分子系统学在菌物分类研究中的应用

菌物的传统分类主要依赖其形态和生理特征,常引起分类系统意见分歧.分子系统学技术是从遗传的角度反映菌物种群的关系,能更客观地反映菌物的系统进化.通过概述分子系统学的主要技术方法描述了其在菌物系统分类研究中的应用.参28.     

植物生物技术在黑麦草遗传改良中的应用

黑麦草是重要的牧草和草坪草,是畜牧业和草坪业重要的产业支柱.由于高度自交不亲和,传统遗传改良困难而复杂.生物技术尤其是转基因技术为其遗传改良带来希望.本文概述了组织培养技术、基因遗传转化技术、分子标记及数量性状基因定位、分子标记辅助育种等技术在黑麦草遗传改良中的应用及获得的成果;评述了遗传改良的重要意义,以及黑麦草遗传改良的主要目标,如品质改良、提高病害抗性、降低毒性生物碱浓度、控制花粉致敏性、抗除草剂品种的培育、提高抗逆性及其作为生物反应器的潜在应用价值等;并分析了功能基因组学的研究及RNA干扰技术在黑麦草研究中可能的应用前景.     

微卫星标记技术在淡水腹足类种群遗传学研究中的应用

综述了淡水腹足类微卫星位点的获取方法、微卫星重复序列的特点以及微卫星标记技术在其种群遗传学研究中的应用,着重分析了微卫星多态性在淡水腹足类种群遗传多样性、种群遗传结构、遗传分化、交配系统、种群关系研究中的应用.淡水腹足类普遍表现为杂合体缺失,种群遗传多样性降低.淡水腹足类近交和自体受精现象比较频繁以及地理隔离导致种群间遗传分化.利用微卫星标记研究遗传杂合度,结合群体近交系数和基因分化系数在一定程度上反映了淡水腹足类的交配系统.根据不同种群的遗传距离和相似性进行聚类分析在判别种群间的亲缘关系上起到了很大作用.针对淡水腹足类自身的特性,微卫星分子标记技术在淡水腹足类入侵生物学、分类阶元,寄生虫的分子流行病学等研究领域有广泛的应用前景.     

基于psbA基因的噬藻体遗传多样性研究进展

噬藻体作为一类感染蓝藻的特异性病毒,广泛分布于不同水生态系统中。随着水体富营养化的加剧,蓝藻水华频繁爆发,具有潜在控藻能力的生物因子——噬藻体的研究备受关注。目前对于噬藻体的研究主要集中在其分离纯化及生物学特性等,因缺乏广泛通用的分子标记致使其遗传多样性研究受限。以编码光合作用反应中心D1蛋白的psb A基因为靶基因,综述了海洋、淡水环境中噬藻体psb A基因遗传多样性的最新研究进展,分析了噬藻体在不同自然环境中的分布及差异,同时也提出了噬藻体多样性研究中存在的一些问题。     

高等植物线粒体基因组研究新进展

与其它真核生物相比，高等植物线粒体基因组不仅在大小，组织结构．基因组成和表达，RNA编辑等方面具有突出特点，而且线粒体基因组与核基因组之间存在着广泛的信息交流线粒体基因组作为一个半自主性的遗传系统，其组织结构的雏持和生理功能的发挥受到核基因组的调控作用，本文就这些方面的研究进展作了简要评述．     

小分子RNA及其在化学品毒理学中应用的展望

小分子RNA,包括siRNA、miRNA、piRNA等,在基因表达调控过程中扮演了至关重要的角色.对小分子RNA生物发生和功能的认知将有助于促进基因沉默的机制研究和基因治疗.本文归纳了近些年关于小分子RNA的重大研究成果以及应用于毒理学研究的案例,并对毒理学未来研究小分子RNA的重点和方向作出展望.     

