Genomic View of Bipolar Disorder Revealed by Whole Genome Sequencing in a Genetic Isolate

Bipolar disorder is a common, heritable mental illness characterized by recurrent episodes of mania and depression. Despite considerable effort to elucidate the genetic underpinnings of bipolar disorder, causative genetic risk factors remain elusive. We conducted a comprehensive genomic analysis of bipolar disorder in a large Old Order Amish pedigree. Microsatellite genotypes and high-density SNP-array genotypes of 388 family members were combined with whole genome sequence data for 50 of these subjects, comprising 18 parent-child trios. This study design permitted evaluation of candidate variants within the context of haplotype structure by resolving the phase in sequenced parent-child trios and by imputation of variants into multiple unsequenced siblings. Non-parametric and parametric linkage analysis of the entire pedigree as well as on smaller clusters of families identified several nominally significant linkage peaks, each of which included dozens of predicted deleterious variants. Close inspection of exonic and regulatory variants in genes under the linkage peaks using family-based association tests revealed additional credible candidate genes for functional studies and further replication in population-based cohorts. However, despite the in-depth genomic characterization of this unique, large and multigenerational pedigree from a genetic isolate, there was no convergence of evidence implicating a particular set of risk loci or common pathways. The striking haplotype and locus heterogeneity we observed has profound implications for the design of studies of bipolar and other related disorders.     

An Evidence for Host Translation Inhibitory Factor Encoded in a Polydnavirus,Cotesia glomerata Bracovirus,Genome and Its Expression in Parasitized Cabbage White Butterfly,Pieris rapae

Polydnavirus is a DNA virus symbiotic to some endoparasitic wasps and plays a critical role in accomplishing successful parasitic life cycle of host wasps. Host translation inhibitory factor (HTIF) has been found in some polydnaviral genomes and performs parasitic functions leading to host immunosuppression and redirecting host nutrient usage to wasp development. The cabbage white butterfly, Pieris rapae, parasitized by a gregarious endoparasitoid, Cotesia glomerata, undergoes several physiological alterations including immune malfunctioning and failure of pupal metamorphosis. C. glomerata possesses its own symbiotic polydnavirus, C. glomerata bracovirus (CgBV). Its genome consisted of at least 12 segments in unequal amounts. Parasitized P. rapae hemolymph contained HTIF-like protein, which was determined through an immunoblotting assay using HTIF antibody of C. plutellae bracovirus (CpBV). RT-PCR using HTIF primers of CpBV produced an HTIF-like gene in P. rapae larvae parasitized by C. glomerata. Also, this HTIF-like gene was encoded in CgBV genome and its partial sequence of CgBV showed highly homology (98.5%) to amino acid sequence of an HTIF of CpBV, called CpBV15a. These results suggest that a common HTIF-like moiety may be shared among Cotesia-associated bracovirus.     

1株梅花鹿源狂犬病街毒株全基因组测序与分析

对1株梅花鹿源性狂犬病街毒株(DRV)进行全基因组克隆,对全长cDNA进行测序分析.RT-PCR扩增克隆覆盖全基因组9个重叠基因片段,基因组3'和5'末端采取3,-RACE和5'-RACE方法,9个重叠基因片段序列拼接得到DRV全基因组cDNA序列,共11 863个核苷酸.DRV毒株全基因组构成与其他狂犬病毒基因组构成相似,由5个编码区组成,基因起始位点和终止位点高度保守,在核蛋白和糖蛋白的重要抗原位点有个别氨基酸发生变异,对已完成全基因组测序的几个基因1型毒株分别进行了N、P、M、G、L基因核苷酸及氨基酸的同源性比较.与其他具有代表性的毒株进行N基因序列比较建立的系统进化树表明,DRV毒株属于基因1型,与中国人用疫苗株3aG同源性最高为94%,与分类位置未确定的北高加索毒株(WCBV)的同源性最低为71%.本研究结果可为狂犬病毒各项分子生物学研究提供理论参考.     

