作者机构：
[Fu, Ziying; Fan, Zihui; Cui, Zhongdan; Chen, Qicai; Zhang, Guimin] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Yang, Lijian; Jia, Ya] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Peoples R China.
通讯机构：
[Ziying Fu] H;Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei 430079, China
摘要：
The Lombard effect, ref erring to an involuntary rise in vocal intensity, is a widespread vertebrate mecha-nism that aims to maintain signal efficiency in response to ambient noise. Previous studies showed that the Lombard effect could be sufficiently implemented at subcortical levels and operated by continuously monitoring background noise, requiring some subcortical auditory sensitive neurons to have continuous responses to background noise. However, such neurons have not been well characterized. The inferior colliculus (IC) is a major auditory integration center under the auditory cortex and provides projections to the putative vocal pattern generator in the brainstem. Thus, it is reasonable to speculate that the IC is a likely auditory nucleus candidate having background noise responding neurons (BNR neurons). In the present study, we isolated 183 sound-sensitive IC neurons in a constant frequency-frequency mod-ulation bat, Hipposideros pratti, and found that around 19% of these IC neurons are BNR neurons when stimulated with 70 dB SPL background white noise. Their firing rates in response to noise increased with increasing noise intensity and could be suppressed by sound stimulation. Furthermore, compared to neu-rons with similar best frequencies, the BNR neurons had smaller Q 10-dB values and lower noise-induced minimal threshold change, indicating that BNR neurons received fewer inhibitory inputs. These results suggested that the BNR neurons are ideal candidates for collecting information about background noise. We proposed that the BNR neurons synapsed with neurons in vocal-pattern-generating networks in the brainstem and initiated the Lombard effect by a feed-forward loop. (c) 2023 Elsevier B.V. All rights reserved.
作者机构：
[Luo, Jingwen; Li, Mengyun; Chen, Feng; Xu, Wenliang; Gao, Yanan; Guo, Yanjun; Qiao, Mengfei; Xu, WL] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan, Peoples R China.;[Guo, Yanjun] Xinjiang Normal Univ, Coll Life Sci, Urumqi, Peoples R China.;[Persson, Staffan] Univ Copenhagen, Copenhagen Plant Sci Ctr, Frederiksberg, Denmark.;[Persson, Staffan] Shanghai Jiao Tong Univ, Sch Life Sci & Biotechnol, Joint Int Res Lab Metab & Dev Sci, Shanghai, Peoples R China.;[Zeng, Wei; Zeng, W] Taizhou Univ, Sch Life Sci, Taizhou, Peoples R China.
通讯机构：
[Zeng, W ] T;[Xu, WL ] C;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan, Peoples R China.;Taizhou Univ, Sch Life Sci, Taizhou, Peoples R China.
作者机构：
[Wei, Fuwen; Hu, Yibo] Chinese Acad Sci, CAS Key Lab Anim Ecol & Conservat Biol, Beijing 100101, Peoples R China.;[Wei, Fuwen; Yang, Guang] Southern Marine Sci & Engn Guangdong Lab Guangzhou, Guangzhou 511458, Peoples R China.;[Yu, Li; Wang, Xiaoping] Yunnan Univ, Sch Life Sci, State Key Lab Conservat & Utilizat Bioresources Yu, Kunming 650091, Peoples R China.;[Guo, Yalong; Xu, Yongchao] Chinese Acad Sci, Inst Bot, State Key Lab Systemat & Evolut Bot, Beijing 100093, Peoples R China.;[Shi, Peng; Yang, Hui] Chinese Acad Sci, Kunming Inst Zool, State Key Lab Genet Resources & Evolut, Kunming 650201, Peoples R China.
通讯机构：
[Yibo Hu; Fuwen Wei] C;[Li Yu; Yalong Guo; Peng Shi; Guang Yang; Suhua Shi] S;[Shuangquan Huang] I;CAS Key Lab of Animal Ecology and Conservation Biology, Chinese Academy of Sciences, Beijing, 100101, China.;State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, School of Life Sciences, Yunnan University, Kunming, 650091, China.
