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Parée T, Noble L, Ferreira Gonçalves J, Teotónio H. rec-1 loss of function increases recombination in the central gene clusters at the expense of autosomal pairing centers. Genetics 2024; 226:iyad205. [PMID: 38001364 DOI: 10.1093/genetics/iyad205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/03/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
Meiotic control of crossover (CO) number and position is critical for homologous chromosome segregation and organismal fertility, recombination of parental genotypes, and the generation of novel genetic combinations. We here characterize the recombination rate landscape of a rec-1 loss of function modifier of CO position in Caenorhabditis elegans, one of the first ever modifiers discovered. By averaging CO position across hermaphrodite and male meioses and by genotyping 203 single-nucleotide variants covering about 95% of the genome, we find that the characteristic chromosomal arm-center recombination rate domain structure is lost in the loss of function rec-1 mutant. The rec-1 loss of function mutant smooths the recombination rate landscape but is insufficient to eliminate the nonuniform position of CO. Lower recombination rates in the rec-1 mutant are particularly found in the autosomal arm domains containing the pairing centers. We further find that the rec-1 mutant is of little consequence for organismal fertility and egg viability and thus for rates of autosomal nondisjunction. It nonetheless increases X chromosome nondisjunction rates and thus male appearance. Our findings question the maintenance of recombination rate heritability and genetic diversity among C. elegans natural populations, and they further suggest that manipulating genetic modifiers of CO position will help find quantitative trait loci located in low-recombining genomic regions normally refractory to discovery.
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Affiliation(s)
- Tom Parée
- Institut de Biologie de l'École Normale Supérieure, CNRS UMR, 8197, Inserm U1024, PSL Research University, Paris F-75005, France
| | - Luke Noble
- Institut de Biologie de l'École Normale Supérieure, CNRS UMR, 8197, Inserm U1024, PSL Research University, Paris F-75005, France
- EnviroDNA, 95 Albert St., Brunswick, Victoria 3065, Australia
| | - João Ferreira Gonçalves
- Institut de Biologie de l'École Normale Supérieure, CNRS UMR, 8197, Inserm U1024, PSL Research University, Paris F-75005, France
| | - Henrique Teotónio
- Institut de Biologie de l'École Normale Supérieure, CNRS UMR, 8197, Inserm U1024, PSL Research University, Paris F-75005, France
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2
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Shaver AO, Miller IR, Schaye ES, Moya ND, Collins J, Wit J, Blanco AH, Shao FM, Andersen EJ, Khan SA, Paredes G, Andersen EC. Quantifying the fitness effects of resistance alleles with and without anthelmintic selection pressure using Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.01.578300. [PMID: 38370666 PMCID: PMC10871296 DOI: 10.1101/2024.02.01.578300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
Albendazole and ivermectin are the two most commonly co-administered anthelmintic drugs in mass-drug administration programs worldwide. Despite emerging resistance, we do not fully understand the mechanisms of resistance to these drugs nor the consequences of delivering them in combination. Albendazole resistance has primarily been attributed to variation in the drug target, a beta-tubulin gene. Ivermectin targets glutamate-gated chloride channel (GluCl) genes, but it is unknown whether these genes are involved in ivermectin resistance in nature. Using Caenorhabditis elegans, we defined the fitness costs associated with loss of the drug target genes singly or in combinations of the genes that encode GluCl subunits. We quantified the loss-of function effects on three traits: (i) multi-generational competitive fitness, (ii) fecundity, and (iii) development. In competitive fitness and development assays, we found that a deletion of the beta-tubulin gene ben-1 conferred albendazole resistance, but ivermectin resistance required loss of two GluCl genes (avr-14 and avr-15) or loss of three GluCl genes (avr-14, avr-15, and glc-1). The fecundity assays revealed that loss of ben-1 did not provide any fitness benefit in albendazole and that no GluCl deletion mutants were resistant to ivermectin. Next, we searched for evidence of multi-drug resistance across the three traits. Loss of ben-1 did not confer resistance to ivermectin, nor did loss of any single GluCl subunit or combination confer resistance to albendazole. Finally, we assessed the development of 124 C. elegans wild strains across six benzimidazoles and seven macrocyclic lactones to identify evidence of multi-drug resistance between the two drug classes and found a strong phenotypic correlation within a drug class but not across drug classes. Because each gene affects various aspects of nematode physiology, these results suggest that it is necessary to assess multiple fitness traits to evaluate how each gene contributes to anthelmintic resistance.
