Genetics Commons^™

Meta-Analysis Of Uveal Melanoma Genome-Wide Association Studies Identifies Novel Risk Loci And Population Effect Size Heterogeneity., Georgia Mies, Noah L. Tsao, Alexandre Houy, Sarah E. Coupland, Helen Kalirai, Asta Försti, Kari Hemminki, Hauke Thomsen, Marc-Henri Stern, Carol L. Shields, Scott M. Damrauer, Katheryn G. Ewens, Arupa Ganguly, Iain Mathieson

Wills Eye Hospital Papers

Uveal melanoma (UM) is a rare but frequently metastasizing cancer. Genome-wide association studies have identified three common genome-wide significant germline risk loci. Here, we perform a genome-wide association study on 401 new cases and conduct a meta-analysis with three independent previously published cohorts for a total sample size of 2,426 cases. We confirm the three previously identified risk loci and identify four additional genome-wide significant loci. We find that eye pigmentation-decreasing variants are systematically associated with increased UM risk and that selection for lighter pigmentation in the past 5,000 years explains about 73% of the difference in UM incidence between …

Functional Protein Biomarkers Based On Distributions Of Expression Levels In Single-Cell Imaging Data, Misung Yi, Tingting Zhan, Hallgeir Rui, Inna Chervoneva

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

MOTIVATION: The intra-tumor heterogeneity of protein expression is well recognized and may provide important information for cancer prognosis and predicting treatment responses. Analytic methods that account for spatial heterogeneity remain methodologically complex and computationally demanding for single-cell protein expression. For many functional proteins, single-cell expressions vary independently of spatial localization in a substantial proportion of the tumor tissues, and incorporation of spatial information may not affect the prognostic value of such protein biomarkers.

RESULTS: We developed a new framework for using the distributions of functional single-cell protein expression levels as cancer biomarkers. The quantile functions of single-cell expressions are used …

Codon Composition In Human Oocyters Reveals Age-Associated Defects In Mrna Decay, Pavla Brachova, Lane K. Christenson, Nehemiah S. Alvarez

Department of Biomedical and Translational Sciences Faculty Publications

Oocytes from women of advanced reproductive age exhibit diminished developmental potential, but the underlying mechanisms remain incompletely defined. Oocyte maturation depends on translational control of maternal mRNA synthesized during growth. We performed a computational analysis on human oocytes from women < 30 versus ≥40 years and observed that mRNA GC content correlates negatively with half-life in oocytes from young (< 30 yr) but positively with oocytes from aged (>40 yr) women. In young oocytes, longer mRNA half-life is associated with lower protein abundance, whereas in aged oocytes GC content correlates positively with protein abundance. During the GV-to-MII transition, codon composition stratifies stability: codons that support rapid translation (optimal) stabilize mRNA, while slow-translating codons (non-optimal) promote decay. With reproductive aging, GC-containing codons become more optimal and align with increased …

Effects Of Protein-Enriched Nutritional Support On Skeletal Muscle Mass And Rehabilitative Outcomes In Brain Tumor Patients: A Randomized Controlled Trial, Kye Hee Cho, Eun Young Han, Min Kyu Jung, Chang Moo Kang, Ji Cheol Shin, Sang Hee Im

Faculty, Staff and Student Publications

Patients with brain tumors require extensive and prolonged rehabilitation efforts as they suffer from lesion-induced motor weakness as well as treatment-related side effects, often leading to a significant decline in function. Protein supplements have shown positive effects on promoting muscle strength and physical performance in various tumor etiologies. However, reports on their effects specifically in brain tumor patients remain scarce. This study aims to investigate the feasibility and efficacy of protein supplements in enhancing rehabilitative outcomes via muscle strengthening and functional gain in brain tumor patients with neurological demise. Sixty brain tumor patients were randomly assigned to either a protein …

