Marine Life Science & Technology最新文献

{"title":"Expression analyses of stress-responsive genes in the hermatypic coral <i>Acropora tenuis</i> and its symbiotic dinoflagellates after exposure to the herbicide Diuron.","authors":"Hiroshi Ishibashi, Seigo Minamide, Ichiro Takeuchi","doi":"10.1007/s42995-023-00183-0","DOIUrl":"10.1007/s42995-023-00183-0","url":null,"abstract":"<p><p>Diuron is one of the most frequently applied herbicides in sugarcane farming in southern Japan, and Australia. In addition, it is used as a booster substance in copper-based antifouling paints. Due to these various uses, Diuron is released into the marine environment; however, little information is available on gene expression in corals and their symbiotic algae exposed to Diuron. We investigated the effects of Diuron on stress-responsive gene expression in the hermatypic coral <i>Acropora tenuis</i> and its symbiotic dinoflagellates. After seven days of exposure to 1 µg/L and 10 µg/L Diuron, no significant changes in the body colour of corals were observed. However, quantitative reverse transcription-polymerase chain reaction analyses revealed that the expression levels of stress-responsive genes, such as heat shock protein 90 (<i>HSP90</i>), <i>HSP70</i>, and calreticulin (<i>CALR</i>), were significantly downregulated in corals exposed to 10 µg/L of Diuron for seven days. Moreover, aquaglyceroporin was significantly downregulated in corals exposed to environmentally relevant concentrations of 1 µg/L Diuron. In contrast, no such effects were observed on the expression levels of other stress-responsive genes, such as oxidative stress-responsive proteins, methionine adenosyltransferase, and green/red fluorescent proteins. Diuron exposure had no significant effect on the expression levels of <i>HSP90</i>, <i>HSP70</i>, or <i>HSP40</i> in the symbiotic dinoflagellates. These results suggest that stress-responsive genes, such as <i>HSP</i>s, respond differently to Diuron in corals and their symbiotic dinoflagellates and that <i>A. tenuis HSP</i>s and <i>CALR</i>s may be useful molecular biomarkers for predicting stress responses induced by the herbicide Diuron.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00183-0.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"289-299"},"PeriodicalIF":5.8,"publicationDate":"2023-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449730/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10164511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Short-chain fatty acids (SCFAs) as potential resuscitation factors that promote the isolation and culture of uncultured bacteria in marine sediments.","authors":"Chun-Shui Sun,&nbsp;Liu-Yan Zhou,&nbsp;Qi-Yun Liang,&nbsp;Xiao-Man Wang,&nbsp;Yi-Xuan Lei,&nbsp;Zhen-Xing Xu,&nbsp;Feng-Qing Wang,&nbsp;Guan-Jun Chen,&nbsp;Zong-Jun Du,&nbsp;Da-Shuai Mu","doi":"10.1007/s42995-023-00187-w","DOIUrl":"10.1007/s42995-023-00187-w","url":null,"abstract":"<p><p>Many marine bacteria are difficult to culture because they are dormant, rare or found in low-abundances. Enrichment culturing has been widely tested as an important strategy to isolate rare or dormant microbes. However, many more mechanisms remain uncertain. Here, based on 16S rRNA gene high-throughput sequencing and metabolomics technology, it was found that the short-chain fatty acids (SCFAs) in metabolites were significantly correlated with uncultured bacterial groups during enrichment cultures. A pure culture analysis showed that the addition of SCFAs to media also resulted in high efficiency for the isolation of uncultured strains from marine sediments. As a result, 238 strains belonging to 10 phyla, 26 families and 82 species were successfully isolated. Some uncultured rare taxa within <i>Chlorobi</i> and <i>Kiritimatiellaeota</i> were successfully cultured<i>.</i> Amongst the newly isolated uncultured microbes, most genomes, e.g. bacteria, possess SCFA oxidative degradation genes, and these features might aid these microbes in better adapting to the culture media. A further resuscitation analysis of a viable but non-culturable (VBNC) <i>Marinilabiliales</i> strain verified that the addition of SCFAs could break the dormancy of <i>Marinilabiliales</i> in 5 days, and the growth curve test showed that the SCFAs could shorten the lag phase and increase the growth rate. Overall, this study provides new insights into SCFAs, which were first studied as resuscitation factors in uncultured marine bacteria. Thus, this study can help improve the utilisation and excavation of marine microbial resources, especially for the most-wanted or key players.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00187-w.