作者机构：
[Yun Cao; Mengmeng Liu; Wenying Zhang; Xiaotong Zhang] China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China;National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China;School of Public Health, Anhui Medical University, Hefei 230032, China;[Mats Tysklind] Department of Chemistry, Umea University, Umea SE-901 87, Sweden;College of Life Science, Huazhong Normal University, Wuhan 430079, China
通讯机构：
[Xianliang Wang] C;China CDC Key Laboratory of Environment and Population Health, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China<&wdkj&>National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing 100021, China<&wdkj&>School of Public Health, Anhui Medical University, Hefei 230032, China
摘要：
To explore the multicenter characteristics of endocrine-like phthalate esters (PAEs) in household dust and propose effective control strategies for global indoor public health. An on-site observational investigation was conducted in nine Chinese cities from 2018 to 2019. A total of 246 household dust samples were collected and analyzed for ten PAE congeners using Gas Chromatography-Mass Spectrometry (GC-MS). Questionnaires were used to gather information on building conditions, indoor behaviors, and ventilation habits. In residential dust from the nine cities, the total concentrations of the ten PAE congeners (∑PAEs) ranged from 0.921 to 29097.297 µg/g. Dicyclohexyl phthalate (DCHP) and di (2-ethylhexyl) phthalate (DEHP) were the dominant congeners in ∑PAEs. Childhood exposure to PAEs through dust ingestion was four orders of magnitude higher than through inhalation, with a carcinogenic risk of 5.47 × 10−6 for DEHP exposure in household dust. Higher ∑PAEs concentrations were associated with higher temperature, double glazing, wall paint usage, television and computer use, and indoor plant growth. This multicenter on-site investigation confirmed PAE pollution characteristics and uncovered the inacceptable risk of daily DEHP exposure in household dust under real living conditions. Effective mitigation measures based on household-related information, residential characteristics, decoration materials, and lifestyle should be taken to build a healthy household environment.
摘要：
<jats:title>Abstract</jats:title>
<jats:sec>
<jats:title>Backgrounds and Aims</jats:title>
<jats:p>The hypothesis that plants evolve features that protect accessible pollen from consumption by flower visitors remains poorly understood.</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Methods</jats:title>
<jats:p>To explore potential chemical defence against pollen consumption, we examined the pollinator assemblage, foraging behaviour, visitation frequency and pollen transfer efficiency in Rhododendron molle, a highly toxic shrub containing rhodojaponin III. Nutrient (protein and lipid) and toxic components in pollen and other tissues were measured.</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Key Results</jats:title>
<jats:p>Overall in the five populations studied, floral visits by butterflies and bumblebees were relatively more frequent than visits by honeybees. All foraged for nectar but not pollen. Butterflies did not differ from bumblebees in the amount of pollen removed per visit, but deposited more pollen per visit. Pollination experiments indicated that R. molle was self-compatible, but both fruit and seed production were pollen-limited. Our analysis indicated that the pollen was not protein-poor and had a higher concentration of the toxic compound rhodojaponin III than petals and leaves, this compound was undetectable in nectar.</jats:p>
</jats:sec>
<jats:sec>
<jats:title>Conclusion</jats:title>
<jats:p>Pollen toxicity in Rhododendron flowers may discourage pollen robbers (bees) from taking the freely accessible pollen grains, while the toxin-free nectar rewards effective pollinators, promoting pollen transfer. This preliminary study supports the hypothesis that chemical defence in pollen would be likely to evolve in species without physical protection from pollinivores.</jats:p>
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摘要：
Porcine pleuropneumonia is one of the respiratory diseases that pigs are susceptible to Actinobacillus pleuropneumoniae (A. pleuropneumoniae), poses a great threat to the global pig industry. Glutathione (GSH) is an important sulfur source, cellular antioxidant and virulence determinant of many pathogenic bacteria. In this study, roles of two HbpA-like proteins HbpA1 and HbpA2 of A. pleuropneumoniae were analyzed. A. pleuropneumoniae mutants without HbpA2 were basically unable to grow in chemically defined medium (CDM) with GSH as the sole sulfur source and had significantly reduced oxidative tolerance; whereas mutation in hbpA1 led to reduced survival under low-temperature environments. Neither HbpA1 nor HbpA2 affects utilization of heme. These two HbpA-like proteins are not associated with the virulence of A. pleuropneumoniae. Our results reveal the correlation of A. pleuropneumoniae HbpA1 and HbpA2 in GSH utilization, highlight the roles of HbpA1 in the cold stress resistance and HbpA2 in the anti-oxidative response. GSH limitation is not a way to attenuate colonization and pathogenicity of A. pleuropneumoniae.
