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Lin Q, Tu X, Li X, Gou F, Gao H, Lu Z, Feng J, Ying Y, Hu C. Effects of low protein diets on acid-base balance, electrolyte balance, intestinal structure, and amino acid transport in piglets. J Anim Physiol Anim Nutr (Berl) 2024; 108:1107-1118. [PMID: 38567963 DOI: 10.1111/jpn.13954] [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: 12/11/2023] [Revised: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 07/09/2024]
Abstract
Reducing the dietary crude protein (CP) could effectively reduce pressure on protein ingredient supplies. However, few data have been reported about the extent to which CP can be reduced and whether limiting the use of soybean meal leads to electrolyte imbalance. In this experiment, using the low protein (LP) diet [2% lower than NRC (2012)], seventy-two piglets (35 days old) were randomly divided into 2 groups with 6 replicates of 6 piglets each: CON group (CP = 18.5%) and LP group (CP = 16.5%), to investigate the effect of the LP diet on electrolyte balance, acid-base balance, intestinal structure and amino acid transport in piglets. The results revealed that the LP diet decreased the average daily gain and dietary CP digestibility, and damaged the villi structure of the small intestine. Compared with the CON diet, the potassium content decreased and the chlorine content increased in the LP diet, and similar trends were shown in piglet serum. The arterial pH, pCO2, HCO3 -, and base excess of piglets in the LP group were lower than those in the CON group, while pO2 was higher than those in the CON group. Interestingly, the LP diet significantly increased the lysine content in piglet serum and significantly decreased the levels of arginine, leucine, and glutamic acid. Furthermore, the LP diet significantly affected the expression of some amino acid transport vectors (B0AT1, EAAC1, and y+LAT1). In summary, these findings suggested that the LP diet leads to acid-base imbalance, amino acid transport disorder and amino acids imbalance in piglets, and the dietary electrolyte may be a key factor in the impact of the LP diet on piglet growth performance and intestinal health.
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Affiliation(s)
- Qian Lin
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Xiaodian Tu
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Xin Li
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Feiyang Gou
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Hui Gao
- Animal Husbandry Technology Promotion and Breeding Livestock and Poultry Monitoring Station of Zhejiang Province, Hangzhou, China
| | - Zeqing Lu
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Jie Feng
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
| | - Yongfei Ying
- Animal Husbandry Technology Promotion and Breeding Livestock and Poultry Monitoring Station of Zhejiang Province, Hangzhou, China
| | - Caihong Hu
- College of Animal Sciences, Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, China
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2
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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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3
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Bell AD, Chou HT, Valencia F, Paaby AB. Beyond the reference: gene expression variation and transcriptional response to RNA interference in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2023; 13:jkad112. [PMID: 37221008 PMCID: PMC10411595 DOI: 10.1093/g3journal/jkad112] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/11/2023] [Accepted: 05/15/2023] [Indexed: 05/25/2023]
Abstract
Though natural systems harbor genetic and phenotypic variation, research in model organisms is often restricted to a reference strain. Focusing on a reference strain yields a great depth of knowledge but potentially at the cost of breadth of understanding. Furthermore, tools developed in the reference context may introduce bias when applied to other strains, posing challenges to defining the scope of variation within model systems. Here, we evaluate how genetic differences among 5 wild Caenorhabditis elegans strains affect gene expression and its quantification, in general and after induction of the RNA interference (RNAi) response. Across strains, 34% of genes were differentially expressed in the control condition, including 411 genes that were not expressed at all in at least 1 strain; 49 of these were unexpressed in reference strain N2. Reference genome mapping bias caused limited concern: despite hyperdiverse hotspots throughout the genome, 92% of variably expressed genes were robust to mapping issues. The transcriptional response to RNAi was highly strain- and target-gene-specific and did not correlate with RNAi efficiency, as the 2 RNAi-insensitive strains showed more differentially expressed genes following RNAi treatment than the RNAi-sensitive reference strain. We conclude that gene expression, generally and in response to RNAi, differs across C. elegans strains such that the choice of strain may meaningfully influence scientific inferences. Finally, we introduce a resource for querying gene expression variation in this dataset at https://wildworm.biosci.gatech.edu/rnai/.
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Affiliation(s)
- Avery Davis Bell
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr NW, EBB Building, Atlanta, GA 30332, USA
| | - Han Ting Chou
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr NW, EBB Building, Atlanta, GA 30332, USA
| | - Francisco Valencia
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr NW, EBB Building, Atlanta, GA 30332, USA
| | - Annalise B Paaby
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr NW, EBB Building, Atlanta, GA 30332, USA
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4
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Lee D, Fox B, Palomino D, Panda O, Tenjo F, Koury E, Evans K, Stevens L, Rodrigues P, Kolodziej A, Schroeder F, Andersen E. Natural genetic variation in the pheromone production of C. elegans. Proc Natl Acad Sci U S A 2023; 120:e2221150120. [PMID: 37339205 PMCID: PMC10293855 DOI: 10.1073/pnas.2221150120] [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: 12/15/2022] [Accepted: 05/10/2023] [Indexed: 06/22/2023] Open
Abstract
From bacterial quorum sensing to human language, communication is essential for social interactions. Nematodes produce and sense pheromones to communicate among individuals and respond to environmental changes. These signals are encoded by different types and mixtures of ascarosides, whose modular structures further enhance the diversity of this nematode pheromone language. Interspecific and intraspecific differences in this ascaroside pheromone language have been described previously, but the genetic basis and molecular mechanisms underlying the variation remain largely unknown. Here, we analyzed natural variation in the production of 44 ascarosides across 95 wild Caenorhabditis elegans strains using high-performance liquid chromatography coupled to high-resolution mass spectrometry. We discovered wild strains defective in the production of specific subsets of ascarosides (e.g., the aggregation pheromone icas#9) or short- and medium-chain ascarosides, as well as inversely correlated patterns between the production of two major classes of ascarosides. We investigated genetic variants that are significantly associated with the natural differences in the composition of the pheromone bouquet, including rare genetic variants in key enzymes participating in ascaroside biosynthesis, such as the peroxisomal 3-ketoacyl-CoA thiolase, daf-22, and the carboxylesterase cest-3. Genome-wide association mappings revealed genomic loci harboring common variants that affect ascaroside profiles. Our study yields a valuable dataset for investigating the genetic mechanisms underlying the evolution of chemical communication.
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Affiliation(s)
- Daehan Lee
- Department of Molecular Biosciences, Northwestern University, Evanston, IL60208
- Department of Biology, Kyung Hee University, Seoul02447, Republic of Korea
- Department of Biological Sciences, Sungkyunkwan University, Suwon16419, Republic of Korea
| | - Bennett W. Fox
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Diana Fajardo Palomino
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Oishika Panda
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Francisco J. Tenjo
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Emily J. Koury
- Department of Molecular Biosciences, Northwestern University, Evanston, IL60208
| | - Kathryn S. Evans
- Department of Molecular Biosciences, Northwestern University, Evanston, IL60208
| | - Lewis Stevens
- Department of Molecular Biosciences, Northwestern University, Evanston, IL60208
- Tree of Life, Wellcome Sanger Institute, CambridgeCB10 1SA, United Kingdom
| | - Pedro R. Rodrigues
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Aiden R. Kolodziej
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Frank C. Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, NY14850
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY14850
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL60208
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5
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Laue HE, Moroishi Y, Jackson BP, Palys TJ, Baker ER, Korrick SA, Madan JC, Karagas MR. Bacterial Modification of the Association Between Arsenic and Autism-Related Social Behavior Scores. EXPOSURE AND HEALTH 2023; 15:347-354. [PMID: 37840773 PMCID: PMC10569445 DOI: 10.1007/s12403-022-00494-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 05/23/2022] [Accepted: 05/30/2022] [Indexed: 10/17/2023]
Abstract
Arsenic is related to neurodevelopmental outcomes and is associated with the composition of the gut microbiome. Data on the modifying role of the microbiome are limited. We probed suggestive relationships between arsenic and social behaviors to quantify the modifying role of the infant gut microbiome. We followed children for whom arsenic concentrations were quantified in 6-week-old toenail clippings. Scores on the Social Responsiveness Scale (SRS-2), which measures autism-related social behaviors, were provided by caregivers when the child was approximately 3 years of age. Metagenomic sequencing was performed on infant stools collected at 6 weeks and 1 year of age. To evaluate modification by the top ten most abundant species and functional pathways, we modeled SRS-2 total T-scores as a function of arsenic concentrations, microbiome features dichotomized at their median, and an interaction between exposure and the microbiome, adjusting for other trace elements and sociodemographic characteristics. As compared to the standardized population (SRS-2 T-scores = 50), participants in our study had lower SRS-2 scores (n = 78, mean = 44, SD = 5).The relative abundances of several functional pathways identified in 6-week stool samples modified the arsenic-SRS-2 association, including the pathways of valine and isoleucine biosynthesis; we observed no association among those with high relative abundance of each pathway [β = - 0.67 (95% CI - 1.46, 0.12)], and an adverse association [β = 1.67 (95% CI 0.3, 3.04), pinteraction= 0.05] among infants with low relative abundance. Our findings indicate the infant gut microbiome may alter neurodevelopmental susceptibility to environmental exposures.