Genome-Wide Analysis In Over 1 Million Individuals Of European Ancestry Yields Improved Polygenic Risk Scores For Blood Pressure Traits, Jacob M Keaton, Zoha Kamali, Tian Xie, Ahmad Vaez, Ariel Williams, Slavina B Goleva, Alireza Ani, Evangelos Evangelou, Jacklyn N Hellwege, Loic Yengo, William J Young, Matthew Traylor, Ayush Giri, Zhili Zheng, Jian Zeng, Daniel I Chasman, Andrew P Morris, Mark J Caulfield, Shih-Jen Hwang, Jaspal S Kooner, David Conen, John R Attia, Alanna C Morrison, Ruth J F Loos, Kati Kristiansson, Reinhold Schmidt, Andrew A Hicks, Peter P Pramstaller, Christopher P Nelson, Nilesh J Samani, Lorenz Risch, Ulf Gyllensten, Olle Melander, Harriette Riese, James F Wilson, Harry Campbell, Stephen S Rich, Bruce M Psaty, Yingchang Lu, Jerome I Rotter, Xiuqing Guo, Kenneth M Rice, Peter Vollenweider, Johan Sundström, Claudia Langenberg, Martin D Tobin, Vilmantas Giedraitis, Jian'an Luan, Jaakko Tuomilehto, Zoltan Kutalik, Samuli Ripatti, Veikko Salomaa, Giorgia Girotto, Stella Trompet, J Wouter Jukema, Pim Van Der Harst, Paul M Ridker, Franco Giulianini, Veronique Vitart, Anuj Goel, Hugh Watkins, Sarah E Harris, Ian J Deary, Peter J Van Der Most, Albertine J Oldehinkel, Bernard D Keavney, Caroline Hayward, Archie Campbell, Michael Boehnke, Laura J Scott, Thibaud Boutin, Chrysovalanto Mamasoula, Marjo-Riitta Järvelin, Annette Peters, Christian Gieger, Edward G Lakatta, Francesco Cucca, Jennie Hui, Paul Knekt, Stefan Enroth, Martin H De Borst, Ozren Polašek, Maria Pina Concas, Eulalia Catamo, Massimiliano Cocca, Ruifang Li-Gao, Edith Hofer, Helena Schmidt, Beatrice Spedicati, Melanie Waldenberger, David P Strachan, Maris Laan, Alexander Teumer, Marcus Dörr, Vilmundur Gudnason, James P Cook, Daniela Ruggiero, Ivana Kolcic, Eric Boerwinkle, Michela Traglia, Terho Lehtimäki, Olli T Raitakari, Andrew D Johnson, Christopher Newton-Cheh, Morris J Brown, Anna F Dominiczak, Peter J Sever, Neil Poulter, John C Chambers, Roberto Elosua, David Siscovick, Tõnu Esko, Andres Metspalu, Rona J Strawbridge, Markku Laakso, Anders Hamsten, Jouke-Jan Hottenga, Eco De Geus, Andrew D Morris, Colin N A Palmer, Ilja M Nolte, Yuri Milaneschi, Jonathan Marten, Alan Wright, Eleftheria Zeggini, Joanna M M Howson, Christopher J O'Donnell, Tim Spector, Mike A Nalls, Eleanor M Simonsick, Yongmei Liu, Cornelia M Van Duijn, Adam S Butterworth, John N Danesh, Cristina Menni, Nicholas J Wareham, Kay-Tee Khaw, Yan V Sun, Peter W F Wilson, Kelly Cho, Peter M Visscher, Joshua C Denny, Million Veteran Program, Lifelines Cohort Study, Charge Consortium, Icbp Consortium, Daniel Levy, Todd L Edwards, Patricia B Munroe, Harold Snieder, Helen R Warren

Faculty, Staff and Student Publications

Hypertension affects more than one billion people worldwide. Here we identify 113 novel loci, reporting a total of 2,103 independent genetic signals (P < 5 × 10-8) from the largest single-stage blood pressure (BP) genome-wide association study to date (n = 1,028,980 European individuals). These associations explain more than 60% of single nucleotide polymorphism-based BP heritability. Comparing top versus bottom deciles of polygenic risk scores (PRSs) reveals clinically meaningful differences in BP (16.9 mmHg systolic BP, 95% CI, 15.5-18.2 mmHg, P = 2.22 × 10-126) and more than a sevenfold higher odds of hypertension risk (odds ratio, 7.33; 95% CI, 5.54-9.70; P = 4.13 × 10-44) in an independent dataset. Adding PRS into hypertension-prediction models increased the area under the receiver operating characteristic curve (AUROC) from 0.791 (95% CI, 0.781-0.801) to 0.826 (95% CI, 0.817-0.836, ∆AUROC, 0.035, P = 1.98 × 10-34). We compare the 2,103 loci results in non-European ancestries and show significant PRS associations in a large African-American sample. Secondary analyses implicate 500 genes previously unreported for BP. Our study highlights the role of increasingly large genomic studies for precision health research.

