present here the iterative design process implemented across the Clinical Genome Resource (ClinGen) that led to the development of an action plan to operationalize JEDI principles across three major domains, with specific deliverables and commitments …

Characterizing Features Affecting Local Ancestry Inference Performance In Admixed Populations, Jessica Honorato-Mauer, Nirav N Shah, Adam X Maihofer, Clement C Zai, Sintia Belangero, Caroline M Nievergelt, Marcos Santoro, Elizabeth G Atkinson

Faculty, Staff and Students Publications

In recent years, significant efforts have been made to improve methods for genomic studies of admixed populations using local ancestry inference (LAI). Accurate LAI is crucial to ensure that downstream analyses accurately reflect the genetic ancestry of research participants. Here, we test analytic strategies for LAI to provide guidelines for optimal accuracy, focusing on admixed populations reflective of Latin America's primary continental ancestries-African (AFR), Amerindigenous (AMR), and European (EUR). Simulating linkage-disequilibrium-informed admixed haplotypes under a variety of 2- and 3-way admixture models, we implemented a standard LAI pipeline, testing the impact of reference panel composition, DNA data type, demography, and …

Design And Implementation Of An Action Plan For Justice, Equity, Diversity, And Inclusion Within The Clinical Genome Resource, Alice B Popejoy, Deborah I Ritter, Danielle Azzariti, Jonathan S Berg, Joanna E Bulkley, Mildred Cho, Claudia Gonzaga-Jauregui, Teri E Klein, Daphne O Martschenko, Akinyemi Oni-Orisan, Erin M Ramos, Heidi L Rehm, Erin R Riggs, Matthew W Wright, Michael Yudell, Sharon E Plon, Joannella Morales

Faculty, Staff and Students Publications

How might members of a large, multi-institutional research and resource consortium foster justice, equity, diversity, and inclusion as central to its mission, goals, governance, and culture? These four principles, often referred to as JEDI, can be aspirational-but to be operationalized, they must be supported by concrete actions, investments, and a persistent long-term commitment to the principles themselves, which often requires self-reflection and course correction. We present here the iterative design process implemented across the Clinical Genome Resource (ClinGen) that led to the development of an action plan to operationalize JEDI principles across three major domains, with specific deliverables and commitments …

Update On Cancer Screening In Children With Syndromes Of Bone Lesions, Hereditary Leiomyomatosis And Renal Cell Carcinoma Syndrome, And Other Rare Syndromes, Orli Michaeli, Sun Young Kim, Sarah G Mitchell, Marjolijn C J Jongmans, Jonathan D Wasserman, Melissa R Perrino, Anirban Das, Suzanne P Macfarland, Sarah R Scollon, Mary-Louise C Greer, Nara Sobreira, Bailey Gallinger, Philip J Lupo, David Malkin, Kami Wolfe Schneider, Kris Ann P Schultz, William D Foulkes, Emma R Woodward, Douglas R Stewart

Faculty, Staff and Students Publications

The management of children with syndromes associated with an increased risk of benign and malignant neoplasms is a complex challenge for health care professionals. The 2023 American Association for Cancer Research Childhood Cancer Predisposition Workshop provided updated consensus guidelines on cancer surveillance in these syndromes, aiming to improve early detection and intervention and reduce morbidity associated with such neoplasms. In this article, we review several of the rare conditions discussed in this workshop. Ollier disease and Maffucci syndrome are enchondromatoses (disorders featuring benign bone lesions) with up to 50% risk of malignancy, including chondrosarcoma. These patients require surveillance with baseline …

