Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping

Pinghui Liu; Qinsheng Chen; Lianglong Zhang; Chengcheng Ren; Biru Shi; Jingxian Zhang; Shuaiyao Wang; Ziliang Chen; Qi Wang; Hui Xie; Qingxia Huang; Huiru Tang

doi:10.52601/bpr.2023.230042

Volume 9 Issue 6

Dec. 2023

Turn off MathJax

Article Contents

Article Navigation > Biophysics Reports > 2023 > 9(6): 299-308

Pinghui Liu, Qinsheng Chen, Lianglong Zhang, Chengcheng Ren, Biru Shi, Jingxian Zhang, Shuaiyao Wang, Ziliang Chen, Qi Wang, Hui Xie, Qingxia Huang, Huiru Tang. Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping[J]. Biophysics Reports, 2023, 9(6): 299-308. doi: 10.52601/bpr.2023.230042

Citation:

Pinghui Liu, Qinsheng Chen, Lianglong Zhang, Chengcheng Ren, Biru Shi, Jingxian Zhang, Shuaiyao Wang, Ziliang Chen, Qi Wang, Hui Xie, Qingxia Huang, Huiru Tang. Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping[J]. Biophysics Reports, 2023, 9(6): 299-308. doi: 10.52601/bpr.2023.230042

Citation:

Pinghui Liu, Qinsheng Chen, Lianglong Zhang, Chengcheng Ren, Biru Shi, Jingxian Zhang, Shuaiyao Wang, Ziliang Chen, Qi Wang, Hui Xie, Qingxia Huang, Huiru Tang. Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping[J]. Biophysics Reports, 2023, 9(6): 299-308. doi: 10.52601/bpr.2023.230042

PDF (1740 KB)

Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping

doi: 10.52601/bpr.2023.230042

1.
State Key Laboratory of Genetic Engineering, School of Life Sciences, Human Phenome Institute, Zhangjiang Fudan International Innovation Center, Metabonomics and Systems Biology Laboratory at Shanghai International Centre for Molecular Phenomics, Zhongshan Hospital, Fudan University, Shanghai 200032, China
2.
Wuhan Laboratory for Shanghai Metabolome Institute (SMI) Ltd, Wuhan 430000, China

More Information

Corresponding author: xiehui@fudan.edu.cn (H. Xie); qingxhuang@fudan.edu.cn (Q. Huang); huiru_tang@fudan.edu.cn (H. Tang)
Received Date: 25 November 2023
Accepted Date: 15 December 2023

Available Online: 05 March 2024

Publish Date: 31 December 2023

Abstract

Abstract

Efficient quantification of fatty-acid (FA) composition (fatty-acidome) in biological samples is crucial for understanding physiology and pathophysiology in large population cohorts. Here, we report a rapid GC-FID/MS method for simultaneous quantification of all FAs in numerous biological matrices. Within eight minutes, this method enabled simultaneous quantification of 50 FAs as fatty-acid methyl esters (FAMEs) in femtomole levels following the efficient transformation of FAs in all lipids including FFAs, cholesterol-esters, glycerides, phospholipids and sphingolipids. The method showed satisfactory inter-day and intra-day precision, stability and linearity (R² > 0.994) within a concentration range of 2–3 orders of magnitude. FAs were then quantified in typical multiple biological matrices including human biofluids (urine, plasma) and cells, animal intestinal content and tissue samples. We also established a quantitative structure-retention relationship (QSRR) for analytes to accurately predict their retention time and aid their reliable identification. We further developed a novel no-additive retention index (NARI) with endogenous FAMEs reducing inter-batch variations to 15 seconds; such NARI performed better than the alkanes-based classical RI, making meta-analysis possible for data obtained from different batches and platforms. Collectively, this provides an inexpensive high-throughput analytical system for quantitative phenotyping of all FAs in 8-minutes multiple biological matrices in large cohort studies of pathophysiological effects.
- Fatty-acidomics,
- High-throughput quantification,
- Structure-retention relationship,
- No-additive retention index