Case Of Human Orthohantavirus Infection, Michigan, Usa, 2021, Samuel M Goodfellow, Robert A Nofchissey, Dustin Arsnoe, Chunyan Ye, Seonghyeon Lee, Jieun Park, Won-Keun Kim, Kartik Chandran, Shannon L M Whitmer, John D Klena, Jonathan W Dyal, Trevor Shoemaker, Diana Riner, Mary Grace Stobierski, Kimberly Signs, Steven B Bradfute

Faculty, Staff and Student Publications

Orthohantaviruses cause hantavirus cardiopulmonary syndrome; most cases occur in the southwest region of the United States. We discuss a clinical case of orthohantavirus infection in a 65-year-old woman in Michigan and the phylogeographic link of partial viral fragments from the patient and rodents captured near the presumed site of infection.

Delineating The Mechanism Of Fragility At Bcl6 Breakpoint Region Associated With Translocations In Diffuse Large B Cell Lymphoma, Vidya Gopalakrishnan, Urbi Roy, Shikha Srivastava, Khyati M Kariya, Shivangi Sharma, Saniya M Javedakar, Bibha Choudhary, Sathees C Raghavan

Faculty, Staff and Student Publications

BCL6 translocation is one of the most common chromosomal translocations in cancer and results in its enhanced expression in germinal center B cells. It involves the fusion of BCL6 with any of its twenty-six Ig and non-Ig translocation partners associated with diffuse large B cell lymphoma (DLBCL). Despite being discovered long back, the mechanism of BCL6 fragility is largely unknown. Analysis of the translocation breakpoints in 5' UTR of BCL6 reveals the clustering of most of the breakpoints around a region termed Cluster II. In silico analysis of the breakpoint cluster sequence identified sequence motifs that could potentially fold into …

Failure To Mate Enhances Investment In Behaviors That May Promote Mating Reward And Impairs The Ability To Cope With Stressors Via A Subpopulation Of Neuropeptide F Receptor Neurons, Julia Ryvkin, Liora Omesi, Yong-Kyu Kim, Mali Levi, Hadar Pozeilov, Lital Barak-Buchris, Bella Agranovich, Ifat Abramovich, Eyal Gottlieb, Avi Jacob, Dick R Nässel, Ulrike Heberlein, Galit Shohat-Ophir

Faculty, Staff and Student Publications

Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward …

Identification And Characterization Of Two Novel Kcnh2 Mutations Contributing To Long Qt Syndrome, Anthony Owusu-Mensah, Jacqueline Treat, Joyce Bernardi, Ryan Pfeiffer, Robert Goodrow, Bright Tsevi, Victoria Lam, Michel Audette, Jonathan M. Cordeiro, Makarand Deo

Electrical & Computer Engineering Faculty Publications

We identified two different inherited mutations in KCNH2 gene, or human ether-a-go-go related gene (hERG), which are linked to Long QT Syndrome. The first mutation was in a 1-day-old infant, whereas the second was in a 14-year-old girl. The two KCNH2 mutations were transiently transfected into either human embryonic kidney (HEK) cells or human induced pluripotent stem-cell derived cardiomyocytes. We performed associated multiscale computer simulations to elucidate the arrhythmogenic potentials of the KCNH2 mutations. Genetic screening of the first and second index patients revealed a heterozygous missense mutation in KCNH2, resulting in an amino acid change (P632L) in the …

Genome-Wide Association Study Of Thoracic Aortic Aneurysm And Dissection In The Million Veteran Program, Derek Klarin, Poornima Devineni, Anoop K Sendamarai, Anthony R Angueira, Sarah E Graham, Ying H Shen, Michael G Levin, James P Pirruccello, Ida Surakka, Purushotham R Karnam, Tanmoy Roychowdhury, Yanming Li, Minxian Wang, Krishna G Aragam, Kaavya Paruchuri, Verena Zuber, Gabrielle E Shakt, Noah L Tsao, Renae L Judy, Ha My T Vy, Shefali S Verma, Daniel J Rader, Ron Do, Joseph E Bavaria, Girish N Nadkarni, Marylyn D Ritchie, Stephen Burgess, Dong-Chuan Guo, Patrick T Ellinor, Scott A Lemaire, Dianna M Milewicz, Cristen J Willer, Pradeep Natarajan, Philip S Tsao, Saiju Pyarajan, Scott M Damrauer

