Probing the heparin-binding domain of human antithrombin III with V8 protease

From structural analysis on genetically abnormal and chemically modified human antithrombin III [Koide, T., Odani, S., Takahashi, K., Ono, T. and Sakuragawa, N. (1984) Proc. Natl Acad. Sci. USA 81, 289-293; Chang, J.-Y. and Tran, T. H., (1986) J. Biol. Chem. 261, 1174-1176; Blackburn, M. N., Smith, R. L., Carson, J. and Sibley, C. C. (1984) J. Biol. Chem. 259, 939-941], the heparin-binding site of antithrombin III has been suggested to be in the region of Pro-41, Arg-47 and Trp-49. In this study the heparin-binding site was probed by preferential cleavage of V8 protease on heparin-treated and non-treated native antithrombin III. The study has been based on the presumption that the heparin-binding site of antithrombin III is situated at exposed surface domain and may be preferentially attacked during limited proteolytic digestion. Partially digested antithrombin III samples were monitored by quantitative amino-terminal analysis and amino acid sequencing to identify the preferential cleavage sites. 1-h-digested antithrombin III was separated on HPLC and peptide fragments were isolated and characterized both qualitatively and quantitatively. The results reveal that Glu-Gly (residues 34-35), Glu-Ala (residues 42-43) and Glu-Leu (residues 50-51) are three preferential cleavage sites for V8 protease and their cleavage, especially the Glu-Ala and the Glu-Leu sites, was drastically inhibited when antithrombin III was preincubated with heparin. Both high-affinity and low-affinity antithrombin-III-binding heparins were shown to inhibit the V8 protease digestion of native antithrombin III, but the high-affinity sample exhibited a higher inhibition activity than the low-affinity heparin. These findings (a) imply that the segment containing residues 34-51 is among the most exposed region of native antithrombin III and (b) support the previous conclusions that this region may play a pivotal role in the heparin binding.     

黄河兰州段鱼类多样性与保护

兰州市是黄河唯一穿城而过的省会城市, 是黄河流域综合治理与高质量发展的重要区域, 了解其鱼类多样性现状及变化趋势对黄河流域水生态保护尤为重要。本文于2020年7-10月对黄河干流兰州段及其4条支流(庄浪河、大通河、湟水河和宛川河)开展了鱼类多样性、分布及影响因素调查, 以Shannon-Wiener多样性指数、Pielou均匀度指数、Simpson优势度指数、Cody和Routledge指数、Bray-Curtis相异性系数对黄河兰州段5条河流鱼类群落进行评估, 同时通过相对多度(relative abundance, RA)判定优势种, 利用非度量多维标度排序(non-metric multidimensional scaling, NMDS)展示物种空间分布格局。本次调查获得鱼类20种, 隶属于4目6科15属。其中, 国家II级重点保护野生动物1种, 受威胁鱼类4种, 中国特有鱼类7种, 黄河特有鱼类4种。区系组成属青藏高原区高原西北亚区, 其中鲤形目种类占绝对优势, 优势种为东方高原鳅(Triplophysa orientalis)、粗壮高原鳅(T. robusta)、鲫(Carassius auratus)和麦穗鱼(Pseudorasbora parva)。庄浪河和黄河干流的α多样性较高。β多样性分析结果表明, 黄河干流与庄浪河、大通河、湟水河和宛川河间的鱼类物种明显不相似; 大通河与湟水河之间以及黄河干流与宛川河之间的鱼类物种组成相似性较高。NMDS分析表明, 黄河兰州段鱼类被划分为地理空间上相近的4个地理群。水利设施建设、外来物种和水体污染可能影响了黄河兰州段鱼类多样性和分布。本研究为黄河兰州段鱼类多样性保护和科学管理以及黄河流域生态保护和高质量发展提供了基础调查数据。     

汾河入黄口夏季微生物群落结构分析

【背景】河流交汇区日益成为流域生态治理的焦点和热点之一。【目的】探明汾河入黄口微生物群落结构及其主要环境影响因子。【方法】应用16S rRNA基因Illumina MiSeq高通量测序技术,分析了汾河入黄口夏季微生物群落结构,并利用典范对应分析(Canonical correspondence analysis,CCA)了解影响微生物群落的主要环境因子。【结果】多样性指数分析表明该区域微生物群落多样性较高。微生物多样性分析发现优势菌门为变形菌门(Proteobacteria)、厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)和放线菌门(Actinobacteria);在属分类水平上,相对丰度最高的菌属为芽孢杆菌属(Bacillus),其次为乳球菌属(Lactococcus)和hgcI_clade。Spearman相关性分析及典范对应分析表明环境因子对水体微生物群落结构具有显著影响。【结论】汾河与黄河微生物群落组成具有一定的差异,不同环境因子对不同微生物的影响程度不同,p H和溶解氧(Dissolved oxygen,DO)是汾河入黄口微生物群落结构的主要影响因子。     

