Genetics and Genomics Commons^™

Saccharomyces Cerevisiae Cdc7 Homology In Drosophila Melanogaster, Marcus R. Hosler, Robert E. Stephenson, Vikki M. Weake

The Summer Undergraduate Research Fellowship (SURF) Symposium

Saccharomyces cerevisiae Dbf4(Dumbbell former 4) and Cdc7(Cell Division Cycle 7) form a complex that phosphorylates Mcm2 (Minichromosome maintenance 2) to initiate DNA replication. Cdc7 is a target for cancer research because there is a Cdc7 ortholog in humans that is necessary for DNA replication and cell survival. Our goal is to characterise a putative Cdc7 homolog in Drosophila melanogaster (dCdc7). We have previously shown that expression of the known Drosophila Dbf4 ortholog, Chiffon, and dCdc7 can rescue yeast cells deficient in active Cdc7. Our hypothesis is that the dCdc7 is activated by Chiffon to phosphorylate MCM2. To test this hypothesis, …

Mutations Of Pdd1 Chromo- And Chromoshadow Domains Reveal Critical Functions For Each During Development Of Tetrahymena Thermophila, Rachel Schwope

All Theses and Dissertations (ETDs)

Pdd1 is a developmentally expressed HP1-like protein of Tetrahymena thermophila that is required during conjugation, when a copy of the cell's transcriptionally silent germline micronucleus differentiates into an active somatic macronucleus. Differentiation of these somatic chromosomes involves genome-wide fragmentation and amplification. These DNA rearrangements are facilitated by an RNAi mechanism, in which small RNAs target silencing histone modifications, H3K9 and H3K27 methylation, to Internal Eliminated Sequences: IESs), which are bound by Pdd1 and later excised from the genome. Pdd1 features two chromodomains, one of which shares homology with that of HP1, and a C-terminal chromoshadow domain. In this study, we …

Catp-6, A C. Elegans Ortholog Of Atp13a2 Park9, Positively Regulates Gem-1, An Slc16a Transporter, Eric J. Lambie, Pamela J. Tieu, Nadja Lebedeva, Diane L. Church, Barbara Conradt

Dartmouth Scholarship

In previous work, we found that gain-of-function mutations that hyperactivate GEM-1 (an SLC16A transporter protein) can bypass the requirement for GON-2 (a TRPM channel protein) during the initiation of gonadogenesis in C. elegans . Consequently, we proposed that GEM-1 might function as part of a Mg 2 + uptake pathway that functions in parallel to GON- 2. In this study, we report that CATP-6, a C. elegans ortholog of the P5B ATPase, ATP13A2 (PARK9), is necessary for gem-1 gain-of-function mutations to suppress the effects of gon-2 inactivation. One possible explanation for this observation is that GEM-1 serves to activate CATP-6, …

Resolution By Unassisted Top3 Points To Template Switch Recombination Intermediates During Dna Replication, M. Rebecca Glineburg, Alejandro Chavez, Vishesh Agrawal, Steven J. Brill, F. Brad Johnson

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The evolutionarily conserved Sgs1/Top3/Rmi1 (STR) complex plays vital roles in DNA replication and repair. One crucial activity of the complex is dissolution of toxic X-shaped recombination intermediates that accumulate during replication of damaged DNA. However, despite several years of study the nature of these X-shaped molecules remains debated. Here we use genetic approaches and two-dimensional gel electrophoresis of genomic DNA to show that Top3, unassisted by Sgs1 and Rmi1, has modest capacities to provide resistance to MMS and to resolve recombination-dependent X-shaped molecules. The X-shaped molecules have structural properties consistent with hemicatenane-related template switch recombination intermediates (Rec-Xs) but not Holliday …

Pathoscope: Species Identification And Strain Attribution With Unassembled Sequencing Data., Owen E Francis, Matthew Bendall, Solaiappan Manimaran, Changjin Hong, Nathan L Clement, Eduardo Castro-Nallar, Quinn Snell, G Bruce Schaalje, Mark J Clement, Keith A Crandall, W Evan Johnson

Computational Biology Institute

Emerging next-generation sequencing technologies have revolutionized the collection of genomic data for applications in bioforensics, biosurveillance, and for use in clinical settings. However, to make the most of these new data, new methodology needs to be developed that can accommodate large volumes of genetic data in a computationally efficient manner. We present a statistical framework to analyze raw next-generation sequence reads from purified or mixed environmental or targeted infected tissue samples for rapid species identification and strain attribution against a robust database of known biological agents. Our method, Pathoscope, capitalizes on a Bayesian statistical framework that accommodates information on sequence …