Faculty, Staff and Student Publications

The current understanding of the genetic determinants of thoracic aortic aneurysms and dissections (TAAD) has largely been informed through studies of rare, Mendelian forms of disease. Here, we conducted a genome-wide association study (GWAS) of TAAD, testing ~25 million DNA sequence variants in 8,626 participants with and 453,043 participants without TAAD in the Million Veteran Program, with replication in an independent sample of 4,459 individuals with and 512,463 without TAAD from six cohorts. We identified 21 TAAD risk loci, 17 of which have not been previously reported. We leverage multiple downstream analytic methods to identify causal TAAD risk genes and …

Rare Variant Enrichment Analysis Supports Greb1l As A Contributory Driver Gene In The Etiology Of Mayer-Rokitansky-Küster-Hauser Syndrome, Angad Jolly, Haowei Du, Christelle Borel, Na Chen, Sen Zhao, Christopher M Grochowski, Ruizhi Duan, Jawid M Fatih, Moez Dawood, Sejal Salvi, Shalini N Jhangiani, Donna M Muzny, André Koch, Konstantinos Rouskas, Stavros Glentis, Efthymios Deligeoroglou, Flora Bacopoulou, Carol A Wise, Jennifer E Dietrich, Ignatia B Van Den Veyver, Antigone S Dimas, Sara Brucker, V Reid Sutton, Richard A Gibbs, Stylianos E Antonarakis, Nan Wu, Zeynep H Coban-Akdemir, Lan Zhu, Jennifer E Posey, James R Lupski

Faculty, Staff and Student Publications

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is characterized by aplasia of the female reproductive tract; the syndrome can include renal anomalies, absence or dysgenesis, and skeletal anomalies. While functional models have elucidated several candidate genes, only WNT4 (MIM: 603490) variants have been definitively associated with a subtype of MRKH with hyperandrogenism (MIM: 158330). DNA from 148 clinically diagnosed MRKH probands across 144 unrelated families and available family members from North America, Europe, and South America were exome sequenced (ES) and by family-based genomics analyzed for rare likely deleterious variants. A replication cohort consisting of 442 Han Chinese individuals with MRKH was …

The Zinc Transporter Zipt-7.1 Regulates Sperm Activation In Nematodes, Yanmei Zhao, Chieh-Hsiang Tan, Amber Krauchunas, Andrea Scharf, Nicholas Dietrich, Kurt Warnhoff, Zhiheng Yuan, Marina Druzhinina, Sam Guoping Gu, Long Miao, Andrew Singson, Ronald E Ellis, Kerry Kornfeld

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Sperm activation is a fascinating example of cell differentiation, in which immotile spermatids undergo a rapid and dramatic transition to become mature, motile sperm. Because the sperm nucleus is transcriptionally silent, this transition does not involve transcriptional changes. Although Caenorhabditis elegans is a leading model for studies of sperm activation, the mechanisms by which signaling pathways induce this transformation remain poorly characterized. Here we show that a conserved transmembrane zinc transporter, ZIPT-7.1, regulates the induction of sperm activation in Caenorhabditis nematodes. The zipt-7.1 mutant hermaphrodites cannot self-fertilize, and males reproduce poorly, because mutant spermatids are defective in responding to activating …

Association Of Body Mass Index With Dna Methylation And Gene Expression In Blood Cells And Relations To Cardiometabolic Disease: A Mendelian Randomization Approach, Michael M. Mendelson, Riccardo E. Marioni, Roby Joehanes, Chunyu Liu, Åsa K. Hedman, Stella Aslibekyan, Ellen W. Demerath, Weihua Guan, Degui Zhi, Chen Yao, Tianxiao Huan, Christine Willinger, Brian Chen, Paul Courchesne, Michael Multhaup, Marguerite R. Irvin, Ariella Cohain, Eric E. Schadt, Megan L. Grove, Jan Bressler, Kari North, Johan Sundström, Stefan Gustafsson, Sonia Shah, Allan F. Mcrae, Sarah E. Harris, Jude Gibson, Paul Redmond, Janie Corley, Lee Murphy, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background

The link between DNA methylation, obesity, and adiposity-related diseases in the general population remains uncertain.

