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Dispersal is an essential natural process that influences community assembly, yet directional dispersal through wind and water may have distinctive effects. Environmental and spatial factors jointly influence community structure, but their relative importance is anticipated to vary with spatial distance, dispersal mode, and season. Accordingly, a systemic survey was conducted in subtropical Chinese mountain lotic systems to distinguish the relative contributions of environmental control and spatial structuring upon communities of macroinvertebrates with different dispersal ability. Macroinvertebrate samples were collected from the upper reaches and five tributaries of the Hanjiang River in October 2017 (autumn) and April 2018 (spring). These macroinvertebrates were identified and classified into three dispersal groups: aquatic passive (AqPa), terrestrial passive (TePa), and terrestrial active (TeAc). Variation partitioning analyses were performed on environmental factors and different sets of spatial factors (overland dispersal: Overland, directional downwind dispersal: AEM_Wind, along watercourse dispersal: Watercourse, and directional downstream dispersal: AEM_Water). Findings showed that both environmental filtering and spatial structuring influenced the structure of macroinvertebrate metacommunities. For AqPa and TePa groups, pure environmental effects were stronger than pure spatial effects based on most distance matrices; however, in AEM_Water, the effects of spatial processes surpassed those of environmental filtering. For TeAc group, the role of environmental control and spatial structuring varied depending on different spatial models. The results also highlighted seasonal shifts in metacommunity structuring processes. Spatial structures featuring direction, especially AEM_Water, were predominant in explaining the construction of macroinvertebrate communities. This work suggests that directional dispersal should be explicitly considered when examining the structure of ecological communities.
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Ecossistema , Rios , Biota , Trietilenofosforamida , ÁguaRESUMO
Revealing the patterns and their mechanisms of microbial community in water transfer projects, especially in inter-basin water transfer projects, is the premise of biohazard warning, water quality monitoring and sustainable management of water resources. Using a river and impounded lakes from the eastern route of South-to-North Water Transfer project as a model system, we studied the diversity and assembly patterns of bacterial communities in artificially connected ecosystems and their influencing factors. Our results showed that water quality improved during the water transfer period (WTP). Further, the latitudinal pattern of bacterioplankton was reversed, which was mainly due to the change of evenness caused by water transfer and had no significant correlation with water quality parameters. Importantly, the spatial heterogeneity of the bacterial communities decreased during the WTP, and the differences in the communities between the impounded lakes and river was more significant in the non-water transfer period (NWTP) than in the WTP, which was the result of water transfer and water quality. Overall, bacterial community was largely shaped by stochastic processes. The bacterial communities had a higher migration rate during the WTP than during the NWTP. We believe that the water transfer increased the risk of biological homogenization while improving water quality. Combined, our work systematically discusses the microbial community pattern and mechanism in the inter-basin water transfer project, providing theoretical support for inter-basin water transfer project planning management and ecological environment protection.
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Microbiota , Qualidade da Água , Bactérias , China , Lagos , Rios/microbiologia , Recursos HídricosRESUMO
Rheb1 is an immediate early gene that functions to activate mammalian target of rapamycin (mTor) selectively in complex 1 (mTORC1). We have demonstrated previously that Rheb1 is essential for myelination in the CNS using a Nestin-Cre driver line that deletes Rheb1 in all neural cell lineages, and recent studies using oligodendrocyte-specific CNP-Cre have suggested a preferential role for mTORC1 is myelination in the spinal cord. Here, we examine the role of Rheb1/mTORC1 in mouse oligodendrocyte lineage using separate Cre drivers for oligodendrocyte progenitor cells (OPCs) including Olig1-Cre and Olig2-Cre as well as differentiated and mature oligodendrocytes including CNP-Cre and Tmem10-Cre. Deletion of Rheb1 in OPCs impairs their differentiation to mature oligodendrocytes. This is accompanied by reduced OPC cell-cycle exit suggesting a requirement for Rheb1 in OPC differentiation. The effect of Rheb1 on OPC differentiation is mediated by mTor since Olig1-Cre deletion of mTor phenocopies Olig1-Cre Rheb1 deletion. Deletion of Rheb1 in mature oligodendrocytes, in contrast, does not disrupt developmental myelination or myelin maintenance. Loss of Rheb1 in OPCs or neural progenitors does not affect astrocyte formation in gray and white matter, as indicated by the pan-astrocyte marker Aldh1L1. We conclude that OPC-intrinsic mTORC1 activity mediated by Rheb1 is critical for differentiation of OPCs to mature oligodendrocytes, but that mature oligodendrocytes do not require Rheb1 to make myelin or maintain it in the adult brain. These studies reveal mechanisms that may be relevant for both developmental myelination and impaired remyelination in myelin disease.