摘要：
Wild animals and plants have developed a variety of adaptive traits driven by adaptive evolution, an important strategy for species survival and persistence. Uncovering the molecular mechanisms of adaptive evolution is the key to understanding species diversification, phenotypic convergence, and inter-species interaction. As the genome sequences of more and more non-model organisms are becoming available, the focus of studies on molecular mechanisms of adaptive evolution has shifted from the candidate gene method to genetic mapping based on genome-wide scanning. In this study, we reviewed the latest research advances in wild animals and plants, focusing on adaptive traits, convergent evolution, and coevolution. Firstly, we focused on the adaptive evolution of morphological, behavioral, and physiological traits. Secondly, we reviewed the phenotypic convergences of life history traits and responding to environmental pressures, and the underlying molecular convergence mechanisms. Thirdly, we summarized the advances of coevolution, including the four main types: mutualism, parasitism, predation and competition. Overall, these latest advances greatly increase our understanding of the underlying molecular mechanisms for diverse adaptive traits and species interaction, demonstrating that the development of evolutionary biology has been greatly accelerated by multi-omics technologies. Finally, we highlighted the emerging trends and future prospects around the above three aspects of adaptive evolution.
作者机构：
[Xiao, Yutao; Liu, Conghui; Liu, Zhenxing; Fan, Wei; Jin, Minghui; Wang, Ping; Liu, Bo; Wu, Chao; Wu, Shigang; Liu, Hangwei; He, Yuan; Chakrabarty, Swapan; Zheng, Weigang] Chinese Acad Agr Sci, Agr Genom Inst Shenzhen, Key Lab Gene Editing Technol Hainan, Shenzhen Branch,Guangdong Lab Lingnan Modern Agr,M, Shenzhen, Peoples R China.;[Jin, Minghui; Wu, Kongming; He, Yuan; Li, Xiaokang] Chinese Acad Agr Sci, Inst Plant Protect, State Key Lab Biol Plant Dis & Insect Pests, Beijing 100193, Peoples R China.;[Yuan, Haibin; Zheng, Weigang] Jilin Agr Univ, Coll Agron, Changchun 130118, Peoples R China.;[Liu, Conghui] Univ Hong Kong, Dept Clin Oncol, Hong Kong 999077, Peoples R China.;[Liu, Kaiyu] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Peoples R China.
通讯机构：
[Kongming Wu] T;[Wei Fan; Yutao Xiao] S;The State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China<&wdkj&>Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China<&wdkj&>Shenzhen Branch, Guangdong Laboratory of Lingnan Modern Agriculture, Key Laboratory of Gene Editing Technologies (Hainan), Ministry of Agriculture and Rural Affairs, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, China
摘要：
BACKGROUND: The black cutworm, Agrotis ipsilon, is a serious global underground pest. Its distinct phenotypic traits, especially its polyphagy and ability to migrate long distances, contribute to its widening distribution and increasing difficulty of control. However, knowledge about these traits is still limited. RESULTS: We generated a high-quality chromosome-level assembly of A. ipsilon using PacBio and Hi-C technology with a contig N50 length of ~ 6.7Mb. Comparative genomic and transcriptomic analyses showed that detoxification-associated gene families were highly expanded and induced after insects fed on specific host plants. Knockout of genes that encoded two induced ABC transporters using CRISPR/Cas9 significantly reduced larval growth rate, consistent with their contribution to host adaptation. A comparative transcriptomic analysis between tethered-flight moths and migrating moths showed expression changes in the circadian rhythm gene AiCry2 involved in sensing photoperiod variations and may receipt magnetic fields accompanied by MagR and in genes that regulate the juvenile hormone pathway and energy metabolism, all involved in migration processes. CONCLUSIONS: This study provides valuable genomic resources for elucidating the mechanisms involved in moth migration and developing innovative control strategies.
作者：
Luo, Jinhong*;Lu, Manman;Luo, Jie;Moss, Cynthia F.