Pinghui Liu, Qinsheng Chen, Lianglong Zhang, Chengcheng Ren, Biru Shi, Jingxian Zhang, Shuaiyao Wang, Ziliang Chen, Qi Wang, Hui Xie, Qingxia Huang, Huiru Tang declar that they have no conflict of interest.
Research involving human blood plasma and urine samples from Chinese adult volunteers, methods and data have been approved by the Ethic Committee of Fudan University (Approval No.: FE21087). All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Declaration of 1975, as revised in 2000 (5). Informed consent was obtained from all patients for being included in the study. Rabbit liver tissue and cecum contents of C57BL/6 mice was collected according to the procedures approved by Experimental Animal Ethics Committee, School of Pharmacy, Fudan University (Approval No.: 2018-03-YL-GW-01). All institutional and national guidelines for the care and use of laboratory animals were followed.
Pinghui Liu and Qinsheng Chen contributed equally to this work.

FullText(HTML)

References(68)

References

Agnew MP, Craigie CR, Weralupitiya G, Reis MM, Johnson PL, Reis MG (2019) Comprehensive evaluation of parameters affecting one-step method for quantitative analysis of fatty acids in meat. Metabolites 9(9): 189. https://doi.org/10.3390/metabo9090189

An Y, Xu W, Li H, Lei H, Zhang L, Hao F, Duan Y, Yan X, Zhao Y, Wu J, Wang Y, Tang H (2013) High-fat diet induces dynamic metabolic alterations in multiple biological matrices of rats. J Proteome Res 12(8): 3755−3768 doi: 10.1021/pr400398b

Bazinet RP, Layé S (2014) Polyunsaturated fatty acids and their metabolites in brain function and disease. Nat Rev Neurosci 15(12): 771−785 doi: 10.1038/nrn3820

Bondia-Pons I, Moltó-Puigmartí C, Castellote AI, López-Sabater MC (2007) Determination of conjugated linoleic acid in human plasma by fast gas chromatography. J Chromatogr A 1157(1-2): 422−429 doi: 10.1016/j.chroma.2007.05.020

Cai J, Zhang J, Tian Y, Zhang L, Hatzakis E, Krausz KW, Smith PB, Gonzalez FJ, Patterson AD (2017) Orthogonal comparison of GC-MS and ¹H NMR spectroscopy for short chain fatty acid quantitation. Anal Chem 89(15): 7900−7906 doi: 10.1021/acs.analchem.7b00848

Cecatto C, Amaral AU, Wajner A, Wajner SM, Castilho RF, Wajner M (2020) Disturbance of mitochondrial functions associated with permeability transition pore opening induced by cis-5-tetradecenoic and myristic acids in liver of adolescent rats. Mitochondrion 50: 1−13 doi: 10.1016/j.mito.2019.09.008

Chen J, Dan L, Tu X, Sun Y, Deng M, Chen X, Hesketh T, Li R, Wang X, Li X (2023) Metabolic dysfunction-associated fatty liver disease and liver function markers are associated with Crohn's disease but not Ulcerative Colitis: a prospective cohort study. Hepatol Int 17(1): 202−214 doi: 10.1007/s12072-022-10424-6

Chen Q, Lu Q, Zhang L, Zhang C, Zhang J, Gu Y, Huang Q, Tang H (2024) A novel endogenous retention-index for minimizing retention-time variations in metabolomic analysis with reversed-phase ultrahigh-performance liquid-chromatography and mass spectrometry. Talanta 268(Pt 1): 125318. https://doi.org/10.1016/j.talanta.2023.125318

Chen YM, Zheng Y, Yu Y, Wang Y, Huang Q, Qian F, Sun L, Song ZG, Chen Z, Feng J, An Y, Yang J, Su Z, Sun S, Dai F, Chen Q, Lu Q, Li P, Ling Y, Yang Z, Tang H, Shi L, Jin L, Holmes EC, Ding C, Zhu TY, Zhang YZ (2020) Blood molecular markers associated with COVID-19 immunopathology and multi-organ damage. EMBO J 39(24): e105896. https://doi.org/10.15252/embj.2020105896

Chiu HH, Kuo CH (2020) Gas chromatography-mass spectrometry-based analytical strategies for fatty acid analysis in biological samples. J Food Drug Anal 28(1): 60−73 doi: 10.1016/j.jfda.2019.10.003

