Institute of Hydrobiology, Chinese Academy Of Sciences

    High genetic diversity in population of Lepturichthys fimbriata from the Yangtze River revealed by microsatellite DNA analysis

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    Lepturichthys fimbriata (Gunther) is one of the benthic and rock-attached fish species that is typically found in torrential flows of the upper reaches of the Yangtze River in China. Several dams in the Yangtze River (the Ertan Dam, the Three Gorges Dam, the Gezhouba Dam, the Xiluodu Dam and the Xiangjiaba Dam (the latter two dams are under construction)) may have significant effects on the habitat and spawning behaviors of L. fimbriata, and could ultimately threaten the survival of this fish. We studied the population genetic diversity of L. fimbriata samples collected at three sites within the Yangtze River and one of its tributaries, the Yalong River. Genetic diversity patterns were determined by analyzing genetic data from 14 polymorphic microsatellite loci isolated in Jinshaia sinensis (Sauvage et Dabry). A high genetic diversity among these L. fimbriata local populations was indicated by the number of microsatellite alleles (A) and the expected heterozygosity. No reductions of genetic diversity in any L. fimbriata population were observed. However, significant population differentiations were observed among three local populations by pairwise comparisons (P<0.001). We deduced that L. fimbriata local populations were not small ones. In addition, the habitat behaviors of rock-attachment and possible residence of L. fimbriata could account for the genetic differences found in local populations.Lepturichthys fimbriata (Gunther) is one of the benthic and rock-attached fish species that is typically found in torrential flows of the upper reaches of the Yangtze River in China. Several dams in the Yangtze River (the Ertan Dam, the Three Gorges Dam, the Gezhouba Dam, the Xiluodu Dam and the Xiangjiaba Dam (the latter two dams are under construction)) may have significant effects on the habitat and spawning behaviors of L. fimbriata, and could ultimately threaten the survival of this fish. We studied the population genetic diversity of L. fimbriata samples collected at three sites within the Yangtze River and one of its tributaries, the Yalong River. Genetic diversity patterns were determined by analyzing genetic data from 14 polymorphic microsatellite loci isolated in Jinshaia sinensis (Sauvage et Dabry). A high genetic diversity among these L. fimbriata local populations was indicated by the number of microsatellite alleles (A) and the expected heterozygosity. No reductions of genetic diversity in any L. fimbriata population were observed. However, significant population differentiations were observed among three local populations by pairwise comparisons (P<0.001). We deduced that L. fimbriata local populations were not small ones. In addition, the habitat behaviors of rock-attachment and possible residence of L. fimbriata could account for the genetic differences found in local populations

    The decline process and major pathways of Microcystis bloom in Taihu Lake, China

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    Eutrophication has become a serious concern in many lakes, resulting in cyanobacterial blooms. However, the mechanism and pathways of cyanobacteria decline are less understood. To identify and define the growth and decline of Microcystis blooms in Taihu Lake of China, and to illuminate the destination of surface floating blooms, we investigated the biomass distribution and variations in colony size, morphology, and floating velocity from October 2008 to September 2009. The results showed that the Microcystis bloom declined in response to biomass decrease, colony disaggregation, buoyancy reduction, and increased phytoplankton biodiversity, and these indicative parameters could be applied for recognition of the development phases of the bloom. Three major decline pathways were proposed to describe the bloom decline process, colony disaggregation (Pathway I), colony settlement (Pathway II), and cell lysis in colonies (Pathway III). We proposed a strategy to define the occurrence and decline of Microcystis blooms, to evaluate the survival state under different stress conditions, and to indicate the efficiency of controlling countermeasures against algal blooms.Eutrophication has become a serious concern in many lakes, resulting in cyanobacterial blooms. However, the mechanism and pathways of cyanobacteria decline are less understood. To identify and define the growth and decline of Microcystis blooms in Taihu Lake of China, and to illuminate the destination of surface floating blooms, we investigated the biomass distribution and variations in colony size, morphology, and floating velocity from October 2008 to September 2009. The results showed that the Microcystis bloom declined in response to biomass decrease, colony disaggregation, buoyancy reduction, and increased phytoplankton biodiversity, and these indicative parameters could be applied for recognition of the development phases of the bloom. Three major decline pathways were proposed to describe the bloom decline process, colony disaggregation (Pathway I), colony settlement (Pathway II), and cell lysis in colonies (Pathway III). We proposed a strategy to define the occurrence and decline of Microcystis blooms, to evaluate the survival state under different stress conditions, and to indicate the efficiency of controlling countermeasures against algal blooms

    14-3-3 zeta Interacts with Stat3 and Regulates Its Constitutive Activation in Multiple Myeloma Cells

