Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of the...Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel(Gigantidas haimaensis) as a model, we explored this hostbacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing(SOX)multienzyme complex with the acquisition of sox B from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham(CBB)cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway(Ru MP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine,isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.展开更多
DEAR EDITOR,Ancient DNA(a DNA) from mollusc shells is considered a potential archive of historical biodiversity and evolution.However, such information is currently lacking for mollusc shells from the deep ocean, espe...DEAR EDITOR,Ancient DNA(a DNA) from mollusc shells is considered a potential archive of historical biodiversity and evolution.However, such information is currently lacking for mollusc shells from the deep ocean, especially those from acidic chemosynthetic environments theoretically unsuitable for longterm DNA preservation. Here, we report on the recovery of mitochondrial and nuclear gene markers by Illumina sequencing of a DNA from three shells of Archivesica nanshaensis – a hydrocarbon-seep vesicomyid clam previously known only from a pair of empty shells collected at a depth of 2626 m in the South China Sea.展开更多
The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are com...The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are common in coastal soft bottom communities;nevertheless,many recorded Rhynchospio specimens around the world are currently undescribed.Here we described a Rhynchospio species based on specimens collected from Qingdao,China.Comparison with the reported DNA sequences of four gene markers(16S rRNA,18S rRNA,28S rRNA,and Histone H3)and brief morphological description of specimens collected from Jinhae Bay,South Korea,previously reported as Rhynchospio aff.asiatica,indicated that they are conspecific.Morphologically,specimens of R.aff.asiatica from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14–17(vs.10–23 in R.asiatica)to near pygidial chaetigers,sperm from chaetiger 11 to 14(vs.from chaetiger 11 to 21–22 in R.asiatica),oocytes from chaetigers 16–17 to 26–39(vs.from 22–24 in R.asiatica),and 4–6(vs.up to 6 in R.asiatica)pygidial cirri.Genetically,Rhynchospio aff.asiatica is most closely related to R.arenincola Hartman,1936 from California,USA with the interspecific distances of 20.02%(16S rRNA),4.50%(18S rRNA),8.44%(28S rRNA),2.74%(Histone H3),and 6.10%(concatenated sequences).Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs,observed on live specimens,may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding segments.Phylogenetic trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades,covering the two subfamilies Spioninae and Nerininae respectively.Two families(i.e.,Poecilochaetidae and Trochochaetidae)in the order Spionida were clustered within Spionidae,supporting a morphology-based proposal that these families bearing a pair of prehensile,grooved palps should be grouped within a more broadly defi ned family Spionidae.Mapping morphological and reproductive characteristics to the phylogenetic trees indicated that the ancestor of spionids might lack branchiae,broadcast spawn thick-envelop oocytes and ect-aquasperm,and produce planktotrophic larvae.展开更多
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0409,SMSEGL20SC02)Research Grants Council of Hong Kong(12101021)Guangdong Natural Science Foundation(2020A1515011117)。
文摘Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel(Gigantidas haimaensis) as a model, we explored this hostbacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing(SOX)multienzyme complex with the acquisition of sox B from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham(CBB)cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway(Ru MP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine,isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou)(SMSEGL20SC02)University Grants Committee of Hong Kong(GRF12102222)。
文摘DEAR EDITOR,Ancient DNA(a DNA) from mollusc shells is considered a potential archive of historical biodiversity and evolution.However, such information is currently lacking for mollusc shells from the deep ocean, especially those from acidic chemosynthetic environments theoretically unsuitable for longterm DNA preservation. Here, we report on the recovery of mitochondrial and nuclear gene markers by Illumina sequencing of a DNA from three shells of Archivesica nanshaensis – a hydrocarbon-seep vesicomyid clam previously known only from a pair of empty shells collected at a depth of 2626 m in the South China Sea.
基金Supported by the China Postdoctoral Science Foundation (No.2021M691866)the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Nos.GML2019ZD0404,GML2019ZD0409)+2 种基金the Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(No.SMSEGL20SC02)the MEL Outstanding Postdoctoral Scholarshipthe Undergraduate Innovation and Entrepreneurship Training Programs at Xiamen University(No.2021103 84077)
文摘The genus Rhynchospio has fronto-lateral horns on prostomium,paired branchiae from chaetiger 2 to near the posterior end,capillary notochaetae only,and more than two pairs of pygidial cirri.Rhynchospio species are common in coastal soft bottom communities;nevertheless,many recorded Rhynchospio specimens around the world are currently undescribed.Here we described a Rhynchospio species based on specimens collected from Qingdao,China.Comparison with the reported DNA sequences of four gene markers(16S rRNA,18S rRNA,28S rRNA,and Histone H3)and brief morphological description of specimens collected from Jinhae Bay,South Korea,previously reported as Rhynchospio aff.asiatica,indicated that they are conspecific.Morphologically,specimens of R.aff.asiatica from Qingdao are characterized by having neuropodial hooded hooks from chaetigers 14–17(vs.10–23 in R.asiatica)to near pygidial chaetigers,sperm from chaetiger 11 to 14(vs.from chaetiger 11 to 21–22 in R.asiatica),oocytes from chaetigers 16–17 to 26–39(vs.from 22–24 in R.asiatica),and 4–6(vs.up to 6 in R.asiatica)pygidial cirri.Genetically,Rhynchospio aff.asiatica is most closely related to R.arenincola Hartman,1936 from California,USA with the interspecific distances of 20.02%(16S rRNA),4.50%(18S rRNA),8.44%(28S rRNA),2.74%(Histone H3),and 6.10%(concatenated sequences).Water flow across the dorsum created by ciliary beating of the branchiae and nototrochs,observed on live specimens,may help transport gametes from reproductive segments in anterior and middle parts to the posterior brooding segments.Phylogenetic trees based on concatenated sequences of four gene markers of 54 spioniform species in 25 genera revealed two clades,covering the two subfamilies Spioninae and Nerininae respectively.Two families(i.e.,Poecilochaetidae and Trochochaetidae)in the order Spionida were clustered within Spionidae,supporting a morphology-based proposal that these families bearing a pair of prehensile,grooved palps should be grouped within a more broadly defi ned family Spionidae.Mapping morphological and reproductive characteristics to the phylogenetic trees indicated that the ancestor of spionids might lack branchiae,broadcast spawn thick-envelop oocytes and ect-aquasperm,and produce planktotrophic larvae.