功能基因组学在环境化学品毒性机制研究中的应用

认识化学品的毒性机制是开展化学品健康风险评估的基础。掌握化学品有害效应的遗传易感性机制是开展精准的健康风险评估的前提。传统的毒理基因组学主要分析化学品暴露诱导的组学表达图谱,不能建立生物学表型与特定基因/通路表达的直接关联。功能基因组学通过敲除或者敲降全基因组或者特定的基因集,建立基因-化学品毒性的直接关联,进而研究化学品致毒的过程和机制,同时可以提供与化学品暴露的遗传易感性相关的分子响应信息。本论文综述了功能基因组学技术的原理及其主要发展,介绍了酵母、鸡DT40细胞和RNA干扰等功能基因组学测试方法的优缺点。同时,详述了CRISPR功能基因组学的原理和特点,以及其在化学品毒性机制研究中的应用,展望了联合应用分子流行病学和CRISPR功能基因组学,开展化学品有害效应的易感性机制研究。     

分子微生物生态学技术在中国油田开发中的应用

分子微生物生态学技术近年来在研究油藏环境中微生物群落和生态系统等方面得到了广泛的应用,已经成为指导微生物采油技术开发和应用的一个不可或缺的工具.本文较系统地总结了我国利用分子微生物生态学方法研究油藏微生物群落结构的进展,其中包括大庆油田和西北部油田的16SrRNA基因序列分析,胜利油田16SrDNA的荧光标记末端多形态限制性片断分析技术(T-RFLP),以及吉林油田应用的DNA基因跟踪检测技术,并指出了存在问题和研究方向.图1参18     

云南高原异龙湖噬藻体psbA基因遗传多样性研究

噬藻体作为一类感染蓝藻的特异性病毒,广泛分布于不同水生态系统中。作为噬藻体的一种靶标基因,编码光合作用反应中心D1蛋白的基因psbA不仅可用于揭示噬藻体的遗传多样性,还可用于探索噬藻体与其宿主蓝藻之间的关系。该文以云南高原富营养化湖泊异龙湖为研究对象,以psbA基因为分子标记,从异龙湖浓缩水样中共获得15条噬藻体psbA环境序列。基于噬藻体的psbA序列构建系统进化树,分析异龙湖水样噬藻体光合作用基因psbA的遗传多样性。研究结果表明:云南高原湖泊异龙湖水体中噬藻体psbA基因类群与海洋、其他淡水湖和日本稻田水体中psbA基因类群不同,与中国东北稻田的生态类群进化距离较近,进化相对独立。异龙湖水体中存在新的噬藻体类群,并且不同季节水样中噬藻体psbA基因序列存在差异,秋季其遗传多样性更加丰富。     

废水生物强化处理技术研究进展

生物强化技术具有高效去除目标污染物、加速系统启动、提高系统抗水力及有机负荷能力以及优化系统菌群结构和增强功能稳定性等功能,在废水生物处理实际应用中潜力巨大.总结了国内外废水生物强化处理技术研究进展,在功能微生物选育方面,通过传统选育手段与基因工程手段并举来实现;在功能菌应用与生物强化处理工艺方面,主要通过所投加的功能菌直接作用或是利用基因水平转移(HGT)来实现生物强化;在分子检测技术方面,随着分子生物学的发展,一些技术如变性梯度凝胶电泳(DGGE)、核糖体间隔基因分析方法(RISA)及荧光原位杂交(FISH)等在与微生物生态学研究中得到了广泛应用.分析认为,应用分子生物学等先进技术手段,探讨废水生物强化处理工程应用过程中的微生物生态学机制,并以此为指导研发高性能菌剂,将是本领域的研究重点与方向之一.     

Unravelling host and symbiont phylogenies of halichondrid sponges (Demospongiae, Porifera) using a mitochondrial marker

We present the first comparative phylogenetic analysis of a selected set of marine sponges and their bacterial associates. The Halichondrida form an important order in demosponge systematics and are of a particular interest due to the production of secondary metabolites. We sequenced a fragment of the cytochrome oxidase subunit 1 (CO1) gene of the sponges and their bacterial associates, compared the reconstructed phylogenies and found evidence for radiation in coevolution. The tree of six host-species associations showed four supported cospeciation events between the sponges and the bacteria. In addition, we present the first gene tree of sponges based on a mitochondrial marker. The tree shows major congruences with previous morphological studies and suggests the applicability of a mitochondrial marker in sponge molecular systematics.     

