GENETIC DIVERSITY OF FIVE FRESHWATER MUSSELS IN GENUS ANODONTA (MOLLUSCA: BIVALVIA) REVEALED BY RAPD ANALYSIS

Unionidae(Bivalvia)are distributed infreshwaters,and represent a significanttaxonof benthic community[1].In China,freshwater mussels are abundant resources[2].Since1949,substantial investigations onthe unionidfau-na had been undertakenin China[3—8].Withreference tooverseas research[9,10],a preliminary reorganization onthe Unionidae was performed accordingtosome classifica-tion characteristics such as shell shape,larvae character-istics,and breeding habit[11].Due tothe serious conver-gence of freshwater muss...     

韩国青羊分布的变化

Amur goral(Nemorhaedus caudatus)is a rare species among Asian mammals. It is listed as Vulnerable in the 1996 IUCN Red List of the Threatened Animals[1], and designated as the natural monument (No. 217) in Republic of Korea[2]. This species is distributed in Northeast and Southwest of China, south of the Russian Far East and the Korean peninsula[3-5].But subspecies are different with inhabitants in China, which occur 5 species of gorals[4].     

Effects of citral on Aspergillus flavus spores by quasi-elastic light scattering and multiplex microanalysis techniques

Litsea cubeba (Lour.) Pers. is a kind of medicinal plantin China. The first report about the antibacterial and anti-phlogistic function of Litsea cubeba (Lour.) Pers. and itsoil appeared in the Zhong Yao Da Ci Dian [1]. Since 1980s,many studies showed that Litsea cubeba oil had wideantibacterial and antifungal activity [2–4]. The antibioticfunctions of Litsea cubeba oil are attributable mainly tocitral [5–7], which amounts to 60%–80% of the essentialoil [8]. Pattnaik [9] reported that…     

Assessment and comparison of recombinant proteins from different sources for the detection of SARS-CoV-2 infection by using protein microarray

COVID-19 (the COVID-19 is a type of disease and resulted from being infected by virus SARS-CoV-2) pandemic is threatening tens of millions of lives around the world [1]. To date, specific drugs or vaccines are still not available for fighting the SARS-CoV-2. Diagnosis and quarantine are still the effective strategies for preventing the virus from spreading. Up to now, various detection methods for SARS-CoV-2 have been developed [2], which play critical roles in controlling the pandemics. According to the targets to be detected, these methods can be divided into three classes: methods for the nucleic acid [3], antigens [4], and antibodies elicited by the virus in the host [5]. Among these methods, the ones for antigens and antibodies could produce results in 10–15 min [6], which are suitable for point-of-care diagnosis, especially the ones for antibodies [7]. Meanwhile, the asymptomatic cases [8] and the false-negative results of nucleic acid testing [9] make the detection methods based on antibodies the best alternatives. The proteins, used in methods for detection of antibodies elicited by SARS-CoV-2 in the host, are critical agents, which could affect the diagnosis results. Given the strong immunogenicity of the nucleocapsid (N protein), spike protein (S protein), and related domains [10] and the potential diagnosis values, we collected 9 S1 proteins, 3 N proteins, 5 S2-related proteins, and receptor-binding domains (RBDs) from ACROBiosystems (Beijing, China), ABclonal (Wuhan, China), Novoprotein (Shanghai, China), Sino Biological (Beijing, China), and KactusBiosystems (Shanghai, China) and fabricated a protein microarray (Fig. 1A) to assess their diagnosis performance. In addition, other proteins such as the angiotensin converting enzyme 2 (ACE2), envelop protein (E), 3C-like protease, and papain-like protease were also included (Fig. 1B).     

Raman spectroscopic study on structure of human immunodeficiency virus (HIV) and hypericin-induced photosensitive damage of HIV

Viruses are agents of some of the most destruc- tive diseases afflicting plants and animals[1]. Viruses also play a central role in experimental methods of molecular and cellular biology, especially in modern genetic engineering[1]. Raman spectroscopy is a pow-erful tool for studying the structure of the whole virion. A number of researches are limited to the conforma-tion of viruses, involving only nucleic acid (RNA or DNA) and its coat protein[1]. Literatures can be found concerning Raman…     

Effects of denaturation and amino acid modification on fluorescence spectrum and hemagglutinating activity of Hericium erinaceum Lectin

In a broad sense, lectins are proteins or glycoproteins ofnon-immune origin that bind specifically to carbohydrates[1]. But most lectins are usually multivalent, which meansthey have more than one carbohydrate-binding site in onemolecule, a property that enables them to agglutinate eryth-rocytes and other cells [2,3]. Some lectins exhibit blood-group specificity [4] and can be used in blood grouping;some agglutinate transformed cells better than the normalones [5]. Therefore, clinical research…     