Bacterial Transcription Factors Grea, Greb And Dksa: Characterization Of Their Interaction With Rna Polymerase And Molecular Mechanism Of Action, Andrey Parshin

Graduate School of Biomedical Sciences Theses and Dissertations

The activity of RNA polymerase (RNAP), the key enzyme of transcription process, is regulated by a large number of transcription factors acting at each step of the transcription cycle. Our research project is focused on studying the structure and function of bacterial transcript cleavage factors GreA, GreB and the stringent response regulator DksA. Gre factors bind in the secondary channel of RNAP in backtracked (inactive) ternary elongation complexes and stimulate the enzyme's intrinsic RNase activity, which is required for suppression of transcription pause and arrest, enhancement of transcription fidelity, and efficient promoter escape. DksA also acts through the RNAP secondary …

Notchless Interacts With Multiple Signaling Pathways During Mouse Peri-Implantation Development, Chiao-Ling Lo

Open Access Dissertations

During peri-implantation, the embryo transitions from a suspension environment in the fallopian tubes to an adherent system within the uterus. Successful transition requires maternal and fetal signaling cascades that establish maternal-fetal boundaries. Failure is common, as ~ 25% of all human pregnancies terminate during these steps. A large-scale mutation study in mice produced two mutants (l11Jus1 and l11Jus4) that are excellent models of this transition. l11Jus1 and l11Jus4 contain missense mutations in the Notchless homolog 1 (Drosophila) (Nle1) gene. NLE1 is thought to signal via the canonical NOTCH pathway in vertebrates. Although in invertebrates and lower vertebrates, NOTCH signaling directs …

Regulation Of D-Galacturonate Metabolism In Caulobacter Crescentus By Humr, A Laci-Family Transcriptional Repressor, Craig Stephens, Aaesha I. Sheikh, Deborah Caswell, Cynthia Dick, Spencer Gang, Justin Jarrell, Ankita Kohli, Amanda Lieu, Jared Lumpe, Meghan Garrett, Jennifer Parker

Biology

The oligotrophic freshwater bacterium Caulobacter crescentus encodes a cluster of genes (CC_1487 to CC_1495) shown here to be necessary for metabolism of D-galacturonate, the primary constituent of pectin, a major plant polymer. Sequence analysis suggests that these genes encode a version of the bacterial hexuronate isomerase pathway. A conserved 14 bp sequence motif is associated with promoter regions of three operons within this cluster, and is conserved in homologous gene clusters in related alpha-Proteobacteria. Embedded in the hexuronate gene cluster is a gene (CC_1489) encoding a member of the LacI family of bacterial transcription factors. This gene product, designated here …

Natural Genetic Variation Affecting Calcium Homeostasis, Rebecca Anna Replogle

Open Access Dissertations

Calcium (Ca) is essential for multiple functions within the body including skeletal health. The level of Ca in the serum is tightly regulated. During periods of habitual low Ca intake, the body senses a decrease in serum Ca and increases renal conversion of 25 hydroxyvitamin D (25(OH)D) to 1,25 dihydroxyvitamin D (1,25(OH)2D). 1,25(OH)2D acts through the vitamin D receptor (VDR) to increase intestinal Ca absorption, renal Ca reabsorption and skeletal Ca resorption. Efficient intestinal Ca absorption, especially during periods of low Ca intake, is critical for protecting bone mass. Ca absorption and its primary regulator, 1,25(OH)2D, are affected by both …

The Genetic Architecture Of Juvenile Migration In Rainbow Trout (Oncorhynchus Mykiss), Benjamin Charles Hecht

Open Access Dissertations

Animal migrations play a critical role in the health and balance of ecological systems and in the evolution and diversification of species, and this is perhaps best displayed amongst salmonid fishes (salmon, trout, and char) who exhibit variation in the propensity to migrate both within and among species. Rainbow and steelhead trout (Oncorhynchus mykiss), members of the salmonid family of fishes, capture this variation throughout their native range. Some populations and ecotypes will remain resident in freshwater habitats throughout their life history; while others have the ability to embark on tremendous marine migrations. Those that migrate undergo a suite of …

Identifying Chromosome Rearrangements In The Allopolyploid Brassica Napus Using Pyrosequencing, Alexandra R. Barbella