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Affiliation(s)
- Amanda O. Shaver
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Isabella R. Miller
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Etta S. Schaye
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Nicolas D. Moya
- Dept. of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - J.B. Collins
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Janneke Wit
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Alyssa H. Blanco
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Fiona M. Shao
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Elliot J. Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Sharik A. Khan
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Gracie Paredes
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Erik C. Andersen
- Dept. of Biology, Johns Hopkins University, Baltimore, Maryland, United States of America
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3
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Crombie TA, McKeown R, Moya ND, Evans K, Widmayer S, LaGrassa V, Roman N, Tursunova O, Zhang G, Gibson S, Buchanan C, Roberto N, Vieira R, Tanny R, Andersen E. CaeNDR, the Caenorhabditis Natural Diversity Resource. Nucleic Acids Res 2024; 52:D850-D858. [PMID: 37855690 PMCID: PMC10767927 DOI: 10.1093/nar/gkad887] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 09/30/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023] Open
Abstract
Studies of model organisms have provided important insights into how natural genetic differences shape trait variation. These discoveries are driven by the growing availability of genomes and the expansive experimental toolkits afforded to researchers using these species. For example, Caenorhabditis elegans is increasingly being used to identify and measure the effects of natural genetic variants on traits using quantitative genetics. Since 2016, the C. elegans Natural Diversity Resource (CeNDR) has facilitated many of these studies by providing an archive of wild strains, genome-wide sequence and variant data for each strain, and a genome-wide association (GWA) mapping portal for the C. elegans community. Here, we present an updated platform, the Caenorhabditis Natural Diversity Resource (CaeNDR), that enables quantitative genetics and genomics studies across the three Caenorhabditis species: C. elegans, C. briggsae and C. tropicalis. The CaeNDR platform hosts several databases that are continually updated by the addition of new strains, whole-genome sequence data and annotated variants. Additionally, CaeNDR provides new interactive tools to explore natural variation and enable GWA mappings. All CaeNDR data and tools are accessible through a freely available web portal located at caendr.org.
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Affiliation(s)
- Timothy A Crombie
- Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, Melbourne, FL, USA
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Ryan McKeown
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Nicolas D Moya
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
- Cell, Molecular, Developmental biology, and Biophysics Graduate Program, ohns Hopkins University, Baltimore, MD, USA
| | - Kathryn S Evans
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Samuel J Widmayer
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Vincent LaGrassa
- Northwestern University Information Technology, Media and Technology Innovation, Northwestern University, Evanston, IL USA
| | - Natalie Roman
- Northwestern University Information Technology, Media and Technology Innovation, Northwestern University, Evanston, IL USA
| | - Orzu Tursunova
- Northwestern University Information Technology, Media and Technology Innovation, Northwestern University, Evanston, IL USA
| | - Gaotian Zhang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Sophia B Gibson
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Claire M Buchanan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Nicole M Roberto
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Rodolfo Vieira
- Northwestern University Information Technology, Media and Technology Innovation, Northwestern University, Evanston, IL USA
| | - Robyn E Tanny
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Erik C Andersen
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
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4
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Shaver AO, Garcia BM, Gouveia GJ, Morse AM, Liu Z, Asef CK, Borges RM, Leach FE, Andersen EC, Amster IJ, Fernández FM, Edison AS, McIntyre LM. An anchored experimental design and meta-analysis approach to address batch effects in large-scale metabolomics. Front Mol Biosci 2022; 9:930204. [PMID: 36438654 PMCID: PMC9682135 DOI: 10.3389/fmolb.2022.930204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 10/10/2022] [Indexed: 11/27/2022] Open
Abstract
Untargeted metabolomics studies are unbiased but identifying the same feature across studies is complicated by environmental variation, batch effects, and instrument variability. Ideally, several studies that assay the same set of metabolic features would be used to select recurring features to pursue for identification. Here, we developed an anchored experimental design. This generalizable approach enabled us to integrate three genetic studies consisting of 14 test strains of Caenorhabditis elegans prior to the compound identification process. An anchor strain, PD1074, was included in every sample collection, resulting in a large set of biological replicates of a genetically identical strain that anchored each study. This enables us to estimate treatment effects within each batch and apply straightforward meta-analytic approaches to combine treatment effects across batches without the need for estimation of batch effects and complex normalization strategies. We collected 104 test samples for three genetic studies across six batches to produce five analytical datasets from two complementary technologies commonly used in untargeted metabolomics. Here, we use the model system C. elegans to demonstrate that an augmented design combined with experimental blocks and other metabolomic QC approaches can be used to anchor studies and enable comparisons of stable spectral features across time without the need for compound identification. This approach is generalizable to systems where the same genotype can be assayed in multiple environments and provides biologically relevant features for downstream compound identification efforts. All methods are included in the newest release of the publicly available SECIMTools based on the open-source Galaxy platform.