Exome Sequencing In Asian Populations Identifies Low-Frequency And Rare Coding Variation Influencing Parkinson’S Disease Risk, Elaine Gy Chew, Zhehao Liu, Zheng Li, Sun Ju Chung, Michelle M Lian, Moses Tandiono, Yue Jing Heng, Ebonne Y Ng, Louis Cs Tan, Wee Ling Chng, Tiak Ju Tan, Esther Kl Peh, Ying Swan Ho, Xiao Yin Chen, Erin Yt Lim, Chu Hua Chang, Jonavan J Leong, Ting Xuan Peh, Ling Ling Chan, Yinxia Chao, Wing-Lok Au, Kumar M Prakash, Jia Lun Lim, Yi Wen Tay, Vincent Mok, Anne Yy Chan, Juei-Jueng Lin, Beom S Jeon, Kyuyoung Song, Clement C Tham, Chi Pui Pang, Jeeyun Ahn, Kyu Hyung Park, Janey L Wiggs, Tin Aung, Ai Huey Tan, Azlina Ahmad Annuar, Mary B Makarious, Cornelis Blauwendraat, Mike A Nalls, Laurie A Robak, Roy N Alcalay, Ziv Gan-Or, Richard Reynolds, Shen-Yang Lim, Yun Xia, Chiea Chuen Khor, Eng-King Tan, Zhenxun Wang, Jia Nee Foo

Faculty, Staff and Students Publications

Parkinson’s disease (PD) is an incurable, progressive and common movement disorder that is increasing in incidence globally because of population aging. We hypothesized that the landscape of rare, protein-altering variants could provide further insights into disease pathogenesis. Here we performed whole-exome sequencing followed by gene-based tests on 4,298 PD cases and 5,512 controls of Asian ancestry. We showed that GBA1 and SMPD1 were significantly associated with PD risk, with replication in a further 5,585 PD cases and 5,642 controls. We further refined variant classification using in vitro assays and showed that SMPD1 variants with reduced enzymatic activity display the strongest …

Secondary Acmg And Non-Acmg Genetic Findings In A Multiethnic Cohort Of 16,713 Pediatric Participants, Amir Hossein Saeidian, Michael E March, Leila Youssefian, Deborah J Watson, Esha Bhandari, Xiang Wang, Xiaonan Zhao, Nichole Marie Owen, Alanna Strong, Margaret H Harr, Elizabeth Bhoj, Elaine Zackai, Hassan Vahidnezhad, Johann E Gudjonsson, Stephen D Cederbaum, Joshua L Deignan, Joseph Glessner, Wayne W Grody, Hakon Hakonarson

Faculty, Staff and Students Publications

Purpose: Clinical next-generation sequencing is an effective approach for identifying pathogenic sequence variants that are medically actionable for participants and families but are not associated with the participant's primary diagnosis. These variants are called secondary findings (SFs). According to the literature, there is no report of the types and frequencies of SFs in a large pediatric cohort that includes substantial African-American participants. We sought to investigate the types (including American College of Medical Genetics and Genomics [ACMG] and non-ACMG-recommended gene lists), frequencies, and rates of SFs, as well as the effects of SF disclosure on the participants and families of …

Unveiling Novel Genetic Variants In 370 Challenging Medically Relevant Genes Using The Long Read Sequencing Data Of 41 Samples From 19 Global Populations, Yanfeng Ji, Junfan Zhao, Jiao Gong, Fritz J Sedlazeck, Shaohua Fan

Faculty, Staff and Students Publications

Background: A large number of challenging medically relevant genes (CMRGs) are situated in complex or highly repetitive regions of the human genome, hindering comprehensive characterization of genetic variants using next-generation sequencing technologies. In this study, we employed long-read sequencing technology, extensively utilized in studying complex genomic regions, to characterize genetic alterations, including short variants (single nucleotide variants and short insertions and deletions) and copy number variations, in 370 CMRGs across 41 individuals from 19 global populations.

Results: Our analysis revealed high levels of genetic variants in CMRGs, with 68.73% exhibiting copy number variations and 65.20% containing short variants that may …

Genetic Testing For Supravalvar Aortic Stenosis: What To Do When It Is Not Williams Syndrome, Sara B Stephens, Tyler Novy, Gabrielle N Spurzem, Benjamin Jacob, Taylor Beecroft, Emily Soludczyk, Beth A Kozel, Justin Weigand, Shaine A Morris

Faculty, Staff and Students Publications

Background: We aimed to describe the frequency and yield of genetic testing in supravalvar aortic stenosis (SVAS) following negative evaluation for Williams-Beuren syndrome (WS).

