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1.
In the study, we characterized 29 Streptococcus iniae isolates from diseased olive flounder Paralichthys olivaceus in Korea from 2000 to 2005. Biochemical characteristics of 29 isolates using API 20 strep were identical. Through analysis of repetitive sequence-based PCR (rep-PCR) using BoxA primer and random amplified polymorphic DNA using p14 primer, 29 isolates of S. iniae were divided into two genotypes. The isolates were divided into two clusters by comparison of genetic distance using a sequence of the capsular polysaccharide D gene that was consistent with genotyping by the rep-PCR. The isolates belonging to genotype 1 in rep-PCR analysis showed a high virulence in the flounder, while the isolates belonging to genotype 2 were relatively low in virulence. Therefore, a correlation between the genotype and the virulence of S. iniae isolates has been identified.  相似文献   

2.
Sixty-four isolates of Flavobacterium psychrophilum from ayu, Plecoglossus altivelis altivelis (Temminck & Schlegel), and other fish (n=16) in Japan and the type strain (NCIMB 1947(T)) were typed using pulsed-field gel electrophoresis (PFGE) with endonuclease BlnI and XhoI. These isolates were classified into 20 clusters and 42 genotypes by PFGE analysis. The most predominant cluster of isolates from ayu was cluster XII (n=20), followed by clusters XVII, XVI, XX, XI, IX, X, XIII and XV; the remaining 17 isolates from other fish were divided into clusters I, II, III, IV, V, VI, VII, VIII, XIV, XVIII and XIX. The PFGE genotype of isolates from ayu clearly differed from those of other fish. The isolates from ayu in Gunma Prefecture belonged to clusters XII, XVI, XVII and XX, and the strains of three of these clusters (XII, XVII and XX) were isolated from ayu in 15 of 19 prefectures. PFGE typing enabled more accurate classification of isolates into clusters than previously achieved by analysing the restriction fragment length polymorphism of PCR products. These results suggest that F. psychrophilum isolated from ayu and other fish are genetically different and strains with several PFGE types have spread within Japan.  相似文献   

3.
The phenotypic and genetic characterizations of 58 isolates of the fish pathogen Nocardia seriolae , from amberjack, Seriolae dumerili , yellowtail, Seriola quinqueradiata , Japanese flounder, Paralichthys olivaceus , and chub mackerel, Scomber japonicus, in Japan from 1970–2005, were examined to investigate the epidemiological relationship between isolates. The phenotypic and genetic characterizations were determined by α-glucosidase activity and biased sinusoidal field gel electrophoresis (BSFGE) analysis, respectively. There was no α-glucosidase activity in strains isolated from 2000–05 ( n  = 50) with a few exceptions ( n  = 3), while all strains isolated from 1970–90 ( n  = 8) were positive. In BSFGE analysis, digestions with restriction enzymes Xba  I and Ase  I produced 15 and 16 restriction patterns, respectively. All restriction patterns obtained from 50 strains isolated during 2000–05 were unrelated to those obtained from eight strains isolated during 1970–90, with the exception of two strains isolated during recent outbreaks. Based on the phenotypic and genetic characterizations, recent outbreaks of nocardiosis in Japan are suggested to be epidemiologically unrelated to earlier outbreaks in Japan. Although a low genetic relationship was observed in the restriction pattern between recent and earlier isolates, identity was confirmed between these groups of isolates because five representative strains showed 99.9% homology with N. seriolae ATCC43993T in the 16S rRNA sequence.  相似文献   

4.
ABSTRACT: Random amplified polymorphic DNA (RAPD) was studied to detect genetic markers for three economically important Japanese laminarian species, Laminaria japonica Areschoug, L. religiosa Miyabe and L. ochotensis Miyabe, which were sampled from their representative localities on the coasts from Tsugaru Straits to the Sea of Japan. DNA templates for RAPD were extracted from lamina using a DNA extraction kit and were purified with glassmilk. Reproducible RAPD markers for these three species were detected using three random primers from a total of 15 tested. In L. japonica and L. religiosa , these RAPD markers were confirmed to be useful for populations from other localities. The three species studied showed high intraspecific and interspecific band sharing index (BSI) values. Like annual typical L. religiosa from other localities, biennial individuals identified as putative L. religiosa from Atsuta could be discriminated from L. japonica but not from L. ochotensis by any of the RAPD genetic markers studied so far.  相似文献   