Chu PN, Chu FF, Zhang Y, Wu C, Zeng RJ (2015) A robust direct-transesterification method for microalgae. Energy Sources Part A 37(23): 2583−2590 doi: 10.1080/15567036.2012.733481

Coon AM, Setzen G, Musah RA (2023) Mass spectrometric interrogation of earwax: toward the detection of Ménière's disease. ACS Omega 8(30): 27010−27023 doi: 10.1021/acsomega.3c01943

Dai X, Hou H, Zhang W, Liu T, Li Y, Wang S, Wang B, Cao H (2020) Microbial metabolites: critical regulators in NAFLD. Front Microbiol 11: 567654. https://doi.org/10.3389/fmicb.2020.567654

Dalile B, Van Oudenhove L, Vervliet B, Verbeke K (2019) The role of short-chain fatty acids in microbiota-gut-brain communication. Nat Rev Gastroenterol hepatolo 16(8): 461−478 doi: 10.1038/s41575-019-0157-3

Ecker J, Scherer M, Schmitz G, Liebisch G (2012) A rapid GC-MS method for quantification of positional and geometric isomers of fatty acid methyl esters. J Chromatogr B Analyt Technol Biomed Life Sci 897: 98−104 doi: 10.1016/j.jchromb.2012.04.015

Fahy E, Subramaniam S, Brown HA, Glass CK, Merrill AH, Jr., Murphy RC, Raetz CR, Russell DW, Seyama Y, Shaw W, Shimizu T, Spener F, van Meer G, VanNieuwenhze MS, White SH, Witztum JL, Dennis EA (2005) A comprehensive classification system for lipids. J Lipid Res 46(5): 839−861 doi: 10.1194/jlr.E400004-JLR200

Frampton J, Murphy KG, Frost G, Chambers ES (2020) Short-chain fatty acids as potential regulators of skeletal muscle metabolism and function. Nat Metab 2(9): 840−848 doi: 10.1038/s42255-020-0188-7

Gao X, Pujos-Guillot E, Martin JF, Galan P, Juste C, Jia W, Sebedio JL (2009) Metabolite analysis of human fecal water by gas chromatography/mass spectrometry with ethyl chloroformate derivatization. Anal Biochem 393(2): 163−175 doi: 10.1016/j.ab.2009.06.036

Garlito B, Portolés T, Niessen WMA, Navarro JC, Hontoria F, Monroig Ó, Varó I, Serrano R (2019) Identification of very long-chain (>C24) fatty acid methyl esters using gas chromatography coupled to quadrupole/time-of-flight mass spectrometry with atmospheric pressure chemical ionization source. Anal Chim Acta 1051: 103−109 doi: 10.1016/j.aca.2018.11.001

Glaser C, Demmelmair H, Koletzko B (2010) High-throughput analysis of fatty acid composition of plasma glycerophospholipids. J Lipid Res 51(1): 216−221 doi: 10.1194/jlr.D000547

Goyal A, Dubey N, Verma A, Agrawal A (2023) Erucic acid: a possible therapeutic agent for neurodegenerative diseases. Curr Mol Med.

Han J, Lin K, Sequeira C, Borchers CH (2015) An isotope-labeled chemical derivatization method for the quantitation of short-chain fatty acids in human feces by liquid chromatography-tandem mass spectrometry. Anal Chim Acta 854: 86−94 doi: 10.1016/j.aca.2014.11.015

Han LD, Xia JF, Liang QL, Wang Y, Wang YM, Hu P, Li P, Luo GA (2011) Plasma esterified and non-esterified fatty acids metabolic profiling using gas chromatography-mass spectrometry and its application in the study of diabetic mellitus and diabetic nephropathy. Anal Chim Acta 689(1): 85−91 doi: 10.1016/j.aca.2011.01.034

Han X (2016) Lipidomics for studying metabolism. Nat Rev Endocrinol 12(11): 668−679 doi: 10.1038/nrendo.2016.98

Héberger K (2007) Quantitative structure-(chromatographic) retention relationships. J Chromatogr A 1158(1-2): 273−305 doi: 10.1016/j.chroma.2007.03.108