Evaluation of combined morphological and molecular techniques for marine nematode (<Emphasis Type="Italic">Terschellingia</Emphasis> spp.) identification

Marine nematodes, which play an important role in many ecosystems, include a number of apparently cosmopolitan taxa that exhibit broad biogeographic ranges even though there is no obvious dispersal phase in their lifecycle. In this study, standard taxonomic approaches to marine nematode identification in conjunction with multivariate statistical analysis of morphometric data were compared with molecular techniques. Specimens of the marine nematode Terschellingia longicaudata that had been identified by their morphological features were investigated from a range of localities (East and West Atlantic, Bahrain, Malaysia) and habitats (estuarine, intertidal, subtidal) using molecular approaches based on the amplification and sequencing of the small subunit ribosomal RNA (18S rRNA). The study revealed that the majority of the morphologically defined T. longicaudata specimens share a single 18S rRNA sequence and apparently belong to a single taxon distributed from the British Isles to Malaysia. In addition, 18S rRNA analysis also revealed two additional sequences. One of these sequences was found in both the British Isles and Mexico, the other was recorded only from British waters. Individuals collected in Bahrain and identified from their morphology as T. longicaudata had two highly divergent 18S rRNA sequences. Separate morphological and morphometric approaches to identification of specimens from the same sites that had been formalin-preserved did not support evidence of multiple genotypes revealed previously by molecular analysis. Current taxonomy based on morphological characters detected using light-microscopy may be unable to discriminate possible species complexes. Biodiversity of marine nematodes may often be underestimated due to the presence of morphologically cryptic species complexes. High-throughput techniques such as DNA barcoding would aid in species identification but may require thorough analysis of multiple nuclear and mitochondrial molecular markers.     

黄杨科植物化学分类学初探

黄杨科（Buxaceae)是有5属60余种植物的小科，系统位置较为复杂，本文讨论了黄杨科植物甾体生物碱成分的结构特征；以甾体生物碱作为化学分类学的特征物质。初步探讨了黄杨科植物化学分类学的依据和系统位置；同时讨论了黄杨属（Buxus)，板凳果属（Pachysandra,又称富贵草属）和野扇花属（Sarcococca)3属间的相互关系。这些结果基本上支持Takhtajan的黄杨科分类系统。     

海洋环境中多环芳烃的微生物降解研究进展

多环芳烃 (PAHs)是一类广泛分布于海洋环境中的含有两个苯环以上的有毒有害污染物 ,主要来源于人类活动和能源利用过程 ,如石油、煤、木材等的燃烧过程 ,石油及石油化工产品的生产过程 ,海上通过地面径流、污水排放及机动车辆等燃料不完全燃烧后的废气随大气颗粒的沉降进入海洋环境中 .由于多环芳烃的潜在毒性、致癌性及致畸诱变作用[1,2 ] ,通过生物累积及食物链的传递作用 ,给海洋生物、生态环境和人体健康带来极大危害 ,已引起各国环境科学家的极大重视 .美国环保局在上世纪 80年代把 16种未带分支的多环芳烃确定为环境中的优先污染物[…     

土壤中抗生素的生态毒性及其分子生物标志物技术的研究进展

抗生素作为抑菌或杀菌药物被广泛应用于畜禽养殖中。不能完全被机体吸收的抗生素经由畜禽排泄物直接进入环境。随着耐药基因和超级病菌的出现,抗生素产生的环境问题引起了广泛关注。土壤是环境中抗生素最主要的累积场所之一,对土壤中抗生素的生态毒性及其分子生物指示指标的研究具有重要意义。本文在总结国内外相关研究的基础上,阐述了抗生素对土壤中微生物、动物和植物所产生的毒性以及分子生物标志物在土壤抗生素污染研究中的应用,并对未来的研究工作进行了展望。     