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Encéfalo/crescimento & desenvolvimento , Proteínas Monoméricas de Ligação ao GTP/fisiologia , Complexos Multiproteicos/fisiologia , Bainha de Mielina/fisiologia , Células-Tronco Neurais/fisiologia , Neuropeptídeos/fisiologia , Oligodendroglia/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Encéfalo/citologia , Ciclo Celular/genética , Ciclo Celular/fisiologia , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Knockout , Proteínas Monoméricas de Ligação ao GTP/genética , Complexos Multiproteicos/genética , Neuropeptídeos/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo , Serina-Treonina Quinases TOR/genéticaRESUMO
Excessive food/energy intake is linked to obesity and metabolic disorders, such as diabetes. The hypothalamus in the brain plays a critical role in the control of food intake and peripheral metabolism. The signaling pathways in hypothalamic neurons that regulate food intake and peripheral metabolism need to be better understood for developing pharmacological interventions to manage eating behavior and obesity. Mammalian target of rapamycin (mTOR), a serine/threonine kinase, is a master regulator of cellular metabolism in different cell types. Pharmacological manipulations of mTOR complex 1 (mTORC1) activity in hypothalamic neurons alter food intake and body weight. Our previous study identified Rheb1 (Ras homolog enriched in brain 1) as an essential activator of mTORC1 activity in the brain. Here we examine whether central Rheb1 regulates food intake and peripheral metabolism through mTORC1 signaling. We find that genetic deletion of Rheb1 in the brain causes a reduction in mTORC1 activity and impairs normal food intake. As a result, Rheb1 knockout mice exhibit hypoglycemia and increased lipid mobilization in adipose tissue and ketogenesis in the liver. Our work highlights the importance of central Rheb1 signaling in euglycemia and energy homeostasis in animals.
Assuntos
Tecido Adiposo/metabolismo , Encéfalo/metabolismo , Ingestão de Alimentos/genética , Deleção de Genes , Hipoglicemia/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Neuropeptídeos/genética , Animais , Peso Corporal , Homeostase , Hipoglicemia/metabolismo , Metabolismo dos Lipídeos , Fígado/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Complexos Multiproteicos/metabolismo , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Phytoplankton functional groups have been increasingly utilized in elucidating and predicting the response of phytoplankton species to environmental conditions and seasonal succession in various aquatic systems including lakes, rivers and reservoirs. However, it is still unclear whether the trait-based functional classification can be applied to spring-type lakes. To understand the temporal and spatial characteristics of phytoplankton functional groups and their responses to environmental factors in spring-type urban lake in northern China, an investigation was conducted in Daming Lake from May 2020 to September 2021. The findings revealed the identification of 98 phytoplankton taxa belonging to 6 phyla, predominantly being Chlorophyta (39.8%), Bacillariophyta (35.7%) and Cyanophyta (15.3%). The dominant species were Microcystis sp., Merismopedia minima, Synedra acus and Scenedesmus quadricauda. These phytoplankton taxa were categorized into 21 functional groups, with 6 dominant functional groups (abbreviated as D, MP, P, J, Lo, and W1). Among them, the functional group D, primarily constituted by S. acus, exhibited absolute predominance. The seasonal succession sequence of the dominant functional groups was as follows: D/P/J/MP/ Lo ââ D/P/W1/MP/Lo/J â D/P/J â D/MP â D/P/MP. Throughout the investigation period, the trophic level index (TLI) ranged from 39.10 to 71.13, and the Q index was from 1.91 to 2.91, both indicating a medium health state for Daming Lake, which was consistent with the evaluation results of the diversity index. The results of redundancy analysis revealed that the main driving factors of phytoplankton FG biomass and composition were water temperature (WT), total nitrogen (TN), transparency (SD), TN:TP (N:P), redox potential (ORP), chemical oxygen demand (CODMn) and pH. The dominance of the functional group D positively correlated with water temperature, TN, CODMn, pH and N:P but negatively correlated with SD. It was observed that functional groups and the Q index can objectively indicate the seasonal succession of phytoplankton and the water quality status of Daming Lake. Our discoveries have significant implications for the comprehension of the effects of urbanization on phytoplankton dynamics and for enhancing lake management practices to foster sustainable urban development.