Methods and results: This retrospective cohort study included patients with SVAS at our institution who had a negative evaluation for WS from May 1991 to September 2021. SVAS was defined as (1) peak supravalvar velocity of ≥2 meters/second, (2) sinotubular junction or ascending aortic Z score < -2.0, or (3) sinotubular junction Z score < -1.5 with family history of SVAS. Patients with complex congenital heart disease, aortic valve disease as the primary condition, or only postoperative SVAS were excluded. Genetic testing and diagnoses were reported. Of 162 patients who were WS negative meeting inclusion criteria, 61 had genetic testing results available (38%). Chromosomal microarray had been performed in 44 of 61 and was nondiagnostic for non-WS causes of SVAS. Sequencing of 1 or more genes was performed in 47 of 61. Of these, 39 of 47 underwent ELN sequencing, 20 of 39 (51%) of whom had a diagnostic variant. Other diagnoses made by gene sequencing were Noonan syndrome (3 PTPN11, 1 RIT1), Alagille …

Genetic Analysis Of Hereditary Gingival Fibromatosis Associated Sos1 Missense Variants Of Uncertain Significance In Caenorhabditis Elegans, Himani Patel

Theses

Hereditary gingival fibromatosis (HGF) is a disease that can present as benign overgrowth of gingival tissue in the mouth. The overgrowth can enclose the entire mouth and teeth in severe cases or present itself in a concentrated area. Researchers have identified that mutations in the SOS1 gene can be responsible for HGF. This disease can impair basic functions related to the mouth. Eating, smiling, speaking can all be affected. Additionally, excess inflammation can cause periodontal disease because of the difficulty in maintaining proper oral health. Periodontal disease can lead to severe bone loss which can lead to complete loss of …

Solid Organ Transplantation In Methylmalonic Acidemia And Propionic Acidemia: A Points To Consider Statement Of The American College Of Medical Genetics And Genomics (Acmg), Kuntal Sen, Lindsay C Burrage, Kimberly A Chapman, Ilona Ginevic, George V Mazariegos, Brett H Graham, Acmg Therapeutics Committe

Faculty, Staff and Students Publications

No abstract provided.

Exploring Genetic And Neural Risk Of Specific Reading Disability Within A Nuclear Twin Family Case Study: A Translational Clinical Application, Tina Thomas, Griffin Litwin, David J Francis, Elena L Grigorenko

Faculty, Staff and Students Publications

Imaging and genetic studies have characterized biological risk factors contributing to specific reading disability (SRD). The current study aimed to apply this literature to a family of twins discordant for SRD and an older sibling with reading difficulty. Intraclass correlations were used to understand the similarity of imaging phenotypes between pairs. Reading-related genes and brain region phenotypes, including asymmetry indices representing the relative size of left compared to right hemispheric structures, were descriptively examined. SNPs that corresponded between the SRD siblings and not the typically developing (TD) siblings were in genes ZNF385D, LPHN3, CNTNAP2, FGF18, NOP9 …

Multi-Ancestry Genome-Wide Association Analyses Improve Resolution Of Genes And Pathways Influencing Lung Function And Chronic Obstructive Pulmonary Disease Risk, Nick Shrine, Abril G. Izquierdo, Jing Chen, Richard Packer, Robert J. Hall, Anna L. Guyatt, Chiara Batini, Rebecca J. Thompson, Chandan Puvuluri, Vidhi Malik, Brian D. Hobbs, Matthew Moll, Wonji Kim, Ruth Tal-Singer, Per Bakke, Katherine A. Fawcett, Catherine John, Kayesha Coley, Noemi Nicole Piga, Sinjini Sikdar, Martin D. Tobin, Et Al.

