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排序方式: 共有476条查询结果,搜索用时 62 毫秒
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高通量测序技术广泛应用于环境真核微生物多样性的研究,可检获较之传统形态学方法更高的多样性。然而,检获的高分子多样性与基于形态的物种多样性在构成上的差异仍然不明。本研究首次对比分析了基于形态学的南黄海沉积物中的纤毛虫物种多样性与基于核糖体18S DNA和c DNA高通量测序的多样性异同。结果表明:形态鉴定获得8纲、20目、30科、36属共97种纤毛虫;DNA测序检获10纲、28目、55科、76属共174个OTUs;而通过c DNA测序获取的纤毛虫多样性最高,获10纲、31目、68科、99属共284个OTUs。研究发现,形态学方法检获的纤毛虫均为底栖生纤毛虫;两种分子手段检获的多样性更高,群落结构更为近似,覆盖了形态鉴定所获的绝大部分类群。但DNA测序还检获了序列比例高达90%的浮游类群,可能源于包囊或死亡沉降的物种;而c DNA测序检获了约7%的浮游纤毛虫序列。较之DNA测序,c DNA法检获的底栖纤毛虫在群落结构上与形态学结果更为接近。本研究表明,分子手段有助于更全面地揭示沉积物中的纤毛虫多样性,DNA测序可同时揭示休眠包囊、胞外DNA及过去群落的信息,而c DNA测序在研究活动纤毛虫多样性上更有优势。 相似文献
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CAI Xiaopeng QU Meng DING Shaoxiong WANG Hangjun WANG Hongjie HU Luyi SU Yongquan 《海洋学报(英文版)》2013,32(6):40-46
Two morphotypes of Plectropomus leopardus have been identified; morphometric and meristic analyses show that there is no diagnostic difference between them. A difference in color pattern was the most appropriate phenotypic character with which to distinguish between the two morphotypes. Complete mitochondrial DNA sequencing, however, indicated a clear difference between the two morphotypes. Barcoding analysis revealed no significant difference (P>0.05) in CO1 or ND2 divergence among intramorphotypic individuals, even between geographically separated populations, whereas the intermorphotypic CO1 and ND2 divergences were large enough (averaging 0.95% for CO1 and 1.37% for ND2) to clearly discriminate between the two morphotypes. The color pattern difference, geographical distribution, together with the mtDNA and barcode sequencing data, suggest that the two morphotypes should be of two subspecies or even two species. 相似文献
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采用线粒体D-loop区测序技术,对巢湖、滆湖、洪泽湖、鄱阳湖和太湖5个地理群体的黄颡鱼(Pelteobagrus fulvidraco)遗传多样性及种群遗传结构进行了研究。结果表明,890个位点中变异位点有151个,简约信息位点24个。143个个体共检测到72个单倍型,平均单倍型多样性指数为0.951±0.011,核苷酸多样性为指数为0.00614±0.00087。鄱阳湖群体和其它4个湖泊群体的遗传距离相对比较大,滆湖和巢湖的遗传距离最小,总体遗传分化指数Fst为0.0896(P<0.01)。群体间基因流系数Nm=2.22,表明5个黄颡鱼种群间存在着一定的基因流动。 相似文献
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采用荧光染色法对黄、东海春、秋季中华哲水蚤(Calanus sinicus)个体核酸含量进行了研究,初步探讨了RNA∶DNA比对中华哲水蚤生长状况的指示作用。结果表明,中华哲水蚤在饥饿培养24h后RNA∶DNA比值显著降低;雄性个体RNA含量和RNA∶DNA比值显著低于雌体和C5期幼体;春、秋季(2009年5月和2010年11月)个体RNA含量和RNA∶DNA比值存在显著的空间变化,两者最高值均出现在近岸;两个月份DNA含量相对稳定,在2.5—3.5μg/ind之间;个体RNA含量和RNA:DNA比值与叶绿素之间显著正相关,说明饵料是中华哲水蚤的生长过程中重要的影响因素。 相似文献
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Groundwater plays an important role in New Zealand water supplies and hence monitoring activities are conducted regularly. Most monitoring programmes aim to evaluate groundwater chemistry and almost completely overlook the microbial component in this ecosystem. In our present study, the bacterial community structure of groundwater in the Wairarapa Valley was examined using the terminal restriction fragment length polymorphism (T-RFLP), and relationships between bacterial community structure and groundwater chemistry, aquifer confinement and groundwater usage were explored. In addition, the results from this study were compared with a previous T-RFLP survey of the same area in an attempt to detect changes in bacterial community structure over time. The data obtained suggested that bacterial community structure was related to groundwater chemistry, especially to redox conditions. Species composition showed minimal variation over time if groundwater chemistry remained unchanged. These findings reflect the potential of using bacterial communities as biological indicators to evaluate the health of groundwater ecosystems. We suggest that it is important to include this type of broad bacterial diversity assessment criteria into regular groundwater monitoring activities. 相似文献
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Elucidating the scale of gene flow among populations is an important challenge for understanding the ecological dynamics and local adaptation of marine organisms. We assessed whether gene flow is restricted even at a small spatial scale in the Japanese common intertidal goby Chaenogobius annularis, using highly polymorphic DNA markers, involving the mitochondrial DNA (mtDNA) control region and 15 microsatellite DNA (msDNA), because past ecological studies have suggested low dispersal ability for rocky intertidal fishes. We found significant heterogeneities between four neighboring local populations by both mtDNA and msDNA analyses. In addition, no genetic heterogeneity was detected by either method across generations within a population; it was considered that such genetic differentiation is retained across generations and that the gene flow of this species is restricted to within a radius of a few kilometers. This is the first report showing a clear genetic subdivision in rocky intertidal fish. 相似文献