Institute of Hydrobiology, Chinese Academy Of Sciences
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Effect of Salinity on the Zooplankton Community in the Pearl River Estuary
Understanding the relationship between the zooplankton distribution and salinity may provide key information to understand ecosystem function under the condition of a global mean sea level rise caused by global climate change. However, little is known about how increasing salinity level will affect the entire zooplankton community on a large scale. Here we completed 1 year of field investigations on the Pearl River Estuary and analyzed the distribution and structure of the zooplankton community. A total of 68 zooplankton species were identified during the survey. The number and diversity (richness, evenness, Shannon index, and Simpson's index) of the zooplankton species decreased as salinity increased from 0.10 to 21.26. Salinity negatively affected the abundances of rotifers, cladocerans, and total zooplankton, while it had little effect on copepod abundance. Some salt-tolerant species, such as Keratella tropica, Polyarthra vulgaris, and Paracalanus crassirostris, survived at high-salinity sites. A pattern was observed at all sites: the peak in copepod abundance always occurred when rotifers were abundant (sites S1 and S2) or after rotifer abundance reached a maximum level (sites S3, S4, and S5). In general, salinity was the most important environmental factor shaping zooplankton biodiversity and abundance. This study provides insight into potential biodiversity and structure of the zooplankton community in response to salinity change
Lipid production is more than doubled by manipulating a diacylglycerol acyltransferase in algae
Oleaginous algae have the ability to synthesize a high level of triacylglycerol (TAG) and are considered as the next-generation feedstock for biofuel production. Manipulating algal lipid biosynthetic pathways has potential to overproduce TAG and represents a feasible way toward bringing down algae-derived biofuels production cost. Here we dissected functional roles and engineering potential of six diacylglycerol acyltransferase (DGAT) genes from the marine alga Phaeodactylum tricornutum. PtDGAT1, PtDGAT2B, and PtDGAT3, residing at the chloroplast endoplasmic reticulum (ER) readily for utilizing both chloroplast- and ER-derived diacylglycerol, were transcriptionally correlated with TAG accumulation. Heterologous expression in yeast, in vitro assay and overexpression in P. tricornutum all supported that PtDGAT1 surpassed the other five PtDGATs in synthesizing TAG. Compared to wild type P. tricornutum, the PtDGAT1-overexpressing strain produced more than doubled TAG and total lipids, which reached 57% and 73% of dry weight, respectively, record-high levels ever achieved in this alga. Our results demonstrated the strategy of screening proper engineering targets and manipulating a single gene to pull carbon flux to lipids for TAG hyper-accumulation without growth compromise. The engineered alga with a great trait improvement may serve as a potent lipid producer for production uses
Contextual impacts on individual and synchronous breathing rate variations in three captive odontocete groups