Methods and Findings

We conducted an association study of body mass index (BMI) and differential methylation for over 400,000 CpGs assayed by microarray in whole-blood-derived DNA from 3,743 participants in the Framingham Heart Study and the Lothian Birth Cohorts, with independent replication in three external cohorts of 4,055 participants. We examined variations in whole blood gene expression and conducted Mendelian randomization analyses to investigate the functional and clinical relevance of the findings. We identified novel and previously reported BMI-related differential methylation at 83 CpGs …

Dna Methylation Signatures Of Chronic Low-Grade Inflammation Are Associated With Complex Diseases, Symen Ligthart, Carola Marzi, Stella Aslibekyan, Michael M. Mendelson, Karen N. Conneely, Toshiko Tanaka, Elena Colicino, Lindsay L. Waite, Roby Joehanes, Weihua Guan, Jennifer A. Brody, Cathy Elks, Riccardo Marioni, Min A. Jhun, Golareh Agha, Jan Bressler, Cavin K. Ward-Caviness, Brian H. Chen, Tianxiao Huan, Kelly Bakulski, Elias L. Salfati, Whi-Empc Investigators, Giovanni Fiorito, Charge Epigenetics Of Coronary Heart Disease, Simone Wahl, Katharina Schramm, Jin Sha, Dena G. Hernandez, Allan C. Just, Jennifer A. Smith, Donna K. Arnett

Epidemiology and Environmental Health Faculty Publications

Background: Chronic low-grade inflammation reflects a subclinical immune response implicated in the pathogenesis of complex diseases. Identifying genetic loci where DNA methylation is associated with chronic low-grade inflammation may reveal novel pathways or therapeutic targets for inflammation.

Results: We performed a meta-analysis of epigenome-wide association studies (EWAS) of serum C-reactive protein (CRP), which is a sensitive marker of low-grade inflammation, in a large European population (n = 8863) and trans-ethnic replication in African Americans (n = 4111). We found differential methylation at 218 CpG sites to be associated with CRP (P < 1.15 × 10^–7) in the discovery panel …

Population And Demographic Structure Of Ixodes Scapularis Say In The Eastern United States., Joyce M. Sakamoto, Jerome Goddard, Jason L. Rasgon

CALS Publications

INTRODUCTION: The most significant vector of tick-borne pathogens in the United States is Ixodes scapularis Say (the blacklegged tick). Previous studies have identified significant genetic, behavioral and morphological differences between northern vs. southern populations of this tick. Because tick-borne pathogens are dependent on their vectors for transmission, a baseline understanding of the vector population structure is crucial to determining the risks and epidemiology of pathogen transmission. METHODS: We investigated population genetic variation of I. scapularis populations in the eastern United States using a multilocus approach. We sequenced and analyzed the mitochondrial COI and 16S genes and three nuclear genes (serpin2, …

Trip/Nopo E3 Ubiquitin Ligase Promotes Ubiquitylation Of Dna Polymerase Η, Heather A. Wallace, Julie A. Merkle, Michael C. Yu, Taloa G. Berg, Ethan Lee, Giovanni Bosco, Laura A. Lee

Dartmouth Scholarship

We previously identified a Drosophila maternal effect-lethal mutant named ‘no poles’ (nopo). Embryos from nopo females undergo mitotic arrest with barrel-shaped, acentrosomal spindles during the rapid cycles of syncytial embryogenesis because of activation of a Chk2-mediated DNA checkpoint. NOPO is the Drosophila homolog of human TNF receptor associated factor (TRAF)-interacting protein (TRIP), which has been implicated in TNF signaling. NOPO and TRIP contain RING domains closely resembling those of known E3 ubiquitin ligases. We herein sought to elucidate the mechanism by which TRIP/NOPO promotes genomic stability by performing a yeast two-hybrid screen to identify potential substrates/interactors. We identified members of …

Dna Methylation Arrays As Surrogate Measures Of Cell Mixture Distribution, Eugene Houseman, William P. Accomando, Devin C. Koestler, Brock C. Christensen, Carmen J. Marsit

Dartmouth Scholarship

There has been a long-standing need in biomedical research for a method that quantifies the normally mixed composition of leukocytes beyond what is possible by simple histological or flow cytometric assessments. The latter is restricted by the labile nature of protein epitopes, requirements for cell processing, and timely cell analysis. In a diverse array of diseases and following numerous immune-toxic exposures, leukocyte composition will critically inform the underlying immuno-biology to most chronic medical conditions. Emerging research demonstrates that DNA methylation is responsible for cellular differentiation, and when measured in whole peripheral blood, serves to distinguish cancer cases from controls.