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Affiliation(s)
- Hannah E. Laue
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
- One Medical Center Dr, WTRB 700, Lebanon, NH 03766, USA
| | - Yuka Moroishi
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Brian P. Jackson
- Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
| | - Thomas J. Palys
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Emily R. Baker
- Department of Obstetrics and Gynecology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA
| | - Susan A. Korrick
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA, USA
| | - Juliette C. Madan
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
- Division of Neonatology, Department of Pediatrics, Children’s Hospital at Dartmouth, Hanover, NH, USA
| | - Margaret R. Karagas
- Department of Epidemiology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
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6
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He Y, Lei JN, Zhu S, Liu YF, Xu YJ. Monomethyl branched-chain fatty acids-a pearl dropped in the ocean. Crit Rev Food Sci Nutr 2023:1-13. [PMID: 37140184 DOI: 10.1080/10408398.2023.2207655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
As an emerging group of bioactive fatty acids, monomethyl branched-chain fatty acids (mmBCFAs) have sparked the interest of many researchers both domestically and internationally. In addition to documenting the importance of mmBCFAs for growth and development, there is increasing evidence that mmBCFAs are highly correlated with obesity and insulin resistance. According to previous pharmacological investigations, mmBCFAs also exhibit anti-inflammatory effects and anticancer properties. This review summarized the distribution of mmBCFAs, which are widely found in dairy products, ruminants, fish, and fermented foods. Besides, we discuss the biosynthesis pathway in different species and detection methods of mmBCFAs. With the hope to unveil their mechanisms of action, we recapitulated detailed the nutrition and health benefits of mmBCFAs. Furthermore, this study provides a thorough, critical overview of the current state of the art, upcoming difficulties, and trends in mmBCFAs.
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Affiliation(s)
- Yuan He
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Reacher Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Jing-Nan Lei
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Reacher Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Shuang Zhu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Reacher Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Yuan-Fa Liu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Reacher Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
| | - Yong-Jiang Xu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, National Engineering Reacher Center for Functional Food, National Engineering Laboratory for Cereal Fermentation Technology, Collaborative Innovation Center of Food Safety and Quality Control in Jiangsu Province, Jiangnan University, Wuxi, Jiangsu, People's Republic of China
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7
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Yao R, Cools A, Matthijs A, Deyn PPD, Maes D, Janssens GPJ. Peculiarities in the Amino Acid Composition of Sow Colostrum and Milk, and Their Potential Relevance to Piglet Development. Vet Sci 2023; 10:vetsci10040298. [PMID: 37104453 PMCID: PMC10141862 DOI: 10.3390/vetsci10040298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 04/28/2023] Open
Abstract
The composition of mother's milk is considered the ideal diet for neonates. This study investigated how conserved or variable the amino acid profile of sow colostrum and milk is throughout lactation, compared with other studies in sows and other species. Twenty-five sows (parity one to seven) from one farm with gestation lengths of 114 to 116 d were sampled on d 0, 3, and 10 after parturition. The total amino acid profile of the samples was analyzed through ion-exchange chromatography, and the results were displayed as the percentage of total amino acid and compared with literature data. Most of the amino acid concentrations in sow milk decreased significantly (p < 0.05) throughout the lactation period, while the amino acid profile generally showed a conserved pattern, especially from d 3 to d 10, and was rather similar across different studies. Glutamine + glutamate was the most abundant amino acid in milk at all sampling moments, accounting for 14-17% of total amino acids. The proportions of proline, valine, and glycine in sow milk nearly accounted for 11%, 7%, and 6% respectively, and were higher compared to human, cow, and goat milk, while the methionine proportion was less than the other three. Compared to the large variations often reported in macronutrient concentrations, the amino acid profile of sow milk in the present study, as well as in others, seems well conserved across the lactation period. Similarities with characteristic differences were also observed between sow milk and piglet body composition, which might reflect the nutrition requirements of preweaning piglets. This study warrants further research exploring the link between the whole amino acid profile and the particular amino acids for suckling piglets and could facilitate insight for optimizing creep feed.
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Affiliation(s)
- Renjie Yao
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - An Cools
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Anneleen Matthijs
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Peter P De Deyn
- Laboratory of Neurochemistry and Behaviour, Faculty of Pharmaceutical, Biomedical and Veterinary Sciences, Faculty of Medicine and Health Sciences, University of Antwerp, 2610 Antwerp, Belgium
| | - Dominiek Maes
- Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
| | - Geert P J Janssens
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
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8
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Bell AD, Chou HT, Paaby AB. Beyond the reference: gene expression variation and transcriptional response to RNAi in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.24.533964. [PMID: 36993640 PMCID: PMC10055391 DOI: 10.1101/2023.03.24.533964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A universal feature of living systems is that natural variation in genotype underpins variation in phenotype. Yet, research in model organisms is often constrained to a single genetic background, the reference strain. Further, genomic studies that do evaluate wild strains typically rely on the reference strain genome for read alignment, leading to the possibility of biased inferences based on incomplete or inaccurate mapping; the extent of reference bias can be difficult to quantify. As an intermediary between genome and organismal traits, gene expression is well positioned to describe natural variability across genotypes generally and in the context of environmental responses, which can represent complex adaptive phenotypes. C. elegans sits at the forefront of investigation into small-RNA gene regulatory mechanisms, or RNA interference (RNAi), and wild strains exhibit natural variation in RNAi competency following environmental triggers. Here, we examine how genetic differences among five wild strains affect the C. elegans transcriptome in general and after inducing RNAi responses to two germline target genes. Approximately 34% of genes were differentially expressed across strains; 411 genes were not expressed at all in at least one strain despite robust expression in others, including 49 genes not expressed in reference strain N2. Despite the presence of hyper-diverse hotspots throughout the C. elegans genome, reference mapping bias was of limited concern: over 92% of variably expressed genes were robust to mapping issues. Overall, the transcriptional response to RNAi was strongly strain-specific and highly specific to the target gene, and the laboratory strain N2 was not representative of the other strains. Moreover, the transcriptional response to RNAi was not correlated with RNAi phenotypic penetrance; the two germline RNAi incompetent strains exhibited substantial differential gene expression following RNAi treatment, indicating an RNAi response despite failure to reduce expression of the target gene. We conclude that gene expression, both generally and in response to RNAi, differs across C. elegans strains such that choice of strain may meaningfully influence scientific conclusions. To provide a public, easily accessible resource for querying gene expression variation in this dataset, we introduce an interactive website at https://wildworm.biosci.gatech.edu/rnai/ .
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Affiliation(s)
- Avery Davis Bell
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA
| | - Han Ting Chou
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA
| | - Annalise B. Paaby
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA
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9
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Venkatesan A, Jimenez Castro PD, Morosetti A, Horvath H, Chen R, Redman E, Dunn K, Collins JB, Fraser JS, Andersen EC, Kaplan RM, Gilleard JS. Molecular evidence of widespread benzimidazole drug resistance in Ancylostoma caninum from domestic dogs throughout the USA and discovery of a novel β-tubulin benzimidazole resistance mutation. PLoS Pathog 2023; 19:e1011146. [PMID: 36862759 PMCID: PMC10013918 DOI: 10.1371/journal.ppat.1011146] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 03/14/2023] [Accepted: 01/22/2023] [Indexed: 03/03/2023] Open
Abstract
Ancylostoma caninum is an important zoonotic gastrointestinal nematode of dogs worldwide and a close relative of human hookworms. We recently reported that racing greyhound dogs in the USA are infected with A. caninum that are commonly resistant to multiple anthelmintics. Benzimidazole resistance in A. caninum in greyhounds was associated with a high frequency of the canonical F167Y(TTC>TAC) isotype-1 β-tubulin mutation. In this work, we show that benzimidazole resistance is remarkably widespread in A. caninum from domestic dogs across the USA. First, we identified and showed the functional significance of a novel benzimidazole isotype-1 β-tubulin resistance mutation, Q134H(CAA>CAT). Several benzimidazole resistant A. caninum isolates from greyhounds with a low frequency of the F167Y(TTC>TAC) mutation had a high frequency of a Q134H(CAA>CAT) mutation not previously reported from any eukaryotic pathogen in the field. Structural modeling predicted that the Q134 residue is directly involved in benzimidazole drug binding and that the 134H substitution would significantly reduce binding affinity. Introduction of the Q134H substitution into the C. elegans β-tubulin gene ben-1, by CRISPR-Cas9 editing, conferred similar levels of resistance as a ben-1 null allele. Deep amplicon sequencing on A. caninum eggs from 685 hookworm positive pet dog fecal samples revealed that both mutations were widespread across the USA, with prevalences of 49.7% (overall mean frequency 54.0%) and 31.1% (overall mean frequency 16.4%) for F167Y(TTC>TAC) and Q134H(CAA>CAT), respectively. Canonical codon 198 and 200 benzimidazole resistance mutations were absent. The F167Y(TTC>TAC) mutation had a significantly higher prevalence and frequency in Western USA than in other regions, which we hypothesize is due to differences in refugia. This work has important implications for companion animal parasite control and the potential emergence of drug resistance in human hookworms.
