Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explor...Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.展开更多
Cold seeps are pervasive along the continental margin worldwide,and are recognized as hotspots for elemental cycling pathway on Earth.In this study,analyses of pore water geochemical compositions of one-400 cm piston ...Cold seeps are pervasive along the continental margin worldwide,and are recognized as hotspots for elemental cycling pathway on Earth.In this study,analyses of pore water geochemical compositions of one-400 cm piston core(S3)and the application of a mass balance model are conducted to assess methane-associated biogeochemical reactions and uncover the relationship of methane in shallow sediment with gas hydrate reservoir at the Makran accretionary wedge off Pakistan.The results revealed that approximately 77%of sulfate is consumed by the predominant biogeochemical process of anaerobic oxidation of methane.However,the estimated sulfate-methane interface depth is-400 cm below sea floor with the methane diffusive flux of 0.039 mol/(m^(2)·a),suggesting the activity of methane seepage.Based on the δ^(13)C_(DIC) mass balance model combined with the contribution proportion of different dissolved inorganic carbon sources,this study calculated the δ^(13)C of the exogenous methane to be-57.9‰,indicating that the exogenous methane may be a mixture source,including thermogenic and biogenic methane.The study of pore water geochemistry at Makran accretionary wedge off Pakistan may have considerable implications for understanding the specific details on the dynamics of methane in cold seeps and provide important evidence for the potential occurrence of subsurface gas hydrate in this area.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.91858208,92358301)the Laoshan Laboratory(No.LSKJ 202203500),the China Postdoctoral Science Foundation of China(No.2019M663209)the Fundamental Research Funds for the Central Universities in China(No.19lGPY100)。
文摘Bathymodiolus mussels distribute in both deep-sea cold seep and hydrothermal vent environments,whose endosymbiotic gill tissue is a prominent character for the adaptation of extreme habitats.However,few studies explored the adaptation mechanisms through comparative transcriptome sequencing and analysis of different tissues between seep mussels and vent mussels.We performed the comparative transcriptome sequencing and analysis for three tissue types(gill,mantle,and adductor muscle)of Bathymodiolus mussels collected from a cold seeping site Station S 11 and the 50-km away hydrothermal field Minami-Ensei Knoll in the Okinawa Trough.Results show that gene expression patterns had distinct tissue specificity.Compared with the non-endosymbiotic tissues(mantle and adductor muscle),the significantly strengthened gene functions in endosymbiotic gill included microbial recognition(fibrinogen C domain-containing protein 1-B-like(fibcd),fibrinogen-related protein 8(frp),peptidoglycan recognition proteins(pgrp),and C-type lectin(clec)),cell apoptosis and immunity(interferon regulatory factor 1/2-like 1(ir f),cathepsin D(ctsd),caspase 2(casp 2)),and antioxidant capacity(copper/zinc superoxide dismutase(czsod),glutathione peroxidase(gpx),selenoprotein(sel)),in both seep and vent individuals.Consistent with metal accumulation,high expression levels of genes related to heavy metal detoxification(cytochrome P 450(cyp),ferritin-like(ftl),metallothionein(mt),glutathione S-transferase(gst))were also observed in gill.Moreover,to adapt to high hydrostatic pressure in the deep sea,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathways associated with cellular community were significantly enriched in all three tissues,suggesting the regulation of cell structure and cell adhesion at transcriptional level.This study obtained gene expression profiles of deep-sea mussels subsisting at cold seep and hydrothermal vent sites,which could lay foundations for comprehensive investigations of molecular basis in adaptation of deep-sea mussels to the two extreme ecosystems.
基金The National Natural Science Foundation of China under contract Nos 41606087,91858208,and 42076069the Taishan Scholar Special Experts Project under contract No.TS201712079+1 种基金the National Key Basic Research and Development Program of China under contract No.2017YFC0307704the Marine Geological Survey Program of China Geological Survey under contract Nos DD20190518 and DD20190819。
文摘Cold seeps are pervasive along the continental margin worldwide,and are recognized as hotspots for elemental cycling pathway on Earth.In this study,analyses of pore water geochemical compositions of one-400 cm piston core(S3)and the application of a mass balance model are conducted to assess methane-associated biogeochemical reactions and uncover the relationship of methane in shallow sediment with gas hydrate reservoir at the Makran accretionary wedge off Pakistan.The results revealed that approximately 77%of sulfate is consumed by the predominant biogeochemical process of anaerobic oxidation of methane.However,the estimated sulfate-methane interface depth is-400 cm below sea floor with the methane diffusive flux of 0.039 mol/(m^(2)·a),suggesting the activity of methane seepage.Based on the δ^(13)C_(DIC) mass balance model combined with the contribution proportion of different dissolved inorganic carbon sources,this study calculated the δ^(13)C of the exogenous methane to be-57.9‰,indicating that the exogenous methane may be a mixture source,including thermogenic and biogenic methane.The study of pore water geochemistry at Makran accretionary wedge off Pakistan may have considerable implications for understanding the specific details on the dynamics of methane in cold seeps and provide important evidence for the potential occurrence of subsurface gas hydrate in this area.