Long-Term Survival After Multidisciplinary Management Of Resected Pancreatic Adenocarcinoma, Matthew H G Katz, Huamin Wang, Jason B Fleming, Charlotte C Sun, Rosa F Hwang, Robert A Wolff, Gauri Varadhachary, James L Abbruzzese, Christopher H Crane, Sunil Krishnan, Jean-Nicolas Vauthey, Eddie K Abdalla, Jeffrey E Lee, Peter W T Pisters, Douglas B Evans

Faculty, Staff and Student Publications

INTRODUCTION: Actual 5-year survival rates of 10-18% have been reported for patients with resected pancreatic adenocarcinoma (PC), but the use of multimodality therapy was uncommon in these series. We evaluated long-term survival and patterns of recurrence in patients treated for PC with contemporary staging and multimodality therapy.

METHODS: We analyzed 329 consecutive patients with PC evaluated between 1990 and 2002 who underwent resection. Each received a multidisciplinary evaluation and a standard operative approach. Pre- or postoperative chemotherapy and/or chemoradiation were routine. Surgical specimens of 5-year survivors were re-reviewed. A multivariate model of factors associated with long-term survival was constructed.

RESULTS: …

Ovarian Development In Mice Requires The Gata4-Fog2 Transcription Complex, Nikolay L. Manuylov, Fatima O. Smagulova, Lyndsay Leach, Sergei G. Tevosian

Dartmouth Scholarship

We have demonstrated previously that mammalian sexual differentiation requires both the GATA4 and FOG2 transcriptional regulators to assemble the functioning testis. Here we have determined that the sexual development of female mice is profoundly affected by the loss of GATA4-FOG2 interaction. We have also identified the Dkk1 gene, which encodes a secreted inhibitor of canonical beta-catenin signaling, as a target of GATA4-FOG2 repression in the developing ovary. The tissue-specific ablation of the beta-catenin gene in the gonads disrupts female development. In Gata4(ki/ki); Dkk1(-/-) or Fog2(-/-); Dkk1(-/-) embryos, the normal ovarian gene expression pattern is partially restored. Control of ovarian development …

Similar Levels Of X-Linked And Autosomal Nucleotide Variation In African And Non-African Populations Of Drosophila Melanogaster, Nadia D. Singh, J. Michael Macpherson, Jeffrey D. Jensen, Dmitri A. Petrov

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Levels of molecular diversity in Drosophila have repeatedly been shown to be higher in ancestral, African populations than in derived, non-African populations. This pattern holds for both coding and noncoding regions for a variety of molecular markers including single nucleotide polymorphisms and microsatellites. Comparisons of X-linked and autosomal diversity have yielded results largely dependent on population of origin.

Results: In an attempt to further elucidate patterns of sequence diversity in Drosophila melanogaster, we studied nucleotide variation at putatively nonfunctional X-linked and autosomal loci in sub-Saharan African and North American strains of D. melanogaster. We combine our experimental …

The Allantois And Chorion, When Isolated Before Circulation Or Chorio-Allantoic Fusion, Have Hematopoietic Potential, Brandon M. Zeigler, Daisuke Sugiyama, Michael Chen, Yalin Guo, K. M. Downs, N. A. Speck

Dartmouth Scholarship

The chorio-allantoic placenta forms through the fusion of the allantois (progenitor tissue of the umbilical cord), with the chorionic plate. The murine placenta contains high levels of hematopoietic stem cells, and is therefore a stem cell niche. However, it is not known whether the placenta is a site of hematopoietic cell emergence, or whether hematopoietic cells originate from other sites in the conceptus and then colonize the placenta. Here, we show that the allantois and chorion, isolated prior to the establishment of circulation, have the potential to give rise to myeloid and definitive erythroid cells following explant culture. We further …

A Role For Cetp Taqib Polymorphism In Determining Susceptibility To Atrial Fibrillation: A Nested Case Control Study, Folkert W. Asselbergs, Jason H. Moore, Maarten P. Van Den Berg, Eric B. Rimm

Dartmouth Scholarship

Studies investigating the genetic and environmental characteristics of atrial fibrillation (AF) may provide new insights in the complex development of AF. We aimed to investigate the association between several environmental factors and loci of candidate genes, which might be related to the presence of AF. A nested case-control study within the PREVEND cohort was conducted. Standard 12 lead electrocardiograms were recorded and AF was defined according to Minnesota codes. For every case, an age and gender matched control was selected from the same population (n = 194). In addition to logistic regression analyses, the multifactor-dimensionality reduction (MDR) method and interaction …