Breathing rates are often collected both in the wild and in captivity to inform on cetaceans' internal state. However, few studies have investigated the effect of various factors on this breathing rate. We investigated the variations of individual and synchronous breathing rates depending on individual features (species, sex, age), displayed behavior, social parameters (social grouping), and environmental parameters (diurnal variation, presence of enrichment, unusual events, and presence of visitors in three groups of captive odontocetes (Yangtze finless porpoises, Neophocaena asiaeorentalis asiaeorientalis, East-Asian finless porpoises, Neophocaena asiaeorentalis sunameri, bottlenose dolphins, Tursiops truncatus). Both individual and synchronous breathing rates were the highest when animals engaged in energetic or social behaviors. Individual breathing rate decreased but synchronous breathing rate increased with the presence of enrichment. Both rates increased during unusual events (e.g., pool cleaning, presence of a diver in the pool, noise, transport) and when public was present for Yangtze finless porpoises. Finally, synchronous breathing rate increased for Yangtze finless porpoises when experiencing social separation. We suggest that individual and synchronous breathing rates are useful parameters to measure, both in wild and captive animals, to obtain information on their arousal/stress state. However, these rates should be interpreted with caution and should be used together with other parameters to allow more accurate inferences
Genetic Differentiation of an Endangered Megalobrama terminalis Population in the Heilong River within the Genus Megalobrama
Megalobrama terminalis, which inhabits the Sino-Russian Heilong-Amur River Basin, has decreased critically since the 1960s. It has been listed in the Red Book of Endangered Fish Species by the Russian Federation in 2004. To guide the utilization and conservation programs of M. terminalis in the Heilong River (MTH), 3.1 kb of mitochondrial DNA (mtDNA) concatenated sequences and sequence-related amplified polymorphism (SRAP) markers (15 primer combinations) were applied to explore the genetic divergence and population differentiation of MTH within the genus Megalobrama. Clear genetic divergence between MTH and six other populations of the genus Megalobrama was found by haplotype network (mtDNA) and principal component (SRAP) analyses. Moreover, the STRUCTURE analysis based on SRAP data showed that MTH could be assigned to a particular cluster, whereas conspecific M. terminalis in the Qiantang River and Jinsha River Reservoir belonged to the same cluster. Analysis of molecular variance (AMOVA) and Fst statistics for the mtDNA and SRAP data revealed significant genetic variance and differentiation among all detected populations. Taken together, the results suggest that MTH has a strong genetic differentiation from other populations within the genus Megalobrama, which contributes to effective utilization in artificial cultivation and breeding of MTH. Furthermore, these results also provide a scientific basis for the management of MTH as a separate conservation unit
Evaluation of microplastic polyvinylchloride and antibiotics tetracycline co-effect on the partial nitrification process
This study investigated the co-effect of microplastic polyvinylchloride and antibiotics tetracycline to partial nitrification process in treating high ammonia wastewater. The average ammonia oxidation rate of all reactors was 53.58, 56.17 and 42.08 mg.N/L.h in round 1, round 7 and round 13, respectively. The ammonia oxidation rate was reduced to 89.40%, 79.08%, 80.60%, 73.37%, 69.50%, 75.72%, 98.93% and 66.04% from 1st round of test to 13th round of test at reactor R1 to R8. The average nitrosation rate was always over 80% in all conditions tested. Tetracycline removal rate was attributed to sludge adsorption in all reactors and was increased continuously with the increment of tetracycline concentration. The nitrous oxide emission was keep decreasing from round 1 to round 13 in all reactors tested. The microbial community results revealed that with the existence of tetracycline and microplastics, the relative abundance of Bacteroidetes were reduced and Proteobacteria were increased
