MetaboLightsapplication/xmlftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/m_MTBLS15431_MSImaging_positive__v2_maf.tsvftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/m_MTBLS15431_MSImaging_negative__v2_maf.tsvftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/a_MTBLS15431_MSImaging_positive_.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/i_Investigation.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/s_MTBLS15431.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/a_MTBLS15431_MSImaging_negative_.txtftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240514-2-2-2-pos.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240517-2-2-2-neg.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240516-8-2-2-2-pos-50um.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240516-4-2-2-pos-50um.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240516-8-2-3-2-pos-50um.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240517-4-2-2-neg.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240517-8-2-2-2-neg.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240515-8-2-4-2-pos.raw.zipftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431/FILES/RAW_FILES/snjin-240517-8-2-3-2-neg.raw.zipprimary200OKftp://ftp.ebi.ac.uk/pub/databases/metabolights/studies/public/MTBLS15431<p>The results from four scans in the negative mode and five scans in the positive mode were imported into Cardinal for processing, including the background removal, peak alignment, and peak selection. The metabolites were annotated against LuMet-Space version 1.0 using PySM and mass2adduct strategies.</p>MetaboLightsPublicMS Imaging - positiveMS Imaging - negativeA multilamellar organelle for chemosymbiosis in an aplacophoran mollusc adapted to anoxic cold seep sediment. 10.1101/2025.01.16.633305.Yunlong LiOcean University of ChinaPosteriorAnteriorMiddlemass spectrometry assayChaetoderma shenloonghttps://www.ebi.ac.uk/metabolights/MTBLS15431Jin Sun. Ocean University of China. jin_sun@ouc.edu.cn.Li Yunlong. Ocean University. China. ylify@connect.ust.hk. 0.<p>The .raw outputs were transformed into .imzML files using HDI version 1.6.</p>Specimen partylify@connect.ust.hk<p>Eight individuals of Chaetoderma shenloong were collected from Haima methane seep in the South China Sea using a 50 cm long push-core mounted on the remotely operated vehicle (ROV) Pioneer on the research vessel (R/V) Xiangyanghong 01 of the First Institute of Oceanography, Ministry of Natural Resources (MNR), China, September 2022. The sample were flash-frozen in liquid nitrogen in 15ml tubes and then stored at -80°C</p>Metabolomics<p>This work did not have any histological identification. It was based in HE staining.