Tyroserleutide tripeptide affects calcium homeostasis of human hepatocarcinoma BEL-7402 cells

Copyright by Science in China Press 2005 Primary hepatocarcinoma is one of the most fre-quent digestive-tract cancers, particularly in China. The incidence and death rate of primary hepatocarci-noma in China is the highest in the world, with about 1100 thousands people dying from primary hepatocar-cinoma per year[1]. Although the chemotherapeutic agents are the main therapeutic approach for hepato- carcinoma, they are relatively ineffective and result in many toxic and side effects. Accordin…     

Back to the future of oridonin： again, compound from medicinal herb shows potent antileukemia efficacies in vitro and in vivo

Traditional Chinese Medicine （TCM） has been widely and successfully used in treating illnesses ranging from inflammation to cancer, and compounds from medicinal herbs and minerals are playing more and more important roles in taming various kinds of diseases [1 ], exemplified by artemisinin and arsenic trioxide （ATO）. Artemisinin （or Qinghaosu in Chinese） is isolated from a plant called sweet wormwood （Artemisia annua; or Qinghao in Chi- nese） which has been used as an antipyretic remedy for more than 1500 years in China. Artemisinin has impressive parasiticidal properties in vitro and in vivo, and is now one of the most important class of antimalarial agents [2, 3]. ATO is a common, naturally occurring substance which had been used in China for a long time as a therapeutic agent for some severe diseases with the ancient philosophy of ＇treating an evil with a toxic＇ [4]. In 1990s, ATO was shown to be able to cause partial differentiation at low dose and apoptosis at high concentration of acute promyelocytic leukemia （APL） cells [5], and induce complete remission in 90% of patients with relapsed or refractory APL [6-8]. These paradigms suggest that TCM is the treasure house not only for the Chinese people, but also for the whole human beings. It is our responsibility to develop evidence-based therapeutic approaches from TCM for diseases with poor prognosis.     

中国枝角类低额溞属一新记录——密刺低额溞Simocephalus congener(Koch,1841)（英文）

<正>The genus Simocephalus Schoedler 1858,a large,nonpelagic daphniidae,are abundant in the littoral zone,expecially with submerged aquatic vegetation in freshwater bodies all over the world.More than 63 specific and subspecific names have been proposed.But in the recent research,all of them were divided into 4 subgenus and regarded as 20valid names[1].More than 12 species of genus Simocephalus were recorded in China[2—5],and most of them need to be re-examined according to modern standards.The valid of Simocephalus congener was controversial.Most authors suppose S.congener to be a synonym of S.exspinosus or a variety in the last century[1].Nowadays,S.     

Two distinct conjugal transfer systems on Streptomyces plasmid pZL1

The mechanism of conjugal transfer of plasmids in Gram-negative and unicellular Gram-positive bacteria is commonly via a type IV secretion system （T4SS） [1]. The genes encoding the T4S proteins are usually arranged in a single operon or a few operons. In Gram-negative Agrobacterium tumefaciens, the T4SS is encoded by the virB and virD operons （11 and 5 genes, respectively） [2]. Streptomyces are multicellular mycelial Gram-positive bac- teria that form unicellular spores. There are fundamental dif- ferences in the mechanisms of conjugal transfer between Streptomyces plasmids and those of Gram-negative and uni- cellular Gram-positive bacteria. Conjugal transfer of Streptomyces plasmids requires a tra gene encoding an FtsK/SpolIIE-family DNA translocator and a few adjacent genes [3]. No bacterial T4SS has previously been found on Streptomyces conjugative plasmids. We reported here the co- existence of both a T4SS-like and an FtsK/SpolIIE-family DNA translocator on a 128-kb Streptomyces plasmid, pZL 1.     

Genetic variability among freshwater mussel Anodonta woodiana (Lea, 1834) (Bivalvia: Unionidae) populations recently introduced in Poland

The alien Chinese mussel Anodonta woodiana was first reported in Poland in the system of heated lakes near Konin in 1993. Genetic studies with use of three molecular techniques (isoenzyme electrophoresis, PCR-RFLP and sequence analysis of a COI gene fragment) were carried out on the Polish first populations of A. woodiana. The studies have revealed low genetic variation between the populations (Nei's genetic distance for 12 loci ranged 0.000 to 0.007) as well as their considerable polymorphism. Each population averaged 2.28 alleles per locus, 2.72 alleles per polymorphic locus, and 75% polymorphic loci. Restriction analysis of the COI gene fragment have not revealed variability between the analysed specimens, including males and females. Restriction enzymes, ScrFI, Csp6I, and EcoRI used in the COI gene fragment PCR-RFLP generate distinct restriction patterns, which can be molecular markers for A. woodiana. The sequence obtained for COI fragment was the same in the examined female and male specimens and represents F mitotype (DNA was isolated from somatic tissues). The divergence between A. woodiana F and M mitotypes is high (34%), however it remains within the range of the general character of the DUI (doubly uniparental inheritance) phenomenon in freshwater bivalves (Unionidae).     