摘要：
The effects of different moisture contents on seed germination and seedling growth of six desert shrubs were determined in a greenhouse. It was found that 5% and 10% limited seed germination and seedling growth, while 15-20% resulted in the highest seed germination and biomass accumulation. In addition, we found that Caragana korshinskii had the strongest survivability, while Nitraria sibirica had the lowest viable survivability. Our results emphasise that cultivation of Caragana korshinskii, which is more drought tolerant, is preferred in desert areas for the recovery of vegetation in the region. Moisture is the most important environmental factor limiting seed regeneration of shrubs in desert areas. Therefore, understanding the effects of moisture changes on seed germination, morphological and physiological traits of shrubs is essential for vegetation restoration in desert areas. In March to June 2023, in a greenhouse using the potting method, we tested the effects of soil moisture changes (5%, 10%, 15%, 20% and 25%) on seed germination and seedling growth of six desert shrubs (Zygophyllum xanthoxylum, Nitraria sibirica, Calligonum mongolicum, Corethrodendron scoparium, Caragana korshinskii, and Corethrodendron fruticosu). Results showed that (1) seed germination percent and vigor index were significantly higher at 15 and 20% soil moisture content than at 5 and 10%; (2) shoot length, primary root length, specific leaf area and biomass of seedlings were significantly higher in the 15% and 20% soil moisture content treatments than in the 5% and 10% treatments; (3) superoxide dismutase activity (SOD) and soluble protein content (SP) decreased with decreasing soil water content, while peroxidase activity (POD) and catalase activity (CAT) showed a decreasing and then increasing trend with increasing soil water content; (4) the six seeds and seedling of shrubs were ranked in order of their survivability in response to changes in soil moisture: Caragana korshinskii > Zygophyllum xanthoxylum > Calligonum mongolicum > Corethrodendron scoparium > Corethrodendron fruticosu > Nitraria sibirica. Our study shows that shrub seedlings respond to water changes by regulating morphological and physiological traits together. More importantly, we found that C. korshinskii, Z. xanthoxylum and C. mongolicum were more survivable when coping with water deficit or extreme precipitation. The results of the study may provide a reference for the selection and cultivation of similar shrubs in desert areas under frequent extreme droughts in the future.
摘要：
Ubiquitination is a fascinating post-translational modification that has received continuous attention since its discovery. In this review, we first provide a concise overview of the E3 ubiquitin ligases, delving into classification, characteristics and mechanisms of ubiquitination. We then specifically examine the ubiquitination pathways mediated by the N/C-degrons, discussing their unique features and substrate recognition mechanisms. Finally, we offer insights into the current state of development pertaining to inhibitors that target the N/C-degron pathways, as well as the promising advances in the field of PROTAC (PROteolysis TArgeting Chimeras). Overall, this review offers a comprehensive understanding of the rapidly-evolving field of ubiquitin biology.
摘要：
Gastrodia daweishanensis Ying Qin & Yan Liu (Orchidaceae), a new species from Yunnan, China is described. The new species is similar to G. putaoensis X. H. Jin, but differs from the latter by its yellow flowers, perianth tube ventrally distinctly swollen near the base forming a pouch-shaped outgrowth and inner surface of the front half densely pubescent. The detailed information of the new species, including morphological descriptions, illustrations, phenology, etymology and conservation assessment are provided.