Master's Theses

Allopolyploids form through the hybridization of two or more diploid genomes. A challenge to reproduction in allopolyploids is that pairing can occur between homologous chromosomes or homeologous chromosomes (i.e.different subgenomes.). Crossover between homeologous chromosomes can result in chromosome rearrangements that lower fertility and overall fitness. Rearrangements can alter the dosage of either entire chromosomes or just parts of chromosomes. Understanding the frequency and extent of rearrangements will help to explain the evolution and genome stabilization of agriculturally important allopolyploid species. Pyrosequencing is a useful tool in the study dosage changes in allopolyploids because it allows quantification of the relative contribution …

Fast Quantitative Real-Time Pcr-Based Screening For Common Chromosomal Aneuploidies In Mouse Embryonic Stem Cells, Charlotte D'Hulst, Irena Parvanova, Delia Tomoiaga, Maria L. Sapar, Paul Feinstein

Publications and Research

Chromosomal integrity has been known for many years to affect the ability of mouse embryonic stem cells (mESCs) to contribute to the germline of chimeric mice. Abnormal chromosomes are generally detected by standard cytogenetic karyotyping. However, this method is expensive, time consuming, and often omitted prior to blastocyst injection, consequently reducing the frequency of mESC-derived offspring. Here, we show a fast, accurate, and inexpensive screen for identifying the two most common aneuploidies (Trisomy 8 and loss of chromosome Y) in genetically manipulated mESCs using quantitative real-time PCR (qPCR). Screening against these two aneuploidies significantly increases the fraction of normal mESC …

Gene Expression Life History Markers In A Hatchery And A Wild Population Of Young-Of-The-Year Oncorhynchus Mykiss, Ian D. F. Garrett

Dissertations and Theses

Life history within a single species can vary significantly. Many of these differences are associated with varying environmental conditions. Understanding what environmental conditions cue alternate life histories within a single species has been researched extensively. In salmonid fishes, more than almost any other group, varying environmental conditions give rise to individuals within species that take markedly different life history trajectories.

Oncorhynchus mykissis a species of salmonid native to the Pacific Northwest region of North America. This species has two life history forms, anadromous and resident. The anadromous form spends a portion of its life in ocean while the resident life …

Detecting Modules In Multiplex Networks – An Application For Integrating Expression Profiles Across Multiple Species, Koon-Kiu Yan, Daifeng Wang, Joel Rozowsky, Henry Zheng, Baikang Pei, Mark Gerstein

Yale Day of Data

Multiplex network, a set of networks linked through interconnected layers, is a useful mathematical framework for data integration. Here, we present a general method to detect modules in multiplex networks and apply it in a specific biological context: to simultaneously cluster the genome-wide expression profiles of C. elegans and D. melanogaster generated by the ENOCDE and modENCODE consortia. The method revealed modules that are fundamentally cross-species and can either be conserved or species-specific. In general, the method could be applied in various contexts like the integration of different social networks.

The Tiger Genome And Comparative Analysis With Lion And Snow Leopard Genomes, Yun Sung Cho, Li Hu, Haolong Hou, Hang Lee, Jiaohui Xu, Soowhan Kwon, Sukhun Oh, Hak-Min Kim, Sungwoong Jho, Sangsoo Kim, Young-Ah Shin, Byung Chul Kim, Hyunmin Kim, Chang-Uk Kim, Shu-Jin Luo, Warren E. Johnson, Klaus-Peter Koepfli, A. Schmidt-Kunzel, Jason A. Turner, L. Marker, Cindy K. Harper, Susan M. Miller, Wilhelm Jacobs, Laura D. Bertola, Tae Hyung Kim, Sunghoon Lee, Qian Zhou, Hyun-Ju Jung, Xiao Xu, Priyvrat Gadhvi, Pengwei Xu, Yingqi Xiong, Yadan Luo, Shengkai Pan, Caiyun Gou, Xiuhui Chu, Jilin Zhang, Sanyang Liu, Jing He, Ying Chen, Linfeng Yang, Yulan Yang, Jiaju He, Sha Liu, Junyi Wang, Chul Hong Kim, Hwanjong Kwak, Jong-Soo Kim, Seungwoo Hwang, Junsu Ko, Chang-Bae Kim, Sangtae Kim, Damdin Bayarlkhagva, Woon Kee Paek, Seong-Jin Kim, Stephen J. O'Brien, Jun Wang, Jong Bhak