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Affiliation(s)
- Abhinaya Venkatesan
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
| | - Pablo D. Jimenez Castro
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
- Zoetis, Parsippany, New Jersey, United States of America
- Grupo de Parasitología Veterinaria, Universidad Nacional de Colombia, Colombia
| | - Arianna Morosetti
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
| | - Hannah Horvath
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
| | - Rebecca Chen
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
| | - Elizabeth Redman
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
| | - Kayla Dunn
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
| | - James Bryant Collins
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - James S. Fraser
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, California, United States of America
| | - Erik C. Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Ray M. Kaplan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America
- St. George’s University, School of Veterinary Medicine, Grenada, West Indies
| | - John S. Gilleard
- Faculty of Veterinary Medicine, Host-Parasite Interactions Program, University of Calgary, Alberta, Canada
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10
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Hoedjes KM, Kostic H, Flatt T, Keller L. A Single Nucleotide Variant in the PPARγ-homolog Eip75B Affects Fecundity in Drosophila. Mol Biol Evol 2023; 40:7005670. [PMID: 36703226 PMCID: PMC9922802 DOI: 10.1093/molbev/msad018] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 01/04/2023] [Accepted: 01/18/2023] [Indexed: 01/28/2023] Open
Abstract
Single nucleotide polymorphisms are the most common type of genetic variation, but how these variants contribute to the adaptation of complex phenotypes is largely unknown. Experimental evolution and genome-wide association studies have demonstrated that variation in the PPARγ-homolog Eip75B has associated with longevity and life-history differences in the fruit fly Drosophila melanogaster. Using RNAi knockdown, we first demonstrate that reduced expression of Eip75B in adult flies affects lifespan, egg-laying rate, and egg volume. We then tested the effects of a naturally occurring SNP within a cis-regulatory domain of Eip75B by applying two complementary approaches: a Mendelian randomization approach using lines of the Drosophila Genetic Reference Panel, and allelic replacement using precise CRISPR/Cas9-induced genome editing. Our experiments reveal that this natural polymorphism has a significant pleiotropic effect on fecundity and egg-to-adult viability, but not on longevity or other life-history traits. Our results provide a rare functional validation at the nucleotide level and identify a natural allelic variant affecting fitness and life-history adaptation.
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Affiliation(s)
| | - Hristina Kostic
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
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11
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Karagas MR, McRitchie S, Hoen AG, Takigawa C, Jackson B, Baker ER, Madan J, Sumner SJ, Pathmasiri W. Alterations in Microbial-Associated Fecal Metabolites in Relation to Arsenic Exposure Among Infants. EXPOSURE AND HEALTH 2022; 14:941-949. [PMID: 36776720 PMCID: PMC9918239 DOI: 10.1007/s12403-022-00468-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 12/09/2021] [Accepted: 01/22/2022] [Indexed: 05/13/2023]
Abstract
In utero and early life exposure to inorganic arsenic (iAs) alters immune response in experimental animals and is associated with an increased risk of infant infections. iAs exposure is related to differences in the gut microbiota diversity, community structure, and the relative abundance of individual microbial taxa both in laboratory and human studies. Metabolomics permits a direct measure of molecular products of microbial and host metabolic processes. We conducted NMR metabolomics analysis on infant stool samples and quantified the relative concentrations of 34 known microbial-related metabolites. We examined these metabolites in relation to both in utero and infant log2 urinary total arsenic concentrations (utAs, the sum of iAs and iAs metabolites) collected at approximately 6 weeks of age using linear regression models, adjusted for infant sex, age at sample collection, type of delivery (vaginal vs. cesarean section), feeding mode (breast milk vs. any formula), and specific gravity. Increased fecal butyrate (b = 214.24), propionate (b = 518.33), cholate (b = 8.79), tryptophan (b= 14.23), asparagine (b = 28.80), isoleucine (b = 65.58), leucine (b = 95.91), malonate (b = 50.43), and uracil (b = 36.13), concentrations were associated with a doubling of infant utAs concentrations (p< 0.05). These associations were largely among infants who were formula fed. No clear associations were observed with maternal utAs and infant fecal metabolites. Metabolomic analyses of infant stool samples lend further evidence that the infant gut microbiota is sensitive to As exposure, and these effects may have functional consequences.
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Affiliation(s)
- Margaret R. Karagas
- Department of Epidemiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Susan McRitchie
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Anne G. Hoen
- Department of Epidemiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Cindy Takigawa
- Department of Epidemiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Brian Jackson
- Department of Earth Sciences, Dartmouth College, Hanover, NH, USA
| | - Emily R. Baker
- Department of Obstetrics and Gynecology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Juliette Madan
- Department of Epidemiology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
- Department of Pediatrics & Psychiatry, Children’s Hospital at Dartmouth, Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
| | - Susan J. Sumner
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wimal Pathmasiri
- Nutrition Research Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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12
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Nyaanga J, Andersen EC. Linkage mapping reveals loci that underlie differences in Caenorhabditis elegans growth. G3 GENES|GENOMES|GENETICS 2022; 12:6663991. [PMID: 35961034 PMCID: PMC9526057 DOI: 10.1093/g3journal/jkac207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 08/05/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Growth rate and body size are complex traits that contribute to the fitness of organisms. The identification of loci that underlie differences in these traits provides insights into the genetic contributions to development. Leveraging Caenorhabditis elegans as a tractable metazoan model for quantitative genetics, we can identify genomic regions that underlie differences in growth. We measured postembryonic growth of the laboratory-adapted wild-type strain (N2) and a wild strain from Hawaii (CB4856) and found differences in body size. Using linkage mapping, we identified three distinct quantitative trait loci (QTL) on chromosomes IV, V, and X that are associated with variation in body growth. We further examined these growth-associated quantitative trait loci using chromosome substitution strains and near-isogenic lines and validated the chromosome X quantitative trait loci. In addition, we generated a list of candidate genes for the chromosome X quantitative trait loci. These genes could potentially contribute to differences in animal growth and should be evaluated in subsequent studies. Our work reveals the genetic architecture underlying animal growth variation and highlights the genetic complexity of growth in Caenorhabditis elegans natural populations.
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Affiliation(s)
- Joy Nyaanga
- Department of Molecular Biosciences, Northwestern University , Evanston, IL 60208, USA
- Interdisciplinary Biological Sciences Program, Northwestern University , Evanston, IL 60208, USA
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University , Evanston, IL 60208, USA
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13
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Widmayer SJ, Crombie TA, Nyaanga JN, Evans KS, Andersen EC. C. elegans toxicant responses vary among genetically diverse individuals. Toxicology 2022; 479:153292. [PMID: 35995124 PMCID: PMC9573778 DOI: 10.1016/j.tox.2022.153292] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 08/15/2022] [Accepted: 08/17/2022] [Indexed: 11/25/2022]
Abstract
The genetic variability of toxicant responses among indisviduals in humans and mammalian models requires practically untenable sample sizes to create comprehensive chemical hazard risk evaluations. To address this need, tractable model systems enable reproducible and efficient experimental workflows to collect high-replication measurements of exposure cohorts. Caenorhabditis elegans is a premier toxicology model that has revolutionized our understanding of cellular responses to environmental pollutants and boasts robust genomic resources and high levels of genetic variation across the species. In this study, we performed dose-response analysis across 23 environmental toxicants using eight C. elegans strains representative of species-wide genetic diversity. We observed substantial variation in EC10 estimates and slope parameter estimates of dose-response curves of different strains, demonstrating that genetic background is a significant driver of differential toxicant susceptibility. We also showed that, across all toxicants, at least one C. elegans strain exhibited a significantly different EC10 or slope estimate compared to the reference strain, N2 (PD1074), indicating that population-wide differences among strains are necessary to understand responses to toxicants. Moreover, we quantified the heritability of responses (phenotypic variance attributable to genetic differences between individuals) to each toxicant exposure and observed a correlation between the exposure closest to the species-agnostic EC10 estimate and the exposure that exhibited the most heritable response. At least 20% of the variance in susceptibility to at least one exposure level of each compound was explained by genetic differences among the eight C. elegans strains. Taken together, these results provide robust evidence that heritable genetic variation explains differential susceptibility across an array of environmental pollutants and that genetically diverse C. elegans strains should be deployed to aid high-throughput toxicological screening efforts.
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Affiliation(s)
- Samuel J Widmayer
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
| | - Timothy A Crombie
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
| | - Joy N Nyaanga
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
| | - Kathryn S Evans
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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14
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Mangu JCK, Rai N, Mandal A, Olsson PE, Jass J. Lysinibacillus sphaericus mediates stress responses and attenuates arsenic toxicity in Caenorhabditis elegans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 835:155377. [PMID: 35460794 DOI: 10.1016/j.scitotenv.2022.155377] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 03/15/2022] [Accepted: 04/14/2022] [Indexed: 06/14/2023]
Abstract
Exposure to toxic metals alters host response and that leads to disease development. Studies have revealed the effects of metals on microbial physiology, however, the role of metal resistant bacteria on host response to metals is unclear. The hypothesis that xenobiotic interactions between gut microbes and arsenic influence the host physiology and toxicity was assessed in a Caenorhabditis elegans model. The arsenic-resistant Lysinibacillus sphaericus B1CDA was fed to C. elegans to determine the host responses to arsenic in comparison to Escherichia coli OP50 food. L. sphaericus diet extended C. elegans lifespan compared to E. coli diet, with an increased expression of genes involved in lifespan, stress response and immunity (hif-1, hsp-16.2, mtl-2, abf-2, clec-60), as well as reduced fat accumulation. Arsenic-exposed worms fed L. sphaericus also had a longer lifespan than those fed E. coli and had an increased expression of genes involved in cytoprotection, stress resistance (mtl-1, mtl-2) and oxidative stress response (cyp-35A2, isp-1, ctl-2, sod-1), together with a decreased accumulation of reactive oxygen species (ROS). In comparison with E. coli, L. sphaericus B1CDA diet increased C. elegans fitness while detoxifying arsenic induced ROS and extending lifespan.
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Affiliation(s)
| | - Neha Rai
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Abul Mandal
- Systems Biology Research Center, School of Bioscience, University of Skövde, Skövde, Sweden
| | - Per-Erik Olsson
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden
| | - Jana Jass
- The Life Science Centre-Biology, School of Science and Technology, Örebro University, Örebro, Sweden.