摘要：
Cyanobacteria are important primary producers, contributing to 25% of the global carbon fixation through photosynthesis. They serve as model organisms to study the photosynthesis, and are important cell factories for synthetic biology. To enable efficient genetic dissection and metabolic engineering in cyanobacteria, effective and accurate genetic manipulation tools are required. However, genetic manipulation in cyanobacteria by the conventional homologous recombination-based method and the recently developed CRISPR-Cas gene editing system require complicated cloning steps, especially during multi-site editing and single base mutation. This restricts the extensive research on cyanobacteria and reduces its application potential. In this study, a highly efficient and convenient cytosine base editing system was developed which allows rapid and precise C -> T point mutation and gene inactivation in the genomes of Synechocystis and Anabaena. This base editing system also enables efficient multiplex editing and can be easily cured after editing by sucrose counter-selection. This work will expand the knowledge base regarding the engineering of cyanobacteria. The findings of this study will encourage the biotechnological applications of cyanobacteria. An efficient cytosine base editor was developed in cyanobacteria, which allows rapid and precise C -> T point mutation and gene inactivation. This genome editing tool will accelerate the metabolic engineering and fundamental researches in cyanobacteria.
摘要：
Xiao et al. identified functions of α1,4‐galactosyltransferase 1 (α4GT1) in spermatogenesis of Drosophila melanogaster. They found that α4GT1 was expressed at a significantly higher level in the testis than in the ovary of Drosophila, and that the hatching rate was significantly decreased when α4GT1 RNAi males were crossed with w1118 females, with only a few mature sperm present in the seminal vesicle of α4GT1 RNAi flies. They further showed that the individualization complex (IC) in the testes of α4GT1 RNAi flies was scattered and did not move synchronically, compared with the clustered IC observed in control flies, and that the apoptosis signals in the sperm bundles of α4GT1 RNAi flies were significantly increased. Moreover, they found that the expression of several individualization‐related genes, such as Shrub, Obp44a and Hanibi was significantly decreased, whereas the expression of several apoptosis‐related genes, including Dronc and Drice, was significantly increased in the testes of α4GT1 RNAi flies. Their results suggest that α4GT1 may play dual roles in Drosophila spermatogenesis by regulating the sperm individualization process and maintaining the survival of sperm bundles. Abstract Spermatogenesis is critical for insect reproduction and the process is regulated by multiple genes. Glycosyltransferases have been shown to participate in the development of Drosophila melanogaster; however, their role in spermatogenesis is still unclear. In this study, we found that α1,4‐galactosyltransferase 1 (α4GT1) was expressed at a significantly higher level in the testis than in the ovary of Drosophila. Importantly, the hatching rate was significantly decreased when α4GT1 RNA interference (RNAi) males were crossed with w1118 females, with only a few mature sperm being present in the seminal vesicle of α4GT1 RNAi flies. Immunofluorescence staining further revealed that the individualization complex (IC) in the testes from α4GT1 RNAi flies was scattered and did not move synchronically, compared with the clustered IC observed in the control flies. Terminal deoxyribonucleotide transferase (TdT)‐mediated dUTP nick end labeling (TUNEL) assay showed that apoptosis signals in the sperm bundles of α4GT1 RNAi flies were significantly increased. Moreover, the expression of several individualization‐related genes, such as Shrub, Obp44a and Hanabi, was significantly decreased, whereas the expression of several apoptosis‐related genes, including Dronc and Drice, was significantly increased in the testes of α4GT1 RNAi flies. Together, these results suggest that α4GT1 may play dual roles in Drosophila spermatogenesis by regulating the sperm individualization process and maintaining the survival of sperm bundles.
期刊：
International Journal of Molecular Sciences,2024年25(13) ISSN：1661-6596
通讯作者：
Zheng, Y
作者机构：
[Wang, Yufeng; Wang, Haolin; Cao, Zhixian; Duan, Xin] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Peoples R China.;[Zheng, Ya; Su, Na] Shanghai Normal Univ, Sch Life Sci, Shanghai 200234, Peoples R China.