期刊：
JOURNAL OF COMPARATIVE PHYSIOLOGY A-NEUROETHOLOGY SENSORY NEURAL AND BEHAVIORAL PHYSIOLOGY,2023年209(1):203-214 ISSN：0340-7594
通讯作者：
Luo, Jinhong;Moss, Cynthia F
作者机构：
[Lu, Manman; Luo, Jie; Luo, Jinhong] Cent China Normal Univ, Sch Life Sci, Inst Evolut & Ecol, Wuhan 430079, Peoples R China.;[Moss, Cynthia F.] Johns Hopkins Univ, Dept Psychol & Brain Sci, Baltimore, MD 21218 USA.
通讯机构：
[Luo, Jinhong] I;[Moss, Cynthia F] D;Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University, Wuhan, 430079, China.;Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, 21218, USA. cynthia.
摘要：
Diverse animal taxa are capable of rapidly modifying vocalizations to mitigate interference from environmental noise. Echolocating bats, for example, must frequently perform sonar tasks in the presence of interfering sounds. Numerous studies have documented sound production flexibility in echolocating bats; however, it remains unknown whether noise-induced vocal modifications (NIVMs) mitigate interference effects on echoes or calls. In this study, we leverage echo level compensation behavior of echolocating bats to answer this question. Using a microphone array, we recorded echolocation calls of Hipposideros pratti trained to approach and land on a perch in the laboratory under quiet and noise conditions. We found that H. pratti exhibited echo level compensation behavior during approaching flights, which depended critically on distance to the landing perch. Broadcast noise delayed and affected the rate of echo level compensation in H. pratti. Moreover, H. pratti increased vocalization amplitude, i.e., exhibited the Lombard effect, while also adjusting call duration and bandwidth with increasing noise levels. Quantitative analyses of the data show that H. pratti relies on echo feedback, not vocal feedback, to adjust signals in the presence of noise. These findings provide compelling evidence that NIVMs in echolocating animals and non-echolocating animals operate through different mechanisms.
作者机构：
[Wang, Yao; Zheng, Yong; He, Shao-Ping; Xu, Shang-Wei; Li, Xue-Bao; Li, XB; Li, Yang; Zheng, Y] Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;[Li, Li; Li, L] Huazhong Agr Univ, Coll Biomed & Hlth, Wuhan 430070, Peoples R China.;[Li, Li; Li, L] Huazhong Agr Univ, Coll Life Sci & Technol, Wuhan 430070, Peoples R China.;[Wang, Yao] Sichuan Agr Univ, Maize Res Inst, Wenjiang 611130, Sichuan, Peoples R China.
通讯机构：
[Li, XB ; Zheng, Y] C;[Li, L ] H;Cent China Normal Univ, Sch Life Sci, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Peoples R China.;Huazhong Agr Univ, Coll Biomed & Hlth, Wuhan 430070, Peoples R China.;Huazhong Agr Univ, Coll Life Sci & Technol, Wuhan 430070, Peoples R China.
摘要：
Transcription factors GhERF108 and GhARF7 interact to establish ethylene-auxin crosstalk, which activates downstream secondary cell wall (SCW)-related genes to facilitate fiber SCW formation in cotton. Phytohormones play indispensable roles in plant growth and development. However, the molecular mechanisms underlying phytohormone-mediated regulation of fiber secondary cell wall (SCW) formation in cotton (Gossypium hirsutum) remain largely underexplored. Here, we provide mechanistic evidence for functional interplay between the APETALA2/ethylene response factor (AP2/ERF) transcription factor GhERF108 and auxin response factors GhARF7-1 and GhARF7-2 in dictating the ethylene-auxin signaling crosstalk that regulates fiber SCW biosynthesis. Specifically, in vitro cotton ovule culture revealed that ethylene and auxin promote fiber SCW deposition. GhERF108 RNA interference (RNAi) cotton displayed remarkably reduced cell wall thickness compared with controls. GhERF108 interacted with GhARF7-1 and GhARF7-2 to enhance the activation of the MYB transcription factor gene GhMYBL1 (MYB domain-like protein 1) in fibers. GhARF7-1 and GhARF7-2 respond to auxin signals that promote fiber SCW thickening. GhMYBL1 RNAi and GhARF7-1 and GhARF7-2 virus-induced gene silencing (VIGS) cotton displayed similar defects in fiber SCW formation as GhERF108 RNAi cotton. Moreover, the ethylene and auxin responses were reduced in GhMYBL1 RNAi plants. GhMYBL1 directly binds to the promoters of GhCesA4-1, GhCesA4-2, and GhCesA8-1 and activates their expression to promote cellulose biosynthesis, thereby boosting fiber SCW formation. Collectively, our findings demonstrate that the collaboration between GhERF108 and GhARF7-1 or GhARF7-2 establishes ethylene-auxin signaling crosstalk to activate GhMYBL1, ultimately leading to the activation of fiber SCW biosynthesis.