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"400-414"},"PeriodicalIF":5.7,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449756/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10112155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diversity, community structure, and quantity of eukaryotic phytoplankton revealed using 18S rRNA and plastid 16S rRNA genes and pigment markers: a case study of the Pearl River Estuary.","authors":"Shumin Xu, Guihao Li, Cui He, Yi Huang, Dan Yu, Huiwen Deng, Zhuyin Tong, Yichong Wang, Christine Dupuy, Bangqin Huang, Zhuo Shen, Jie Xu, Jun Gong","doi":"10.1007/s42995-023-00186-x","DOIUrl":"10.1007/s42995-023-00186-x","url":null,"abstract":"<p><p>Understanding consistencies and discrepancies in characterizing diversity and quantity of phytoplankton is essential for better modeling ecosystem change. In this study, eukaryotic phytoplankton in the Pearl River Estuary, South China Sea were investigated using nuclear 18S rRNA and plastid 16S or 23S rRNA genes and pigment analysis. It was found that 18S abundance poorly explained the variations in total chlorophyll <i>a</i> (Chl-<i>a</i>). However, the ratios of log-transformed 18S abundance to Chl-<i>a</i> in the major phytoplankton groups were generally environment dependent, suggesting that the ratio has potential as an indicator of the physiological state of phytoplankton. The richness of 18S-based operational taxonomic units was positively correlated with the richness of 16S-based amplicon sequence variants of the whole phytoplankton community, but insignificant or weak for individual phytoplankton groups. Overall, the 18S based, rather than the 16S based, community structure had a greater similarity to pigment-based estimations. Relative to the pigment data, the proportion of haptophytes in the 18S dataset, and diatoms and cryptophytes in the 16S dataset, were underestimated. This study highlights that 18S metabarcoding tends to reflect biomass-based community organization of eukaryotic phytoplankton. Because there were lower copy numbers of plastid 16S than 18S per genome, metabarcoding of 16S probably approximates cell abundance-based community organization. Changes in biomass organization of the pigment-based community were sensitive to environmental changes. Taken together, multiple methodologies are recommended to be applied to more accurately profile the diversity and community composition of phytoplankton in natural ecosystems.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00186-x.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"415-430"},"PeriodicalIF":5.8,"publicationDate":"2023-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449762/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10164513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Expanding the application range of the <i>κ</i>‑carrageenase OUC-FaKC16A when preparing oligosaccharides from <i>κ</i>-carrageenan and furcellaran.","authors":"Chengcheng Jiang,&nbsp;Francesco Secundo,&nbsp;Xiangzhao Mao","doi":"10.1007/s42995-023-00181-2","DOIUrl":"10.1007/s42995-023-00181-2","url":null,"abstract":"<p><p>Carrageenan oligosaccharides are important products that have demonstrated numerous bioactivities useful in the food, medicine, and cosmetics industries. However, the specific structure-function relationships of carrageenan oligosaccharides are not clearly described due to the deficiency of high specific carrageenases. Here, a truncated mutant OUC-FaKC16Q based on the reported <i>κ</i>-neocarratetrose (N<i>κ</i>4)-producing <i>κ</i>-carrageenase OUC-FaKC16A from <i>Flavobacterium algicola</i> was constructed and further studied. After truncating the C-terminal Por_Secre_tail (PorS) domain (responsible for substrate binding), the catalytic efficiency and temperature stability decreased to a certain extent. Surprisingly, this truncation also enabled OUC-FaKC16Q to hydrolyze N<i>κ</i>4 into <i>κ</i>-neocarrabiose (N<i>κ</i>2). The offset of Arg₂₆₅ residue in OUC-FaKC16Q may explain this change. Moreover, the high catalytic abilities, the main products, and the degradation modes of OUC-FaKC16A and OUC-FaKC16Q toward furcellaran were also demonstrated. Data suggested OUC-FaKC16A and OUC-FaKC16Q could hydrolyze furcellaran to produce mainly the desulfated oligosaccharides DA-G-(DA-G4S)₂ and DA-G-DA-G4S, respectively. As a result, the spectrum of products of <i>κ</i>-carrageenase OUC-FaKC16A has been fully expanded in this study, indicating its promising potential for application in the biomanufacturing of carrageenan oligosaccharides with specific structures.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00181-2.