Hellmuth C, Weber M, Koletzko B, Peissner W (2012) Nonesterified fatty acid determination for functional lipidomics: comprehensive ultrahigh performance liquid chromatography-tandem mass spectrometry quantitation, qualification, and parameter prediction. Anal Chem 84(3): 1483−1490 doi: 10.1021/ac202602u

Hu Q, Sun Y, Yuan P, Lei H, Zhong H, Wang Y, Tang H (2022) Quantitative structure-retention relationship for reliable metabolite identification and quantification in metabolomics using ion-pair reversed-phase chromatography coupled with tandem mass spectrometry. Talanta 238(2): 123059. https://doi.org/10.1016/j.talanta.2021.123059

Huang Q, Lei H, Dong M, Tang H, Wang Y (2019a) Quantitative analysis of 10 classes of phospholipids by ultrahigh-performance liquid chromatography tandem triple-quadrupole mass spectrometry. Analyst 144(13): 3980−3987 doi: 10.1039/C9AN00676A

Huang WW, Hong BH, Sun JP, Tan R, Bai KK, Yang T, Wu H, Yi RZ (2019b) Comparing the simultaneous determination of cis- and trans-palmitoleic acid in fish oil using HPLC and GC. Lipids Health Dis 18(1): 86. https://doi.org/10.1186/s12944-019-1033-4

Hummasti S, Hotamisligil GS (2010) Endoplasmic reticulum stress and inflammation in obesity and diabetes. Circ Res 107(5): 579−591 doi: 10.1161/CIRCRESAHA.110.225698

Ichihara K, Fukubayashi Y (2010) Preparation of fatty acid methyl esters for gas-liquid chromatography. J Lipid Res 51(3): 635−640 doi: 10.1194/jlr.D001065

Jiang R, Jiao Y, Zhang P, Liu Y, Wang X, Huang Y, Zhang Z, Xu F (2017) Twin derivatization strategy for high-coverage quantification of free fatty acids by liquid chromatography-tandem mass spectrometry. Anal Chem 89(22): 12223−12230 doi: 10.1021/acs.analchem.7b03020

Kaliszan R (2007) QSRR: quantitative structure-(chromatographic) retention relationships. Chem Rev 107(7): 3212−3246 doi: 10.1021/cr068412z

Kim CH (2018) Microbiota or short-chain fatty acids: which regulates diabetes? Cell Mol Immunol 15(2): 88−91

Kovats E (1958) Gas chromatographic characterization of organic compounds, I. retention indices of aliphatic halides, alcohols, aldehydes and ketones. Helv Chim Acta 3(41): 1915−1932

Lepage G, Roy CC (1986) Direct transesterification of all classes of lipids in a one-step reaction. J Lipid Res 27(1): 114−120 doi: 10.1016/S0022-2275(20)38861-1

Li D, Zhang L, Dong F, Liu Y, Li N, Li H, Lei H, Hao F, Wang Y, Zhu Y, Tang H (2015a) Metabonomic changes associated with atherosclerosis progression for LDLR^-/- mice. J Proteome Res 14(5): 2237−2254 doi: 10.1021/acs.jproteome.5b00032

Li J, Huang Q, Wang Y, Cui M, Xu K, Suo C, Liu Z, An Y, Jin L, Tang H, Chen X, Jiang Y (2023a) Circulating lipoproteins mediate the association between cardiovascular risk factors and cognitive decline: a community-based cohort study. Phenomics. https://doi.org/10.1007/s43657-023-00120-2

Li L, Zang Q, Li X, Zhu Y, Wen S, He J, Zhang R, Abliz Z (2023b) Spatiotemporal pharmacometabolomics based on ambient mass spectrometry imaging to evaluate the metabolism and hepatotoxicity of amiodarone in HepG2 spheroids. J Pharm Anal 13(5): 483−493 doi: 10.1016/j.jpha.2023.04.007

Li Y, Xu S, Zhang X, Yi Z, Cichello S (2015b) Skeletal intramyocellular lipid metabolism and insulin resistance. Biophys Rep 1: 90−98 doi: 10.1007/s41048-015-0013-0

Lin PY, Huang SY, Su KP (2010) A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression. Biol Psychiatry 68(2): 140−147 doi: 10.1016/j.biopsych.2010.03.018