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15
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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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16
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Wolff ID, Hollis JA, Wignall SM. Acentrosomal spindle assembly and maintenance in Caenorhabditis elegans oocytes requires a kinesin-12 nonmotor microtubule interaction domain. Mol Biol Cell 2022; 33:ar71. [PMID: 35594182 PMCID: PMC9635285 DOI: 10.1091/mbc.e22-05-0153] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
During the meiotic divisions in oocytes, microtubules are sorted and organized by motor proteins to generate a bipolar spindle in the absence of centrosomes. In most organisms, kinesin-5 family members crosslink and slide microtubules to generate outward force that promotes acentrosomal spindle bipolarity. However, the mechanistic basis for how other kinesin families act on acentrosomal spindles has not been explored. We investigated this question in Caenorhabditis elegans oocytes, where kinesin-5 is not required to generate outward force and the kinesin-12 family motor KLP-18 instead performs this function. Here we use a combination of in vitro biochemical assays and in vivo mutant analysis to provide insight into the mechanism by which KLP-18 promotes acentrosomal spindle assembly. We identify a microtubule binding site on the C-terminal stalk of KLP-18 and demonstrate that a direct interaction between the KLP-18 stalk and its adaptor protein MESP-1 activates nonmotor microtubule binding. We also provide evidence that this C-terminal domain is required for KLP-18 activity during spindle assembly and show that KLP-18 is continuously required to maintain spindle bipolarity. This study thus provides new insight into the construction and maintenance of the oocyte acentrosomal spindle as well as into kinesin-12 mechanism and regulation.
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Affiliation(s)
- Ian D Wolff
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Jeremy A Hollis
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Sarah M Wignall
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
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17
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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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18
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Crombie TA, Chikuturudzi C, Cook DE, Andersen EC. An automated approach to quantify chemotaxis index in C. elegans. MICROPUBLICATION BIOLOGY 2022; 2022:10.17912/micropub.biology.000567. [PMID: 35647500 PMCID: PMC9136590 DOI: 10.17912/micropub.biology.000567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/09/2022] [Accepted: 05/23/2022] [Indexed: 11/21/2022]
Abstract
Chemotaxis assays are used extensively to study behavioral responses of Caenorhabditis nematodes to environmental cues. These assays result in a chemotaxis index (CI) that denotes the behavioral response of a population of nematodes to a particular compound and can range from 1 (maximum attraction) to -1 (maximum avoidance). Traditional chemotaxis assays have low throughput because researchers must manually setup experimental populations and score CIs. Here, we describe an automated methodology that increases throughput by using liquid-handling robots to setup experimental populations and a custom image analysis package, ct, to automate the scoring of CIs from plate images.
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Affiliation(s)
- Timothy A Crombie
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Chido Chikuturudzi
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Daniel E Cook
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
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19
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Camacho J, de Conti A, Pogribny IP, Sprando RL, Hunt PR. Assessment of the Effects of Organic vs. Inorganic Arsenic and Mercury in Caenorhabditis elegans. Curr Res Toxicol 2022; 3:100071. [PMID: 35602005 PMCID: PMC9118485 DOI: 10.1016/j.crtox.2022.100071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/26/2022] [Accepted: 04/20/2022] [Indexed: 01/03/2023] Open
Abstract
Similar developmental delays and oxidative stress with 20x DMA relative to NaAsO2. Dissimilar gene expression and locomotion with organic vs. inorganic mercury. Dissimilar unfolded protein responses for organic vs. inorganic arsenic and mercury. Across phyla, methylation has opposite effects on arsenic vs. mercury toxicity.
Exposures to mercury and arsenic are known to pose significant threats to human health. Effects specific to organic vs. inorganic forms of these toxic elements are less understood however, especially for organic dimethylarsinic acid (DMA), which has recently been detected in pups of rodent dams orally exposed to inorganic sodium (meta)arsenite (NaAsO2). Caenorhabditis elegans is a small animal alternative toxicity model. To fill data gaps on the effects of DMA relative to NaAsO2, C. elegans were exposed to these two compounds alongside more thoroughly researched inorganic mercury chloride (HgCl2) and organic methylmercury chloride (meHgCl). For timing of developmental milestone acquisition in C. elegans, meHgCl was 2 to 4-fold more toxic than HgCl2, and NaAsO2 was 20-fold more toxic than DMA, ranking the four compounds meHgCl > HgCl2 > NaAsO2 ≫ DMA for developmental toxicity. Methylmercury induced significant decreases in population locomotor activity levels in developing C. elegans. DMA was also associated with developmental hypoactivity, but at >100-fold higher concentrations than meHgCl. Transcriptional alterations in native genes were observed in wild type C. elegans adults exposed to concentrations equitoxic for developmental delay in juveniles. Both forms of arsenic induced genes involved in immune defense and oxidative stress response, while the two mercury species induced proportionally more genes involved in transcriptional regulation. A transgenic bioreporter for activation of conserved proteosome specific unfolded protein response was strongly activated by NaAsO2, but not DMA at tested concentrations. HgCl2 and meHgCl had opposite effects on a bioreporter for unfolded protein response in the endoplasmic reticulum. Presented experiments indicating low toxicity for DMA in C. elegans are consistent with human epidemiologic data correlating higher arsenic methylation capacity with resistance to arsenic toxicity. This work contributes to the understanding of the accuracy and fit-for-use categories for C. elegans toxicity screening and its usefulness to prioritize compounds of concern for further testing.
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Affiliation(s)
- Jessica Camacho
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Aline de Conti
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Igor P. Pogribny
- Food and Drug Administration, National Center for Toxicological Research, 3900 NCTR Rd, Jefferson, AR 72079, United States
| | - Robert L. Sprando
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
| | - Piper Reid Hunt
- Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Applied Research and Safety Assessment, 8301 Muirkirk Road, Laurel, MD 20708, United States
- Corresponding author.
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20
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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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21
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Andersen EC, Rockman MV. Natural genetic variation as a tool for discovery in Caenorhabditis nematodes. Genetics 2022; 220:iyab156. [PMID: 35134197 PMCID: PMC8733454 DOI: 10.1093/genetics/iyab156] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 09/11/2021] [Indexed: 11/12/2022] Open
Abstract
Over the last 20 years, studies of Caenorhabditis elegans natural diversity have demonstrated the power of quantitative genetic approaches to reveal the evolutionary, ecological, and genetic factors that shape traits. These studies complement the use of the laboratory-adapted strain N2 and enable additional discoveries not possible using only one genetic background. In this chapter, we describe how to perform quantitative genetic studies in Caenorhabditis, with an emphasis on C. elegans. These approaches use correlations between genotype and phenotype across populations of genetically diverse individuals to discover the genetic causes of phenotypic variation. We present methods that use linkage, near-isogenic lines, association, and bulk-segregant mapping, and we describe the advantages and disadvantages of each approach. The power of C. elegans quantitative genetic mapping is best shown in the ability to connect phenotypic differences to specific genes and variants. We will present methods to narrow genomic regions to candidate genes and then tests to identify the gene or variant involved in a quantitative trait. The same features that make C. elegans a preeminent experimental model animal contribute to its exceptional value as a tool to understand natural phenotypic variation.
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Affiliation(s)
- Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60201, USA
| | - Matthew V Rockman
- Department of Biology and Center for Genomics & Systems Biology, New York University, New York, NY 10003, USA
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22
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Heaton A, Milligan E, Faulconer E, Allen A, Nguyen T, Weir SM, Glaberman S. Variation in copper sensitivity between laboratory and wild strains of Caenorhabditis elegans. CHEMOSPHERE 2022; 287:131883. [PMID: 34818820 DOI: 10.1016/j.chemosphere.2021.131883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/09/2021] [Accepted: 08/11/2021] [Indexed: 06/13/2023]
Abstract
Ecological risk assessments of chemicals are frequently based on laboratory toxicity data from a small number of model species that may be reared in labs for years or decades. These populations can undergo many processes in the lab including artificial selection, founder effect, and genetic drift, and may not adequately represent their wild counterparts, potentially undermining the goal of protecting natural populations. Here we measure variation in lethality to copper chloride among strains of an emerging model species in toxicology, Caenorhabditis elegans. We tested four wild strains from Chile, Germany, Kenya, and Madeira (Portugal) against several versions of the standard laboratory N2 strain from Bristol, UK used in molecular biology. The four wild strains were more sensitive than any of the N2 strains tested with copper. We also found that the standard N2 strain cultured in the laboratory for >1 year was less sensitive than a recently cultured N2 strain as well as a cataloged ancestral version of the N2 strain. These results suggest that toxicologists should be cognizant of performing toxicity testing with long-held animal cultures, and should perhaps use multiple strains as well as renew cultures periodically in the laboratory. This study also shows that multi-strain toxicity testing with nematodes is highly achievable and useful for understanding variation in intra- and interspecific chemical sensitivity.
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Affiliation(s)
- Andrew Heaton
- Department of Biology, University of South Alabama, Mobile, AL, USA; Grand Bay National Estuarine Research Reserve, Moss Point, MS, USA
| | - Emma Milligan
- Department of Biology, University of South Alabama, Mobile, AL, USA
| | | | - Andrew Allen
- Department of Biology, University of South Alabama, Mobile, AL, USA
| | - Timothy Nguyen
- Department of Biology, University of South Alabama, Mobile, AL, USA
| | - Scott M Weir
- Department of Biology, Queens University of Charlotte, Charlotte, NC, USA
| | - Scott Glaberman
- Department of Biology, University of South Alabama, Mobile, AL, USA; Department of Environmental Science & Policy, George Mason University, Fairfax, VA, USA.