通讯机构：
[Zheng, Y ] S;Shanghai Normal Univ, Sch Life Sci, Shanghai 200234, Peoples R China.
摘要：
Drosophila spermatogenesis involves the renewal of germline stem cells, meiosis of spermatocytes, and morphological transformation of spermatids into mature sperm. We previously demonstrated that Ocnus (ocn) plays an essential role in spermatogenesis. The ValRS-m (Valyl-tRNA synthetase, mitochondrial) gene was down-regulated in ocn RNAi testes. Here, we found that ValRS-m-knockdown induced complete sterility in male flies. The depletion of ValRS-m blocked mitochondrial behavior and ATP synthesis, thus inhibiting the transition from spermatogonia to spermatocytes, and eventually, inducing the accumulation of spermatogonia during spermatogenesis. To understand the intrinsic reason for this, we further conducted transcriptome-sequencing analysis for control and ValRS-m-knockdown testes. The differentially expressed genes (DEGs) between these two groups were selected with a fold change of ≥2 or ≤1/2. Compared with the control group, 4725 genes were down-regulated (dDEGs) and 2985 genes were up-regulated (uDEGs) in the ValRS-m RNAi group. The dDEGs were mainly concentrated in the glycolytic pathway and pyruvate metabolic pathway, and the uDEGs were primarily related to ribosomal biogenesis. A total of 28 DEGs associated with mitochondria and 6 meiosis-related genes were verified to be suppressed when ValRS-m was deficient. Overall, these results suggest that ValRS-m plays a wide and vital role in mitochondrial behavior and spermatogonia differentiation in Drosophila.
摘要：
After aging in the environment, some nanoplastics will carry different charges and functional groups, thereby altering their toxicological effects. To evaluate the potential impact of aging of nanoplastics on the mammalian reproductive system, we exposed C57BL/6 male mice to a dose of 5 mg/kg/d polystyrene nanoparticles (PS-NPs) with different functional groups (unmodified, carboxyl functionalized and amino functionalized) for 45 days for this study. The results suggest that PS-NPs with different functional groups triggered oxidative stress, a decreased in the testis index, disruption of the outer wall of the seminiferous tubules, reduction in the number of spermatogonia cells and sperm counts, and an increased in sperm malformations. We performed GO and KEGG enrichment analysis on the differentially expressed proteins, and found they were mainly enriched in protein transport, RNA splicing and mTOR signaling. We confirmed that the PI3K-AKT-mTOR pathway is over activated, which may lead to reduction of spermatogonia stem cells by over differentiation. Strikingly, PS-NPs with functional group modifications are more toxic than those of unmodified polystyrene, and that PS-NPs with positively charged amino modifications are the most toxic. This study provides a new understanding for correctly evaluating the toxicological effects of plastic aging, and of the mechanism responsible for the reproductive toxicity caused by nanoplastics.
摘要：
<jats:p>During field work on mutualisms between oil bees and Cucurbitaceae in Yunnan, China, we discovered a new species of Thladiantha that we here describe and illustrate. It is overall similar to T. globicarpa A.M.Lu & Zhi Y.Zhang from Guangxi, but differs in the shape of its fruits. DNA sequences of the new species analyzed in the context of a densely sampled phylogeny of Thladiantha confirm its distinctness from all other species. The molecular data also revealed another collection of the new species made in Guangxi in 1937. Like all Thladiantha, the new species offers oil in glandular hairs on its petals and is pollinated by oil-collecting Ctenoplectra bees.