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Gene therapy has been adapted, from the laboratory to the clinic, to treat retinopathies. In contrast to subretinal route, intravitreal delivery of AAV vectors displays the advantage of bypassing surgical injuries, but the viral particles are more prone to be nullified by the host neutralizing factors. To minimize such suppression of therapeutic effect, especially in terms of AAV2 and its derivatives, we introduced three serine-to-glycine mutations, based on the phosphorylation sites identified by mass spectrum analysis, to the XL32 capsid to generate a novel serotype named AAVYC5. Via intravitreal administration, AAVYC5 was transduced more effectively into multiple retinal layers compared with AAV2 and XL32. AAVYC5 also enabled successful delivery of anti-angiogenic molecules to rescue laser-induced choroidal neovascularization and astrogliosis in mice and non-human primates. Furthermore, we detected fewer neutralizing antibodies and binding IgG in human sera against AAVYC5 than those specific for AAV2 and XL32. Our results thus implicate this capsid-optimized AAVYC5 as a promising vector suitable for a wide population, particularly those with undesirable AAV2 seroreactivity.
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Capsídeo , Neovascularização de Coroide , Humanos , Camundongos , Animais , Capsídeo/metabolismo , Dependovirus/genética , Sorogrupo , Transdução Genética , Neovascularização de Coroide/terapia , Tropismo , Proteínas do Capsídeo/metabolismo , Vetores Genéticos/genéticaRESUMO
Trait-based approaches have been widely used to evaluate the effects of variable environments on submerged macrophytes communities. However, little research focused on the response of submerged macrophytes to variable environmental factors in impounded lakes and channel rivers of water transfer project, especially from a whole plant trait network (PTN) perspective. Here, we conducted a field survey designed to clarify the characteristic of PTN topology among impounded lakes and channel rivers of the East Route of South-to-North Water Transfer Project (ERSNWTP) and to unravel the effects of determining factors on the PTN topology structure. Overall, our results showed that leaf-related traits and organ mass allocation traits were the hub traits of PTNs in impounded lakes and channel rivers of the ERSNWTP, which traits with high variability were more likely to be the hub traits. Moreover, PTNs showed different structures among impounded lakes and channel rivers, and PTNs topologies were related to the mean functional variation coefficients of lakes and channel rivers. Specially, higher mean functional variation coefficients represented tight PTN, and lower mean functional variation coefficients indicated loose PTN. The PTN structure was significantly affected by water total phosphorus and dissolved oxygen. Edge density increased, while average path length decreased with increasing total phosphorus. Edge density and average clustering coefficient showed significant decreases with increasing dissolved oxygen, while average path length and modularity exhibited significant increases with increasing dissolved oxygen. This study explores the changing patterns and determinants of trait networks along environmental gradients to improve our understanding of ecological rules regulating trait correlations.
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How neuronal signaling affects brain myelination remains poorly understood. We show dysregulated neuronal RHEB-mTORC1-DLK1 axis impairs brain myelination. Neuronal Rheb cKO impairs oligodendrocyte differentiation/myelination, with activated neuronal expression of the imprinted gene Dlk1. Neuronal Dlk1 cKO ameliorates myelination deficit in neuronal Rheb cKO mice, indicating that activated neuronal Dlk1 expression contributes to impaired myelination caused by Rheb cKO. The effect of Rheb cKO on Dlk1 expression is mediated by mTORC1; neuronal mTor cKO and Raptor cKO and pharmacological inhibition of mTORC1 recapitulate elevated neuronal Dlk1 expression. We demonstrate that both a secreted form of DLK1 and a membrane-bound DLK1 inhibit the differentiation of cultured oligodendrocyte precursor cells into oligodendrocytes expressing myelin proteins. Finally, neuronal expression of Dlk1 in transgenic mice reduces the formation of mature oligodendrocytes and myelination. This study identifies Dlk1 as an inhibitor of oligodendrocyte myelination and a mechanism linking altered neuronal signaling with oligodendrocyte dysfunction.