The Caenorhabditis Elegans F-Box Protein Sel-10 Promotes Female Development And May Target Fem-1 And Fem-3 For Degradation By The Proteasome, Sibylle Jager, Hillel T. Schwartz, H. Robert Horvitz, Barbara Conradt

Dartmouth Scholarship

The Caenorhabditis elegans F-box protein SEL-10 and its human homolog have been proposed to regulate LIN-12 Notch signaling by targeting for ubiquitin-mediated proteasomal degradation LIN-12 Notch proteins and SEL-12 PS1 presenilins, the latter of which have been implicated in Alzheimer's disease. We found that sel-10 is the same gene as egl-41, which previously had been defined by gain-of-function mutations that semidominantly cause masculinization of the hermaphrodite soma. Our results demonstrate that mutations causing loss-of-function of sel-10 also have masculinizing activity, indicating that sel-10 functions to promote female development. Genetically, sel-10 acts upstream of the genes fem-1, fem-2, and fem-3 and …

Parentage Analysis With Genetic Markers In Natural Populations I The Expected Proportion Of Offspring With Unambiguous Paternity, R Chakraborty, T R Meagher, P E Smouse

Faculty, Staff and Student Publications

Recent studies indicate that polymorphic genetic markers are potentially helpful in resolving genealogical relationships among individuals in a natural population. Genetic data provide opportunities for paternity exclusion when genotypic incompatibilities are observed among individuals, and the present investigation examines the resolving power of genetic markers in unambiguous positive determination of paternity. Under the assumption that the mother for each offspring in a population is unambiguously known, an analytical expression for the fraction of males excluded from paternity is derived for the case where males and females may be derived from two different gene pools. This theoretical formulation can also be …

Genetics And Epidemiology Of Gallbladder Disease In New World Native Peoples, K M Weiss, R E Ferrell, C L Hanis, P N Styne

Faculty, Staff and Student Publications

Native peoples of the New World, including Amerindians and admixed Latin Americans such as Mexican-Americans, are highly susceptible to diseases of the gallbladder. These include cholesterol cholelithiasis (gallstones) and its complications, as well as cancer of the gallbladder. Although there is clearly some necessary dietary or other environmental risk factor involved, the pattern of disease prevalence is geographically associated with the distribution of genes of aboriginal Amerindian origin, and levels of risk generally correspond to the degree of Amerindian admixture. This pattern differs from that generally associated with Westernization, which suggests a gene-environment interaction, and that within an admixed population …

Genetically Controlled Variation Of “Acid” Beta-Galactosidase Detected In Rattus Norvegicus By Isoelectric Focusing, T C Douglas, K A Kimmel, P E Dawson

Faculty, Staff and Student Publications

Two genetically variant forms of rat "acid" beta-galactosidase were found to differ in isoelectric point and pH dependence, but not in thermostability or sensitivity to inhibition by p-mercuribenzoate (PMB). The results of two backcrosses and an intercross indicated that the isoelectric focusing phenotypes are controlled by two codominant alleles at a single autosomal locus, for which we propose the name Glb-1. No significant linkage between Glb-1 and albino (LG I), brown (LG II), or hooded (LG VI) was observed. Strain-specific differences in total levels of kidney beta-galactosidase were detected, but it is not yet known whether the variation is controlled …

Three Linked Enzyme Loci In Fishes: Implications In The Evolution Of Vertebrate Chromosomes, D C Morizot, D A Wright, M J Siciliano

Faculty, Staff and Student Publications

A three-point linkage group comprised of loci coding for adenosine deaminase (ADA), glucose-6-phosphate dehydrogenase (G6PDH), and 6-phospho-gluconate dehydrogenase (6PGD) is described in fish of the genus Xiphophorus (Poeciliidae). The alleles at loci in this group were shown to assort independently from the alleles at three other loci--isocitrate dehydrogenase 1 and 2, and glyceraldehyde-3-phosphate dehydrogenase 1. Alleles at the latter three loci also assort independently from each other. Data were obtained by observing the segregation of electrophoretically variant alleles in reciprocal backcross hybrids derived from crosses between either X. helleri guentheri or X. h. strigatus and X. maculatus. The linkage component …