</p><p>The flash-frozen samples were used in analysing the spatial patterns of metabolites in C. shenloong, focusing on the symbiotic digestive gland and the interactions between symbiont and host. A whole individual of C. shenloong was divided into 10 parts from anterior (No.1) to posterior (No. 10) on dry ice while still frozen. Among them, three parts with the symbiotic organ were selected to represent the different sections, including No.2 (around the neck), No.4 (middle of trunk), and No.8 (close to the posterior). After mild thawing, these tissue parts were slowly placed into the optimal cutting temperature (OCT) compound (Cat. 4583, SAKURA) in the mould while carefully avoiding bubbles. Then, the moulds were quickly frozen with the help of dry-ice and transferred to a freezer at -80°C until ready for sectioning. Before tissue sectioning using a cryostat (CM1950, Leica), the embedded tissue blocks were moved to a cryostat chamber for 20 min for the equilibration of temperature. The thickness of the section was set as 20 μm and the sections were mounted onto coated slides.</p>MetabolomicschemosymbiosisChaetoderma shenloonguntargeted analysisdesorption electrospray ionizationspatial metabolomicsMass spectrometry imagingAnteriorMiddleexperimental sampleInvertebrates, Marinehost–microbe symbiosisPosteriorWaters SELECT SERIES MRTDESI_MSI_negativeWatersMetabolomicschemosymbiosisChaetoderma shenloonguntargeted analysisdesorption electrospray ionizationspatial metabolomicsMass spectrometry imagingAnteriorMiddleexperimental sampleInvertebrates, Marinehost–microbe symbiosisPosteriorWaters SELECT SERIES MRTDESI_MSI_negativeWaters<p>The DESI-MSI analysis was performed on a SELECT SERIES@ MRT high mass resolution mass spectrometer (Waters) equipped with DESI XS source. General acquisition parameters were: positive and negative; MS acquisition rate: 0.5 s; source sprayer voltage: 0.5 kV; sampling cone voltage: 50 V; source temperature: 120°C; source sprayer gas pressure: 0.08 Mpa; DESI solvent: 98:2 methanol/water; DESI solvent flow rate: 1.8 µl/min. Pixel sizes: 50 μm. Data was acquired using Masslynx software version 4.2.</p>SkimminDG(42:10)FAHFA(16:0/5-O-18:0)Soyacerebroside IDeoxyriboseDG(44:5)Cyclo(L-prolyl-L-valyl)Zalypsis1,2-Ethanedisulfonic acidFtivazideFluoro 2,2-difluoroacetate3-Oxododecanoyl-CoAErythrosineTandutinibTG(55:8)PG(38:6)Trifluoroacetic acidFAHFA(18:1(9Z)/5-O-18:0)PC(33:0)CardanolmonoeneGinkgoic acidDakh peptidegamma-Glutamyl-beta-cyanoalanine9,10-Epoxyoctadecanoic acidAuxin aLactariamide B15(S)-Hydroxyeicosatrienoic acidCer(t18:0/16:0)LucyobrosidePC(44:2)(E)-2-Cyano-3-(4-hydroxy-3,5-diisopropylphenyl)-N-(3-phenylpropyl)acrylamidePenilloic acidTetranorprostanedioic acidPZ-PeptideErythrinasinate ACebranopadolSar chelateCitrusin IAnnotemoyin 1Psma-hbed-CC3,7R,11R,15-tetramethyl-hexadecanoic acid3-[(3-(2-Carboxyethyl)-4-methylpyrrol-2-YL)methylene]-2-indolinoneN1-AcetylspermidineTG(57:3)PG(38:5)TG(50:8)Pentafluorobenzoyl acetatePteroyltriglutamic acidAzapropazoneCyclohexaneundecanoic