孤独症谱系障碍儿童肠道菌群多样性的研究

目的 分析孤独症谱系障碍(ASD)儿童肠道菌群多样性,为减轻胃肠道症状提供科学依据。方法 选取2018年1-6月在广西壮族自治区妇幼保健院确诊为ASD的儿童20例和健康儿童20例作为研究对象。采集两组儿童粪便提取总DNA,扩增16S rDNA中V4/V5区进行高通量测序,分析ASD儿童肠道菌群多样性。结果 两组在样品文库的覆盖率(Z=242.500,P=0.256)、丰度指标Chao1(Z=250.000,P=0.181)、 ACE(Z=234.000,P=0.365)、Shannon(Z=259.000,P=0.114)和Simpson(Z=146.000,P=0.145)指数上差异均无统计学意义(P>0.05),多样性无差异。门水平上,两组儿童在8种菌群上差异无统计学意义(P>0.05),属水平上,两组儿童在20个属上差异具有统计学意义(P＜0.05)。结论 ASD儿童和健康儿童在肠道菌群属水平上具有差异;临床上可根据不同菌属特点对ASD儿童肠道菌群进行精准调整,保持肠道微生态平衡,减轻ASD儿童胃肠道症状。     

利用ISSR和RAPD标记技术分析灰毡毛忍冬种质资源的遗传多样性

目的:揭示灰毡毛忍冬进行种质资源间的遗传关系。方法:采用ISSR和RAPD标记技术对17份灰毡毛忍冬样品进行遗传多样性分析。结果I:SSR标记的Shannon’s信息指数为0.4054,RAPD标记的Shannon’s信息指数为0.3827,多态性位点百分率分别为82.04%和79.79%。结论:两种标记都能揭示样品间较高的遗传多样性,且ISSR标记多态性高于RAPD标记。     

海洋放线菌的研究概况

由于海洋放线菌能够产生结构新颖、功能多样的次生代谢产物,成为新药来源的重要生物资源.本文综述了海洋放线菌研究的发展历程,介绍了海洋放线菌的概念、分布状况及研究的方法 等,探讨了海洋放线菌的生态功能,以及所生成的次生代谢产物在各领域的运用价值和海洋放线菌的研究方法,简述了现阶段我国海洋放线菌研究存在的问题及未来发展的前景...     

Natural killer cells: integrating diversity with function

The key role of natural killer cells in many aspects of the immune response is now being recognized. The last decade has seen an exponential increase in our understanding of the workings of these cells. Receptor diversity is crucial in allowing natural killer cells to respond effectively to a variety of different pathogens. This article reviews aspects of natural killer cell diversity that combine to generate populations of functional natural killer cells that exist within both the individual and throughout the population at large.     

人参及西洋参栽培土壤微生物种群遗传多样性的RAPD分析

目的 研究不同年生人参、西洋参栽培土壤中微生物种群结构差异。方法 采用RAPD技术对采集自吉林省抚松县的18份人参、西洋参根际土和根围土中的微生物种群结构进行遗传多样性分析。结果 栽培年限对根际土及根围土中的微生物种群结构有显著影响;人参和西洋参栽培土壤中的微生物种群结构也存在差异;寄主植物对土壤微生物种群结构的影响表现有根际效应。结论 人参或西洋参根系分泌物对土壤微生物的定向选择压力可能是造成土壤微生物种群遗传多样性变化的主要原因之一,人参或西洋参栽培土壤中微生物种群结构变化是导致土壤生态功能紊乱以及连作障碍形成的关键因子。     

Koala retrovirus genetic diversity and transmission dynamics within captive koala populations

Koala populations are currently in rapid decline across Australia, with infectious diseases being a contributing cause. The koala retrovirus (KoRV) is a gammaretrovirus present in both captive and wild koala colonies that presents an additional challenge for koala conservation in addition to habitat loss, climate change, and other factors. Currently, nine different subtypes (A to I) have been identified; however, KoRV genetic diversity analyses have been limited. KoRV is thought to be exogenously transmitted between individuals, with KoRV-A also being endogenous and transmitted through the germline. The mechanisms of exogenous KoRV transmission are yet to be extensively investigated. Here, deep sequencing was employed on 109 captive koalas of known pedigree, housed in two institutions from Southeast Queensland, to provide a detailed analysis of KoRV transmission dynamics and genetic diversity. The final dataset included 421 unique KoRV sequences, along with the finding of an additional subtype (KoRV-K). Our analysis suggests that exogenous transmission of KoRV occurs primarily between dam and joey, with evidence provided for multiple subtypes, including nonendogenized KoRV-A. No evidence of sexual transmission was observed, with mating partners found to share a similar number of sequences as unrelated koala pairs. Importantly, both distinct captive colonies showed similar trends. These findings indicate that breeding strategies or antiretroviral treatment of females could be employed as effective management approaches in combating KoRV transmission.