罗霄山脉地区鱼类物种多样性

罗霄山脉是赣江和修水流域与湘江流域的分水岭, 是中国生物多样性保护的关键地区之一。然而, 罗霄山脉地区的鱼类缺乏系统性的研究, 其鱼类物种组成、分布以及受威胁因素尚不清楚。为此, 我们于2014-2018年对罗霄山脉地区11条河流的鱼类进行了系统的调查。结果表明, 该地区共有鱼类5目17科64属113种, 山脉东坡鱼类108种, 高于西坡的72种。从生态类型看, 罗霄山脉鱼类以肉食性、底栖性、定居性类群为主。区系组成上以东亚江河平原类群为主。从物种多样性看, 遂川江、袁水、蜀水和修河的鱼类物种多样性较高, 锦江和富水的鱼类物种多样性较低; β多样性指数揭示遂川江与锦江、禾水、富水间鱼类物种出现一定的分化现象。     

Towards the assessment of the trophic status of South African impoundments for management purposes: Bon Accord Dam

The 1 mg/l phosphate effluent standard legislated in South Africa in 1980 in seven sensitive catchments, and ad hoc eutrophication-related requests, necessitated the monitoring of 53 impoundments throughout the country. Variables that were monitored, and are still being monitored in some cases, included nutrients, chlorophyll a, algal identification, suspended solids and other major inorganic constituents. The measurement of temperature and oxygen profiles was conducted on an ad hoc basis when the sites were visited. The results, as determined from data collected between 1989 and 1998, indicated a range of trophic states from oligotrophic to hyper-eutrophic in the sensitive catchments. The catchments that were covered in the survey are: the Vaal River, Crocodile River (North West Province), Pienaars River, Olifants River (Mpumalanga Province), Letaba River, Buffalo River, Berg River, White Mfolozi River, Mgeni River, Mlazi River and the Molopo River catchments.

The objective of this paper is to discuss the methods, variables and presentation for determining the trophic status of an impoundment for management purposes by using findings in the Bon Accord Dam, a small reservoir near Pretoria. The trophic status of selected impoundments was determined by using the mean total phosphorus (TP) concentrations, the nitrogen to phosphorus ratio, the mean chlorophyll a concentration, the presence of cyanobacteria and the turbidity (measured by means of Secchi disc readings) of the system.

The mean annual phosphorus concentrations dropped from more than 800μg/l to less than 100μg/l in three years, and have remained at that level since 1987. The authors suggest that further reductions in phosphorus input are necessary to prevent eutrophication in the reservoir.     

The influence of flow impoundment and river regulation on the distribution of riverine macroinvertebrates at Mammoth Cave National Park, Kentucky, U.S.A.

The effects of impoundment by a low-head dam and hypolimnetic release from a reservoir on benthic macroinvertebrate assemblages were studied in two lowland rivers. The first river (Green River) was initially divided into three zones (impounded, transitional, erosional) according to hydrological characteristics. The entire reach of the second river (Nolin River) was a regime unit. Only the Green River erosional zone was free-flowing with a linear sequence of riffle-run-pool reaches. A detrended correspondence analysis showed that the Green River impounded and transitional zones were taxonomically indistinguishable while the Green River erosional zone and the Nolin River were each distinct. A canonical correspondence analysis revealed that higher surface velocity, higher summer water temperatures and more turbid conditions, and lower water temperatures were contributing parameters to the separation of the Green River erosional zone, Green River transitional/impounded zones, and the Nolin River, respectively, in ordination space. A series of one-way ANOVA’s testing for differences of macroinvertebrates assemblages between the three Green River zones according to five metrics showed that the Green River erosional zone demonstrated significantly higher values and the transitional and impounded zones were ecologically similar.     