摘要：
This toxicology study was conducted to assess the impact of formaldehyde, a common air pollutant found in Chinese gymnasiums, on the brain function of athletes. In this research, a total of 24 Balb/c male mice of SPF-grade were divided into four groups, each consisting of six mice. The mice were exposed to formaldehyde at different concentrations, including 0 mg/m(3), 0.5mg/m(3), 3.0mg/m(3), and 3.0mg/m(3) in combination with an injection of L-NMMA (N(G)-monomethyl-L-arginine), which is a nitric oxide synthase antagonist. Following a one-week test period (8h per day, over 7days), measurements of biomarkers related to the nitric oxide (NO)/cGMP-cAMP signaling pathway were carried out on the experimental animals post-treatment. The study found that: (1) Exposure to formaldehyde can lead to brain cell apoptosis and neurotoxicity; (2) Additionally, formaldehyde exposure was found to alter the biomarkers of the NO/cGMP-cAMP signaling pathway, with some changes being statistically significant (p < 0.05 or p < 0.01); (3) The use of L-NMMA, an antagonist of the NO/cGMP-cAMP signaling pathway, was found to prevent these biomarker changes and had a protective effect on brain cells. The study suggests that the negative impact of formaldehyde on the brain function of mice is linked to the regulation of the NO/cGMP-cAMP signaling pathway.
作者：
Gomes, Marcelo Pedrosa;Pereira, Eduardo Gusmão;Qiu, Bao-Sheng;Juneau, Philippe
期刊：
FRONTIERS IN PLANT SCIENCE,2023年14:1131656 ISSN：1664-462X
通讯作者：
Gomes, M.P.
作者机构：
[Gomes, Marcelo Pedrosa] Laboratório de Fisiologia de Plantas sob Estresse, Departamento de Botânica, Setor de Ciências Biológicas, Universidade Federal do Paraná, Paraná, Curitiba, Brazil;[Pereira, Eduardo Gusmão] Laboratório de Fisiologia do Estresse Abiótico, Instituto de Ciências Biológicas, Universidade Federal de Viçosa, Minas Gerais, Florestal, Brazil;[Qiu, Bao-Sheng] School of Life Sciences, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Hubei, Wuhan, China;[Juneau, Philippe] Ecotoxicology of Aquatic Microorganisms Laboratory, EcotoQ, GRIL, TOXEN, Department of Biological Sciences, Université du Québec à Montréal, Montréal, Montréal, QC, Canada
通讯机构：
[Gomes, M.P.] L;Laboratório de Fisiologia de Plantas sob Estresse, Paraná, Brazil
通讯作者：
Cuihong Wan<&wdkj&>Cuihong Wan Cuihong Wan Cuihong Wan
作者机构：
[Wan, Cuihong; Huwanixi, Aishuake; Peng, Zhao] Cent China Normal Univ, Sch Life Sci, Wuhan, Hubei, Peoples R China.;[Wan, Cuihong; Huwanixi, Aishuake; Peng, Zhao] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan, Hubei, Peoples R China.;[Wan, Cuihong] Cent China Normal Univ, Sch Life Sci, 152 Luoyu Rd, Wuhan 430079, Peoples R China.;[Wan, Cuihong] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, 152 Luoyu Rd, Wuhan 430079, Peoples R China.