Isolation and characterization of microsatellite loci in western North American Anodonta species

We have developed and characterized 13 microsatellite loci from a group of Anodonta species in western North America, and demonstrated their utility in populations representing two major clades in this genus. Allelic diversity and polymorphic information content were high for all loci, although these characteristics varied across populations. Deviations from Hardy-Weinberg genotypic ratios were not detected, although the estimated frequency of null alleles was high in one population for one locus. This is the first set of microsatellite loci to be developed for freshwater mussels in western North America, and will be useful for describing gene flow patterns among populations.     

濒危植物三棱栎遗传多样性的RAPD分析

用随机扩增多态DNA (RAPD)标记对 5个三棱栎 (Trigonobalanusdoichangensis)居群共 99个个体进行遗传多样性和居群遗传结构分析。 16个引物共检测到 15 7个位点 ,其中多态位点 83个 ,占 5 2 87%。物种水平Shannon多样性指数I =0 2 4 31,Nei基因多样度h =0 15 95 ,种内总遗传变异量Ht=0 16 0 0 ,居群内遗传变异量Hs =0 0 74 9,居群间变异量大于居群内变异量 ,表明三棱栎的遗传变异主要存在于居群之间。与同科植物相比 ,三棱栎遗传多样性较低 ,遗传分化系数Gst =0 5 32 0 ,说明居群间的遗传变异占 5 3 2 0 % ,居群间已出现强烈的遗传分化。当地人的强烈活动造成的生境破碎化和居群隔离 ,以及三棱栎演化过程中的地史变化对其种群发展的影响等 ,可能是造成其居群间强烈的遗传分化和较低遗传多样性的原因。基于本研究结果 ,提出了三棱栎遗传多样性的保护策略。     

Extensive allozyme monomorphism in a threatened species of freshwater mussel, Margaritifera hembeli Conrad (Bivalvia: Margaritiferidae)

A threatened but under-studied component offreshwater biodiversity in North America is thenative freshwater mussels (Bivalvia:Unionoidea: Margaritiferidae and Unionidae). Genetic data suggest that these mussel speciesgenerally exhibit levels of variability similarto other invertebrates. We surveyed allozymevariation in the Louisiana Pearlshell, Margaritifera hembeli (Margaritiferidae), athreatened freshwater mussel. Five examinedpopulations are monomorphic for 25 allozymeloci, the first report of a native freshwatermussel species with extensive allozymemonomorphism. Low genetic diversity appears tobe characteristic of margaritiferids, as anANOVA indicated that mussels of the familyMargaritiferidae have significantly lowerlevels of heterozygosity than the mussels ofthe family Unionidae. Margaritiferids havestrong habitat preferences and modification ofhabitat leads to rapid loss of populations.Although bottlenecks are known to cause lowgenetic variability, margaritiferids mayexhibit meta-population structure withextinction/re-colonization dynamics leading tolow genetic variability. Margaritiferidsgenerally exhibit a patchy distribution with acolonization rate that is approximately twicethat of extinction. Tests of themetapopulation hypothesis will requireadditional allozyme population genetic data aswell as hypervariable microsatellite loci.     

濒危灌木长叶红砂遗传多样性的RAPD分析

应用RAPD分子标记对濒危灌木长叶红砂(Reaumuria trigyna)种群遗传多样性进行了分析.应用18条随机引物对长叶红砂5个种群的95个个体进行扩增,检测到118个位点,其中多态位点105个.结果表明:长叶红砂种群的多态位点比率(P)为88.98%,显示出长叶红砂种群存在较高的遗传多样性.Shannon多样性指数(0.4966)、Nei基因多样性指数(0.3303)和基因分化系数(Gst=0.1425)的分析结果显示,长叶红砂种群遗传变异大多存在于种群内,种群间的遗传分化占14.25%.聚类分析表明,长叶红砂种群遗传距离与地理距离之间无直接相关关系.遗传多样性水平与物种特性和所处不同群落有关,濒危植物并不一定表现为遗传变异水平的降低.     