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23
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Sanchez TR, Hu X, Zhao J, Tran V, Loiacono N, Go YM, Goessler W, Cole S, Umans J, Jones DP, Navas-Acien A, Uppal K. An atlas of metallome and metabolome interactions and associations with incident diabetes in the Strong Heart Family Study. ENVIRONMENT INTERNATIONAL 2021; 157:106810. [PMID: 34365318 PMCID: PMC8490308 DOI: 10.1016/j.envint.2021.106810] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 05/10/2023]
Abstract
BACKGROUND Chronic exposure to certain metals plays a role in disease development. Integrating untargeted metabolomics with urinary metallome data may contribute to better understanding the pathophysiology of diseases and complex molecular interactions related to environmental metal exposures. To discover novel associations between urinary metal biomarkers and metabolism networks, we conducted an integrative metallome-metabolome analysis using a panel of urinary metals and untargeted blood metabolomic data from the Strong Heart Family Study (SHFS). METHODS The SHFS is a prospective family-based cohort study comprised of American Indian men and women recruited in 2001-2003. This nested case-control analysis of 145 participants of which 50 developed incident diabetes at follow up in 2006-2009, included participants with urinary metal and untargeted metabolomic data. Concentrations of 8 creatinine-adjusted urine metals/metalloids [antimony (Sb), cadmium (Cd), lead (Pb), molybdenum (Mo), selenium (Se), tungsten (W), uranium (U) and zinc (Zn)], and 4 arsenic species [inorganic arsenic (iAs), monomethylarsonate (MMA), dimethylarsinate (DMA), and arsenobetaine (AsB)] were measured. Global metabolomics was performed on plasma samples using high-resolution Orbitrap mass spectrometry. We performed an integrative network analysis using xMWAS and a metabolic pathway analysis using Mummichog. RESULTS 8,810 metabolic features and 12 metal species were included in the integrative network analysis. Most metal species were associated with distinct subsets of metabolites, forming single-metal-multiple-metabolite clusters (|r|>0.28, p-value < 0.001). DMA (clustering with W), iAs (clustering with U), together with Mo and Se showed modest interactions through associations with common metabolites. Pathway enrichment analysis of associated metabolites (|r|>0.17, p-value < 0.1) showed effects in amino acid metabolism (AsB, Sb, Se and U), fatty acid and lipid metabolism (iAs, Mo, W, Sb, Pb, Cd and Zn). In stratified analyses among participants who went on to develop diabetes, iAs and U clustered together through shared metabolites, and both were associated with the phosphatidylinositol phosphate metabolism pathway; metals were also associated with metabolites in energy metabolism (iAs, MMA, DMA, U, W) and xenobiotic degradation and metabolism (DMA, Pb) pathways. CONCLUSION In this integrative analysis of multiple metals and untargeted metabolomics, results show common associations with fatty acid, energy and amino acid metabolism pathways. Results for individual metabolite associations differed for different metals, indicating that larger populations will be needed to confirm the metal-metal interactions detected here, such as the strong interaction of uranium and inorganic arsenic. Understanding the biochemical networks underlying metabolic homeostasis and their association with exposure to multiple metals may help identify novel biomarkers, pathways of disease, potential signatures of environmental metal exposure.
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Affiliation(s)
- Tiffany R Sanchez
- Department of Environment Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
| | - Xin Hu
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Jinying Zhao
- Department of Epidemiology, College of Public Health and Health Professions and College of Medicine, University of Florida, Gainesville, FL 32610, USA
| | - ViLinh Tran
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Nancy Loiacono
- Department of Environment Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Young-Mi Go
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | | | - Shelley Cole
- Department of Genetics, Texas Biomedical Research Institute, San Antonio, TX, USA
| | - Jason Umans
- Georgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC, USA; MedStar Health Research Institute, Hyattsville, MD, USA
| | - Dean P Jones
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA
| | - Ana Navas-Acien
- Department of Environment Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA
| | - Karan Uppal
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA 30322, USA
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24
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Snoek BL, Sterken MG, Nijveen H, Volkers RJM, Riksen J, Rosenstiel PC, Schulenburg H, Kammenga JE. The genetics of gene expression in a Caenorhabditis elegans multiparental recombinant inbred line population. G3 (BETHESDA, MD.) 2021; 11:jkab258. [PMID: 34568931 PMCID: PMC8496280 DOI: 10.1093/g3journal/jkab258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/17/2021] [Indexed: 11/29/2022]
Abstract
Studying genetic variation of gene expression provides a powerful way to unravel the molecular components underlying complex traits. Expression quantitative trait locus (eQTL) studies have been performed in several different model species, yet most of these linkage studies have been based on the genetic segregation of two parental alleles. Recently, we developed a multiparental segregating population of 200 recombinant inbred lines (mpRILs) derived from four wild isolates (JU1511, JU1926, JU1931, and JU1941) in the nematode Caenorhabditis elegans. We used RNA-seq to investigate how multiple alleles affect gene expression in these mpRILs. We found 1789 genes differentially expressed between the parental lines. Transgression, expression beyond any of the parental lines in the mpRILs, was found for 7896 genes. For expression QTL mapping almost 9000 SNPs were available. By combining these SNPs and the RNA-seq profiles of the mpRILs, we detected almost 6800 eQTLs. Most trans-eQTLs (63%) co-locate in six newly identified trans-bands. The trans-eQTLs found in previous two-parental allele eQTL experiments and this study showed some overlap (17.5-46.8%), highlighting on the one hand that a large group of genes is affected by polymorphic regulators across populations and conditions, on the other hand, it shows that the mpRIL population allows identification of novel gene expression regulatory loci. Taken together, the analysis of our mpRIL population provides a more refined insight into C. elegans complex trait genetics and eQTLs in general, as well as a starting point to further test and develop advanced statistical models for detection of multiallelic eQTLs and systems genetics studying the genotype-phenotype relationship.
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Affiliation(s)
- Basten L Snoek
- Laboratory of Nematology, Wageningen University, NL-6708 PB Wageningen, The Netherlands
- Theoretical Biology and Bioinformatics, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Mark G Sterken
- Laboratory of Nematology, Wageningen University, NL-6708 PB Wageningen, The Netherlands
| | - Harm Nijveen
- Bioinformatics Group, Wageningen University, NL-6708 PB Wageningen, The Netherlands
| | - Rita J M Volkers
- Laboratory of Nematology, Wageningen University, NL-6708 PB Wageningen, The Netherlands
| | - Joost Riksen
- Laboratory of Nematology, Wageningen University, NL-6708 PB Wageningen, The Netherlands
| | - Philip C Rosenstiel
- Institute for Clinical Molecular Biology, University of Kiel, 24098 Kiel, Germany
- Competence Centre for Genomic Analysis (CCGA) Kiel, University of Kiel, 24098 Kiel, Germany
| | - Hinrich Schulenburg
- Zoological Institute, University of Kiel, 24098 Kiel, Germany
- Max Planck Institute for Evolutionary Biology, 24306 Ploen, Germany
| | - Jan E Kammenga
- Laboratory of Nematology, Wageningen University, NL-6708 PB Wageningen, The Netherlands
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25
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Nyaanga J, Crombie TA, Widmayer SJ, Andersen EC. easyXpress: An R package to analyze and visualize high-throughput C. elegans microscopy data generated using CellProfiler. PLoS One 2021; 16:e0252000. [PMID: 34383778 PMCID: PMC8360505 DOI: 10.1371/journal.pone.0252000] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
High-throughput imaging techniques have become widespread in many fields of biology. These powerful platforms generate large quantities of data that can be difficult to process and visualize efficiently using existing tools. We developed easyXpress to process and review C. elegans high-throughput microscopy data in the R environment. The package provides a logical workflow for the reading, analysis, and visualization of data generated using CellProfiler's WormToolbox. We equipped easyXpress with powerful functions to customize the filtering of noise in data, specifically by identifying and removing objects that deviate from expected animal measurements. This flexibility in data filtering allows users to optimize their analysis pipeline to match their needs. In addition, easyXpress includes tools for generating detailed visualizations, allowing the user to interactively compare summary statistics across wells and plates with ease. Researchers studying C. elegans benefit from this streamlined and extensible package as it is complementary to CellProfiler and leverages the R environment to rapidly process and analyze large high-throughput imaging datasets.
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Affiliation(s)
- Joy Nyaanga
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL, United States of America
| | - Timothy A. Crombie
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Samuel J. Widmayer
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
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26
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Zhang G, Mostad JD, Andersen EC. Natural variation in fecundity is correlated with species-wide levels of divergence in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2021; 11:jkab168. [PMID: 33983439 PMCID: PMC8496234 DOI: 10.1093/g3journal/jkab168] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/03/2021] [Indexed: 01/08/2023]
Abstract
Life history traits underlie the fitness of organisms and are under strong natural selection. A new mutation that positively impacts a life history trait will likely increase in frequency and become fixed in a population (e.g., a selective sweep). The identification of the beneficial alleles that underlie selective sweeps provides insights into the mechanisms that occurred during the evolution of a species. In the global population of Caenorhabditis elegans, we previously identified selective sweeps that have drastically reduced chromosomal-scale genetic diversity in the species. Here, we measured the fecundity of 121 wild C. elegans strains, including many recently isolated divergent strains from the Hawaiian islands and found that strains with larger swept genomic regions have significantly higher fecundity than strains without evidence of the recent selective sweeps. We used genome-wide association (GWA) mapping to identify three quantitative trait loci (QTL) underlying the fecundity variation. In addition, we mapped previous fecundity data from wild C. elegans strains and C. elegans recombinant inbred advanced intercross lines that were grown in various conditions and detected eight QTL using GWA and linkage mappings. These QTL show the genetic complexity of fecundity across this species. Moreover, the haplotype structure in each GWA QTL region revealed correlations with recent selective sweeps in the C. elegans population. North American and European strains had significantly higher fecundity than most strains from Hawaii, a hypothesized origin of the C. elegans species, suggesting that beneficial alleles that caused increased fecundity could underlie the selective sweeps during the worldwide expansion of C. elegans.