通讯机构：
[Cuihong Wan; Cuihong Wan Cuihong Wan Cuihong Wan] S;School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan, Hubei, PR China
摘要：
Nostoc flagelliforme, a terrestrial cyanobacterium spread throughout arid and semi-arid areas, has been long known for its outstanding adaptability to extremely dry conditions. This microorganism is able to recover biological activities within hours after months of anhydrobiosis state, attracting investigation through proteomic analysis. Except for canonical proteome, microproteins encoded by small ORFs (smORFs) have recently been regarded as indispensable participants in metabolic processes. However, the involvement of smORFs in N. flagelliforme remains unknown. Here we first constructed a smORF database in N. flagelliforme using bioinformatic prediction, resulting in 6072 novel smORFs. Then LS-MS/MS analysis was applied to identify expression patterns of microproteins and seek smORFs and their encoded microprotein playing a role during rehydration. In total, 18 novel microproteins were mined based on a smORF searching strategy combined with three proteomic assays, of which five were annotated as ribosomal proteins, one as RNA polymerase subunit, and one as acetohydroxy acid isomeroreductase. We also suggested the possible functions of smORFs according to their expression pattern and discovered two neighboring and homologous smORFs. All these results will expand our knowledge of smORFs-encoded microproteins and their relation to the stress response of extremophilic microorganisms.
期刊：
Annals of Botany,2023年132(6):viii-x ISSN：0305-7364
通讯作者：
Huang, SQ
作者机构：
[Huang, Shuang-Quan; Huang, SQ] Cent China Normal Univ, Sch Life Sci, Inst Evolut & Ecol, Wuhan 430079, Peoples R China.
通讯机构：
[Huang, SQ ] C;Cent China Normal Univ, Sch Life Sci, Inst Evolut & Ecol, Wuhan 430079, Peoples R China.
关键词：
Enantiostyly;floral sexual polymorphism;geitonogamous self-pollination;tracing pollen movement
摘要：
This article comments on:Steven D. Johnson, Jeremy J. Midgley and Nicola Illing. The enantiostylous floral polymorphism of Barberetta aurea (Haemodoraceae) faci
作者：
Ze-Yu Tong;Ling-Yun Wu;Hui-Hui Feng;Meng Zhang;W Scott Armbruster;...
期刊：
国家科学评论(英文),2023年10(10) ISSN：2095-5138
通讯作者：
Susanne S Renner<&wdkj&>Shuang-Quan Huang
作者机构：
[Susanne S Renner] Department of Biology, Washington University , USA;[Ze-Yu Tong; Hui-Hui Feng; Meng Zhang; Shuang-Quan Huang] Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University , China;School of Biological Sciences, University of Portsmouth , UK;Institute of Arctic Biology, University of Alaska Fairbanks , USA;Faculty of Resources and Environmental Science, Hubei University , China
通讯机构：
[Susanne S Renner] D;[Shuang-Quan Huang] I;Department of Biology, Washington University , USA<&wdkj&>Institute of Evolution and Ecology, School of Life Sciences, Central China Normal University , China
摘要：
The services of animal pollinators that deliver compatible pollen to receptive stigmas are essential for the reproduction of many flowering plants [1,2]. The ma
期刊：
American Journal of Botany,2023年110(1) ISSN：0002-9122
作者机构：
[Huang, Shuang-Quan; Xu, Qi; Hao, Kai] Cent China Normal Univ, Inst Evolut & Ecol, Sch Life Sci, Wuhan 430079, Peoples R China.;[Hao, Kai] Chinese Acad Sci, Key Lab Plant Resources Conservat & Sustainable Ut, South China Bot Garden, Guangzhou 510650, Peoples R China.