5.
Argulus is one of the most important fish parasites that cause heavy economic loss to aquaculture industry. The present investigation was undertaken to study the genetic diversity of the Argulus sp. collected from 13 locations representing major aquaculture zones in India by RAPD analysis and to develop species‐specific markers. Thirteen random decamer primers were used to amplify DNA fragments from three individual parasites of each location. Of the 172 bands scored by the primers, 168 were polymorphic. The per cent polymorphic loci and gene diversity values varied within a range of 8.14–43.02 and 0.0342–0.1727 respectively. Nei's genetic similarity between populations across all the primers ranged from 0.363 to 0.969. The dendrogram based on Nei's genetic distance showed two clusters; Bangalore and Mandi populations forming one cluster, and the rest in another cluster. The clusters also revealed strong correlation with the species identified as A. japonicus and A. siamensis respectively by morphological method. The study thus indicated A. siamensis as the major prevalent species in carp culture farms in India. Species‐specific primers were designed from unique sequences cloned from RAPD fragments that could able to identify A. siamensis and A. japonicus separately.  相似文献   

6.
ABSTRACT:   Genetic polymorphisms were investigated to develop a simple and rapid method to differentiate between the two closely related species, Porphyra tenera and Porphyra yezoensis . Polymerase chain reaction (PCR) using the specific primer pair of the ARP4 gene gave length polymorphic single fragments of genomic DNAs from five strains of P. tenera (Japan T-8, JTW; Korea KTY1, KTY2, KTY3) and seven strains of P. yezoensis (Japan TU-1, TU-2, TUH-25, JHU, JA-1; Korea KGJ, KPH). All strains of P. yezoensis had introns 60 bp longer than that of P. tenera . Multiple cleaved amplified polymorphic sequence (CAPS) markers were also developed to differentiate P. tenera and P. yezoensis . This is the first report of length polymorphisms that can be used to differentiate between the two species using only PCR amplification with agarose gel electrophoresis. It is expected that the length polymorphism and plentiful CAPS profiles obtained in this study will be useful in the assessment of genetic diversity within P. tenera and P. yezoensis as well as in breeding science that requires the collection of various strains of the two species.  相似文献   

7.
广东1个鲮原种群体的种质特征及遗传多样性分析   总被引：1，自引：3，他引：1  
收集西江流域肇庆段的野生鲮鱼苗进行跟踪观察,记录其生长情况,测量形态参数,结果表明,该批鲮原种存在体色及生长性能等方面的分化一种体色淡黄,命名为子群体h,一种体色青,命名为子群体q;子群体h的生长性能优于子群体q。从2个子群体中各取24个个体进行RAPD分析。20条随机引物扩增共获得了179条清晰稳定的条带,其中多态性条带为82条。用popgen软件进行RAPD数据处理,结果是总群体的平均杂和度为0.1281,遗传距离为0.1232;子群体h的平均杂和度为0.1248,遗传距离为0.1151;子群体q的平均杂和度为0.1164,遗传距离为0.1010;2个子群体间的遗传距离值为0.1383。这个结果表明,该原种群体遗传多样性较高。  相似文献   

8.
ABSTRACT:   The Japanese mitten crab Eriocheir japonica is a common grapsid species found throughout freshwater and estuarine regions in Japan. In order to obtain information on the genetic variation and population structure of this species, a polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) analysis was conducted on the cytochrome oxidase subunit I (COI) of mitochondrial DNA, on 666 individuals from 19 sample sites covering the three main geographic regions of Japan (Main Islands, Okinawa, and Ogasawara). Genetic analysis using seven restriction enzymes produced an array of 61 composite haplotypes. Three regional groups corresponding to the three geographic regions were clearly identified by cluster and molecular variance model ( amova ) analyses. Each of the three groups showed dominant haplotypes that were almost completely absent in populations from the other geographic areas. Comparison with published information for other species indicates that the degree of genetic divergence between these three main groups is equivalent to the genetic distance between congeneric species. Thus, the population structure of the Japanese mitten crab, as inferred from mtDNA analysis, is formed by genetically distinct groups that closely reflect their geographic distribution in the Japanese archipelago as well as restricted gene flow.  相似文献   