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Affiliation(s)
- Gaotian Zhang
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Jake D Mostad
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
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27
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Wit J, Rodriguez BC, Andersen EC. Natural variation in Caenorhabditis elegans responses to the anthelmintic emodepside. Int J Parasitol Drugs Drug Resist 2021; 16:1-8. [PMID: 33878514 PMCID: PMC8079822 DOI: 10.1016/j.ijpddr.2021.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 11/19/2022]
Abstract
Treatment of parasitic nematode infections depends primarily on the use of anthelmintics. However, this drug arsenal is limited, and resistance against most anthelmintics is widespread. Emodepside is a new anthelmintic drug effective against gastrointestinal and filarial nematodes. Nematodes that are resistant to other anthelmintic drug classes are susceptible to emodepside, indicating that the emodepside mode of action is distinct from previous anthelmintics. The laboratory-adapted Caenorhabditis elegans strain N2 is sensitive to emodepside, and genetic selection and in vitro experiments implicated slo-1, a large K+ conductance (BK) channel gene, in emodepside mode of action. In an effort to understand how natural populations will respond to emodepside, we measured brood sizes and developmental rates of wild C. elegans strains after exposure to the drug and found natural variation across the species. Some of the observed variation in C. elegans emodepside responses correlates with amino acid substitutions in slo-1, but genetic mechanisms other than slo-1 coding variants likely underlie emodepside resistance in wild C. elegans strains. Additionally, the assayed strains have higher offspring production in low concentrations of emodepside (a hormetic effect). We find that natural variation affects emodepside sensitivity, supporting the suitability of C. elegans as a model system to study emodepside responses across natural nematode populations.
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Affiliation(s)
- Janneke Wit
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Briana C Rodriguez
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA.
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28
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Evans KS, van Wijk MH, McGrath PT, Andersen EC, Sterken MG. From QTL to gene: C. elegans facilitates discoveries of the genetic mechanisms underlying natural variation. Trends Genet 2021; 37:933-947. [PMID: 34229867 DOI: 10.1016/j.tig.2021.06.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 06/01/2021] [Accepted: 06/03/2021] [Indexed: 11/15/2022]
Abstract
Although many studies have examined quantitative trait variation across many species, only a small number of genes and thereby molecular mechanisms have been discovered. Without these data, we can only speculate about evolutionary processes that underlie trait variation. Here, we review how quantitative and molecular genetics in the nematode Caenorhabditis elegans led to the discovery and validation of 37 quantitative trait genes over the past 15 years. Using these data, we can start to make inferences about evolution from these quantitative trait genes, including the roles that coding versus noncoding variation, gene family expansion, common versus rare variants, pleiotropy, and epistasis play in trait variation across this species.
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Affiliation(s)
- Kathryn S Evans
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, IL 60208, USA
| | - Marijke H van Wijk
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands
| | - Patrick T McGrath
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
| | - Mark G Sterken
- Laboratory of Nematology, Wageningen University and Research, 6708 PB, Wageningen, The Netherlands.
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29
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Salzer L, Witting M. Quo Vadis Caenorhabditis elegans Metabolomics-A Review of Current Methods and Applications to Explore Metabolism in the Nematode. Metabolites 2021; 11:metabo11050284. [PMID: 33947148 PMCID: PMC8146106 DOI: 10.3390/metabo11050284] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/11/2022] Open
Abstract
Metabolomics and lipidomics recently gained interest in the model organism Caenorhabditis elegans (C. elegans). The fast development, easy cultivation and existing forward and reverse genetic tools make the small nematode an ideal organism for metabolic investigations in development, aging, different disease models, infection, or toxicology research. The conducted type of analysis is strongly depending on the biological question and requires different analytical approaches. Metabolomic analyses in C. elegans have been performed using nuclear magnetic resonance (NMR) spectroscopy, direct infusion mass spectrometry (DI-MS), gas-chromatography mass spectrometry (GC-MS) and liquid chromatography mass spectrometry (LC-MS) or combinations of them. In this review we provide general information on the employed techniques and their advantages and disadvantages in regard to C. elegans metabolomics. Additionally, we reviewed different fields of application, e.g., longevity, starvation, aging, development or metabolism of secondary metabolites such as ascarosides or maradolipids. We also summarised applied bioinformatic tools that recently have been used for the evaluation of metabolomics or lipidomics data from C. elegans. Lastly, we curated metabolites and lipids from the reviewed literature, enabling a prototypic collection which serves as basis for a future C. elegans specific metabolome database.
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Affiliation(s)
- Liesa Salzer
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany;
| | - Michael Witting
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany;
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
- Chair of Analytical Food Chemistry, TUM School of Life Sciences, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany
- Correspondence:
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30
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Evans KS, Wit J, Stevens L, Hahnel SR, Rodriguez B, Park G, Zamanian M, Brady SC, Chao E, Introcaso K, Tanny RE, Andersen EC. Two novel loci underlie natural differences in Caenorhabditis elegans abamectin responses. PLoS Pathog 2021; 17:e1009297. [PMID: 33720993 PMCID: PMC7993787 DOI: 10.1371/journal.ppat.1009297] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/25/2021] [Accepted: 03/02/2021] [Indexed: 11/18/2022] Open
Abstract
Parasitic nematodes cause a massive worldwide burden on human health along with a loss of livestock and agriculture productivity. Anthelmintics have been widely successful in treating parasitic nematodes. However, resistance is increasing, and little is known about the molecular and genetic causes of resistance for most of these drugs. The free-living roundworm Caenorhabditis elegans provides a tractable model to identify genes that underlie resistance. Unlike parasitic nematodes, C. elegans is easy to maintain in the laboratory, has a complete and well annotated genome, and has many genetic tools. Using a combination of wild isolates and a panel of recombinant inbred lines constructed from crosses of two genetically and phenotypically divergent strains, we identified three genomic regions on chromosome V that underlie natural differences in response to the macrocyclic lactone (ML) abamectin. One locus was identified previously and encodes an alpha subunit of a glutamate-gated chloride channel (glc-1). Here, we validate and narrow two novel loci using near-isogenic lines. Additionally, we generate a list of prioritized candidate genes identified in C. elegans and in the parasite Haemonchus contortus by comparison of ML resistance loci. These genes could represent previously unidentified resistance genes shared across nematode species and should be evaluated in the future. Our work highlights the advantages of using C. elegans as a model to better understand ML resistance in parasitic nematodes.
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Affiliation(s)
- Kathryn S. Evans
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois, United States of America
| | - Janneke Wit
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Lewis Stevens
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Steffen R. Hahnel
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Briana Rodriguez
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Grace Park
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Mostafa Zamanian
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Shannon C. Brady
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois, United States of America
| | - Ellen Chao
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Katherine Introcaso
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Robyn E. Tanny
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Erik C. Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- * E-mail:
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31
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Hartman JH, Widmayer SJ, Bergemann CM, King DE, Morton KS, Romersi RF, Jameson LE, Leung MCK, Andersen EC, Taubert S, Meyer JN. Xenobiotic metabolism and transport in Caenorhabditis elegans. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2021; 24:51-94. [PMID: 33616007 PMCID: PMC7958427 DOI: 10.1080/10937404.2021.1884921] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Caenorhabditis elegans has emerged as a major model in biomedical and environmental toxicology. Numerous papers on toxicology and pharmacology in C. elegans have been published, and this species has now been adopted by investigators in academic toxicology, pharmacology, and drug discovery labs. C. elegans has also attracted the interest of governmental regulatory agencies charged with evaluating the safety of chemicals. However, a major, fundamental aspect of toxicological science remains underdeveloped in C. elegans: xenobiotic metabolism and transport processes that are critical to understanding toxicokinetics and toxicodynamics, and extrapolation to other species. The aim of this review was to initially briefly describe the history and trajectory of the use of C. elegans in toxicological and pharmacological studies. Subsequently, physical barriers to chemical uptake and the role of the worm microbiome in xenobiotic transformation were described. Then a review of what is and is not known regarding the classic Phase I, Phase II, and Phase III processes was performed. In addition, the following were discussed (1) regulation of xenobiotic metabolism; (2) review of published toxicokinetics for specific chemicals; and (3) genetic diversity of these processes in C. elegans. Finally, worm xenobiotic transport and metabolism was placed in an evolutionary context; key areas for future research highlighted; and implications for extrapolating C. elegans toxicity results to other species discussed.