Biology Faculty Articles

Tigers and their close relatives (Panthera) are some of the world’s most endangered species. Here we report the de novo assembly of an Amur tiger whole-genome sequence as well as the genomic sequences of a white Bengal tiger, African lion, white African lion and snow leopard. Through comparative genetic analyses of these genomes, we find genetic signatures that may reflect molecular adaptations consistent with the big cats’ hypercarnivorous diet and muscle strength. We report a snow leopard-specific genetic determinant in EGLN1 (Met39>Lys39), which is likely to be associated with adaptation to high altitude. We also detect a …

Ancestry Informative Markers Clarify The Regional Admixture Variation In The Costa Rican Population, Rebeca Campos-Sánchez, Henriette Raventós, Ramiro Barrantes

Human Biology Open Access Pre-Prints

The genetic structure of Costa Rica’s population is complex, both by region and by individual, due to the admixture process that started during the 15th century and historical events thereafter. Previous studies have been done mostly on Amerindian populations and the Central Valley inhabitants using various microsatellites and mtDNA markers. Here, we study for the first time a random sample from all regions of the country with AIMS (Ancestry Informative Markers) to address the individual and regional admixture proportions. A sample of 160 male individuals was screened for 78 AIMs customized in a GoldenGate platform from Illumina. We observed that …

Analysis Of Uniparental Lineages In Two Villages Of Santiago Del Estero, Argentina, Seat Of “Pueblos De Indios” In Colonial Times, Maia Pauro, Angelina García, Rodrigo Nores, Darío A. Demarchi

Human Biology Open Access Pre-Prints

Based on the analysis of the mitochondrial control region and seven biallelic markers of the Y Chromosome, we investigated the genetic composition of two rural populations of southern Santiago del Estero, Argentina, that were seats in colonial times of “pueblos de indios”, a colonial practice that consisted of concentrating the indigenous populations in organized and accessible settlements, to facilitate Christianizing and policing. We found the Native American Y chromosome haplogroup Q1a3a in only 11% (3/27) of the males. Haplogroup R, common in European populations, is the most frequent haplogroup in Santiago del Estero (55%). In contrast, the persistence of Native …

How Studies Of Human Sex Ratios At Birth May Lead To The Understanding Of Several Forms Of Pathology, William H. James

Human Biology Open Access Pre-Prints

This paper deals with the problem of the causes of the variation of sex ratio (proportion male) at birth. This problem is common to a number of areas in biology and medicine e.g. obstetrics, neurology/psychiatry, parasitology, virology, oncology and teratology. It is established that there are significantly biased, but unexplained, sex ratios in each of these fields. Yet workers in them (with the possible exception of virology) have regarded the problem as a minor loose end, irrelevant to the field’s major problems. However, as far as I know, no-one has previously noted that unexplained biased sex ratios occur, and thus …

Genetic Variation Of X-Strs In The Wichí Population From Chaco Province, Argentina, Laura Angela Glesmann, Pablo Francisco Martina, Cecilia Inés Catanesi

Human Biology Open Access Pre-Prints

The Wichí people from Chaco province inhabit the region called Impenetrable Chaqueño, where the climatic conditions are extreme. Besides the scarce communication with the main urban centers, the cultural patterns of the Wichí cause these communities to live in certain degree of isolation. The effect of this situation is an increased genetic differentiation from other populations, as it was observed through autosomal and Y chromosome markers. However, the genetic variation of X chromosome has not been fully analyzed yet. The patterns of allele distribution of different markers of X chromosome can be highly informative in comparative studies, because its special …

The -9/+9 Polymorphism Of The Bradykinin Receptor Beta 2 Gene And Athlete Status: A Study Involving Two European Cohorts., Marek Sawczuk, Yevgeniya I. Timshina, Irina V. Astratenkova, Agnieszka Maciejewska-Karłowska, Agata Leońska-Duniec, Krzysztof Ficek, Leysan J. Mustafina, Paweł Cięszczyk, Tomasz Klocek, Ildus I. Ahmetov

Human Biology Open Access Pre-Prints

Background: Previous studies concerning the relevance of the BDKRB2 gene polymorphisms revealed that the absence (–9 allele) of a 9 base pair sequence in exon 1 of the BDKRB2 gene is correlated with higher skeletal muscle metabolic efficiency, glucose uptake during exercise, as well as endurance athletic performance. Aim: The aim of the study was to investigate the association between the BDKRB2 -9/+9 polymorphism and elite athletic status in two cohorts of east-European athletes. Therefore, we examined the genotype distribution of the BDKRB2 9/+9 polymorphic site in a group of Polish athletes and confirmed the results obtained in a replication …