</jats:p>
摘要：
Acoustic cues are crucial to communication, navigation, and foraging in many animals, which hence face the problem of detecting and discriminating these cues in fluctuating noise levels from natural or anthropogenic sources. Such auditory dynamics are perhaps most extreme for echolocating bats that navigate and hunt prey on the wing in darkness by listening for weak echo returns from their powerful calls in complex, self-generated umwelts.(1)(,)(2) Due to high absorption of ultrasound in air and fast flight speeds, bats operate with short prey detection ranges and dynamic sensory volumes,(3) leading us to hypothesize that bats employ superfast vocal-motor adjustments to rapidly changing sensory scenes. To test this hypothesis, we investigated the onset and offset times and magnitude of the Lombard response in free-flying echolocating greater mouse-eared bats exposed to onsets of intense constant or duty-cycled masking noise during a landing task. We found that the bats invoked a bandwidth-dependent Lombard response of 0.1-0.2 dB per dB increase in noise, with very short delay and relapse times of 20ms in response to onsets and termination of duty-cycled noise. In concert with the absence call time-locking to noise-free periods, these results show that free-flying bats exhibit a superfast, but hard-wired, vocal-motor response to increased noise levels. We posit that this reflex is mediated by simple closed-loop audio-motor feedback circuits that operate independently of wingbeat and respiration cycles to allow for rapid adjustments to the highly dynamic auditory scenes encountered by these small predators.
作者机构：
[Xuan Zhuang] Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China;[Xuan Zhuang] Department of Clinical Medicine, Fujian Medical University, Fuzhou, Fujian, 363000, China;[Xuan Zhuang] Department of Urology, the First Affiliated Hospital of Xiamen University, Xiamen, Fujian, 361003, China;[Jun Ruan] College of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, China;[Canquan Zhou] Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Center for Reproductive Medicine and Department of Gynecology & Obstetrics, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China. zhoucanquan@mail.sysu.edu.cn
通讯机构：
[Zhou, Canquan] G;[Li, Zhiming] I;Guangdong Provincial Key Laboratory of Reproductive Medicine, Guangdong Provincial Clinical Research Center for obstetrical and gynecological diseases, Center for Reproductive Medicine and Department of Gynecology & Obstetrics, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, 510080, China.;Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030, China.
摘要：
F-box proteins play essential roles in various cellular processes of spermatogenesis by means of ubiquitylation and subsequent target protein degradation. They are the substrate-recognition subunits of SKP1-cullin1-F-box protein (SCF) E3 ligase complexes. Dysregulation of F‑box protein‑mediated proteolysis could lead to male infertility in humans and mice. The emerging studies revealed the physiological function, pathological evidence, and biochemical substrates of F-box proteins in the development of male germ cells, which urging us to review the current understanding of how F‑box proteins contribute to spermatogenesis. More functional and mechanistic study will be helpful to define the roles of F-box protein in spermatogenesis, which will pave the way for the logical design of F-box protein-targeted diagnosis and therapies for male infertility, as the spermatogenic role of many F-box proteins remains elusive.
摘要：
The intervention of nectar robbers in plant pollination systems will cause some pollinators to modify their foraging behavior to act as secondary robbers, consequently adopting a mixed foraging strategy. The influence of nectar robbing on pollinator behavior may be affected by spatio-temporal difference of robbing intensity, and consequently, may have different effects on the pollination of host plants. However, whether and how the nectar robbing might influence pollinators under different robbing intensity still needs further investigation. In this study, Symphytum officinale was used to detect the effect of nectar robbers on pollinators under different robbing intensity as well as their effects on plant reproductive success. Six robbing levels and three bumblebees with mixed foraging behaviors were used to evaluate the effect of different robbing intensity on pollinator behavior, visitation rate, flower longevity and pollen deposition. Our results indicated that the robbing rate increased gradually with the proportion of robbed flowers, but which did not affect the frequency of legitimate visits. The increase of robbing rate promoted the corolla abscission, and then enhanced the self-pollen deposition, but which had no significant effect on cross-pollen deposition. These results indicate that the overall fitness of S. officinale was improved by combined self and cross-pollination modes when visited by both pollinators and nectar robbers simultaneously. Although nectar robbing is not uncommon, its consequences for pollination in the interaction web have not been well studied. Our results emphasize the significance of indirect impacts in mediating the adaptive outcomes of species interactions.