Sediment microbial enzyme activity as an indicator of nutrient limitation in the great rivers of the Upper Mississippi River basin

We compared extracellular enzyme activity (EEA) of microbial assemblages in river sediments at 447 sites along the Upper Mississippi, Missouri, and Ohio Rivers with sediment and water chemistry, atmospheric deposition of nitrogen and sulfate, and catchment land uses. The sites represented five unique river reaches—impounded and unimpounded reaches of the Upper Mississippi River, the upper and lower reaches of the Missouri River, and the entire Ohio River. Land use and river chemistry varied significantly between rivers and reaches. There was more agriculture in the two Upper Mississippi River reaches, and this was reflected in higher nutrient concentrations at sites in these reaches. EEA was highest in the two Upper Mississippi River reaches, followed by the lower Missouri River reach. EEA was generally lowest in the upper Missouri River reach. Canonical correlation analysis revealed a strong correlation between EEA and the suite of water and sediment chemistry variables, and the percent of the catchment in anthropogenically dominated land uses, including agriculture and urban development. Nutrient ratios of the waters and sediments suggested carbon (C), nitrogen (N), or phosphorus (P) limitation at a large number of sites in each reach. C-limitation was most pronounced in the unimpounded Mississippi River and lower Missouri River reaches; N-limitation was prevalent in the two Missouri River reaches; and P-limitation dominated the Ohio River. Linking microbial enzyme activities to regional-scale anthropogenic stressors in these large river ecosystems suggests that microbial enzyme regulation of carbon and nutrient dynamics may be sensitive indicators of anthropogenic nutrient and carbon loading.     

Influence of toxic chemicals on the chemotactic response of fish macrophages

The chemotactic efficiency of macrophages isolated from the kidney of spot, Leiostomus xanthurus , and hogchoker, Trinectes maculatus. was determined in fish captured from the York River and the heavily polluted Elizabeth River (Virginia). Chemotactic activity was quantified in Boyden chambers using Escherichia coli as the chemotactic stimulus. Macrophage chemc-taxis was found to be markedly reduced in the Elizabeth River fish as compared to York River controls. Chemotactic migrations of macrophages at 90 min were 55% and 33% for control and experimental spot, respectively. Values for control and experimental hogchoker were 85% and 56%, respectively. The macrophage chemotactic activity of Elizabeth River fish returned to normal (spot, 56%; hogchoker, 80%) after the fish were held in clean water for 3 weeks. This indicates that the decreased chemotactic activity was related to exposure to Elizabeth River pollutants but may be reversible.     

Revision of the species composition of the wood mice from the genus Sylvaemus from the territory of Rostov oblast using karyological, allozyme and molecular genetic analysis

Using karyological, allozyme, and molecular genetic analysis, habitation of the four Sylvaemus wood mice species, pygmy wood mouse (S. uralensis), wood mouse (S. sylvaticus), yellow-necked mouse (S. flavicollis), and yellow-bellied mouse (S. fulvipectus) in Rostov oblast was demonstrated. Sylvaemus uralensis was distributed nearly over nearlythe whole territory of the oblast; S. sylvaticus was found in the central and western parts of the oblast on the right bank area of Don River; S. flavicollis inhabited northern and central parts of the right bank area of Don River; S. fulvipectus was found in the southern parts of the oblast, in the left bank area of Don River. Using the chromosome C-banding technique, it was demonstrated that the pygmy wood mice living in Rostov oblast in the right bank areas of Manych River and Don River in its low course, belonged to the eastern European chromosomal form of S. uralensis. The mice from the outskirts of the town of Salsk, the left bank area of Manych River, were probably hybrids between eastern European and southern European chromosomal forms. Based on the mitochondrial DNA cytochrome b gene fragment sequencing and chromosome C-banding, it was suggested that the wood mice inhabiting Rostov oblast belonged to the southern lineage of S. sylvaticus, living on Apennine Peninsula, Balkan Peninsula, and nearly throughout Ukraine.     

松花江流域大型底栖动物群落结构与水质评价

【目的】松花江流域是中国最早的工业基地之一,其水生态环境遭到严重破坏,环境保护工作面临巨大挑战。开展松花江流域水质评价及典型生物类群多样性状况调查,可为松花江流域生态系统的保护和修复提供依据。【方法】于2016年7月调查整个松花江流域近岸的大型底栖动物群落组成和测定水质理化指标,开展其水质理化特征评价和生物指数评价,并探讨底栖动物群落分布与水环境因子间的关系。【结果】理化指标评价结果显示,南源松花江水质状况最差,处于中度污染;北源松花江处于轻度污染;梧桐河水质最好,处于良好状态。松花江流域3个河段的底栖动物群落结构存在空间差异性。另外,梧桐河的物种多样性最高,北源松花江次之,南源松花江最低。溶解氧和营养元素K的浓度是驱动底栖动物群落组成发生显著性差异的主要环境因子。生物指数评价结果显示,3个河段水质均处于轻度污染状态。【结论】松花江流域水质处于轻度到中度污染状态。有机污染是松花江流域面临的主要水质环境问题,对松花江流域底栖动物群落结构产生了显著影响。因此,控制有机质的输入是维持松花江流域水生态系统平衡的重要举措之一。     