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Affiliation(s)
- Jessica H Hartman
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Samuel J Widmayer
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States
| | | | - Dillon E King
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Katherine S Morton
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Riccardo F Romersi
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Laura E Jameson
- School of Mathematical and Natural Sciences, Arizona State University - West Campus, Glendale, Arizona, United States
| | - Maxwell C K Leung
- School of Mathematical and Natural Sciences, Arizona State University - West Campus, Glendale, Arizona, United States
| | - Erik C Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, United States
| | - Stefan Taubert
- Dept. Of Medical Genetics, Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, the University of British Colombia, Vancouver, BC, Canada
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina
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32
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Goto T, Shimamoto S, Takaya M, Sato S, Takahashi K, Nishimura K, Morii Y, Kunishige K, Ohtsuka A, Ijiri D. Impact on genetic differences among various chicken breeds on free amino acid contents of egg yolk and albumen. Sci Rep 2021; 11:2270. [PMID: 33500483 PMCID: PMC7838262 DOI: 10.1038/s41598-021-81660-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 01/11/2021] [Indexed: 12/12/2022] Open
Abstract
Eggs play important roles as food resources and nutraceuticals, to alleviate malnutrition and to improve health status in the world. Since free amino acids contribute to the nutritional values and food tastes, we investigated a total of 81 eggs from five chicken breeds, which are Australorp, Nagoya (NGY), Rhode Island Red (RIR), Shamo (SHA), Ukokkei, and two F1 hybrids (NGYxRIR and SHAxRIR) to test impact on genetic differences in 10 egg traits, 20 yolk amino acid traits, and 18 albumen amino acid traits. One-way ANOVA revealed significant breed effects on 10 egg traits, 20 yolk amino acid traits, and 15 albumen amino acid traits. Moreover, a significant heterosis effect on yolk aspartic acid was identified. In addition, positive correlations were found broadly among traits within each trait category (egg traits, yolk amino acid traits, and albumen amino acid traits), whereas there were basically no or weak correlations among the trait categories. These results suggest that almost all traits can be dramatically modified by genetic factor, and there will be partially independent production systems of amino acids into yolk and albumen. Since there will be typical quantitative genetic architecture of egg contents, further genetic analyses will be needed.
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Affiliation(s)
- Tatsuhiko Goto
- Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan. .,Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan.
| | - Saki Shimamoto
- Department of Biochemical Science and Technology, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan.,Graduate School of Science and Technology, Niigata University, Niigata, 950-2181, Japan
| | - Masahiro Takaya
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan.,Hokkaido Tokachi Area Regional Food Processing Technology Center, Tokachi Foundation, Obihiro, Hokkaido, 080-2462, Japan
| | - Shun Sato
- Agricultural Research Department, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, 081-0038, Japan
| | - Kanna Takahashi
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Kenji Nishimura
- Department of Life and Food Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, 080-8555, Japan
| | - Yasuko Morii
- Agricultural Research Department, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, 081-0038, Japan
| | - Kyoko Kunishige
- Agricultural Research Department, Animal Research Center, Hokkaido Research Organization, Shintoku, Hokkaido, 081-0038, Japan
| | - Akira Ohtsuka
- Department of Biochemical Science and Technology, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan
| | - Daichi Ijiri
- Department of Biochemical Science and Technology, Kagoshima University, Korimoto, Kagoshima, 890-0065, Japan
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Evans KS, Zdraljevic S, Stevens L, Collins K, Tanny RE, Andersen EC. Natural variation in the sequestosome-related gene, sqst-5, underlies zinc homeostasis in Caenorhabditis elegans. PLoS Genet 2020; 16:e1008986. [PMID: 33175833 PMCID: PMC7682890 DOI: 10.1371/journal.pgen.1008986] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 11/23/2020] [Accepted: 09/23/2020] [Indexed: 12/14/2022] Open
Abstract
Zinc is an essential trace element that acts as a co-factor for many enzymes and transcription factors required for cellular growth and development. Altering intracellular zinc levels can produce dramatic effects ranging from cell proliferation to cell death. To avoid such fates, cells have evolved mechanisms to handle both an excess and a deficiency of zinc. Zinc homeostasis is largely maintained via zinc transporters, permeable channels, and other zinc-binding proteins. Variation in these proteins might affect their ability to interact with zinc, leading to either increased sensitivity or resistance to natural zinc fluctuations in the environment. We can leverage the power of the roundworm nematode Caenorhabditis elegans as a tractable metazoan model for quantitative genetics to identify genes that could underlie variation in responses to zinc. We found that the laboratory-adapted strain (N2) is resistant and a natural isolate from Hawaii (CB4856) is sensitive to micromolar amounts of exogenous zinc supplementation. Using a panel of recombinant inbred lines, we identified two large-effect quantitative trait loci (QTL) on the left arm of chromosome III and the center of chromosome V that are associated with zinc responses. We validated and refined both QTL using near-isogenic lines (NILs) and identified a naturally occurring deletion in sqst-5, a sequestosome-related gene, that is associated with resistance to high exogenous zinc. We found that this deletion is relatively common across strains within the species and that variation in sqst-5 is associated with zinc resistance. Our results offer a possible mechanism for how organisms can respond to naturally high levels of zinc in the environment and how zinc homeostasis varies among individuals.
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Affiliation(s)
- Kathryn S. Evans
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois, United States of America
| | - Stefan Zdraljevic
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois, United States of America
| | - Lewis Stevens
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Kimberly Collins
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Robyn E. Tanny
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
| | - Erik C. Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois, United States of America
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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Sterken MG, Bevers RPJ, Volkers RJM, Riksen JAG, Kammenga JE, Snoek BL. Dissecting the eQTL Micro-Architecture in Caenorhabditis elegans. Front Genet 2020; 11:501376. [PMID: 33240309 PMCID: PMC7670075 DOI: 10.3389/fgene.2020.501376] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 10/13/2020] [Indexed: 01/11/2023] Open
Abstract
The study of expression quantitative trait loci (eQTL) using natural variation in inbred populations has yielded detailed information about the transcriptional regulation of complex traits. Studies on eQTL using recombinant inbred lines (RILs) led to insights on cis and trans regulatory loci of transcript abundance. However, determining the underlying causal polymorphic genes or variants is difficult, but ultimately essential for the understanding of regulatory networks of complex traits. This requires insight into whether associated loci are single eQTL or a combination of closely linked eQTL, and how this QTL micro-architecture depends on the environment. We addressed these questions by testing for independent replication of previously mapped eQTL in Caenorhabditis elegans using new data from introgression lines (ILs). Both populations indicate that the overall heritability of gene expression, number, and position of eQTL differed among environments. Across environments we were able to replicate 70% of the cis- and 40% of the trans-eQTL using the ILs. Testing eight different simulation models, we suggest that additive effects explain up to 60-93% of RIL/IL heritability for all three environments. Closely linked eQTL explained up to 40% of RIL/IL heritability in the control environment whereas only 7% in the heat-stress and recovery environments. In conclusion, we show that reproducibility of eQTL was higher for cis vs. trans eQTL and that the environment affects the eQTL micro-architecture.
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Affiliation(s)
- Mark G. Sterken
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
| | - Roel P. J. Bevers
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
| | - Rita J. M. Volkers
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
| | - Joost A. G. Riksen
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
| | - Jan E. Kammenga
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
| | - Basten L. Snoek
- Laboratory of Nematology, Wageningen University & Research, Wageningen, Netherlands
- Theoretical Biology & Bioinformatics, Utrecht University, Utrecht, Netherlands
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35
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Hunt PR, Camacho JA, Sprando RL. Caenorhabditis elegans for predictive toxicology. CURRENT OPINION IN TOXICOLOGY 2020. [DOI: 10.1016/j.cotox.2020.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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36
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Na H, Zdraljevic S, Tanny RE, Walhout AJM, Andersen EC. Natural variation in a glucuronosyltransferase modulates propionate sensitivity in a C. elegans propionic acidemia model. PLoS Genet 2020; 16:e1008984. [PMID: 32857789 PMCID: PMC7482840 DOI: 10.1371/journal.pgen.1008984] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 09/10/2020] [Accepted: 07/08/2020] [Indexed: 11/19/2022] Open
Abstract
Mutations in human metabolic genes can lead to rare diseases known as inborn errors of human metabolism. For instance, patients with loss-of-function mutations in either subunit of propionyl-CoA carboxylase suffer from propionic acidemia because they cannot catabolize propionate, leading to its harmful accumulation. Both the penetrance and expressivity of metabolic disorders can be modulated by genetic background. However, modifiers of these diseases are difficult to identify because of the lack of statistical power for rare diseases in human genetics. Here, we use a model of propionic acidemia in the nematode Caenorhabditis elegans to identify genetic modifiers of propionate sensitivity. Using genome-wide association (GWA) mapping across wild strains, we identify several genomic regions correlated with reduced propionate sensitivity. We find that natural variation in the putative glucuronosyltransferase GLCT-3, a homolog of human B3GAT, partly explains differences in propionate sensitivity in one of these genomic intervals. We demonstrate that loss-of-function alleles in glct-3 render the animals less sensitive to propionate. Additionally, we find that C. elegans has an expansion of the glct gene family, suggesting that the number of members of this family could influence sensitivity to excess propionate. Our findings demonstrate that natural variation in genes that are not directly associated with propionate breakdown can modulate propionate sensitivity. Our study provides a framework for using C. elegans to characterize the contributions of genetic background in models of human inborn errors in metabolism.
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Affiliation(s)
- Huimin Na
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
| | - Stefan Zdraljevic
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Robyn E. Tanny
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
| | - Albertha J. M. Walhout
- Program in Systems Biology and Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, United States of America
- * E-mail: (AJMW); (ECA)
| | - Erik C. Andersen
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, United States of America
- * E-mail: (AJMW); (ECA)
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37
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The Gene scb-1 Underlies Variation in Caenorhabditis elegans Chemotherapeutic Responses. G3-GENES GENOMES GENETICS 2020; 10:2353-2364. [PMID: 32385045 PMCID: PMC7341127 DOI: 10.1534/g3.120.401310] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Pleiotropy, the concept that a single gene controls multiple distinct traits, is prevalent in most organisms and has broad implications for medicine and agriculture. The identification of the molecular mechanisms underlying pleiotropy has the power to reveal previously unknown biological connections between seemingly unrelated traits. Additionally, the discovery of pleiotropic genes increases our understanding of both genetic and phenotypic complexity by characterizing novel gene functions. Quantitative trait locus (QTL) mapping has been used to identify several pleiotropic regions in many organisms. However, gene knockout studies are needed to eliminate the possibility of tightly linked, non-pleiotropic loci. Here, we use a panel of 296 recombinant inbred advanced intercross lines of Caenorhabditis elegans and a high-throughput fitness assay to identify a single large-effect QTL on the center of chromosome V associated with variation in responses to eight chemotherapeutics. We validate this QTL with near-isogenic lines and pair genome-wide gene expression data with drug response traits to perform mediation analysis, leading to the identification of a pleiotropic candidate gene, scb-1, for some of the eight chemotherapeutics. Using deletion strains created by genome editing, we show that scb-1, which was previously implicated in response to bleomycin, also underlies responses to other double-strand DNA break-inducing chemotherapeutics. This finding provides new evidence for the role of scb-1 in the nematode drug response and highlights the power of mediation analysis to identify causal genes.