摘要：
Insect resistance evolution poses a significant threat to the advantages of biopesticides and transgenic crops utilizing insecticidal Cry-toxins from Bacillus thuringiensis (Bt). However, there is limited research on the relationship between transcriptional regulation of specific toxin receptors in lepidopteran insects and their resistance to Bt toxins. Here, we report the positive regulatory role of the SfGATAe transcription factor on the expression of the ABCC2 gene in Spodoptera frugiperda. DNA regions in the SfABCC2 promoter that are vital for regulation by SfGATAe, utilizing DAP-seq technology and promoter deletion mapping. Through yeast one-hybrid assays, DNA pull-down experiments, and site-directed mutagenesis, we confirmed that the transcription factor SfGATAe regulates the core control site PBS2 in the ABCC2 target gene. Tissue-specific expression analysis has revealed that SfGATAe is involved in the regulation and expression of midgut cells in the fall armyworm. Silencing SfGATAe in fall armyworm larvae resulted in reduced expression of SfABCC2 and decreased sensitivity to Cry1Ac toxin. Overall, this study elucidated the regulatory mechanism of the transcription factor SfGATAe on the expression of the toxin receptor gene SfABCC2 and this transcriptional control mechanism impacts the resistance of the fall armyworm to Bt toxins.
作者机构：
[Han, Suxia; Zhu, Yue] Xi An Jiao Tong Univ, Affiliated Hosp 1, Dept Radiat Oncol, Xian 710061, Shaanxi, Peoples R China.;[Xing, Xiaoke; Chen, Luojun; Yao, Yi; Zhang, Pingfeng; Song, Qibin; Zhu, Yue] Wuhan Univ, Renmin Hosp, Canc Ctr, Wuhan 430060, Peoples R China.;[Zhong, Chunhui; Wang, Fuxing; Liu, Zheng] Chinese Univ Hong Kong, Sch Med, Kobilka Inst Innovat Drug Discovery, Shenzhen 518172, Guangdong, Peoples R China.;[Lu, Xiting; Yu, Zhanwang] Shenzhen Inst Techol, Sch Appl Biol, Shenzhen, Peoples R China.;[Yang, Yongbo] Cent China Normal Univ, Sch Life Sci, Wuhan, Peoples R China.
通讯机构：
[Han, SX ] X;[Zhang, PF ] W;[Liu, Z ] C;Xi An Jiao Tong Univ, Affiliated Hosp 1, Dept Radiat Oncol, Xian 710061, Shaanxi, Peoples R China.;Wuhan Univ, Renmin Hosp, Canc Ctr, Wuhan 430060, Peoples R China.
关键词：
ABCC4;asymmetric ATP binding;degenerate NBD1;methotrexate;MRP4
摘要：
The multidrug resistance-associated protein (MRP) ABCC4 facilitates substrate transport across the cytoplasmic membrane, crucial for normal physiology and mediating multidrug resistance in tumor cells. Despite intensive studies on MRPs, ABCC4's transport mechanism remains incompletely understood. In this study, we unveiled an inward-open conformation with an ATP bound to degenerate NBD1. Additionally, we captured the structure with both ATP and substrate co-bound in the inward-open state. Our findings uncover the asymmetric ATP binding in ABCC4 and provide insights into substrate binding and transport mechanisms. ATP binding to NBD1 is parallel to substrate binding to ABCC4, and is a prerequisite for ATP-bound NBD2-induced global conformational changes. Our findings shed new light on targeting ABCC4 in combination with anticancer therapy.
摘要：
Eukaryotic DNA is packaged into chromatin in the nucleus, restricting the binding of transcription factors (TFs) to their target DNA sites. FOXA1 functions as a pioneer TF to bind condensed chromatin and initiate the opening of local chromatin for gene expression. However, the principles of FOXA1 recruitment and how it subsequently unpacks the condensed chromatin remain elusive. Here, we revealed that FOXA1 intrinsically forms submicron-sized condensates through its N- and C-terminal intrinsically disordered regions (IDRs). Notably, both IDRs enable FOXA1 to dissolve the condensed chromatin. In addition, the DNA-binding capacity of FOXA1 contributes to its ability to both form condensates and dissolve condensed chromatin. Further genome-wide investigation showed that IDRs enable FOXA1 to bind and unpack the condensed chromatin to regulate the proliferation and migration of breast cancer cells. This work provides a principle of how pioneer TFs function to initiate competent chromatin states using their IDRs.