A step-wise discriminant analysis of the effects of long term coal mine drainage and coal dredging on phytoplankton of the Guyandotte River

Phytoplankton was sampled from the lower 60 miles portion of the Guyandotte River where three active coal dredging operations presently exist and five more permits are pending. Comparisons were made with phytoplankton from a similar stretch of the Mud River, a stream of minimal mine drainage and no coal dredges along its entire course.Diatoms were the predominant planktonic algae on both streams. The number of all phytoplankton species was 24% higher for the Mud River than for the Guyandotte River. Equitability and species diversity indices plus the distribution of mine water indicator algae show that the Guyandotte River is heavily polluted with domestic wastes and mine drainage. No correlation could be established for turbidity, specific conductance, or pH and locations of dredging operations, when the data were analyzed for differences among sampling stations.Step-wise discriminant analysis was used to compare the two streams and the biological, physical, and chemical variables. Based on coefficients for canonical variables, conductivity and pH are the two most influential variables in separating the two streams. Analysis of variance indicates that the canonical means of the stations on the Guyandotte River are significantly different from the Mud River stations.     

基于PSR的黄河河口区生态系统健康评价

根据压力-状态-响应(PSR)框架模型,从广义上定义河口区生态系统,将河口及毗邻的陆域、海域生态系统作为一个整体,从压力指标、状态指标、响应指标3个方面构建了黄河河口区生态系统健康评价的指标体系,以研究区1991年数据和相关国家标准为基准,2013年代表现况,利用综合指数法(CEI)评价了黄河河口区的生态系统健康状况。结果显示:黄河河口区生态系统健康评价的响应指数最高(0.9055),压力指数居中(0.8288),状态指数最低(0.6458),综合指数为0.7427。总体来看,与1991年相比,目前黄河河口区生态系统仍处于"健康"状态,但健康状况明显下降,其中状态指数下降最为严重。从区域轻度开发到人类活动强烈干扰阶段,黄河河口区存在过度捕捞、湿地不合理开发、浅海养殖过度及污染物排放等一系列影响生态系统健康的问题,应进行区域的生态恢复和科学管理。     

中国大鲵四种群的遗传结构和地理分化

为了确定栖息地的破碎化和片断化引起中国大鲵的地理分化和遗传结构变异,本文测定了来自广西、河南、陕西和湖南4个地理种群的28条大鲵的mtDNAD loop基因全序列。根据这4个地理种群的地理分布,分成珠江单元(广西种群)、黄河单元(河南种群)和长江单元(湖南和陕西种群)。通过ClustalX、MEGA2.0、DnaSP4.0、Arlequin1.1分析发现,全序列长度为771bp,其中64个多态性核苷酸变异位点,占全部碱基数的8.26%。转换和颠换分别为6和2个,插入/缺失11个。27个单倍型间的序列差异平均为1.32%。3个单元的单倍型多样性指数和核苷酸多样性指数值都偏低,而且珠江单元的这两个指数值都低于长江和黄河两个单元。珠江单元和黄河、长江单元之间分化程度显著(P<0.001),而长江和黄河单元之间差异不显著(P>0.05)。地理单元内分化程度占99.31%,而单元间只有0.69%,表明遗传差异主要发生在单元内,而且各地理单元之间的基因流较频繁。构建的NJ树和MP树显示,27个单倍型呈现一种混杂的分布格局,并未分成代表3个地理单元的聚合群。     

Genetic diversity and population structure of white-spotted charr, Salvelinus leucomaenis, in the Lake Biwa water system inferred from AFLP analysis