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Bainha de Mielina , Proteína Enriquecida em Homólogo de Ras do Encéfalo , Transdução de Sinais , Animais , Camundongos , Diferenciação Celular/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos Transgênicos , Bainha de Mielina/metabolismo , Oligodendroglia/metabolismo , Transdução de Sinais/fisiologia , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismoRESUMO
The genus Exostoma is a group of stenotopic and rheophilic glyptosternine catfishes distributed in South and Southeast Asia. So far, comprehensive studies on mitogenomics referring to this genus are very scarce. In this study, we first sequenced and annotated the complete mitochondrial genomes of Exostoma tibetanum and Exostoma tenuicaudatum-two sympatric congeners from the lower Yarlung Tsangpo River, Tibet, China. The mitogenomes of both species contained 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, one light-strand origin of replication, and one control region, with lengths of 16,528 bp and 16,533 bp, respectively. The mitogenome architecture, nucleotide composition, and codon usage of protein-coding genes were almost identical between the two Exostoma species, although some estimated parameters varied. Phylogenetic analysis strongly supported the monophyly of Exostoma in the subfamily Glyptosternae, and Exostoma tibetanum had the closest relationship to Exostoma tenuicaudatum. The divergence time estimation demonstrated that these two species diverged approximately 1.51 Ma during the early Pleistocene, which was speculated to be triggered by the river system changes caused by the uplift of the southeastern Tibetan Plateau. Selection pressure analyses indicated that all protein-coding genes of Exostoma species underwent a strong purifying selection, while minority positive sites from NADH dehydrogenase complex genes were detected. These findings are expected to promote our understanding of the molecular phylogeny of the genus Exostoma and provide valuable mitogenomic resources for the subfamily Glyptosternae.
Assuntos
Peixes-Gato , Animais , Peixes-Gato/genética , NADH Desidrogenase/genética , Nucleotídeos , Filogenia , RNA de Transferência/genética , RiosRESUMO
The widespread contamination of antibiotic resistance genes (ARGs) in freshwater environment are becoming a serious challenge to human health and ecological safety. Rapid and efficient monitoring of ARGs pollution is of great significance to ARGs control. Water, bottom mud, and fish have all been used to indicate ARG contamination in aquatic environments. However, it is unclear whether macrobenthic invertebrates in the food chain of aquatic environments can be indicators of ARG contamination. In this study, we demonstrated that ARGs including tetA gene, sul2 gene, and km gene were distributed in Chironomidae larvae in Weishan Lake. The ARG distribution was related to animal species, body parts, sampling sites, time, urban environment, animal farming, south-to-north water diversion, food chain, antibiotics, and water storage. Mathematical model predictions of ARG contamination in Weishan Lake were constructed based on the structural equation model (SEM) and the distribution of ARG sul2 in Chironomidae larvae. Influencing factors such as water storage, metal elements, antibiotic, and temperature were found to be closely related to the prediction of ARG contamination. This study provided a new indicator for ARG contamination in freshwater environments and a method to predict ARGs contamination.
Assuntos
Chironomidae , Lagos , Animais , Antibacterianos/análise , Antibacterianos/farmacologia , China , Chironomidae/genética , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos , Humanos , Lagos/química , Larva , ÁguaRESUMO
Hepatosteatosis, characterized by excessive accumulation of lipids in the liver, is a major health issue in modern society. Understanding how altered hepatic lipid metabolism/homeostasis causes hepatosteatosis helps to develop therapeutic interventions. Previous studies identify mitochondrial dysfunction as a contributor to hepatosteatosis. But, the molecular mechanisms of mitochondrial dysfunction leading to altered lipid metabolism remain incompletely understood. Our previous work shows that Rheb, a Ras-like small GTPase, not only activates mTORC1 but also promotes mitochondrial ATP production through pyruvate dehydrogenase (PDH). In this study, we further demonstrate that Rheb controls hepatic triglyceride secretion and reduces diet-induced lipid accumulation in a mouse liver. Genetic deletion of Rheb causes rapid and spontaneous steatosis in the liver, which is unexpected from the role of mTORC1 that enhances lipid synthesis, whereas Rheb transgene remarkably reduces diet-induced hepatosteatosis. Results suggest that the hepatosteatosis in Rheb KO is an outcome of impaired lipid secretion, which is linked to mitochondrial ATP production of hepatocytes. Our findings highlight an under-appreciated role of Rheb in the regulation of hepatic lipid secretion through mitochondrial energy production, with therapeutic implication.