摘要：
Verrucomicrobiota is widely distributed in various habitats including insect guts. It was found to be prevalent in almost all investigated termite guts, whereas their physiological functions are not very clear. In this study we characterized the physiological and genomic properties of Verrucomicrobiota strain TSB47 T isolated from Reticulitermes chinensis . The cells of strain TSB47 T were Gram -stain -negative, nonmotile, and non -spore -forming coccoid with one or more warts. 16S rRNA gene analysis showed that the closest relatives of strain TSB47 T were Opitutaceae strain TAV1 and Ereboglobus luteus Ho45 T (98.3% and 95.4% sequence similarity, respectively). Whole genome analysis revealed that there are a large number of glycoside hydrolase genes, amino acid metabolism genes, complete Mo-Fe nitrogenase and Fe -Fe nitrogenase gene clusters, as well as cbb 3 -type cytochrome oxidase gene in the genome of strain TSB47 T . Strain TSB47 T grows well under anaerobic and microaerophilic conditions with a strong tolerance to oxygen. Physiological and genomic characters of strain TSB47 T indicated its high adaptability to termite gut ecosystem. Based on phenotypic and phylogenetic evidence, we suggest strain TSB47 T as the type species of a novel genus in the family Opitutaceae , for which the name Termitidicoccus mucosus sp. nov. is proposed. The type strain is TSB47 T (CCTCC AB2022447 T ; KCTC 102044 T ). (c) 2023 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.
摘要：
<jats:title>SUMMARY</jats:title><jats:p>Lipocalins constitute a conserved protein family that binds to and transports a variety of lipids while fatty acid desaturases (FADs) are required for maintaining the cell membrane fluidity under cold stress. Nevertheless, it remains unclear whether plant lipocalins promote FADs for the cell membrane integrity under cold stress. Here, we identified the role of OsTIL1 lipocalin in FADs‐mediated glycerolipid remodeling under cold stress. Overexpression and CRISPR/Cas9 mediated gene edition experiments demonstrated that <jats:italic>OsTIL1</jats:italic> positively regulated cold stress tolerance by protecting the cell membrane integrity from reactive oxygen species damage and enhancing the activities of peroxidase and ascorbate peroxidase, which was confirmed by combined cold stress with a membrane rigidifier dimethyl sulfoxide or a H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub> scavenger dimethyl thiourea. <jats:italic>OsTIL1</jats:italic> overexpression induced higher 18:3 content, and higher 18:3/18:2 and (18:2 + 18:3)/18:1 ratios than the wild type under cold stress whereas the gene edition mutant showed the opposite. Furthermore, the lipidomic analysis showed that <jats:italic>OsTIL1</jats:italic> overexpression led to higher contents of 18:3‐mediated glycerolipids, including galactolipids (monoglactosyldiacylglycerol and digalactosyldiacylglycerol) and phospholipids (phosphatidyl glycerol, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine and phosphatidyl inositol) under cold stress. RNA‐seq and enzyme linked immunosorbent assay analyses indicated that <jats:italic>OsTIL1</jats:italic> overexpression enhanced the transcription and enzyme abundance of four ω‐3 FADs (<jats:italic>OsFAD3‐1/3‐2</jats:italic>, <jats:italic>7</jats:italic>, and <jats:italic>8</jats:italic>) under cold stress. These results reveal an important role of <jats:italic>OsTIL1</jats:italic> in maintaining the cell membrane integrity from oxidative damage under cold stress, providing a good candidate gene for improving cold tolerance in rice.</jats:p>