Liu Z, Ezernieks V, Rochfort S, Cocks B (2018) Comparison of methylation methods for fatty acid analysis of milk fat. Food Chem 261: 210−215 doi: 10.1016/j.foodchem.2018.04.053

Loo RL, Lu Q, Carter EM, Liu S, Clark S, Wang Y, Baumgartner J, Tang H, Chan Q (2021) A feasibility study of metabolic phenotyping of dried blood spot specimens in rural Chinese women exposed to household air pollution. J Expo Sci Environ Epidemiol 31(2): 328−344 doi: 10.1038/s41370-020-0252-0

Lopaschuk GD, Ussher JR, Folmes CD, Jaswal JS, Stanley WC (2010) Myocardial fatty acid metabolism in health and disease. Physiol Rev 90(1): 207−258 doi: 10.1152/physrev.00015.2009

Losito I, Facchini L, Valentini A, Cataldi TRI, Palmisano F (2018) Fatty acidomics: Evaluation of the effects of thermal treatments on commercial mussels through an extended characterization of their free fatty acids by liquid chromatography - Fourier transform mass spectrometry. Food Chem 255: 309−322 doi: 10.1016/j.foodchem.2018.02.073

Masood A, Stark KD, Salem N, Jr. (2005) A simplified and efficient method for the analysis of fatty acid methyl esters suitable for large clinical studies. J Lipid Res 46(10): 2299−2305 doi: 10.1194/jlr.D500022-JLR200

Mattarozzi M, Riboni N, Maffini M, Scarpella S, Bianchi F, Careri M (2021) Reversed-phase and weak anion-exchange mixed-mode stationary phase for fast separation of medium-, long- and very long chain free fatty acids by ultra-high-performance liquid chromatography-high resolution mass spectrometry. J Chromatogr A 1648: 462209. https://doi.org/10.1016/j.chroma.2021.462209

Nicholson JK (2021) Molecular phenomic approaches to deconvolving the systemic effects of SARS-CoV-2 infection and post-acute COVID-19 syndrome. Phenomics 1(4): 143−150 doi: 10.1007/s43657-021-00020-3

Ostermann AI, Müller M, Willenberg I, Schebb NH (2014) Determining the fatty acid composition in plasma and tissues as fatty acid methyl esters using gas chromatography – a comparison of different derivatization and extraction procedures. Prostaglandins, Leukot Essen Fatty Acids 91(6): 235−241 doi: 10.1016/j.plefa.2014.10.002

Ovčačíková M, Lísa M, Cífková E, Holčapek M (2016) Retention behavior of lipids in reversed-phase ultrahigh-performance liquid chromatography-electrospray ionization mass spectrometry. J Chromatogr A 1450: 76−85 doi: 10.1016/j.chroma.2016.04.082

Röhrig F, Schulze A (2016) The multifaceted roles of fatty acid synthesis in cancer. Nat Rev Cancer 16(11): 732−749 doi: 10.1038/nrc.2016.89

Romero LO, Massey AE, Mata-Daboin AD, Sierra-Valdez FJ, Chauhan SC, Cordero-Morales JF, Vásquez V (2019) Dietary fatty acids fine-tune Piezo1 mechanical response. Nat Commun 10(1): 1200. https://doi.org/10.1038/s41467-019-09055-7

Tremblay-Franco M, Zerbinati C, Pacelli A, Palmaccio G, Lubrano C, Ducheix S, Guillou H, Iuliano L (2015) Effect of obesity and metabolic syndrome on plasma oxysterols and fatty acids in human. Steroids 99(Pt B): 287−292 doi.org/10.1016/j.steroids.2015.03.019

Vu N, Narvaez-Rivas M, Chen GY, Rewers MJ, Zhang Q (2019) Accurate mass and retention time library of serum lipids for type 1 diabetes research. Anal Bioanal Chem 411(23): 5937−5949 doi: 10.1007/s00216-019-01997-7

Wall R, Ross RP, Fitzgerald GF, Stanton C (2010) Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids. Nutr Rev 68(5): 280−289 doi: 10.1111/j.1753-4887.2010.00287.x

Wang M, Han RH, Han X (2013) Fatty acidomics: global analysis of lipid species containing a carboxyl group with a charge-remote fragmentation-assisted approach. Anal Chem 85(19): 9312−9320 doi: 10.1021/ac402078p