acidPsychosine sulfateStanolone enanthateTG(54:11)Licorice glycoside EPE(36:3)OryzarolN-MethylglucosamineTG(56:7)FA(12:0)2-Isopropyl-3,5-dimethoxy-6-methylpyrazineTG(57:4)BremelanotideArginylglutamineGeraniolDG(33:1)Devd-amcDiaminopimelic acidGlutaminylproline(D-Pen2,D-Pen5)-EnkephalinEthametsulfuron-methyl3-oxo-dodecanoyl-CoAPA(39:0)Diethylaminoethyl-dextran1-PentadeceneDihydrozeatin-9-N-glucoside-O-glucosideSolutol HS 15NitrocelluloseLPE(18:1)2-Methyl-3-furyl methylthiomethyl disulfideSM(41:2)DG(38:3)L-alpha-Amino-1H-pyrrole-1-hexanoic acid(2S)-2-amino-4-{[(1R)-1-[(carboxymethyl)carbamoyl]-2-[(hydroxymethyl)sulfanyl]ethyl]carbamoyl}butanoyl-CoATenocyclidineTG(56:8)4,8 Dimethylnonanoyl carnitine[3H]RosiglitazoneUndecanoylcarnitineN5-(4-Methoxybenzyl)glutamine5-[[5-[[5-(Pyrrol-2-ylidenemethyl)pyrrol-2-ylidene]methyl]-1H-pyrrol-2-yl]methylidene]pyrrole-2-carboxylic acidPA(33:1)2,3,5,6-Tetrafluorobenzenethiol1-[(2S,3R,4S,5R)-3,4-Dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-4-imino-3-methylpyrimidin-2-one1,3-Dihydroxypropan-2-yl oleateDiethylhexyl adipate(R)-2,3-Dihydroxy-isovalerateN-Eicosapentaenoyl GlycineFA 15 (antioxidant)PosatirelinFAHFA(16:1(9Z)/8-O-18:0)PentafluorophenylhydrazineFAHFA(16:0/7-O-18:0)Prostaglandin C1FA(18:1)SM d36:2N-[(4E,8E)-1,3-dihydroxyoctadeca-4,8-dien-2-yl]hexadecanamideAraloside AdUDPTerbutryn(E)-7-PentadecenemebeverineIsoestragoleGermacrane6-Ketomyristic acidRisperidoneDG(32:2)Hexadecanedioic acid(3b,5a,6b,22a,25R)-Furostane-22-methoxy-3,6,26-triol 3-[glucosyl-(1->2)-[xylosyl-(1->3)]-glucosyl-(1->4)-galactoside] 26-glucosideElsamitrucin9,10-Dihydroxystearic acid6-(1,2,3,4-Tetrahydroxybutyl)oxane-2,3,4,5-tetrolFA(18:2)(9S,10S)-9,10-dihydroxyoctadecanoatethienylcyclohexylpiperidineIsolampranthin IIAprindineMahalebosideepsilon-(gamma-Glutamyl)lysineSM(d18:2(4E,14Z)/18:0)L-Prolinamide, glycyl-L-prolyl-L-arginyl-DG(37:4)1-Isopropyl-2,3-dimethylcyclopentane1-[3-(Trifluoromethyl)phenyl]piperazinePE(24:0)NetupitantTG(53:3)FAHFA(16:1(9Z)/5-O-18:0)Eicosanedioic acidPiromidic acid8,8-Diethoxy-2,6-dimethyl-2-octanol6,10,14-Trimethyl-2-methylenepentadecanalSM D41:2Lysylglutamic acidLysosulfatide4-Hydroxytamoxifen-O-glucuronideProstaglandin A1ErgosineN8-AcetylspermidineAvocadyneCL(70:6)4,6-NonadecanedioneCytarabinePhosphatidate(42:5)TigloidinePolypropyleneGlutaminylarginineTG(53:4)5-O-[2-(4-Benzhydrylpiperazin-1-yl)ethyl] 3-O-methyl 2,6-dimethyl-4-(3-nitrophenyl)-3,4-dihydropyridine-3,5-dicarboxylateGanglioside GT3 (d44:0)CL(8:0/18:2(9Z,11Z)/18:2(9Z,11Z)/i-24:0)4-Hydroxybenzyl isothiocyanate rhamnosidePE(36:0)(E)-3-Hydroxy Tamoxifen O-|A-D-GlucuronideProstaglandin B1FA(19:1)Threonic acidUric acid5-Cholesten-3beta-25-diol-3-sulfateTG(57:9)2,2'-Azobis(2-amidinopropane)Sphingomyelin(D44:1)PI(38:5)PS(40:4)PeregrineTG(52:8)beta-Casomorphin-7PC(35:5)20-Carboxy-leukotriene B4N-[1-Hydroxy-3-(morpholin-4-yl)-1-phenylpropan-2-yl]hexadecanamideCorchorifatty