Mathematics & Statistics Faculty Publications

Lung-function impairment underlies chronic obstructive pulmonary disease (COPD) and predicts mortality. In the largest multi-ancestry genome-wide association meta-analysis of lung function to date, comprising 580,869 participants, we identified 1,020 independent association signals implicating 559 genes supported by ≥2 criteria from a systematic variant-to-gene mapping framework. These genes were enriched in 29 pathways. Individual variants showed heterogeneity across ancestries, age and smoking groups, and collectively as a genetic risk score showed strong association with COPD across ancestry groups. We undertook phenome-wide association studies for selected associated variants as well as trait and pathway-specific genetic risk scores to infer possible consequences of …

The Onset Of Exercise-Associated Hyponatremia And Individual Differences In Inappropriate Arginine Vasopressin Excretion: A Review Of Proposed Mechanisms, Michelle Stehman, Stephen A. Maris

Topics in Exercise Science and Kinesiology

Topics in Exercise Science and Kinesiology Volume 2: Issue 1, Article 10, 2021. Exercise-associated hyponatremia (EAH) has been reported to develop during endurance events such as triathlons and marathons. As these events become more popular, the incidence of developing EAH also increases. The development of EAH is commonly associated with the overconsumption of hypotonic fluids such as water and tends to be more prevalent in females. There is also evidence to suggest the inappropriate secretion of arginine vasopressin (AVP) leading to water retention may predispose an individual for developing EAH, especially when coupled with the overconsumption of fluids. Recent research …

Whole Genome Sequence Analysis Of Platelet Traits In The Nhlbi Trans-Omics For Precision Medicine Initiative, Amarise Little, Yao Hu, Quan Sun, Deepti Jain, Jai G. Broome, Ming-Huei Chen, Florian Thibord, Caitlin Mchugh, John Blangero, Joanne E. Curran

School of Medicine Publications

Platelets play a key role in thrombosis and hemostasis. Platelet count (PLT) and mean platelet volume (MPV) are highly heritable quantitative traits, with hundreds of genetic signals previously identified, mostly in European ancestry populations. We here utilize whole genome sequencing from NHLBI's Trans-Omics for Precision Medicine Initiative (TOPMed) in a large multi-ethnic sample to further explore common and rare variation contributing to PLT (n = 61 200) and MPV (n = 23 485). We identified and replicated secondary signals at MPL (rs532784633) and PECAM1 (rs73345162), both more common in African ancestry populations. We also observed rare variation in Mendelian platelet …

Causes Of Color Blindness: Function And Failure Of The Genes That Detect Color, Dylan Taylor

Senior Honors Theses

Color blindness affects nearly 10% of the entire population, with multiple types of color blindness from various genetic mutations. In the following sections, the nature of light and how the human eye perceives light will be discussed. Afterward, the major forms of color blindness and their genetic causes will be considered. Once these genetic causes have been established, the current method for diagnosing color blindness will be investigated, followed by a discussion of the current treatments available to those with color blindness. Finally, a brief discussion will address possible future work for color blindness with the hope of finding better …

Using Active Learning To Build A Foundation For Bioinformatics Training., Stacey E. Wahl Ph.D., Amy L. Olex Ms

Transforming Libraries for Graduate Students

As Health Sciences Libraries evolve, the support they offer graduate students has evolved to incorporate many aspects of the research life cycle. At Tompkins-McCaw Library for the Health Sciences, we have partnered with the Wright Center for Clinical and Translational Research to offer training workshops for graduate students who are interested in using bioinformatics to plan, analyze, or execute scientific experiments. We offer two series: 1) an 8-week, 1-hour per week seminar series providing a general overview of available techniques and 2) a week-long intensive, two hours per session, series on utilizing free databases from the National Center for Biotechnology …

Heterogeneity Of Disease-Causing Variants In The Swedish Galactosemia Population: Identification Of 16 Novel Galt Variants, Annika Ohlsson, Mary Hunt, Anna Wedell, Ulrika Von Döbeln