Retroviral sequences are an ancestral feature of all vertebrate genomes analyzed to date. By infiltrating and becoming a permanent fixture of the host genome, a process known as endogenization, these retroviral elements have helped shape vertebrate evolution. Most endogenization events occurred millions of years ago (1). An exception is the recently discovered koala retrovirus (KoRV), which appears to have endogenized less than 50,000 y ago (1, 2). KoRV is a gammaretrovirus, closely related to gibbon ape leukemia virus (GALV), present in both wild and captive Australian koala populations (3). It is found at 100% prevalence in the northern states of Queensland and New South Wales (3–10); however, a lower prevalence is observed in southern populations (in the states of Victoria and South Australia), with some studies suggesting certain populations are completely KoRV free (4, 11). KoRV has putatively been associated with the onset of neoplasia, including leukemia and lymphoma, blood and bone marrow disorders (myelodysplasia), and a wide range of opportunistic infections, including chlamydiosis, a bacterial pathogen causing koala morbidity, infertility, and mortality (8, 12–16). Uniquely, it is one of the only retroviruses that presents in both endogenous and exogenous forms (3, 17). Despite this, limited research has focused on the exogenous transmission of this virus, with KoRV transmission dynamics and/or mechanisms currently unconfirmed.To date, there are nine identified KoRV subtypes (KoRV-A to I), each having a unique amino acid signature within the hypervariable receptor binding domain (RBD) of the envelope protein (3, 5, 17–21). KoRV-A was the first described subtype (3), which has since been detected in every KoRV-positive koala analyzed (4, 5, 17, 21, 22). It is the only subtype known to have endogenized and is incorporated at multiple sites in the germline DNA of northern koala populations, with consequent transmission through to progeny from both sire and dam (9). As a result, endogenous KoRV-A has been detected in all Queensland and New South Wales koalas analyzed to date at very high copy numbers (5, 6, 23). This endogenized variant is yet to be detected at high enough copy numbers in koala populations residing in southern parts of Australia to be considered endogenous, and evidence for the presence of replication competent virus in these southern populations is relatively weak (6, 9).KoRV subtypes B to I have all been discovered within the last 9 years (5, 18, 19, 21). KoRV-B has been suggested to be more pathogenic compared to KoRV-A based on increased infectivity measured in vitro and some evidence supporting an association with disease (17, 23, 24). Whether the remaining KoRV subtypes are similarly associated with disease outcome remains to be extensively investigated. In comparison to KoRV-A, the prevalence of KoRV-B to I among koala populations is considerably reduced, with their identification in only a portion of the koalas analyzed to date (5–7, 11). Additionally, these subtypes are yet to be detected within the koala germline. Together, this suggests that KoRV subtypes B to I are exogenously acquired, meaning they are not genetically inherited by progeny but instead are derived or transmitted via alternate routes (17, 19, 21, 23).Vertebrates are able to acquire exogenous retroviral sequences in multiple ways. Some exogenous variants, such as those of feline leukemia virus (FeLV), are derived within the host through de novo recombination and are not directly transmissible between individuals (25–27). Alternatively, exogenous sequences can be actively transmitted between infected and uninfected individuals through contact with infectious fluids. Possible routes for exogenous retroviral transmission include sexual (28) and within milk (29, 30), feces (31), and saliva (32). For koalas in particular, there is also the potential for transmission to occur through ingestion of pap, a special form of maternal feces consumed by the joey at pouch emergence (33). A number of studies have highlighted an apparent correlation between the KoRV-B status of koala dams and joeys (17, 23, 34); however, due to the limited sample sizes and the absence of matched samples from fathers, such findings have been purely observational, and statistical significance could not be ascribed. Similarly, contact transmission between adult animals has been assumed based on transition to KoRV-B positive status over repeated sampling of individuals; however, again, these results are based on a limited sample size, and the possibility for an increase in KoRV load over time to confound qPCR analysis cannot be excluded (23).In this study, we sought to investigate KoRV transmission dynamics in captive koala colonies of known pedigree (n = 109). Patterns of KoRV diversity were highlighted within two Southeast Queensland captive populations, providing insight into the complexities of KoRV genetics and evolution. Furthermore, sequence sharing between dam-joey, sire-joey, and mating koala pairs were directly compared to infer the transmission of various KoRV subtypes. This research not only informs future conservation efforts in the management of both captive and wild populations but also provides greater insight into the mechanisms and role of exogenous transmission in shaping a recently endogenized retrovirus.     