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"387-399"},"PeriodicalIF":5.7,"publicationDate":"2023-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449746/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10110064","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ocellatuspyrones A‒G, new antibacterial polypropionates from the Chinese mollusk <i>Placobranchus ocellatus</i>.","authors":"Song-Wei Li,&nbsp;Dan-Dan Yu,&nbsp;Ming-Zhi Su,&nbsp;Li-Gong Yao,&nbsp;Hong Wang,&nbsp;Xueting Liu,&nbsp;Yue-Wei Guo","doi":"10.1007/s42995-023-00179-w","DOIUrl":"10.1007/s42995-023-00179-w","url":null,"abstract":"<p><p>Marine invertebrates serve as rich sources of secondary metabolites with intriguing chemical diversities and a wide spectrum of biological activities. Particularly, marine shell-less sacoglossan mollusks have attracted much attentions due to the fact that mollusks apply complex metabolites as chemical defense agents against to their predators. With the purpose of discovering bioactive secondary metabolites to develop marine-derived medicines from the South China Sea, we have conducted a chemical study on the photosynthetic mollusk <i>Placobranchus ocellatus.</i> As a result, seven new <i>γ</i>-pyrone polypropionates, namely ( ±)-ocellatuspyrone A (<b>1</b>), ( ±)-ocellatuspyrone B (<b>2</b>), and ocellatuspyrones C-G (<b>5</b>, <b>9</b>-<b>12</b>), along with five known polypropionates, have been isolated and characterized from the South China Sea photosynthetic mollusk <i>Placobranchus ocellatus</i>. Extensive spectroscopic analysis, single crystal X-ray diffraction analysis, modified Mosher's method, ECD comparison, CD exciton chirality method, TDDFT-ECD calculation, and chemical conversion were used to determine the structures and absolute configurations of the new compounds and the stereochemistry of undefined known compounds <b>4</b>, <b>6</b> and <b>7</b>. All these isolated polypropionates were evaluated in bioassays for their biological activities, including antibacterial, neuroprotective effect, anti-inflammatory, PTP1B inhibitory, and antiviral activities. Compounds <b>7</b>, <b>8</b> and <b>11</b> were found for the first time to show antibacterial activity against fish pathogenic bacteria <i>Streptococcus parauberis</i> (the main pathogen causing fish streptococcal infections and acute death) with MIC values of 35.8, 34.2, and 37.4 μg/mL, respectively, which might be potential novel antibacterial agents for the treatment of fish infectious diseases.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00179-w.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"373-386"},"PeriodicalIF":5.7,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449759/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10112156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phylogenomic resolution of Imparidentia (Mollusca: Bivalvia) diversification through mitochondrial genomes.","authors":"Yu Wang,&nbsp;Yi Yang,&nbsp;Lingfeng Kong,&nbsp;Takenori Sasaki,&nbsp;Qi Li","doi":"10.1007/s42995-023-00178-x","DOIUrl":"10.1007/s42995-023-00178-x","url":null,"abstract":"<p><p>Despite significant advances in the phylogenomics of bivalves over the past decade, the higher-level phylogeny of Imparidentia (a superorder of Heterodonta) remains elusive. Here, a total of five new mitochondrial sequences (<i>Chama asperella</i>, <i>Chama limbula</i>, <i>Chama dunkeri</i>, <i>Barnea manilensis</i> and <i>Ctena divergens</i>) was added to provide resolution in nodes that required additional study<i>.</i> Although the monophyly of Lucinida remains less clear, the results revealed the overall backbone of the Imparidentia tree and the monophyly of Imparidentia. Likewise, most relationships among the five major Imparidentia lineages-Lucinida, Cardiida, Adapedonta, Myida and Venerida-were addressed with a well-supported topology. Basal relationships of Imparidentia recovered Lucinidae as the sister group to all remaining imparidentian taxa. Thyasiridae is a sister group to other imparidentian bivalves (except Lucinidae species) which is split into Cardiida, Adapedonta and the divergent clade of Neoheterodontei. Neoheterodontei was comprised of Venerida and Myida, the former of which now also contains Chamidae as the sister group to all the remaining venerid taxa. Moreover, molecular divergence times were inferred by calibrating nine nodes in the Imparidentia tree of life by extinct taxa. The origin of these major clades ranged from Ordovician to Permian with the diversification through the Palaeozoic to Mesozoic. Overall, the results obtained in this study demonstrate a better-resolved Imparidentia phylogeny based on mitochondrial genomes.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00178-x.