9.
牙鲆3个养殖群体遗传结构的微卫星分析   总被引：7，自引：2，他引：5       下载免费PDF全文
采用微卫星标记分析技术,用5个多态性的微卫星标记对来自3个不同国家（中国、日本和韩国）的牙鲆养殖群体进行了遗传多样性研究。研究结果表明,3个牙鲆群体平均等位基因在4．8～5．6之间,平均观测杂合度（H0）在0．3917～0．5643之间,平均期望杂合度（HE）在0．5981～0．6264之间。有多个位点在不同的群体中偏离哈代-温伯格平衡。遗传距离分析表明,中国群体与日本群体遗传距离最近,韩国群体与日本群体遗传距离最远。分子方差分析（AMOVA）表明,群体内遗传变异与群体间遗传变异分别占总遗传变异的92．44％和7．56％,固定系数（R）为0．0752（P〈0．001）,表明牙鲆3个养殖群体遗传分化显著。  相似文献   

10.
Streptococcus iniae is an important bacterial pathogen of fish, causing up to 50% mortality in stocks, which has recently been associated with human infections. To determine whether S. iniae isolates from humans and fish are similar, the present authors examined the biochemical profiles and genetic relatedness of these isolates by random amplified polymorphic DNA (RAPD) analysis and repetitive primer polymerase chain reaction(REP PCR). The biochemical profiles differentiated between the human and fish isolates of S. iniae using pyrrolidonyl arylamidase, arginine dehydrogenase, ribose, β-glucoronidase and glycogen as markers. These biochemical results suggest that the fish and human S. iniae isolates are genetically different. However, RAPD and REP PCR do not have the discriminatory power to differentiate between these streptococcus isolates using five different RAPD primers and BoxA primer.  相似文献   

11.
罗氏沼虾浙江养殖群体与缅甸自然群体遗传差异的RAPD分析   总被引：19，自引：2，他引：19  
李明云 《水产学报》2004,28(4):360-364
利用随机扩增多态DNA(RAPD)技术，对浙江省罗氏沼虾养殖群体和新引进的缅甸自然群体的遗传差异进行了比较分析，以期从分子水平了解罗氏沼虾的种群遗传多样性背景及与引种的关系。采用经筛选的22个10bp的随机引物对罗氏沼虾两群体各20尾进行群体RAPD分析。22个引物共检测到139个位点。养殖群体的多态位点比例为30．22％，群体平均杂合度为0．2646，Shannon多样性指数为0．0780，群体内各个体之间的遗传共享度为0．9353，遗传距离为0．0647；自然群体的多态位点比例为33．81％，群体的平均杂合度和Shannon多样性指数分别为0．2888和0．0940，群体内各个体之间的遗传共享度为0．9201，遗传距离为0．0799；两群体之间的遗传距离为0．1845。自然群体的遗传多样性水平比养殖群体要高。利用随机引物S9和S52，在罗氏沼虾两群体间扩增出2条稳定、明显的群体间特异性标记带。  相似文献   

12.
Variability in pathogenicity of Flavobacterium columnare makes disease treatment difficult because there is currently no way to easily recognize those strains that warrant aggressive treatments. In order to identify suitable virulence markers, 17 isolates of F. columnare were cultured from six different fish species. The DNA from all isolates was analysed using random amplified polymorphic DNA (RAPD). Bootstrap analysis of the RAPD data produced a tree with three major groups supported by bootstrap scores of 80-100%. Virulence of the isolates was determined by bath exposure of channel catfish, Ictaluruspunctatus (Rafinesque), and golden shiners, Notemigonus crysoleucas (Mitchill), to broth cultures of F. columnare. In channel catfish, 13 of 17 isolates produced 100% mortality within 48 h post-exposure. All isolates of cyprinid fish origin clustered in a single RAPD group. At least two of the four isolates that were not virulent in channel catfish were of cyprinid fish origin. There was a wide variation in cell morphology between isolates with lengths of cells or cell chains ranging from 3 to 11 microm, even under identical culture conditions. Most of the shorter or single cell isolates fell into a single RAPD group. No clear association was identified between virulence and any other characteristic, including RAPD group.  相似文献   