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Affiliation(s)
- Amanda O. Shaver
- Department of Genetics, University of Georgia, Athens, GA, United States,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Brianna M. Garcia
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States,Department of Chemistry, University of Georgia, Athens, GA, United States
| | - Goncalo J. Gouveia
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States,Department of Biochemistry, University of Georgia, Athens, GA, United States
| | - Alison M. Morse
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
| | - Zihao Liu
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States
| | - Carter K. Asef
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, United States
| | - Ricardo M. Borges
- Walter Mors Institute of Research on Natural Products, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Franklin E. Leach
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States,Department of Environmental Health Science, University of Georgia, Athens, GA, United States
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States
| | - I. Jonathan Amster
- Department of Chemistry, University of Georgia, Athens, GA, United States
| | - Facundo M. Fernández
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, United States
| | - Arthur S. Edison
- Department of Genetics, University of Georgia, Athens, GA, United States,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States,Department of Biochemistry, University of Georgia, Athens, GA, United States
| | - Lauren M. McIntyre
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, United States,University of Florida Genetics Institute, University of Florida, Gainesville, FL, United States,*Correspondence: Lauren M. McIntyre,
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5
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Widmayer SJ, Evans KS, Zdraljevic S, Andersen EC. Evaluating the power and limitations of genome-wide association studies in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2022; 12:6583190. [PMID: 35536194 PMCID: PMC9258552 DOI: 10.1093/g3journal/jkac114] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/02/2022] [Indexed: 11/30/2022]
Abstract
Quantitative genetics in Caenorhabditis elegans seeks to identify naturally segregating genetic variants that underlie complex traits. Genome-wide association studies scan the genome for individual genetic variants that are significantly correlated with phenotypic variation in a population, or quantitative trait loci. Genome-wide association studies are a popular choice for quantitative genetic analyses because the quantitative trait loci that are discovered segregate in natural populations. Despite numerous successful mapping experiments, the empirical performance of genome-wide association study has not, to date, been formally evaluated in C. elegans. We developed an open-source genome-wide association study pipeline called NemaScan and used a simulation-based approach to provide benchmarks of mapping performance in collections of wild C. elegans strains. Simulated trait heritability and complexity determined the spectrum of quantitative trait loci detected by genome-wide association studies. Power to detect smaller-effect quantitative trait loci increased with the number of strains sampled from the C. elegans Natural Diversity Resource. Population structure was a major driver of variation in mapping performance, with populations shaped by recent selection exhibiting significantly lower false discovery rates than populations composed of more divergent strains. We also recapitulated previous genome-wide association studies of experimentally validated quantitative trait variants. Our simulation-based evaluation of performance provides the community with critical context to pursue quantitative genetic studies using the C. elegans Natural Diversity Resource to elucidate the genetic basis of complex traits in C. elegans natural populations.
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Affiliation(s)
- Samuel J Widmayer
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Kathryn S Evans
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Stefan Zdraljevic
- Department of Biological Chemistry, University of California-Los Angeles, Los Angeles, CA 90095, USA
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.,Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL 60611, USA
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6
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The impact of species-wide gene expression variation on Caenorhabditis elegans complex traits. Nat Commun 2022; 13:3462. [PMID: 35710766 PMCID: PMC9203580 DOI: 10.1038/s41467-022-31208-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/08/2022] [Indexed: 12/15/2022] Open
Abstract
Phenotypic variation in organism-level traits has been studied in Caenorhabditis elegans wild strains, but the impacts of differences in gene expression and the underlying regulatory mechanisms are largely unknown. Here, we use natural variation in gene expression to connect genetic variants to differences in organismal-level traits, including drug and toxicant responses. We perform transcriptomic analyses on 207 genetically distinct C. elegans wild strains to study natural regulatory variation of gene expression. Using this massive dataset, we perform genome-wide association mappings to investigate the genetic basis underlying gene expression variation and reveal complex genetic architectures. We find a large collection of hotspots enriched for expression quantitative trait loci across the genome. We further use mediation analysis to understand how gene expression variation could underlie organism-level phenotypic variation for a variety of complex traits. These results reveal the natural diversity in gene expression and possible regulatory mechanisms in this keystone model organism, highlighting the promise of using gene expression variation to understand how phenotypic diversity is generated.