The genetic variations—and the time dependence of such variations—of natural populations of the white-spotted charr ,Salvelinus leucomaenis, in the Lake Biwa water system as well as those of a hatchery-reared population were inferred from AFLP. Upon the application of principal coordinate analysis using 118 polymorphic AFLP fragments based on the Jaccard similarity index, specimens of each of six natural local populations from the inlet rivers of Lake Biwa grouped roughly together, suggesting that each local population was genetically differentiated. The hatchery-reared population was shown to be closely related to the local population in the Seri River, suggesting that the Seri River population originated from hatchery-reared charr due to extensive stocking. Furthermore, specimens of the Yasu River grouped in a somewhat different position from the other natural populations, agreeing well with its geographic distance from the other populations. The nucleotide diversities of six natural populations (Harihata River, Ishida River, two reaches of the Takatoki River, Ane River, and Yasu River) in 2002 or 2003 were relatively low (π = 0.067–0.146%) compared with that of the Seri River (0.278%) and the hatchery-reared charr (0.316%). The nucleotide diversity in the five local populations (Ishida River, two reaches of the Takatoki River, Ane River, and Yasu River) remained at a low level from 1994 to 2002/2003, but only the nucleotide diversity in the Harihata River actually decreased. From 1994 to 2002/2003, the nucleotide diversity in the Seri River remained at a higher level among the natural populations from 1994 to 2002/2003; it was enhanced by the artificial release of hatchery-reared charr before 1994. In order to conserve the genetic diversity of the white-spotted charr in the Lake Biwa water system, it is necessary to prevent the stocking of hatchery-reared charr in reaches where hatchery-reared charr have not previously been stocked.     

Introduced populations as genetic reservoirs for imperiled species: a case study of the Arkansas River Shiner (Notropis girardi)

The Arkansas River Shiner is a threatened species that has been extirpated throughout much of its native range (Arkansas River drainage) and remaining populations are imperiled. Prior to 1978, this species was accidently introduced to the Pecos River (Rio Grande drainage) via bait bucket, and has since persisted for over 30 years. Genetic data show that the Pecos River population maintains comparable levels of diversity at mitochondrial DNA and microsatellite loci relative to native range populations. Hence, we examined several factors that could be responsible for high introduced genetic diversity including (a) multiple introductions from genetically distinct sources (b) introduction of individuals from a genetically diverse source followed by rapid population expansion, (c) presence of life-history traits that foster propagule diversity and wide spatio-temporal demographic and genetic mixing; and (d) introduction to a suitable habitat in the non-native range. Our findings indicate Arkansas River Shiner was likely introduced from the Canadian River and subsequently experienced rapid population expansion that mitigated loss of diversity during the founding event. Threats to native Arkansas River Shiner have increased due to ongoing drought and water resource development, thus a finding of high diversity in the Pecos River suggests conservation significance of this non-native population. Further, it identifies the Pecos River as both a refuge for native endemic fishes and of genetic diversity of introduced, yet threatened, species.     

基于理想参照系-关键指标的赤水河流域生态系统质量变化趋势分析

赤水河流域是长江上游重要的生态安全屏障,针对赤水河流域经济开发与生态环境保护的突出矛盾,基于MODIS数据产品提取赤水河流域2000—2018年归一化植被指数（NDVI）、叶面积指数（LAI）、表层水分含量指数（SWCI）和陆地表面温度（LST）生态系统质量关键指标,利用ENVI主成分分析构建遥感生态指数（RSEI）,计算赤水河流域2000—2018年生态系统质量,进行Sen+Mann-Kendall趋势分析,并与贵州习水自然保护区林地最优状态下RSEI值进行比较,进而量化区域生态系统质量恢复潜力,为赤水河流域生态恢复、绿水青山就是金山银山重要理论实现提供科学参考。结果表明：RSEI能够很好地反映赤水河流域生态系统质量时空分布特征,且绿度和湿度对赤水河流域生态系统质量起关键作用。赤水河流域RSEI平均值为0.613,高值区域主要分布在下游湿润常绿阔叶林区,中游河谷中山阔叶林林、常绿针叶林区,上游镇雄县、威信县和叙永县交界处的高山常绿针叶林、落叶阔叶林区。赤水河流域近20年生态系统质量以整体以改善为主,但局部仍出现退化现象,其中生态系统质量显著改善面积占总面积的6.12%,轻微改善面积占59.51%,轻微退化面积占23.17%,显著退化面积占1.49%。赤水河流域林地RSEI值与理想参照系RESI值差距在10%以上面积占林地总面积的49.82%,主要分布在大方县、桐梓县、播州区及怀仁市、习水县部分地区。     