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In the title compound, C(18)H(16)N(2)O(2), the central pyridazine ring forms dihedral angles of 77.08â (5)° and 84.62â (5)° with the two benzene rings. The dihedral angle between the two benzene rings is 68.18â (4)°. A very weak intra-molecular C-Hâ¯N hydrogen bond and an intra-molecular C-Hâ¯π inter-action occur. The crystal structure is stabilized by weak inter-molecular C-Hâ¯O hydrogen bonds and weak C-Hâ¯π and π-π stacking inter-actions [centroid-centroid distance = 3.6867â (10)â Å].
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Infection caused by pathogenic bacteria carrying antibiotic resistance genes (ARGs) is a serious challenge to human health. Water environment, including water and surface sediments, is an important repository of ARGs, and the activity of aquatic animal can affect the development of ARG pollution in the water environment. Macrobenthic invertebrates are an important component of aquatic ecosystems, and their effects on ARG development in aquatic environments remain unreported. The distribution of ARGs, including tetA gene, sul2 gene, and kan gene, in Chironomidae larvae is demonstrated in this study for the first time. The ARG distribution was related to sampling points, metal elements, and seasons. Animal models demonstrated that Chironomidae larvae enriched ARGs from water and passed them on to downstream predators in the food chain. Conjugative transfer mediated by resistant plasmids was crucial in the spread of ARG in Chironomidae larvae, and upregulated expression of trfAp gene and trbBp gene was the molecular mechanism. Escherichia in Proteobacteria and Flavobacterium in Bacteroidetes, which are gram-negative bacteria in Chironomidae larvae, are the primary host bacteria of ARGs confirmed via resistance screening and DNA sequencing of V4 region of 16S rRNA gene. Feeding experiments further confirmed that ARGs from Chironomidae larvae can be enriched in the fish gut. Research gaps in food chain between sediments and fish are addressed in this study, and Chironomidae larvae is an important enricher of ARGs in the freshwater environment.
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Antibacterianos , Chironomidae , Animais , Antibacterianos/farmacologia , Chironomidae/genética , Resistência Microbiana a Medicamentos/genética , Ecossistema , Cadeia Alimentar , Água Doce , Genes Bacterianos , Humanos , Larva , RNA Ribossômico 16SRESUMO
Neuronal activity increases energy consumption and requires balanced production to maintain neuronal function. How activity is coupled to energy production remains incompletely understood. Here, we report that Rheb regulates mitochondrial tricarboxylic acid cycle flux of acetyl-CoA by activating pyruvate dehydrogenase (PDH) to increase ATP production. Rheb is induced by synaptic activity and lactate and dynamically trafficked to the mitochondrial matrix through its interaction with Tom20. Mitochondria-localized Rheb protein is required for activity-induced PDH activation and ATP production. Cell-type-specific gain- and loss-of-function genetic models for Rheb reveal reciprocal changes in PDH phosphorylation/activity, acetyl-CoA, and ATP that are not evident with genetic or pharmacological manipulations of mTORC1. Mechanistically, Rheb physically associates with PDH phosphatase (PDP), enhancing its activity and association with the catalytic E1α-subunit of PDH to reduce PDH phosphorylation and increase its activity. Findings identify Rheb as a nodal point that balances neuronal activity and neuroenergetics via Rheb-PDH axis.