关键词：
Geranium;chemical defense;generalist insects;pollen feeding;pollen grain size;pollen nutrition;pollen transfer efficiency
摘要：
PREMISE: Why have pollen grains evolved to be exceptionally large in some species? Pollen feeding hypothesis suggests that if the proportion of pollen amounts for feeding is reduced in a flower, the low allocation to pollen number would allow pollen grains to be larger. METHODS: To examine whether species with large pollen grains experience low pollen consumption, the behavior of insects feeding on nectar and pollen was observed and pollen transfer efficiency was estimated for four visitor types in Geranium delavayi. To see whether bees actively collected pollen, the numbers of grains in pollen baskets and on the body were compared. Both nutritional value (total protein and lipid) and chemical defense (phenolic metabolites) in pollen against pollen feeders were measured. RESULTS: Bumblebees and honeybees foraged for nectar, rarely groomed pollen into corbiculae, and had > 5× higher pollen transfer efficiency than smaller solitary bees and flies, which were pollen eaters that removed more pollen but deposited less. Pollen grains were characterized by low protein and high lipid content with a low protein-lipid ratio, an unfavorable combination for bumblebees. Three secondary metabolites were significantly higher in pollen grains (7.77 mg/g) than in petals (1.08 mg/g) and in nectar (0.44 mg/g), suggesting stronger chemical defense in pollen. CONCLUSIONS: Our results indicated that large bees took nectar but little of the nutritionally poor and highly toxic pollen. These data support one prediction of the pollen feeding hypothesis, that species with few and large pollen grains would also have low pollen consumption rates. This article is protected by copyright. All rights reserved.
摘要：
Engleromyces goetzei Henn (EgH) is a natural fungus that has been used as a traditional edible and medicine for long time in Southwest China. Our study found EgH aqueous extract (EgH‐AE) has very strong activities on antioxidant and anti‐inflammation. At the same time, we also found EgH‐AE has good biocompatibility and cell protective function, so it is biosafe, EgH‐AE may have the prospect of developing into functional beverage. Abstract High body mass index (high BMI, obesity) is a serious public health problem, and “obesity‐induced oxidative stress, inflammation, and cancer” have become modern epidemic diseases. We carried out this study to explore a functional beverage that may protect against obesity‐induced diseases. The Engleromyces goetzei Henn herbal tea is such a candidate. For this study, we carried out LC–MS analysis of E. goetzei Henn aqueous extract (EgH‐AE); then used the Caco‐2 cell line for the model cells and treated the cells with t‐BHP to form an oxidative stress system. An MTT assay was used for testing the biocompatibility and cytoprotective effects; reactive oxygen species and malondialdehyde determination was used for evaluating the antioxidative stress effect; TNF‐α and IL‐1β were used for observing the anti‐inflammatory effect, and 8‐OHdG for monitoring anticancer activity. The results of this study demonstrate that the EgH‐AE has very good biocompatibility with the Caco‐2 cell line and has good cytoprotective, antioxidant, anti‐inflammatory, and anticancer properties. It is clear that EgH‐AE, a kind of ancient herbal tea, may be used to develop a functional beverage that can be given to people with a high BMI to protect against obesity‐induced diseases.
作者机构：
[Yang, Yi-Wen; Chen, Si-Zhuo; Huang, Da; Qiu, Bao-Sheng; Yu, Chen; Liu, Ke; Qiu, BS] Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;[Yang, Yi-Wen; Chen, Si-Zhuo; Huang, Da; Qiu, Bao-Sheng; Yu, Chen; Liu, Ke; Qiu, BS] Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;[Yang, Yi-Wen] Jiujiang Univ, Coll Pharm & Life Sci, Jiujiang 332000, Jiangxi, Peoples R China.;[Chen, Min] Univ Sydney, Sch Life & Environm Sci, Sydney, NSW 2006, Australia.
通讯机构：
[Chen, M ] U;[Qiu, BS ] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.;Univ Sydney, Sch Life & Environm Sci, Sydney, NSW 2006, Australia.
摘要：
Expanded orange carotenoid protein paralogs in subaerial Nostoc species functionally specialize as singlet oxygen quenchers or phycobilisome fluorescence quenchers to survive desiccation tolerance. Orange carotenoid protein (OCP) is a photoactive protein that participates in the photoprotection of cyanobacteria. There are 2 full-length OCP proteins, 4 N-terminal paralogs (helical carotenoid protein [HCP]), and 1 C-terminal domain-like carotenoid protein (CCP) found in Nostoc flagelliforme, a desert cyanobacterium. All HCPs (HCP1 to 3 and HCP6) from N. flagelliforme demonstrated their excellent singlet oxygen quenching activities, in which HCP2 was the strongest singlet oxygen quencher compared with others. Two OCPs, OCPx1 and OCPx2, were not involved in singlet oxygen scavenging; instead, they functioned as phycobilisome fluorescence quenchers. The fast-acting OCPx1 showed more effective photoactivation and stronger phycobilisome fluorescence quenching compared with OCPx2, which behaved differently from all reported OCP paralogs. The resolved crystal structure and mutant analysis revealed that Trp111 and Met125 play essential roles in OCPx2, which is dominant and long acting. The resolved crystal structure of OCPx2 is maintained in a monomer state and showed more flexible regulation in energy quenching activities compared with the packed oligomer of OCPx1. The recombinant apo-CCP obtained the carotenoid pigment from holo-HCPs and holo-OCPx1 of N. flagelliforme. No such carotenoid transferring processes were observed between apo-CCP and holo-OCPx2. The close phylogenetic relationship of OCP paralogs from subaerial Nostoc species indicates an adaptive evolution toward development of photoprotection: protecting cellular metabolism against singlet oxygen damage using HCPs and against excess energy captured by active phycobilisomes using 2 different working modes of OCPx.