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    The 14-3-3 proteins are a family of regulatory signaling molecules that interact with other proteins in a phosphorylation-dependent manner and function as adapter or scaffold proteins in signal transduction pathways. One family member, 14-3-3 zeta, is believed to function in cell signaling, cycle control, and apoptotic death. A systematic proteomic analysis done in our laboratory has identified signal transducers and activators of transcription 3 (Stat3) as a novel 14-3-3 zeta interacting protein. Following our initial finding, in this study, we provide evidence that 14-3-3 zeta interacts physically with Stat3. We further demonstrate that phosphorylation of Stat3 at Ser727 is vital for 14-3-3 zeta interaction and mutation of Ser727 to Alanine abolished 14-3-3 zeta/Stat3 association. Inhibition of 14-3-3 zeta protein expression in U266 cells inhibited Stat3 Ser727 phosphorylation and nuclear translocation, and decreased both Stat3 DNA binding and transcriptional activity. Moreover, 14-3-3 zeta is involved in the regulation of protein kinase C (PKC) activity and 14-3-3 zeta binding to Stat3 protects Ser727 dephosphorylation from protein phosphatase 2A (PP2A). Taken together, our findings support the model that multiple signaling events impinge on Stat3 and that 14-3-3 zeta serves as an essential coordinator for different pathways to regulate Stat3 activation and function in MM cells.The 14-3-3 proteins are a family of regulatory signaling molecules that interact with other proteins in a phosphorylation-dependent manner and function as adapter or scaffold proteins in signal transduction pathways. One family member, 14-3-3 zeta, is believed to function in cell signaling, cycle control, and apoptotic death. A systematic proteomic analysis done in our laboratory has identified signal transducers and activators of transcription 3 (Stat3) as a novel 14-3-3 zeta interacting protein. Following our initial finding, in this study, we provide evidence that 14-3-3 zeta interacts physically with Stat3. We further demonstrate that phosphorylation of Stat3 at Ser727 is vital for 14-3-3 zeta interaction and mutation of Ser727 to Alanine abolished 14-3-3 zeta/Stat3 association. Inhibition of 14-3-3 zeta protein expression in U266 cells inhibited Stat3 Ser727 phosphorylation and nuclear translocation, and decreased both Stat3 DNA binding and transcriptional activity. Moreover, 14-3-3 zeta is involved in the regulation of protein kinase C (PKC) activity and 14-3-3 zeta binding to Stat3 protects Ser727 dephosphorylation from protein phosphatase 2A (PP2A). Taken together, our findings support the model that multiple signaling events impinge on Stat3 and that 14-3-3 zeta serves as an essential coordinator for different pathways to regulate Stat3 activation and function in MM cells

    A small internal antisense RNA (aftsH) of all3642 (ftsH) in Anabaena sp PCC 7120

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    In bacteria, FtsH proteases are involved in quality maintenance of membrane proteins and cellular regulation at the level of protein stability. Among the 4 predicted ftsH genes in the cyanobacterium Anabaena sp. PCC 7120, namely alr1262, all3642, all4776 and all4936, at least the first two showed reduced transcription in specialized N-2-fixing cells called heterocysts. In contrast, the transcription of a small internal antisense RNA (aftsH) of all3642 was up-regulated in heterocysts. Overexpression of the antisense RNA suppressed the expression of all3642, alr1262 and all4776. Control of promoter and modulation by antisense RNA may both contribute to gene regulation in heterocysts of filamentous cyanobacteria.In bacteria, FtsH proteases are involved in quality maintenance of membrane proteins and cellular regulation at the level of protein stability. Among the 4 predicted ftsH genes in the cyanobacterium Anabaena sp. PCC 7120, namely alr1262, all3642, all4776 and all4936, at least the first two showed reduced transcription in specialized N-2-fixing cells called heterocysts. In contrast, the transcription of a small internal antisense RNA (aftsH) of all3642 was up-regulated in heterocysts. Overexpression of the antisense RNA suppressed the expression of all3642, alr1262 and all4776. Control of promoter and modulation by antisense RNA may both contribute to gene regulation in heterocysts of filamentous cyanobacteria

    Effects of dietary protein level on growth performance, nitrogen and energy budget of juvenile hybrid sturgeon, Acipenser baerii female xA. gueldenstaedtii male