Wang Z, Chen Z, Zhang L, Wang X, Hao G, Zhang Z, Shao L, Tian Y, Dong Y, Zheng C, Wang J, Zhu M, Weintraub WS, Gao R (2018) Status of hypertension in China: results from the China hypertension survey, 2012-2015. Circulation 137(22): 2344−2356 doi: 10.1161/CIRCULATIONAHA.117.032380

Wu D, Zhang Y, Dong S, Zhong C (2021a) Mutual interaction of microbiota and host immunity during health and diseases. Biophys Rep 7(4): 326−340 doi: 10.52601/bpr.2021.200045

Wu Q, Huang QX, Zeng HL, Ma S, Lin HD, Xia MF, Tang HR, Gao X (2021b) Prediction of metabolic disorders using NMR-based metabolomics: the Shanghai Changfeng study. Phenomics 1(4): 186−198 doi: 10.1007/s43657-021-00021-2

Xia F, Feng R, Xu FG, Su H, He C, Hu YJ, Wan JB (2019) Quantification of phospholipid fatty acids by chemical isotope labeling coupled with atmospheric pressure gas chromatography quadrupole- time-of-flight mass spectrometry (APGC/Q-TOF MS). Anal Chim Acta 1082: 86−97 doi: 10.1016/j.aca.2019.06.065

Xia M, Ma S, Huang Q, Zeng H, Ge J, Xu W, Wu Q, Wu L, Li X, Ma H, Chen L, Li Q, Aleteng Q, Hu Y, He W, Pan B, Lin H, Zheng Y, Wang S, Tang H, Gao X (2022) NAFLD-related gene polymorphisms and all-cause and cause-specific mortality in an Asian population: the Shanghai Changfeng Study. Aliment Pharmacol Ther 55(6): 705−721 doi: 10.1111/apt.16772

Xia M, Zeng H, Wang S, Tang H, Gao X (2021) Insights into contribution of genetic variants towards the susceptibility of MAFLD revealed by the NMR-based lipoprotein profiling. J Hepatol 74(4): 974−977 doi: 10.1016/j.jhep.2020.10.019

Xu Z, Harvey K, Pavlina T, Dutot G, Zaloga G, Siddiqui R (2010) An improved method for determining medium- and long-chain FAMEs using gas chromatography. Lipids 45(2): 199−208 doi: 10.1007/s11745-009-3382-7

Zhang H, Wang Z, Liu O (2015) Development and validation of a GC-FID method for quantitative analysis of oleic acid and related fatty acids. J Pharm Anal 5(4): 223−230 doi: 10.1016/j.jpha.2015.01.005

Zhang J, Chen Q, Zhang L, Shi B, Yu M, Huang Q, Tang H (2024) Simultaneously quantifying hundreds of acylcarnitines in multiple biological matrices within ten minutes using ultrahigh-performance liquid-chromatography and tandem mass spectrometry. J Pharm Anal 14(1): 140−148 doi: 10.1016/j.jpha.2023.10.004

Zhang S, Zhao J, Xie F, He H, Johnston LJ, Dai X, Wu C, Ma X (2021) Dietary fiber-derived short-chain fatty acids: a potential therapeutic target to alleviate obesity-related nonalcoholic fatty liver disease. Obes Rev 22(11): e13316. https://doi.org/10.1111/obr.13316

Zhao L, Ni Y, Su M, Li H, Dong F, Chen W, Wei R, Zhang L, Guiraud SP, Martin FP, Rajani C, Xie G, Jia W (2017) High throughput and quantitative measurement of microbial metabolome by gas chromatography/mass spectrometry using automated alkyl ahloroformate derivatization. Anal Chem 89(10): 5565−5577 doi: 10.1021/acs.analchem.7b00660

Zhu Z, Han Z, Halabelian L, Yang X, Ding J, Zhang N, Ngo L, Song J, Zeng H, He M, Zhao Y, Arrowsmith CH, Luo M, Bartlett MG, Zheng YG (2021) Identification of lysine isobutyrylation as a new histone modification mark. Nucleic Acids Res 49(1): 177−189 doi: 10.1093/nar/gkaa1176

Supplements(1)