通讯机构：
[Qiu, BS ] C;Cent China Normal Univ, Sch Life Sci, Wuhan 430079, Hubei, Peoples R China.;Cent China Normal Univ, Hubei Key Lab Genet Regulat & Integrat Biol, Wuhan 430079, Hubei, Peoples R China.
摘要：
Hypothetical chloroplast open reading frames (ycfs) are putative genes in the plastid genomes of photosynthetic eukaryotes. Many ycfs are also conserved in the genomes of cyanobacteria, the presumptive ancestors of present-day chloroplasts. The functions of many ycfs are still unknown. Here, we generated knock-out mutants for ycf51 (sll1702) in the cyanobacterium Synechocystis sp. PCC 6803. The mutants showed reduced photoautotrophic growth due to impaired electron transport between photosystem II (PSII) and PSI. This phenotype results from greatly reduced PSI content in the ycf51 mutant. The ycf51 disruption had little effect on the transcription of genes encoding photosynthetic complex components and the stabilization of the PSI complex. In vitro and in vivo analyses demonstrated that Ycf51 cooperates with PSI assembly factor Ycf3 to mediate PSI assembly. Furthermore, Ycf51 interacts with the PSI subunit PsaC. Together with its specific localization in the thylakoid membrane and the stromal exposure of its hydrophilic region, our data suggest that Ycf51 is involved in PSI complex assembly. Ycf51 is conserved in all sequenced cyanobacteria, including the earliest branching cyanobacteria of the Gloeobacter genus, and is also present in the plastid genomes of glaucophytes. However, Ycf51 has been lost from other photosynthetic eukaryotic lineages. Thus, Ycf51 is a PSI assembly factor that has been functionally replaced during the evolution of oxygenic photosynthetic eukaryotes. Chloroplast reading frame Ycf51 is a photosystem I assembly factor conserved in all sequenced cyanobacteria and glaucophyte plastids but lost from other photosynthetic eukaryotic lineages.
摘要：
Genome streamlining, as a natural process in the evolution of microbes, has become a common approach for generating ideal chassis cells for synthetic biology studies and industrial applications. However, systematic genome reduction remains a bottleneck in the generation of such chassis cells with cyanobacteria, due to very time-consuming genetic manipulations. Synechococcus elongatus PCC 7942, a unicellular cyanobacterium, is a candidate for systematic genome reduction, as its essential and nonessential genes have been experimentally identified. Here, we report that at least 20 of the 23 over 10 kb nonessential gene regions could be deleted and that stepwise deletions of these regions could be achieved. A septuple-deletion mutant (genome reduced by 3.8%) was generated, and the effects of genome reduction on the growth and genome-wide transcription were investigated. In the ancestral triple to sextuple mutants (b, c, d, e1), an increasingly large number of genes (up to 998) were upregulated relative to the wild type, while slightly fewer genes (831) were upregulated in the septuple mutant (f). In a different sextuple mutant (e2) derived from the quintuple mutant d, much fewer genes (232) were upregulated. Under the standard conditions in this study, the mutant e2 showed a higher growth rate than the wild type, e1 and f. Our results indicate that it is feasible to extensively reduce the genomes of cyanobacteria for generation of chassis cells and for experimental evolutionary studies.