Isolation and characterization of fifteen polymorphic microsatellite loci in the threatened freshwater mussel Solenaia oleivora (Bivalvia: Unionidae)

Freshwater mussels are among the most endangered fauna in the world, while little is known about their genetic diversity. We isolated 15 polymorphic microsatellite loci in a threatened freshwater mussel, Solenaia oleivora. The characteristics of these loci were tested with 46 individuals. The number of alleles per locus ranged from 2 to 15, and the PIC value ranged from 0.250 to 0.880. The observed and expected heterozygosity ranged from 0.167 to 0.929 and from 0.297 to 0.900, with an average of 0.562 and 0.647, respectively. Eight loci deviated significantly from Hardy–Weinberg equilibrium. These polymorphic microsatellites will be useful for the assessment of population genetic diversity and resource conservation of S. oleivora. Cross-species amplification demonstrated that six of 15 microsatellite loci amplified successfully in two other unionid species.     

三种摇蚊幼虫RAPD扩增条件的优化及在昆虫系统发育分析中的应用

为了研究摇蚊科昆虫种群遗传的多样性,以促进对其资源的合理保护,以萨摩亚摇蚊Chironomus samoensisEdwards基因组DNA为模板,对摇蚊幼虫的RAPD扩增条件进行优化,建立了摇蚊幼虫RAPD扩增反应的最佳体系:按照利用优化的RAPD扩增条件进行研究,实验有着良好的重现性。用16个随机引物对3种摇蚊幼虫类群各10个个体进行RAPD扩增,其中萨摩亚摇蚊共扩增出78个条带,多态座位率为41.03%,Shannon遗传多样性指数为0.2570,群体内相似度为0.8730;红裸须摇蚊Propsilocerus akamusi(Tokunaga)共75个条带,多态座位率为44.0%,Shannon遗传多样性指数为0.2472,群体内相似度为0.8731;刺铗长足摇蚊Tanypus punctipennis(Fabricius)共67个条带,多态座位率为41.79%,Shannon遗传多样性指数为0.1943,群体内相似度为0.9066。聚类分析结果表明,刺铗长足摇蚊与红裸须摇蚊的亲缘关系较近。     

Conservation genetics of endangeredBrasenia schreberi based on RAPD and AFLP markers

Brasenia schreberi J.F. Gmelin is a declared endangered species found in the lakes and ponds of South Korea. For planning its conservation strategy, we examined the genetic diversity within and among six populations, using randomly amplified polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP). Polymorphisms were more frequently detected per loci with AFLP (69.3%) than RAPD (36.8%). High genetic diversity was recognized within populations: polymorphic loci (PPL) values ranged from 36.3% in the CJM population to 74.5% in the GGT population, with a mean value of 47.8% based on AFLP markers. Great genetic differentiation (θ^B) was detected among the six populations (0.670 on RAPD and 0.196 on AFLP), and we calculated a low rate of gene flow (N_em), i.e., 0.116 on RAPD and 0.977 on AFLP. Furthermore, a Mantel test revealed that no correlation existed between genetic distances and geographical distances among the six local populations, based on RAPD or AFLP markers. These results are attributed to a number of factors, including an insufficient length of time for genetic diversity to be reduced following a natural decline in population size and isolation, adaptation of the genetic system to small population conditions, and a restricted gene flow rate. Based on both its genetic diversity and population structure, we suggest that a strategy for conserving and restoringB. schreberi must focus on maintaining historical processes, such as high levels of outbreeding, while monitoring increased gene flow among populations. This is because a reduction in genetic diversity as a result of genetic drift is undesirable.     

Analysis of genetic diversity in red clover (Trifolium pratense L.) breeding populations as revealed by RAPD genetic markers.

Red clover is an important forage legume species for temperate regions and very little is known about the genetic organization of its breeding populations. We used random amplified polymorphic DNA (RAPD) genetic markers to address the genetic diversity and the distribution of variation in 20 breeding populations and cultivars from Chile, Argentina, Uruguay, and Switzerland. Genetic distances were calculated for all possible pairwise combinations. A high level of polymorphism was found and the proportion of polymorphic loci across populations was 74.2%. A population derived from a non-certified seedlot displayed a higher proportion of polymorphic loci than its respective certified seedlot. Gene diversity values and population genetics parameters suggest that the populations analyzed are diverse. An analysis of molecular variance (AMOVA) revealed that the largest proportion of variation (80.4%) resides at the within population level. RAPD markers are a useful tool for red clover breeding programs. A dendrogram based on genetic distances divided the breeding populations analyzed into three distinct groups. The amount and partition of diversity observed can be of value in identifying the populations that parents of synthetic cultivars are derived from and to exploit the variation available in the populations analyzed.