acid FGranatin BFinasterideTG(47:5)2-O-Methyl-L-fucoseFA(20:1)1alpha,3beta,22R-Trihydroxyergosta-5,24E-dien-26-oic acid 3-O-b-D-glucoside 26-O-[b-D-glucosyl-(1->4)-b-D-glucosyl-(1->2)-6-acetyl-b-D-glucosyl] esterPregnan-20-oneCortoloneMethylenediphosphonic acidPA(37:1)3,4-Dimethyl-5-pentyl-2-furanundecanoic acidFA(9:0)SM(d18:2(4E,14Z)/23:0)MetoclopramideDavercinCer(d18:2(4E,14Z)/16:0)5-Sulfo-1,3-benzenedicarboxylic acidMethyl 16-hydroxyhexadecanoateNeogitogenin 3-[glucosyl-(1->2)-glucosyl-(1->4)-galactoside]PA(42:5)Durupcoside B6-HydroxysandoricinDurupcoside A16-Hydroxyhexadecanoic acidCitronellic acidTaurine lactateGeraniinFolcepriMcp-tva-argipressinPhytanic acid3-Formyl RifamycinEnkephalin LPA(49:0)Arginyl-Gamma-glutamatePhylloquinolDG(31:1)DG(36:2)RandilonginZ-Gly-Gly-Arg-AMC(S)-10,16-Dihydroxyhexadecanoic acid2-TetradecylglycidateTG(47:4)Arachisprenol 12AS 1-29,12,13-TriHOMEIsopentyl isopentanoateSM(d36:2)FA(20:0)D-erythro-L-galacto-NonuloseSM(d18:2(4E,14Z)/24:2(5Z,9Z))4-(4-Amino-2,3-dichlorophenyl)-5,6-dichlorobenzene-1,2,3-triamineEtheno adenosine triphosphateProlyl-Gamma-glutamate(Tyr4,D-Phe12)-BombesinTG(53:7)Prometryn2,3,4-Trihydroxybutanoic acidVPGPR EnterostatinDG(37:0)Semilepidinoside BBovinic acidFAHFA(16:0/7-O-16:0)L-Menthyl (R,S)-3-hydroxybutyrate5-Methylcytidine2,2'-Azobis(amidinopropane)FAHFA(16:1(9Z)/7-O-18:0)(9R,10S,12Z)-9,10-Dihydroxy-8-oxo-12-octadecenoic acidPhenylalanylthreonineCoffeastereneEthylphosphatePE(28:1)Disialyllacto-N-tetraose[(2S,3R)-3-Hydroxy-2-[[(5E,8E,11E,14E)-tetracosa-5,8,11,14-tetraenoyl]amino]octadecyl] 2-(trimethylazaniumyl)ethyl phosphateCastor oilTetrahydrocortisolCheritamineAngiotensinogenTG(60:11)PE(46:0)2-Decaprenyl-6-methoxy-1,4-benzoquinoneTG(46:5)SM(d42:0)5alpha-AndrostaneCasomorphin(R)-CitronellalDG(46:4)Ustiloxin BGedatolisibStearoyllactic acid3-Decaprenyl-4-hydroxybenzoic acid2-Nitrophenyl octyl etherIODODIFLUNISAL1,2-Dioleoyl-rac-glycerol8-Methylnonenoate1-(1,2,3,4,5-Pentahydroxypent-1-yl)-1,2,3,4-tetrahydro-beta-carboline-3-carboxylate10-Acetoxy-10,11-dihydro-5h-dibenz[b,f]azepine-5-carboxamideDG(44:10)9E-Heptadecenoic acidParomomycin3,4-Dimethyl-5-propyl-2-furantridecanoic acid1-Phenyl-4-(trifluoromethyl)piperazine11-Mercapto-1-undecanolSM(d44:1)Benzenemethanol, 4-(1-(3,4-bis(difluoromethoxy)phenyl)-2-(3-methyl-1-oxido-4-pyridinyl)ethyl)-alpha,alpha-bis(trifluoromethyl)-QuinestrolPunicalaginPE(20:2)PC(22:2)3,4-Dimethyl-5-propyl-2-furanundecanoic acidmanidipineCarotaminePanatellinDeoxycholyltyrosineMG(20:4)(D-Ala1)-Peptide TFAHFA(16:0/8-O-16:0)FA(10:0)TG(59:8)OmapatrilatDG(35:1)3-(all-trans-octaprenyl)benzene-1,2-diolTG(36:0)Benzoylstaurosporinesorbitol lactateOctacosyl ferulate3-Dodecyloxypropane-1,2-diolFA(20:4)4-{[1,3-Bis(hexadecanoyloxy)propan-2-yl]oxy}-4-oxobutanoic acidTrigoneoside