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Snoek BL, Sterken MG, Hartanto M, van Zuilichem AJ, Kammenga JE, de Ridder D, Nijveen H. WormQTL2: an interactive platform for systems genetics in Caenorhabditis elegans. Database (Oxford) 2020; 2020:baz149. [PMID: 31960906 PMCID: PMC6971878 DOI: 10.1093/database/baz149] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/30/2019] [Accepted: 12/13/2019] [Indexed: 12/19/2022]
Abstract
Quantitative genetics provides the tools for linking polymorphic loci to trait variation. Linkage analysis of gene expression is an established and widely applied method, leading to the identification of expression quantitative trait loci (eQTLs). (e)QTL detection facilitates the identification and understanding of the underlying molecular components and pathways, yet (e)QTL data access and mining often is a bottleneck. Here, we present WormQTL2, a database and platform for comparative investigations and meta-analyses of published (e)QTL data sets in the model nematode worm C. elegans. WormQTL2 integrates six eQTL studies spanning 11 conditions as well as over 1000 traits from 32 studies and allows experimental results to be compared, reused and extended upon to guide further experiments and conduct systems-genetic analyses. For example, one can easily screen a locus for specific cis-eQTLs that could be linked to variation in other traits, detect gene-by-environment interactions by comparing eQTLs under different conditions, or find correlations between QTL profiles of classical traits and gene expression. WormQTL2 makes data on natural variation in C. elegans and the identified QTLs interactively accessible, allowing studies beyond the original publications. Database URL: www.bioinformatics.nl/WormQTL2/.
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Affiliation(s)
- Basten L Snoek
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
- Theoretical Biology and Bioinformatics, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Mark G Sterken
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
| | - Margi Hartanto
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
| | - Albert-Jan van Zuilichem
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
| | - Jan E Kammenga
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
| | - Dick de Ridder
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
| | - Harm Nijveen
- Bioinformatics Group, Wageningen University, Droevendaalsesteeg 1, NL-6708 PB Wageningen, The Netherlands
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Shih PY, Lee JS, Shinya R, Kanzaki N, Pires-daSilva A, Badroos JM, Goetz E, Sapir A, Sternberg PW. Newly Identified Nematodes from Mono Lake Exhibit Extreme Arsenic Resistance. Curr Biol 2019; 29:3339-3344.e4. [PMID: 31564490 DOI: 10.1016/j.cub.2019.08.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/24/2019] [Accepted: 08/09/2019] [Indexed: 01/26/2023]
Abstract
Extremophiles have much to reveal about the biology of resilience, yet their study is limited by sampling and culturing difficulties [1-3]. The broad success and small size of nematodes make them advantageous for tackling these problems [4-6]. We investigated the arsenic-rich, alkaline, and hypersaline Mono Lake (CA, US) [7-9] for extremophile nematodes. Though Mono Lake has previously been described to contain only two animal species (brine shrimp and alkali flies) in its water and sediments [10], we report the discovery of eight nematode species from the lake, including microbe grazers, parasites, and predators. Thus, nematodes are the dominant animals of Mono Lake in species richness. Phylogenetic analysis suggests that the nematodes originated from multiple colonization events, which is striking, given the young history of extreme conditions at Mono Lake [7, 11]. One species, Auanema sp., is new, culturable, and survives 500 times the human lethal dose of arsenic. Comparisons to two non-extremophile sister species [12] reveal that arsenic resistance is a common feature of the genus and a preadaptive trait that likely allowed Auanema to inhabit Mono Lake. This preadaptation may be partly explained by a variant in the gene dbt-1 shared with some Caenorhabditis elegans natural populations and known to confer arsenic resistance [13]. Our findings expand Mono Lake's ecosystem from two known animal species to ten, and they provide a new system for studying arsenic resistance. The dominance of nematodes in Mono Lake and other extreme environments and our findings of preadaptation to arsenic raise the intriguing possibility that nematodes are widely pre-adapted to be extremophiles.
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Affiliation(s)
- Pei-Yin Shih
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
| | - James Siho Lee
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
| | - Ryoji Shinya
- Department of Agriculture, Meiji University and JST PRESTO, 1-1-1, Higashimita, Tama-ku, Kawasaki-shi, Kanagawa 214-8571, Japan
| | - Natsumi Kanzaki
- Kansai Research Center, Forestry and Forest Products Research Institute, 68 Nagaikyutaroh, Momoyama, Fushimi, Kyoto, Kyoto 612-0855, Japan
| | - Andre Pires-daSilva
- School of Life Sciences, University of Warwick, Gibbet Hill, Coventry CV4 7AL, UK
| | - Jean Marie Badroos
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Elizabeth Goetz
- Department of Biology and the Environment, Faculty of Natural Sciences, University of Haifa, Derch Kiryat Amal, Oranim, Tivon 3600600, Israel
| | - Amir Sapir
- Department of Biology and the Environment, Faculty of Natural Sciences, University of Haifa, Derch Kiryat Amal, Oranim, Tivon 3600600, Israel.
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA.
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40
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Brady SC, Zdraljevic S, Bisaga KW, Tanny RE, Cook DE, Lee D, Wang Y, Andersen EC. A Novel Gene Underlies Bleomycin-Response Variation in Caenorhabditis elegans. Genetics 2019; 212:1453-1468. [PMID: 31171655 PMCID: PMC6707474 DOI: 10.1534/genetics.119.302286] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Accepted: 05/30/2019] [Indexed: 12/14/2022] Open
Abstract
Bleomycin is a powerful chemotherapeutic drug used to treat a variety of cancers. However, individual patients vary in their responses to bleomycin. The identification of genetic differences that underlie this response variation could improve treatment outcomes by tailoring bleomycin dosages to each patient. We used the model organism Caenorhabditis elegans to identify genetic determinants of bleomycin-response differences by performing linkage mapping on recombinants derived from a cross between the laboratory strain (N2) and a wild strain (CB4856). This approach identified a small genomic region on chromosome V that underlies bleomycin-response variation. Using near-isogenic lines, and strains with CRISPR-Cas9 mediated deletions and allele replacements, we discovered that a novel nematode-specific gene (scb-1) is required for bleomycin resistance. Although the mechanism by which this gene causes variation in bleomycin responses is unknown, we suggest that a rare variant present in the CB4856 strain might cause differences in the potential stress-response function of scb-1 between the N2 and CB4856 strains, thereby leading to differences in bleomycin resistance.
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Affiliation(s)
- Shannon C Brady
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208
| | - Stefan Zdraljevic
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208
| | - Karol W Bisaga
- Weinberg College of Arts and Sciences, Northwestern University, Evanston, Illinois 60208
| | - Robyn E Tanny
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| | | | - Daehan Lee
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| | - Ye Wang
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
| | - Erik C Andersen
- Molecular Biosciences, Northwestern University, Evanston, Illinois 60208
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208
- Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, Illinois 60611
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Amino Acids Influencing Intestinal Development and Health of the Piglets. Animals (Basel) 2019; 9:ani9060302. [PMID: 31159180 PMCID: PMC6617173 DOI: 10.3390/ani9060302] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/25/2019] [Accepted: 05/28/2019] [Indexed: 12/16/2022] Open
Abstract
Simple Summary The health of piglets is an important issue in pig production. Nutritional support for intestinal development is a significant component of piglet care, and amino acids are essential for intestinal growth and development. For suckling piglets, the sows’ milk and the maternal environment shape the structure and support the function of the intestinal tract. The composition of milk affects intestinal morphology and the digestive, absorption and barrier function. After weaning, the optimal nutritional strategies of their diet are necessary to guarantee the piglets’ intestinal development and growth performance. Amino acids are the most important ingredient in piglet diets. The aim of this review is to collect and analyze the relationship between amino acid nutrition and intestinal development of piglets, and elucidate the impacts on piglet health. Abstract The amino acids and other components of diet provide nourishment for piglet intestinal development and maturation. However, early-weaned piglets struggle with tremendous stress, impairing normal intestinal health and leading to intestinal dysfunction and even death. The high prevalence worldwide of post-weaning diarrhoea syndrome (PWDS) in piglets has led to much interest in understanding the important role of nutrients in the establishment and maintenance of a functional intestinal tract. In particular, the impacts of amino acids on these functions must be considered. Amino acid levels greatly influence intestinal development in weaning piglets. The lack of amino acids can cause marked structural and functional changes in the intestine. Therefore, a comprehensive understanding of the functions of amino acids is necessary to optimize amino acid requirements of the developing intestinal tract to maximize piglet health and growth performance. This review summarizes the role of specific amino acids (arginine, glutamate, threonine, sulphur-containing amino acids (SCAAs), and branched-chain amino acids (BCAAs)) that have been proven to be beneficial for the intestinal health of weaned piglets.
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