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"326-336"},"PeriodicalIF":5.7,"publicationDate":"2023-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449738/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10110065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Morphological and molecular examination of the ciliate family Lagynusidae (Protista, Ciliophora, Prostomatea) with descriptions of two new genera and two new species from China.","authors":"Limin Jiang,&nbsp;Congcong Wang,&nbsp;Saleh A Al-Farraj,&nbsp;Hunter N Hines,&nbsp;Xiaozhong Hu","doi":"10.1007/s42995-023-00174-1","DOIUrl":"10.1007/s42995-023-00174-1","url":null,"abstract":"<p><p>Ciliates in the class Prostomatea play an important role in the global microbial loop due to their significant abundances and broad feeding strategies at the foundation of food webs. Despite their importance in ecosystems, the taxonomy and systematics of this group of ciliates has long been poorly understood, with this being especially true for members of the family Lagynusidae. Here we examine four lagynusids collected from sandy beaches in China, using silver-staining and 18S rRNA gene sequencing techniques. These investigations revealed two new genera and two new species and provided details for two little known forms: <i>Penardella marina</i> gen. nov., sp. nov., <i>Apolagynus cucumis</i> (as reported by Penard. Études sur les infusoires d'eau douce. Georg and Cie, Genève, 1922) gen. nov., comb. nov., <i>Lagynus minutus</i> sp. nov., and <i>Lagynus elegans</i> (Engelmann in Z Wiss Zool 11:347-393, 1862) Quennerstedt (Acta Univ Lund 4:1-48, 1867). <i>Penardella</i> gen. nov. can be morphologically distinguished by having more than three dikinetidal perioral kineties. <i>Apolagynus</i> gen. nov. differs from the closely related genus <i>Lagynus</i> in the absence of a conspicuous neck-like region. The ciliature of <i>Apolagynus cucumis</i> is revealed here for the first time, which demonstrates the classification of this species within Lagynusidae. Furthermore, <i>Apolagynus binucleatus</i> (Jiang et al., 2021) comb. nov. is established according to the new finding. The results of our phylogenetic analyses based on the 18S rRNA gene support the establishment of two new genera and indicate that Lagynusidae is monophyletic, which further strengthens its valid taxonomic status.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 2","pages":"178-195"},"PeriodicalIF":5.7,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10232704/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9637821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response of <i>Salmonella enterica</i> serovar Typhimurium to alginate oligosaccharides fermented with fecal inoculum: integrated transcriptomic and metabolomic analyses.","authors":"Jiaying Cheng,&nbsp;Mengshi Xiao,&nbsp;Xinmiao Ren,&nbsp;Francesco Secundo,&nbsp;Ying Yu,&nbsp;Shihao Nan,&nbsp;Weimiao Chen,&nbsp;Changliang Zhu,&nbsp;Qing Kong,&nbsp;Youtao Huang,&nbsp;Xiaodan Fu,&nbsp;Haijin Mou","doi":"10.1007/s42995-023-00176-z","DOIUrl":"10.1007/s42995-023-00176-z","url":null,"abstract":"<p><p>Alginate oligosaccharides (AOS), extracted from marine brown algae, are a common functional feed additive; however, it remains unclear whether they modulate the gut microbiota and microbial metabolites. The response of <i>Salmonella enterica</i> serovar Typhimurium, a common poultry pathogen, to AOS fermented with chicken fecal inocula was investigated using metabolomic and transcriptomic analyses. Single-strain cultivation tests showed that AOS did not directly inhibit the growth of <i>S</i>. Typhimurium. However, when AOS were fermented by chicken fecal microbiota, the supernatant of fermented AOS (F-AOS) exhibited remarkable antibacterial activity against <i>S</i>. Typhimurium, decreasing the abundance ratio of <i>S</i>. Typhimurium in the fecal microbiota from 18.94 to 2.94%. Transcriptomic analyses showed that the 855 differentially expressed genes induced by F-AOS were mainly enriched in porphyrin and chlorophyll metabolism, oxidative phosphorylation, and <i>Salmonella</i> infection-related pathways. RT-qPCR confirmed that F-AOS downregulated key genes involved in flagellar assembly and the type III secretory system of <i>S</i>. Typhimurium, indicating metabolites in F-AOS can influence the growth and metabolism of <i>S</i>. Typhimurium. Metabolomic analyses showed that 205 microbial metabolites were significantly altered in F-AOS. Among them, the increase in indolelactic acid and 3-indolepropionic acid levels were further confirmed using HPLC. This study provides a new perspective for the application of AOS as a feed additive against pathogenic intestinal bacteria.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00176-z.