Study on the co-effect of maifanite-based photocatalyst and humic acid in the photodegradation of organic pollutant
In this study, the co-effect of clay mineral-based photocatalyst and humic acid on the photodegradation of dye was revealed for the first time. The clay mineral-based photocatalyst, maifanite/g-C3N4, was prepared using the co-calcining method. The physical and chemical properties of the maifanite/g-C3N4 photocatalysts with various ratios were characterized by multiple characterization methods, including SEM, XPS, BET, UV-Vis, FTIR, contact angle, and XRD. The respective degradation experiment of humic acid and RhB was performed using maifanite/g-C3N4 photocatalysts. The degradation process of mixture solution of humic acid and RhB was measured using EEM and UV-vis. The result indicates that in the presence of humic acid, low ratio of maifanite/g-C3N4 inhibits the production of by-products derived from the interaction of humic acid and the degradation of RhB. However, high ratio of maifanite/g-C3N4 is not conducive to the degradation of RhB. The ratio of 1:3 for maifanite/g-C3N4 is optimal for the photodegradation of RhB in the presence of humic acid. This article provides a new perspective to develop the co-effect of clay mineral and humic acid in the photodegradation of organic pollutant
巢湖沿岸带底栖动物群落结构及其环境质量评价
2013年3月、6月、9月和11月四个季度对巢湖沿岸带24个站点(12个区域)底栖动物进行调查,分析了群落结构特征并进行环境质量评价。本次调查共采集到底栖动物64属种,以寡毛类和水生昆虫为主,合计占总种类数的68.7%。底栖动物的平均密度和平均生物量(无灰干重)分别是(1005±233)ind./m^2和(2.24±1.29)g/m^2。巢湖沿岸带底栖动物优势类群为颤蚓类和摇蚊幼虫。利用底栖动物种类数、寡毛类密度占比、摇蚊幼虫密度占比和软体动物密度占比四个指标,对巢湖沿岸带环境质量进行综合评价,结果显示巢湖东岸环境质量优于西岸,靠近合肥市的万年埠处于严重污染状态。典型对应分析结果表明,影响底栖动物群落结构的主要环境因子有底质、电导率和总氮。建议通过改善底质环境,恢复水生植被,削减总氮等措施来恢复巢湖沿岸带底栖动物群落多样性,提高巢湖生态环境质量
微藻种质资源库--藻类科学研究和产业发展的重要平台
微藻是指一类形态微小,能够进行光合作用,以单细胞或简单多细胞形式存在的藻类。作为一类重要的生物资源,活体微藻的保藏和共享服务是开展藻类科学研究和藻类产业发展的必要平台和基础。坐落于中国科学院水生生物研究所的淡水藻种库(FACHB-Collection)正式成立于1973年, 1996年作为创会成员加入中国科学院典型培养物保藏委员会;2019年成为国家水生生物种质资源库的核心成员。该库保藏逾3400株微藻,隶属于9门169属。年均为国内外用户提供2500株藻株,并提供藻种鉴定、分离纯化和培养技术等方面的服务和咨询。文章回顾了国际微藻种质资源库的发展历史和现状,介绍了国内微藻种质资源保藏情况,着重介绍国家水生生物种质资源库--淡水藻种库在库藏藻株多样性、共享服务、藻株无菌化、超低温保藏技术及优良品种选育与应用等方面的进展,瞄准提升我国在藻类学研究和藻类产业研发的竞争力,提出了藻种资源库未来发展的建议
多倍体银鲫nanos2等位多态性、共线性和表达模式分析
为研究生殖干细胞(Germline stem cells, GSCs)的标记基因nanos2的功能,在银鲫(Carassius gibelio)中克隆了两个nanos2的同源基因(Homologs),将其命名为Cgnanos2a和Cgnanos2b,等位、系统进化树和共线性分析表明,在银鲫进化历程中发生了额外的两轮多倍化事件,是一个异源六倍体。qPCR分析表明Cgnanos2a和Cgnanos2b在5月龄银鲫精巢中的表达水平最高,其次是卵巢;对在孵化后25-190d的卵巢中的表达动态分析表明,孵化后25d的卵巢中的Cgnanos2a和Cgnanos2b转录水平最高,随后表达水平急剧下降;并且Cgnanos2a和Cgnanos2b呈现出偏向表达的特征。切片RNA原位杂交实验结果表明, Cgnanos2a和Cgnanos2b均特异地在银鲫卵巢邻近生殖上皮的胞囊(Cyst)中一类直径小于20 μm的细胞中表达, Cgnanos2a在精巢精小囊边缘一类单个或两个紧紧相邻的细胞中高表达,推测是银鲫的GSCs。此外,还可在精原细胞和初级精母细胞中检测到Cgnanos2a和Cgnanos2b的转录本。研究通过对nanos2阳性细胞的追踪描绘了银鲫卵巢早期胞囊的发育过程,为后续分离银鲫GSCs奠定了基础;同时对银鲫nanos2两个歧化的部分同源基因的序列特征、进化及表达特征分析,为研究鱼类多次多倍化事件后重复基因的进化提供了一个典型例子
蓝藻胞外多聚物生物合成、群体形成与微囊藻水华
有毒微囊藻水华在太湖、巢湖和滇池等饮用水源地频繁暴发,对居民健康和水产养殖等构成严重威胁,亟需开发新技术加以有效控制和利用。在水华暴发时,蓝藻大量分泌胞外多聚物而形成细胞群体,是蓝藻水华发生的关键和前提。蓝藻群体中胶质状胞外多聚物由胞外多糖、蛋白质和其他生物大分子组成,对其结构、功能和生物合成途径研究了解仍然有限。生物信息学和比较基因组学分析发现微囊藻和其他多种蓝藻中编码大量的具有称之为PEP-CTERM结构域的潜在胞外蛋白质,这些潜在的蛋白质可能通过特殊的分选系统分泌到细胞表面,与胞外多糖相互作用形成结构更复杂的胞外多聚物,介导细胞群体的形成和水华发生。亟需建立微囊藻遗传操作技术,深入揭示胞外多聚物生物合成和群体形成的分子机制,寻找控制蓝藻胞外多聚物的组装和分泌及群体形成的关键靶点,将有助于揭示蓝藻水华形成机理及开发新型控藻技术