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    An 8-week growth trial was conducted to estimate the optimal dietary protein level for juvenile hybrid sturgeon. Acipenser baerii female xA. gueldenstaedtii male (initial body weight, 25.1 +/- 0.12 g). Effects of protein levels on nitrogen and energy budget of the fish were studied. Seven isoenergetic diets were formulated to contain seven levels of crude protein (250, 300, 350, 400, 450, 500 and 550 g kg(-1)) and each diet was fed to triplicate groups of fifty fish at 21.4 +/- 0.6 degrees C in twenty one 1 m(3) concrete tanks. The results showed that specific growth rate (SGR) increased when dietary protein levels increased from 250 to 400 g kg(-1) and then decreased significantly. Feed intake (FI) decreased steadily with increasing dietary protein levels. Fish fed 250 g kg(-1) protein diets showed the lowest feed efficiency (FE), and those fed 500 and 550 g kg(-1) protein diets showed significantly higher values than the other diets except 450 g kg(-1). Protein retention efficiency (PRE) was highest in 250-300 g kg(-1) groups, followed by 350-500 g kg(-1) groups and was significantly lower in 550 g kg(-1) group. Proportions of nitrogen intake (CN) allocated to excretory nitrogen (UN) were lowest in 250-300 g kg(-1) protein diets, followed by 350-500 g kg(-1) protein diets and highest in 550 g kg(-1) protein diet, whereas recovered (growth) nitrogen (RN) followed the inverse pattern with UN. Percentages of gross energy intake (IE) used for excretory energy (UE) increased steadily when dietary protein levels increased. Fish fed 400-550 g kg(-1) protein diets showed significantly higher proportion of metabolizable energy (ME) than those fed 250-350 g kg(-1) protein diets. The lowest and highest percentages of recovered (growth) (RE) were observed in 250 and 550 g kg(-1) groups. Nitrogen and energy budget equation of the fish fed 350 g kg(-1) protein diet was 100CN = 11.72FN + 58.78UN + 29.50RN and 100 IE = 35.08FE + 4.53UE + 34.16ME + 26.23RE. Five-parameter saturation kinetic model and second-order polynomial regression analysis indicated that the optimal dietary protein level for maximal growth of the fish was 340 and 370 g kg(-1). Diets with excessive protein contents not only resulted in inferior growth performance but also high proportions of protein and energy used for excretion. (c) 2012 Elsevier B.V. All rights reserved.An 8-week growth trial was conducted to estimate the optimal dietary protein level for juvenile hybrid sturgeon. Acipenser baerii female xA. gueldenstaedtii male (initial body weight, 25.1 +/- 0.12 g). Effects of protein levels on nitrogen and energy budget of the fish were studied. Seven isoenergetic diets were formulated to contain seven levels of crude protein (250, 300, 350, 400, 450, 500 and 550 g kg(-1)) and each diet was fed to triplicate groups of fifty fish at 21.4 +/- 0.6 degrees C in twenty one 1 m(3) concrete tanks

    Use of a Generalized Additive Model to Investigate Key Abiotic Factors Affecting Microcystin Cellular Quotas in Heavy Bloom Areas of Lake Taihu

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    Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation.Lake Taihu is the third largest freshwater lake in China and is suffering from serious cyanobacterial blooms with the associated drinking water contamination by microcystin (MC) for millions of citizens. So far, most studies on MCs have been limited to two small bays, while systematic research on the whole lake is lacking. To explain the variations in MC concentrations during cyanobacterial bloom, a large-scale survey at 30 sites across the lake was conducted monthly in 2008. The health risks of MC exposure were high, especially in the northern area. Both Microcystis abundance and MC cellular quotas presented positive correlations with MC concentration in the bloom seasons, suggesting that the toxic risks during Microcystis proliferations were affected by variations in both Microcystis density and MC production per Microcystis cell. Use of a powerful predictive modeling tool named generalized additive model (GAM) helped visualize significant effects of abiotic factors related to carbon fixation and proliferation of Microcystis (conductivity, dissolved inorganic carbon (DIC), water temperature and pH) on MC cellular quotas from recruitment period of Microcystis to the bloom seasons, suggesting the possible use of these factors, in addition to Microcystis abundance, as warning signs to predict toxic events in the future. The interesting relationship between macrophytes and MC cellular quotas of Microcystis (i.e., high MC cellular quotas in the presence of macrophytes) needs further investigation

    Lzts2 Regulates Embryonic Cell Movements and Dorsoventral Patterning through Interaction with and Export of Nuclear beta-Catenin in Zebrafish

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    Leucine zipper tumor suppressor 2 (Lzts2) functions in the development and progression of various tumors, but its activities in vertebrate embryogenesis remain unclear. Here, we demonstrate that lzts2 transcripts are of maternal origin in zebrafish embryos. Activation of BMP signaling up-regulates zygotic expression of lzts2, whereas canonical Wnt signaling acts upstream of BMP signaling to inhibit lzts2 expression. Abrogation of lzts2 expression by its specific morpholino-enhanced gastrula convergence and extension (CE) movements, dorsalized early embryos, and inhibited specification of midline progenitors for pancreas, liver, and heart. In contrast, ectopic expression of lzts2 led to the delay of CE movements and midline convergence of organ progenitors and resulted in a certain ratio of ventralized embryos. Mechanistically, Lzts2 regulates the migration of embryonic cells and dorsoventral patterning through its limitation of Wnt/beta-catenin activity, because it physically interacts with beta-catenin-1 and -2 and transports them out of the nucleus. In addition, both beta-catenin-1 and -2 exhibit redundant functions in activation of Stat3 signaling and in induction of Wnt5/11 expression through inhibition of BMP signaling and stimulation of Cyclops and Squint expression. Thus, Lzts2 regulates gastrula CE movements, dorsoventral patterning, and midline convergence and specification of organ precursors through interaction with and the export of nuclear beta-catenins in zebrafish

    圆形碘泡虫和关桥碘泡虫的形态学与免疫原性研究

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    鄱阳湖江豚种群现状与保护的研究

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