缅甸北部克钦地区蚊类种群组成初报

目的了解缅甸北部地区的蚊类种群构成及对蚊类物种多样性进行初步观察。方法2008年8-9月分别在靠近中国边境地区的4个居民点用CDC诱蚊灯捕蚊,对所获蚊虫进行分类计数和对数据进行统计学分析。结果人房共捕获蚊虫2亚科8属17亚属45种2268只,牛房共捕获蚊虫2亚科7属12亚属33种1703只,其中发现人房主要优势蚊种和优势度依次为微小按蚊（58.16）、可赫按蚊（46.27）、伪杂鳞库蚊（45.68）、三带喙库蚊（41.97）、杰普尔按蚊（40.18）;牛房主要优势蚊种和优势度分别为可赫按蚊（34.37）、三带喙库蚊（34.30）、微小按蚊（29.13）、美彩按蚊（27.68）。人房、牛房蚊虫的多样性指数和均匀性指数分别为2.61、1.58和2.68、0.48。结论主要疟疾媒介微小按蚊是当地人房的优势种,牛房捕获的微小按蚊绝对数量少于人房。     

山西省庞泉沟自然保护区有瓣蝇类物种多样性初探

目的调查山西省庞泉沟自然保护区有瓣蝇类的种数、特有种及区系特征。方法采用昆虫学分类原理与方法。结果在山西省庞泉沟自然保护区发现有瓣蝇类6科64属142种。其中蝇科,无论在属级水平还是种级水平,均占有较大优势,分别占该保护区已知属数和种数的32.81%和49.30%。文中记录动物三界以上的广布种34种,占该保护区分布种数的23.94%,六界广布种5种,占该保护区分布种数的3.52%。特有种4种,占该保护区分布种数的2.82%。结论山西省庞泉沟自然保护区有瓣蝇类的区系特征是以古北界区系成分为主。     

脑卒中后抑郁症患者肠道菌群的多样性分析

目的通过检测卒中后抑郁症患者粪便标本的微生物种群分布变化情况,分析患者肠道菌群变化情况与抑郁状态之间的 相互联系,为临床治疗提供新思路。方法通过使用Roche/45 高通量测序平台对32 例卒中后抑郁症患者大便标本中的16S RNA V3区进行定性分析,与30例正常健康成人粪便标本统计数据进行比较。结果与正常健康成人对比卒中后抑郁症患者粪 便中细菌菌群中细菌物种OTU信息量明显增加（P<0.01）,多样性指数（Shannon）增大（P<0.05）和物种均一度指标（Evenness）也 有所增加但无统计学差异（P>0.05）,肠道菌群丰度在门水平上拟杆菌门,变形菌门,梭杆菌门均较正常健康对照组明显增加（P< 0.05）,厚壁菌门数量明显减少（P<0.05）。在科水平上Acidaminococcaceae,Rikenellaceae,Sutterellaceae,Fusobacteriaceae, Porphyromonadaceae,Enterobacteriaceae,比例明显增加（P<0.05） ,Bacteroidaceae,Ruminococcaceae,Prevotellaceae, Lachnospiraceae,Erysipelotrichaceae 细菌比例明显减少（P<0.05）。在属水平上Phascolarctobacterium,Clostridium XIX, Escherichia/Shigella,Roseburia,Lachnospiracea incertae sedis,Blautia,Oscillibacter,Parasutterella,Megamonas 比例明显升高（P< 0.05）,Bacteroides,Prevotella,Faecalibacterium,Ruminococcus,Dialister细菌比例明显减少（P<0.05）。结论卒中后抑郁症患者肠 道微生态环境中细菌群落的多样性和均衡性与正常人群存在明显差异。