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7
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Crombie TA, Battlay P, Tanny RE, Evans KS, Buchanan CM, Cook DE, Dilks CM, Stinson LA, Zdraljevic S, Zhang G, Roberto NM, Lee D, Ailion M, Hodgins KA, Andersen EC. Local adaptation and spatiotemporal patterns of genetic diversity revealed by repeated sampling of Caenorhabditis elegans across the Hawaiian Islands. Mol Ecol 2022; 31:2327-2347. [PMID: 35167162 PMCID: PMC9306471 DOI: 10.1111/mec.16400] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/23/2022] [Accepted: 02/03/2022] [Indexed: 11/28/2022]
Abstract
The nematode Caenorhabditis elegans is among the most widely studied organisms, but relatively little is known about its natural ecology. Genetic diversity is low across much of the globe but high in the Hawaiian Islands and across the Pacific Rim. To characterize the niche and genetic diversity of C. elegans on the Hawaiian Islands and to explore how genetic diversity might be influenced by local adaptation, we repeatedly sampled nematodes over a three‐year period, measured various environmental parameters at each sampling site, and whole‐genome sequenced the C. elegans isolates that we identified. We found that the typical Hawaiian C. elegans niche comprises moderately moist native forests at high elevations (500–1,500 m) where ambient air temperatures are cool (15–20°C). Compared to other Caenorhabditis species found on the Hawaiian Islands (e.g., Caenorhabditis briggsae and Caenorhabditis tropicalis), we found that C. elegans were enriched in native habitats. We measured levels of genetic diversity and differentiation among Hawaiian C. elegans and found evidence of seven genetically distinct groups distributed across the islands. Then, we scanned these genomes for signatures of local adaptation and identified 18 distinct regions that overlap with hyper‐divergent regions, which may be maintained by balancing selection and are enriched for genes related to environmental sensing, xenobiotic detoxification, and pathogen resistance. These results provide strong evidence of local adaptation among Hawaiian C. elegans and contribute to our understanding of the forces that shape genetic diversity on the most remote volcanic archipelago in the world.
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Affiliation(s)
- Timothy A Crombie
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Paul Battlay
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Robyn E Tanny
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Kathryn S Evans
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Claire M Buchanan
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Daniel E Cook
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Clayton M Dilks
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Loraina A Stinson
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Stefan Zdraljevic
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA.,Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, USA
| | - Gaotian Zhang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Nicole M Roberto
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Daehan Lee
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - Kathryn A Hodgins
- School of Biological Sciences, Monash University, Melbourne, Australia
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
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8
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Lim J, Kim J, Lee J. Natural variation in reproductive timing and X-chromosome non-disjunction in Caenorhabditis elegans. G3-GENES GENOMES GENETICS 2021; 11:6373895. [PMID: 34550364 PMCID: PMC8664432 DOI: 10.1093/g3journal/jkab327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 09/02/2021] [Indexed: 11/12/2022]
Abstract
Caenorhabditis elegans hermaphrodites first produce a limited number of sperm cells, before their germline switches to oogenesis. Production of progeny then ensues until sperm is depleted. Male production in the self-progeny of hermaphrodites occurs following X-chromosome non-disjunction during gametogenesis, and in the reference strain increases with age of the hermaphrodite parent. To enhance our understanding of the reproductive timecourse in Caenorhabditis elegans, we measured and compared progeny production and male proportion during the early and late reproductive periods of hermaphrodites for 96 wild Caenorhabditis elegans strains. We found that the two traits exhibited natural phenotypic variation with few outliers and a similar reproductive timing pattern as previous reports. Progeny number and male proportion were not correlated in the wild isolates, implying that isolates with a large brood size did not produce males at a higher rate. We also identified loci and candidate genetic variants significantly associated with male-production rate in the late and total reproductive periods. Our results provide an insight into life history traits in wild Caenorhabditis elegans strains.
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Affiliation(s)
- Jiseon Lim
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826
| | - Jun Kim
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
| | - Junho Lee
- Department of Biological Sciences, Seoul National University, Seoul, Korea 08826.,Institute of Molecular Biology and Genetics, Seoul National University, Seoul, Korea 08826.,Research Institute of Basic Sciences, Seoul National University, Seoul, Korea 08826
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