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Metabolismo Energético , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Mitocôndrias/metabolismo , Neurônios/metabolismo , Complexo Piruvato Desidrogenase/metabolismo , Proteína Enriquecida em Homólogo de Ras do Encéfalo/metabolismo , Animais , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Camundongos , Fosforilação , Complexo Piruvato Desidrogenase/genética , Proteína Enriquecida em Homólogo de Ras do Encéfalo/genéticaRESUMO
Debris flow is a typical natural disaster in mountainous areas. Its occurrence has serious impacts on the ecological environment and the life, property safety of local people. The structure of mountain riverbed plays an important role in maintaining the ecological stability of debris flow gullies (DFGs) and improving the ecological condition. However, the effects of hydro-geomorphological processes induced by riverbed structure on local macroinvertebrates have not been well examined. A functional approach was applied to macroinvertebrate data collected in a field survey at sites with different riverbed structure to investigate the response of macroinvertebrate functional traits and environment factors to riverbed structure-induced processes. Riverbed structure was quantitatively calculated by concavity-convexity degree. The results showed that (a) Macroinvertebrates were mainly composed of individuals with the ability of avoiding risks and recovering quickly in DFGs. (b) The environmental factors affecting macroinvertebrates (i.e., average particle size, velocity, flow rate, water depth, and gradient) had a great relationship with riverbed structure. (c) Only 3 (trophic habit, attachment and drift) of the 10 benthic functional traits in the study area had a good correlation with riverbed structure. This study thus found that riverbed structure, as a complex of various environmental factors directly or indirectly affected the community structure and functional traits of macroinvertebrates in DFGs. Besides, it was more suitable for macroinvertebrates of different species to live, and more conducive to the maintenance of ecological stability when the concavity-convexity degree value was about 0.075. Because 5 environmental factors affecting macroinvertebrates were moderate when the degree of concavity was about 0.075. These results can provide scientific basis for ecological conservation and management in DFGs where eco-environment is very fragile.
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Invertebrados , Rios , Animais , China , Ecossistema , Monitoramento AmbientalRESUMO
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motor neurons. Improving neuronal survival in ALS remains a significant challenge. Previously, we identified Lanthionine synthetase C-like protein 1 (LanCL1) as a neuronal antioxidant defense gene, the genetic deletion of which causes apoptotic neurodegeneration in the brain. Here, we report in vivo data using the transgenic SOD1G93A mouse model of ALS indicating that CNS-specific expression of LanCL1 transgene extends lifespan, delays disease onset, decelerates symptomatic progression, and improves motor performance of SOD1G93A mice. Conversely, CNS-specific deletion of LanCL1 leads to neurodegenerative phenotypes, including motor neuron loss, neuroinflammation, and oxidative damage. Analysis reveals that LanCL1 is a positive regulator of AKT activity, and LanCL1 overexpression restores the impaired AKT activity in ALS model mice. These findings indicate that LanCL1 regulates neuronal survival through an alternative mechanism, and suggest a new therapeutic target in ALS.
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Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Longevidade , Neurônios Motores/metabolismo , Neurônios Motores/patologia , Receptores Acoplados a Proteínas G/metabolismo , Animais , Sobrevivência Celular , Sistema Nervoso Central/patologia , Deleção de Genes , Células HeLa , Humanos , Inflamação/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Especificidade de Órgãos , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia , TransgenesRESUMO
Rock carp, Procypris rabaudi (Tchang), is an endemic fish species in China. We sequenced the complete mitochondrial genome of it by high-fidelity polymerase chain reaction with conserved primers and primer walking sequencing method. The complete mitochondrial genome of rock carp is 16595 bp in length and contains 13 protein-coding genes, two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes and one control region, with an identical order to that of most other vertebrates. The origin of L-strand replication (OL) in rock carp mitochondrion is located in a cluster of five tRNA genes (WANCY region) with 35 nucleotides in length. The control region is located between the tRNA-Pro and tRNA-Phe genes and is 943 bp in length. Three conserved sequence blocks (CSB), an extended termination associated sequence (ETAS), an AT-repeat microsatellite sequence and a putative promoter sequence for H-strand transcription (HSP) were identified within this region. The microsatellite sequence has a very low variation, with only one repeat alteration in 50 checked individuals (from 12 to 13 repeats). The phylogenetic analysis for rock carp was performed with Bayesian and Maximum likelihood (ML) methods based on the concatenated nucleotide sequence of 12 protein-coding genes on the heavy strand. The result suggested that traditional taxonomic barbines possibly originated more early than cyprininaes; rock carp was placed at the position between barbines and cyprininaes, while has a closer relationship with cyprininaes than barbines.