硝化作用微生物的分子生物学研究进展

回顾了硝化作用微生物的分子生物学研究进展 ,主要介绍了硝化作用微生物的种类 ,包括氨氧化菌、亚硝酸氧化菌、异养氨氧化菌和厌氧氨氧化菌 .这些微生物的系统发育分析表明亚硝化菌的系统发育相对简单 ,而硝化细菌则要复杂许多 .还介绍了在硝化作用微生物生态学研究中应用的分子生物学技术 ,如PCR、变性梯度胶电泳 (DGGE)、原位荧光杂交 (FISH)等 ,以及不同类群细菌中与硝化作用相关的酶类及其基因 .文章的最后还提出了一些研究展望 .图 3参 35     

Using vertebrate environmental DNA from seawater in biomonitoring of marine habitats

Conservation and management of marine biodiversity depends on biomonitoring of marine habitats, but current approaches are resource-intensive and require different approaches for different organisms. Environmental DNA (eDNA) extracted from water samples is an efficient and versatile approach to detecting aquatic animals. In the ocean, eDNA composition reflects local fauna at fine spatial scales, but little is known about the effectiveness of eDNA-based monitoring of marine communities at larger scales. We investigated the potential of eDNA to characterize and distinguish marine communities at large spatial scales by comparing vertebrate species composition among marine habitats in Qatar, the Arabian Gulf (also known as the Persian Gulf), based on eDNA metabarcoding of seawater samples. We conducted species accumulation analyses to estimate how much of the vertebrate diversity we detected. We obtained eDNA sequences from a diverse assemblage of marine vertebrates, spanning 191 taxa in 73 families. These included rare and endangered species and covered 36% of the bony fish genera previously recorded in the Gulf. Sites of similar habitat type were also similar in eDNA composition. The species accumulation analyses showed that the number of sample replicates was insufficient for some sampling sites but suggested that a few hundred eDNA samples could potentially capture >90% of the marine vertebrate diversity in the study area. Our results confirm that seawater samples contain habitat-characteristic molecular signatures and that eDNA monitoring can efficiently cover vertebrate diversity at scales relevant to national and regional conservation and management.     

海洋中微塑料的环境行为和生态影响

微塑料一般指直径小于5 mm的微小型塑料颗粒或碎片,海洋中常见的微塑料类型主要包括聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯等。由于形状、颜色多变,分子量大,结构稳定,粒径范围与浮游植物相近,海洋中的微塑料很容易被对浮游植物、浮游动物和其他海洋动物等产生影响。微塑料还可以为病毒、细菌提供附着载体,影响浮游植物分布,进入海洋生物消化道或进一步转移到组织中对机体产生毒性效应,甚至通过捕食作用沿食物链传递,对高等动物及人类健康造成威胁。此外,微塑料可以作为海水中痕量化学物质的吸附载体,对生物产生联合毒性。根据目前对微塑料的研究进展情况,未来应加强对海洋微塑料分离、鉴定技术的研发以及海洋微塑料的生物毒性效应和生物传递效应机制等问题的研究。     

Contrasting effects of variable species recruitment on marine sessile communities

The species composition, density, and frequency of recruitment into any given habitat are highly variable in most biological systems that rely on dispersive propagules (larvae, seeds, spores, etc.). There are few direct experimental studies of how recruitment variation between single species influences the composition and assembly of whole communities in many of these systems. We manipulated recruitment of a variety of single taxa and followed their effects on the subsequent development of hard-substrate communities of sessile animals living in temperate marine waters. The effects of recruitment on communities were complex. Patterns of recruitment of individual species influenced community structure, but these effects varied greatly depending on the identity of species recruits, the time of community development, and location across three different sites. Variable recruitment of arborescent bryozoans and didemnid ascidians had little effect on community structure. At one site, recruitment of the colonial ascidian Botryllus schlosseri had short-lived effects on community structure, while barnacles had more persistent effects. At another site, recruitment of B. schlosseri and the bryozoan Watersipora subtorquata had strong persistent effects on community structure, dominating space where they recruited and influencing the abundances of a variety of different taxa. Differences in the effects of species recruitment on communities appear to be caused by differences between the ecology and life history of recruiting species as well as differences in background processes between sites. These results demonstrate that discrete recruitment events that vary between single species can be important drivers of community composition but are likely to be heavily influenced by the local environment, even within a single species.