Articles

The aim was to determine disease-causing variants in the GALT gene which codes for the enzyme galactose-1-phosphate uridylyltransferase. Loss of activity of this enzyme causes classical galactosemia-a life threatening, treatable disorder, included in the Swedish newborn screening program since 1967. A total of 66 patients with the disease are known in Sweden and 56 index patients were investigated. An additional two patients with Duarte galactosemia were included. The disease-causing variants were identified in all patients. As reported from other countries only a few variants frequently recur in severe disease. The two variants p.(Gln188Arg) (c.563A>G) and p.(Met142Lys) (c.425T>A) are …

Epigenetic Age Acceleration Assessed With Human White-Matter Images, Karen Hodgson, Melanie A. Carless, Hemant Kulkarni, Joanne E. Curran, Emma Sprooten, Emma E. Knowles, Samuel R. Mathias, Harald H. H. Goring, Nailin Yao, Rene L. Olvera, Laura Almasy, Ravindranath Duggirala, John Blangero, David C. Glahn

School of Medicine Publications

The accurate estimation of age using methylation data has proved a useful and heritable biomarker, with acceleration in epigenetic age predicting a number of age-related phenotypes. Measures of white matter integrity in the brain are also heritable and highly sensitive to both normal and pathological aging processes across adulthood. We consider the phenotypic and genetic interrelationships between epigenetic age acceleration and white matter integrity in humans. Our goal was to investigate processes that underlie interindividual variability in age-related changes in the brain. Using blood taken from a Mexican-American extended pedigree sample (n = 628; age = 23.28-93.11 years), epigenetic …

Molecular Genetics Of Ms4a6a And Alzheimer's Disease, Ryan Harpole

Lewis Honors College Capstone Collection

Increased Alzheimer’s disease (AD) risk has previously been associated with a SNP called rs610932 near the gene MS4A6A. The goal of this experiment was to quantify the expression of two MS4A6A isoforms in the brains of AD and non-AD subjects, particularly as a function of rs610932 genotype. According to an article titled “Alzheimer’s Disease Susceptibility Variants in the MS4A6A Gene are Associated with Altered Levels of MS4A6A Expression in Blood”, MS4A6A has four different isoforms that have been reported to be differentially expressed in the blood of AD subjects compared to non-AD subjects (Petroula et al., 2014). After statistically …

Genetic Mapping Of Secretion And Functional Determinants Of The Vibrio Cholerae Tcpf Colonization Factor, Shelly J. Krebs, Thomas J. Kirn, Ronald K. Taylor

Dartmouth Scholarship

Colonization of the human small intestine by Vibrio cholerae requires the type IV toxin-coregulated pilus (TCP). TcpF, which is encoded within the tcp operon, is secreted from the bacterial cell by the TCP apparatus and is also essential for colonization. Bacteria lacking tcpF are deficient in colonization, and anti-TcpF antibodies are protective in the infant mouse cholera model. In order to elucidate the regions of the protein that are required for secretion through the TCP apparatus and for its function in colonization, random mutagenesis of tcpF was performed. Analysis of these mutants suggests that multiple regions throughout the protein influence …

Microevolutionary Patterns And Molecular Markers: The Genetics Of Geographic Variation In Ascaris Suum, Steven A. Nadler

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Molecular markers have been used only rarely to characterize the population genetic structure of nematodes. Published studies have suggested that different taxa may show distinct genetic architectures. Isoenzyme and RAPD markers have been used to investigate geographic variation of Ascaris suum at the level of infrapopulations (nematodes within individual hosts), within localities, and among geographic regions. Independent estimates of genetic differentiation among population samples based on isoenzyme and RAPD data showed similar patterns and substantial correlation. Heterozygote deficiencies within infrapopulations and large values for inbreeding coefficients among infrapopulations suggested that the composition of these populations was not consistent with a …