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Cipriniformes/genética , Genoma Mitocondrial/genética , Filogenia , Animais , Composição de Bases/genética , Códon/genética , DNA Intergênico/genética , Genes de RNAr , Fases de Leitura Aberta/genética , RNA de Transferência/genéticaRESUMO
The growth factor receptor bound protein GRB10 is an imprinted gene product and a key negative regulator of the insulin, IGF1 and mTORC1 signaling pathways. GRB10 is highly expressed in mouse fetal liver but almost completely silenced in adult mice, suggesting a potential detrimental role of this protein in adult liver function. Here we show that the Grb10 gene could be reactivated in adult mouse liver by acute endoplasmic reticulum stress (ER stress) such as tunicamycin or a short-term high-fat diet (HFD) challenge, concurrently with increased unfolded protein response (UPR) and hepatosteatosis. Lipogenic gene expression and acute ER stress-induced hepatosteatosis were significantly suppressed in the liver of the liver-specific GRB10 knockout mice, uncovering a key role of Grb10 reactivation in acute ER stress-induced hepatic lipid dysregulation. Mechanically, acute ER stress induces Grb10 reactivation via an ATF4-mediated increase in Grb10 gene transcription. Our study demonstrates for the first time that the silenced Grb10 gene can be reactivated by acute ER stress and its reactivation plays an important role in the early development of hepatic steatosis.
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Estresse do Retículo Endoplasmático , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Proteína Adaptadora GRB10/metabolismo , Inativação Gênica , Fígado/metabolismo , Fígado/patologia , Fator 4 Ativador da Transcrição/metabolismo , Envelhecimento/metabolismo , Animais , Dieta Hiperlipídica , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Ácidos Graxos/biossíntese , Fígado Gorduroso/genética , Comportamento Alimentar , Proteína Adaptadora GRB10/genética , Deleção de Genes , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Especificidade de Órgãos/efeitos dos fármacos , Tunicamicina/farmacologiaRESUMO
BACKGROUND: The non-target effect of Bacillus thuringiensis (Bt) toxins in aquatic ecosystems is crucial to improve the present assessment of Bt-transgenic plants, particularly where crops are cultivated near aquatic ecosystems. We conducted decomposition experiments during two growing seasons to determine the effects of Bt-transgenic rice litter with and without insecticide application on the meiobenthos communities in a field ditch. RESULTS: The community composition of meiobenthos colonised on leaf litter was not significantly different between Bt and non-Bt rice. The abundance of meiobenthos colonising leaves differed between insecticide application and control, and this insecticide effect interacted with rice type. No Bt toxin was detected in field ditch water. Leaf decomposition and nutrient content were comparable for both Bt and non-Bt rice with or without insecticide application. CONCLUSION: Bt-transgenic rice litter had no effect on the meiobenthos community composition in field ditches, but the chronic persistence of transgenic litter in nature needs to be taken into account at large scales in aquatic ecosystems. © 2016 Society of Chemical Industry.
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Bacillus thuringiensis/genética , Toxinas Bacterianas/análise , Oryza/química , Folhas de Planta/química , Animais , Organismos Aquáticos , Toxinas Bacterianas/genética , Biodegradação Ambiental , China , Ecossistema , Endotoxinas/metabolismo , Inseticidas , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente ModificadasRESUMO
Although human disturbance indirectly influences lotic assemblages through modifying physical and chemical conditions, identifying thresholds of human disturbance would provide direct evidence for preventing anthropogenic degradation of biological conditions. In the present study, we used data obtained from tributaries of the Three Gorges Reservoir in China to detect effects of human disturbance on streams and to identify disturbance thresholds for benthic diatoms. Diatom species composition was significantly affected by three in-stream stressors including TP, TN and pH. Diatoms were also influenced by watershed % farmland and natural environmental variables. Considering three in-stream stressors, TP was positively influenced by % farmland and % impervious surface area (ISA). In contrast, TN and pH were principally affected by natural environmental variables. Among measured natural environmental variables, average annual air temperature, average annual precipitation, and topsoil % CaCO3, % gravel, and total exchangeable bases had significant effects on study streams. When effects of natural variables were accounted for, substantial compositional changes in diatoms occurred when farmland or ISA land use exceeded 25% or 0.3%, respectively. Our study demonstrated the rationale for identifying thresholds of human disturbance for lotic assemblages and addressed the importance of accounting for effects of natural factors for accurate disturbance thresholds.