13.
In Japan and Korea, outbreaks of scuticociliatosis have frequently occurred in Japanese flounder, Paralichthys olivaceus . Morphological observations and small subunit rRNA gene sequences have shown that the causative agent of scuticociliatosis in the flounder is Miamiensis avidus (syn. Philasterides dicentrarchi ). In this study, we elucidated the antigenic differences between six Japanese M. avidus isolates as an initial step toward developing an effective vaccine against the disease. Four Japanese flounder isolates (IyoI, Nakajima, JF05To and Mie0301 isolates), one spotted knifejaw, Oplegnathus punctatus, isolate (SK05Kyo), and one ridged-eye flounder, Pleuronichthys cornutus , isolate (RF05To) were subjected to serological analysis. Antisera against IyoI, SK05Kyo, Nakajima and Mie0301 isolates were raised in rabbits and used for immobilization assays and Western blotting. Immobilization assays showed that the six isolates could be divided into three groups, tentatively designated serotype I for IyoI, JF05To, RF05To, SK05Kyo, serotype II for Nakajima and serotype III for Mie0301. Western blotting results supported these three serotypes, with marked similarities in the banding profiles of IyoI, JF05To, RF05To and SK05Kyo isolates, which were distinct from the Nakajima and Mie0301 isolates. Three isolates, IyoI, Nakajima and Mie0301 that were selected as representatives of each serotype, were highly pathogenic to Japanese flounder by experimental infection. Based on these findings, we propose that there are at least three M. avidus serotypes in Japan.  相似文献   

14.
采用随机扩增多态性DNA(RAPD)技术对取自长江中上游合川、木洞、涪陵、彭水、巫山、宜昌及岳阳7个江段的南方鲇(Silurus meridionalisChen)野生群体的遗传多样性进行了分析,24个随机引物共检测出327个位点(200~2500 bp)。各群体的多态位点比例在28.75%~48.62%之间,基因多样性指数为0.2047~0.3074。遗传距离显示长江中上游南方鲇各群体间有一定遗传分化,其中,木洞和合川群体间遗传距离最小为0.0537),而合川和岳阳群体间的遗传距离最大(0.1205),群体间遗传分化系数为0.1866。聚类分析(UPGMA)显示,7个群体聚为两大类群,合川和木洞亲缘关系最近,首先聚在一起,之后与彭水、涪陵、巫山群体相继聚类形成类群Ⅰ,岳阳和宜昌群体则聚类形成类群Ⅱ。Shannon指数分析表明,长江中上游南方鲇野生群体间种质资源状况良好,遗传多样性水平较高。  相似文献   

15.
The prevalence of two serotypes of Streptococcus parauberis isolated from the olive flounder, Paralichthys olivaceus, was evaluated in a total of 29 isolates between 2003 and 2010 in Korea. Streptococcus parauberis isolates were divided into two serologically distinct types (serotype 1 and serotype 2), except for one strain (S1091), using an agglutination assay with rabbit antiserum, and serotype 1 was identified as the dominant type (24 of 29 isolates) in this study. To identify the characteristics of the two serotypes of S. parauberis, we conducted a biochemical test using the API 20 Strep kit, a transmission electron microscopy (TEM) assay, sequence analysis of 16S‐23S rRNA intergenic spacer region (ISR) and a pathogenicity test. In TEM, both serotypes possessed polysaccharide capsule layers around the cell surface when bacterial cells were treated with a homologous serotype of rabbit antiserum. However, we were unable to discriminate serotype‐specific biochemical characteristics and genetic characteristics of 16S‐23S rRNA ISR between the two serotypes. In the pathogenicity test, the serotype 1 strains induced significantly higher mortality than the serotype 2 strains in olive flounder when experimentally inoculated via the intraperitoneal route.  相似文献   

16.
ABSTRACT:   To elucidate the species status of Pinctada fucata in China, P. fucata martensii in Japan and P. imbricata in Australia, one population of each taxon was studied using internal transcribed spacer 1 and 2 (ITS1, and ITS2) and amplified fragment length polymorphism (AFLP) markers. ITS1 and ITS2 were 401–405 and 229–237 bp long, respectively. Twenty-nine ITS1 and 15 ITS2 unique genotypes were obtained from 44 and 34 individuals, respectively, with some genotypes shared by two or three populations. In AFLP analysis, each individual exhibited a distinct phenotype. No population had diagnostic markers. Mean genetic divergences within and among the three populations were very low and overlapped (between-population: 0.7–0.9% for ITS1, 0.9–1.3% for ITS2, and 53.3–55.6% for AFLP; within-population: 0.5–0.9% for ITS1, 0.8–1.2% for ITS2, and 50.4–53.6% for AFLP). Low levels of genetic differentiation were observed among the three populations while the Australian population is partially genetically isolated. Under an infinite allele model, genetic differentiation among populations was not significant based on a permutation test. Under an infinite site model, most F ST values were not significant for ITS data although they were significant for AFLP data. Network analysis using ITS data indicated that individuals from the same population did not cluster together. Analysis of molecular variance ( amova ) demonstrated that > 94% variation was contributed by within-population variation. These findings suggest that the three taxa are conspecific and Pinctada fucata is the correct name.  相似文献   