线粒体全基因组揭示嫩江流域史前人群遗传结构的动态变化

嫩江流域是中国东北地区古代先民的重要栖息地之一。自新石器时代开始这里的先民一直以渔猎经济为主要生活方式,直到新石器时代晚期至早期青铜时代才开始兼营畜牧业和少量的种植业。嫩江流域青铜时代的生业模式的转变是否伴随着外来人群的融合与替代一直是考古研究的热点。为了探讨嫩江流域新石器时代与青铜铁器时代人群的构成是否改变,我们对嫩江流域新石器时代至青铜铁器时代的24个个体进行了线粒体全基因组分析。分析结果表明：嫩江流域青铜铁器时代人群与新石器时代人群具有一定遗传连续性的同时,晚期人群与西辽河地区古代人群有着更近的遗传联系,表明西辽河地区古代居民对嫩江流域青铜铁器时代人群具有部分遗传贡献。结合考古学文化、古气候学数据以及语言学证据,我们推测距今4000-3000年间,西辽河地区古代居民曾迁入到嫩江流域,并留下遗传印记。     

塔里木河流域生态系统健康评价

通过收集2000 年以来塔里木河流域的生态、经济和社会状况资料,分析影响该流域生态系统健康的因素,采用指标体系分析法和专家咨询法,确立塔里木河流域生态系统健康评价指标体系和评价标准,计算得出流域生态健康评价指标权重,并对流域生态健康状况进行了评价.结果表明:塔里木河源流的阿克苏河、叶尔羌河和开都河-孔雀河流域的山区生态系统的健康状态处于"中等"级别,和田河流域的山区生态处于"优"级别;阿克苏河、叶尔羌河和和田河流域的平原绿洲区生态处于"优"级别,开都河-孔雀河流域的平原绿洲区生态处于"中等"级别;四源流的荒漠区生态处于"差"级别;塔里木河干流上游生态处于"优"级别,中游生态处于"中等"级别,下游生态处于"差"级别.评价结果基本与实际相符,说明使用的评价方法是切实可行的.该研究结论将为流域生态环境的综合治理提供科学依据.     

雅鲁藏布江流域底栖动物多样性及生态评价

雅鲁藏布江起源于喜马拉雅山,是世界上海拔最高的河流之一,是流经我国西藏境内重要的国际河流,其河流生态系统具有特殊地貌及生态条件。研究该流域底栖动物多样性分布特征及其影响因子,是科学评价该区域河流生态系统健康状况,实现资源可持续开发利用的基础。2009年10月—2010年6月期间,以底栖动物作为指示物种,对雅江流域干支流及堰塞湖的14个采样断面进行河流生态评价。采用Alpha及Beta生物多样性指数分别指示局部采样河段及全区域的底栖动物多样性。对采样断面底栖动物组成分析发现:14个采样断面共采集到底栖动物110种,隶属57科102属。雅江干流底栖动物种类数最高为29,平均为19。支流年楚河种类数为17。支流拉萨河,尼洋河,帕龙藏布的最高种类数分别为25,33,36;平均种类数分别为21,21,22,生物多样性普遍高于干流。整个流域中底栖动物平均种类数相差不大,但种类组成和密度相差较大。调查区域的Beta多样性指数β高于低海拔地区的相似的山区河流,说明雅江流域内底栖动物群落差异性高于正常海拔地区。对14个采样断面的物种组成进行除趋势对应分析表明:影响雅江流域底栖动物多样性的主要因素为河型,河床阻力结构,堤岸结构,水流流速。保持稳定的阶梯-深潭结构和自然堤岸结构,以及适宜的流速有利于保护雅江河流生态。     

安徽省淮河水系短颌鲚群体遗传多样性

短颌鲚(Coilia brachygnathus)是一种小型经济鱼类,同时也是大型肉食性鱼类和江豚(Neophocaena phocaenoides)的饵料,在食物链中占据重要地位,受过度捕捞、环境污染以及栖息地破坏等多种因素的影响,短颌鲚野生资源面临严重威胁。目前有关淮河短颌鲚遗传资源的数据仍然缺乏。本研究采用微卫星分子标记对安徽省淮河水系短颌鲚5个群体进行遗传多样性分析。结果显示,10个微卫星位点在所有短颌鲚样本中均具有高度多态性,多态信息含量(PIC)0.852～0.942;5个短颌鲚群体均显示出较高的遗传多样性水平,期望杂合度H_e为0.879～0.903,多态信息含量(PIC)0.851～0.881。分子方差分析(AMOVA)显示,大多数遗传变异存在于群体内(97.88%),群体间的遗传变异仅为2.12%。5个群体遗传分化水平较低(F_st <0.05),其中,遗传分化系数最小的是浍河和颍河群体(F_st=0.004)且二者间遗传距离最近(D_a=0.161);遗传分化系数最大的是凤台和王家...