XIIIap-MenthaneHouttuyninPE(32:2)TG(46:3)Selenohomocystine1-Deoxy-D-xyluloseCytidine7-(3,5-Dimethyl-1,2-Oxazol-4-Yl)-6-Methoxy-2-Methyl-4-(Quinolin-4-Yl)-9h-Pyrimido[4,5-B]indole3,4-Dimethyl-5-pentyl-2-furannonanoic acidCL(11:0/18:2(9Z,11Z)/18:2(9Z,11Z)/a-21:0)(-)-ArctigeninTriricinolein1,2-Dipalmitoyl-3-succinylglycerolLyciumin DGlutamyllysineGanglioside GM3 (d34:1)TG(60:10)Diethylene glycol distearate3-(2-Heptenyloxy)-2-hydroxypropyl undecanoateFAHFA(16:0/5-O-16:0)FenamiphosChenodeoxycholyltyrosineAzobis(2 amidinopropane)(2r,3r,5s,6r)-2,6-Bis(hydroxymethyl)piperidine-3,4,5-triolPS(42:7)3-Oxotetradecanoic acid(2S,3R,4S,5R,6R)-6-Ethyloxane-2,3,4,5-tetrolSanguiin H11ThreonylphenylalanineSulfatide (D36:2)Prolyl-Glutamine12-hydroxyheptadecanoic acid9,10-Epoxystearic acidDodecylglycerolOctadecyl fumarateGoyaglycoside gLumequoylacetoneAlpha-Hydroxy-tamoxifen-O-glucuronideOctadecaneuropeptideNeoacrimarine BAvocadene(2S)-1-(6-Chloro-5-fluoroindol-1-yl)propan-2-amineCyclopassifloside VIIEthyl octanoatePA(35:0)Docosanedioic acidPyro-L-glutaminyl-L-glutamineButylcyclohexaneArmillaramidebeta-D-galactosylDimethylphosphate(2R,6S)-2,6-Diaminoheptanedioic acidMilbemycin A4Tetraisopropylpyrophosphoric acid amideMuricatacinMycophenolic acid O-acyl-glucuronidePC(33:3)TG(55:7)Mucronine DRosiglitazoneMuroctasin5-MethyldecanoylcarnitineTG(62:15)TG(51:3)ErgocristinefalseSpatial metabolomics in the seep holobiont Chaetoderma shenloong hosting chemosymbiont using DESISymbiosis with chemoautotrophic bacteria has evolved in many animal lineages inhabiting reducing habitats such as hydrothermal vents, allowing these holobionts to thrive in dark biospheres. In certain instances, the symbionts have become intracellular, residing within specialised bacteriocytes. The integration of microbial symbionts with eukaryotic cells vary across known animals; however, no specialised organelle dedicated to chemosynthesis has been identified yet. Here, we report a mode of symbiosis where sulphur-oxidising bacteria cultured within spherical multilamellar compartments (~12 μm) in the cold-seep aplacophoran mollusc Chaetoderma shenloong. This organelle, which we name ‘dracosphera’, is ubiquitous within the hypertrophied and intricately reticulate digestive gland of C. shenloong, which has otherwise lost most of its gut. Given that the symbionts are strictly anaerobic and the host resides in anoxic sediments tens of centimetres below the surface, the dracosphera may serve to minimise oxygen diffusion to the bacteria, akin to mechanisms observed in microbial diazotrophs or termite hindguts, as supported by our genomic and spatial transcriptomic analyses. Hypoxic conditions have been known to induce radical adaptations in meiofauna, exemplified by the acquisition of hydrogenosomes. Our discovery of similarly exceptional adaptations in C. shenloong provides new insights into the evolution of such organelles also in larger animals.2026-08-232026-08-22MTBLS15431