17.
Infectious haematopoietic necrosis virus from salmonids cultured in Korea   总被引：1，自引：0，他引：1  
Abstract. Four isolates of infectious haematopoietic necrosis virus (IHNV) were obtained from rainbow trout, Oncorhynchus mykiss (Walbaum), and masu salmon, Oncorhynchus masou (Walbaum), fry during epizootics at hatcheries in Korea. The four isolates of IHNV were compared with three from salmonids in the USA (SRCV, OSV and RB-76) by analysis of virion proteins in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and neutralization tests, with two monoclonal antibodies raised against SRCV (MAb SRCV/A4) and RB-76 (MAb RB/B5). Based on the antigenicity and the size of the structural proteins, one Korean isolate from masu salmon (SCS) is similar to RB-76 and is an electropherotype 1. The other three isolates from rainbow trout (PRT, YRT and MRT) were identical to each other in the mobilities of their virion proteins in SDS-PAGE, and although their nucleocapsid (N) proteins comigrated with that of the RB-76 isolate, they differed from RB-76 in the smaller matrix 2 (M2) protein they contained. In addition, the three Korean isolates (PRT, YRT and MRT) could be divided into two groups by reactivity with MAb RB/B5. While the YRT isolate was neutralized by this MAb, the PRT and MRT isolates were not, suggesting that there are at least two neutralizing antigenic variants of IHNV in Korea.  相似文献   

18.
In order to provide baseline information for the genetic resources, genetic variation in wild and cultured Pinctada fucata martensii from southern Korea and Japan was studied using nucleotide sequence analysis of 379 base pairs (bp) in the mitochondrial cytochrome oxidase subunit I gene (COI). The study included three hatchery stocks from Korea (Tongyeong) and Japan (Mie and Tsushima) and one wild stock from Korea (Geoje). A total of 3 haplotypes were identified in hatchery stocks of 78 individuals, of which 63 individuals shared 1 haplotype. Overall, nucleotide diversity (π) was low, ranging from 0.000 to 0.002, and haplotype diversity (h) ranged from 0.000 to 0.541. Considerably low haplotype and nucleotide diversities in hatchery stock indicated that low effective population size and consecutive selective breeding of P. fucata martensii could be responsible for the reduction in genetic variation. The wild stock exhibited low haplotype diversity (0.507 ± 0.039) with two shared haplotypes. The results of the present study with first record of wild pearl oyster in Korea support the possibility that the transplanted pearl oyster for overwintering experiments could have survived in winter. In order to enhance and/or maintain genetic diversity in the hatchery stock, further research should be directed toward genetic monitoring and evaluation of the hatchery and wild pearl oysters.  相似文献   

19.
应用AFLP标记分析了西北太平洋沿岸大弹涂鱼(Boleophthalmus pectinirostris)的遗传多样性和群体结构.利用6对选择性引物对采自日本、韩国、越南及中国广西、广东、福建、台湾和浙江8个群体的126尾大弹涂鱼进行扩增.在15～500 bp之间得到186条条带,其中多态性片段160条,多态性比例为86.02％,每对引物组合扩增片段为25～36条,每对引物组合多态位点检出率为52.0％～96.42％.各群体的多态性位点比例在27.96％～57.53％之间,其中韩国群体的多态性位点比例最高,广东群体的多态性位点比例最低.各群体间Nei's遗传距离为0.038～0.151,遗传距离较大.各群体间遗传分化指数Fst值为0.175～0.459,均检测到显著的遗传分化(P=o.ooo).基于遗传距离矩阵构建的NJ系统树显示,大弹涂鱼的8个群体被分为了两支,其中日本、韩国及台湾群体聚为岛屿支系,浙江、福建、广东、广西和越南群体聚为大陆支系.AMOVA分析显示,大部分的变异组分来自于各群体内个体间,且组群间、群体间及群体内均存在明显的遗传分化.群体间遗传分化系数Gst为0.385 7,群体间的基因流Nm为0.796 4,群体间基因交流弱于其他多数鱼类.  相似文献   

20.
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