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 2","pages":"242-256"},"PeriodicalIF":5.7,"publicationDate":"2023-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10232696/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9587932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative genome analysis of three euplotid protists provides insights into the evolution of nanochromosomes in unicellular eukaryotic organisms.","authors":"Didi Jin,&nbsp;Chao Li,&nbsp;Xiao Chen,&nbsp;Adam Byerly,&nbsp;Naomi A Stover,&nbsp;Tengteng Zhang,&nbsp;Chen Shao,&nbsp;Yurui Wang","doi":"10.1007/s42995-023-00175-0","DOIUrl":"10.1007/s42995-023-00175-0","url":null,"abstract":"<p><p>One of the most diverse clades of ciliated protozoa, the class Spirotrichea, displays a series of unique characters in terms of eukaryotic macronuclear (MAC) genome, including high fragmentation that produces nanochromosomes. However, the genomic diversity and evolution of nanochromosomes and gene families for spirotrich MAC genomes are poorly understood. In this study, we assemble the MAC genome of a representative euplotid (a new model organism in Spirotrichea) species, <i>Euplotes aediculatus</i>. Our results indicate that: (a) the MAC genome includes 35,465 contigs with a total length of 97.3 Mb and a contig N50 of 3.4 kb, and contains 13,145 complete nanochromosomes and 43,194 predicted genes, with the majority of these nanochromosomes containing tiny introns and harboring only one gene; (b) genomic comparisons between <i>E. aediculatus</i> and other reported spirotrichs indicate that average GC content and genome fragmentation levels exhibit interspecific variation, and chromosome breaking sites (CBSs) might be lost during evolution, resulting in the increase of multi-gene nanochromosome; (c) gene families associated with chitin metabolism and FoxO signaling pathway are expanded in <i>E. aediculatus</i>, suggesting their potential roles in environment adaptation and survival strategies of <i>E. aediculatus</i>; and (d) a programmed ribosomal frameshift (PRF) with a conservative motif 5'-AAATAR-3' tends to occur in longer genes with more exons, and PRF genes play an important role in many cellular regulation processes.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00175-0.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 3","pages":"300-315"},"PeriodicalIF":5.7,"publicationDate":"2023-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10449743/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10110063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation and characterization of three pairs of verrucosidin epimers from the marine sediment-derived fungus <i>Penicillium cyclopium</i> and configuration revision of penicyrone A and related analogues.","authors":"Yan-He Li,&nbsp;Attila Mándi,&nbsp;Hong-Lei Li,&nbsp;Xiao-Ming Li,&nbsp;Xin Li,&nbsp;Ling-Hong Meng,&nbsp;Sui-Qun Yang,&nbsp;Xiao-Shan Shi,&nbsp;Tibor Kurtán,&nbsp;Bin-Gui Wang","doi":"10.1007/s42995-023-00173-2","DOIUrl":"10.1007/s42995-023-00173-2","url":null,"abstract":"<p><p>Verrucosidins, a methylated α-pyrone class of polyketides rarely reported upon, have been implicated in one or more neurological diseases. Despite the significance of verrucosidins as neurotoxins, the absolute configurations of most of the derivatives have not been accurately characterized yet. In this study, three pairs of C-9 epimeric verrucosidin derivatives, including the known compounds penicyrones A and B (<b>1a/1b</b>) and 9-<i>O</i>-methylpenicyrones A and B (<b>2a/2b</b>), the new compounds 9-<i>O-</i>ethylpenicyrones A and B (<b>3a/3b</b>), together with the related known derivative verrucosidin (<b>4</b>), were isolated and identified from the culture extract of <i>Penicillium cyclopium</i> SD-413, which was obtained from the marine sediment collected from the East China sea. Their structures were established based on an in-depth analysis of nuclear magnetic resonances (NMR) and mass spectroscopic data. Determination of the absolute configurations of these compounds was accomplished by Mosher's method and time-dependent density functional theory (TDDFT) calculations of electronic circular dichroism (ECD) and optical rotation (OR). The configurational assignment of penicyrone A demonstrated that the previously reported C-6 absolute configuration of verrucosidin derivatives needs to be revised from (6<i>S</i>) to (6<i>R</i>). The 9<i>R</i>/9<i>S</i> epimers of compounds <b>1-3</b> were found to exhibit growth inhibition against some pathogenic bacteria, indicating that they have potential as lead compounds for the creation of antimicrobial agents.</p><p><strong>Supplementary information: </strong>The online version contains supplementary material available at 10.1007/s42995-023-00173-2.</p>","PeriodicalId":53218,"journal":{"name":"Marine Life Science & Technology","volume":"5 2","pages":"223-231"},"PeriodicalIF":5.7,"publicationDate":"2023-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10232390/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9939878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}