Separation of Bacterial Ribosomal Ribonucleic Acid from Its Macromolecular Precursors by Polyacrylamide Gel Electrophoresis

Electrophoresis on polyacrylamide gels was found to be a powerful technique for separating the mature from the precursor forms of bacterial ribosomal nucleic acid (rRNA). The separation of the 16S rRNA from its precursor was, for all practical purposes, complete; that of the 23S rRNA from its precursor was detectable but incomplete. When mature and precursor rRNA preparations were heated to randomize secondary structure, etc., and then cooled, it was found that electrophoretic mobility differences between mature forms of rRNA and their precursors persisted. This, in conjunction with the rather large electrophoretic mobility differences between mature and precursor forms, can be taken as strong evidence for a molecular weight difference between mature rRNA and its precursor forms of RNA. With the 16S rRNA, this difference could be as large as 130,000 daltons.     

一株高度变异的中国SV40分离株的全基因组序列分析

对SV40中国云南分离株YNQD38进行了全基因组核苷酸序列测定。覆盖了整个基因组的9个重叠的基因片段被扩增和测序,与其它SV40株进行了序列比对并基于全基因序列建立了遗传进化树。结果显示:基因组全长5125bp,基因组构成与其它SV40毒株相似,均有6个开放读码框架和1个调控区。YNQD38与已被证实高度保守的其它SV40比,全基因组核苷酸同源性仅为91.0%。在SV40的保守区VP1、VP2、VP3、小t抗原(t-ag)和部分大T抗原(不包括大T抗原C末端)区,YNQD38与其它SV40之间核苷酸同源性分别为90.7%~91.1%、91.7%~92.0%、90.2%~90.8%、92.8%~93.3%、88.5%~89.7%。在SV40的可变区大T抗原C末端(T-ag-C)编码区,YNQD38同源性更低,仅为65.7%~74.3%。YNQD38发生在保守区的核苷酸变异多为无义突变,而发生在变异区的核苷酸变异多为有义突变。YNQD38的调控区缺少一个完整的72bp增强子,这种特别的调控区的结构以前未见报道。基于整个基因组构建的进化树显示该株病毒形成了一个独特的组。以上结果表明YNQD38是目前报道的SV40中变异最大的一株,而且也是第一株被完整测序的SV40中国株。这个报道不仅为SV40中国株的基础研究提供了一个完整清楚的分子生物学资料,还对这样一株高度变异的SV40能否成为人类致病因子进行了初步探讨。     

Separation of the Polypeptides of Chlamydia and Its Cell Walls by Polyacrylamide Gel Electrophoresis

The polypeptide composition of Chlamydia was examined by acrylamide gel electrophoresis. When the polypeptide patterns of purified infectious elementary bodies (EB) of C. psittaci meningopneumonitis strain, 6BC strain, and C. trachomatis T'ang strain were compared, no significant differences were observed. The polypeptide patterns of whole EB and reticulate bodies (RB) appeared to overlap, but differences were found. In EB cell walls, nine main and several minor bands of polypeptides were observed in gels containing sodium lauryl sulfate, and the eighth main band from the top of the gel stained positive with periodic acid-Schiff reagent. On the other hand, the polypeptides in bands 3, 6, and 8 in EB cell walls were missing or minor in RB cell walls, and the ninth band was clearly stained by PAS. Band 8 was also stained slightly. Purified subunits, which occur as a lattice structure on the inside layer of EB cell walls but are largely missing in RB cell walls, contained bands 4, 6, and 8, and band 8 was PAS positive. These results indicate that significant polypeptide synthesis or reorganization in the cell walls occurs during the growth cycle.     

皱边石杉基因组总DNA保存期间的质量检测分析

目的:用CTAB法提取皱边石杉叶片的基因组总DNA,对DNA储存于4℃的TE缓冲溶液与65℃水浴促溶2种实验处理进行为期30d的稳定性对比实验。方法:对比分析保存于4℃的TE缓冲溶液中与65℃进行2～3次水浴促进DNA溶解释放处理的DNA的稳定性及完整性变化。结果:保存于4℃TE缓冲溶液中的DNA样品非常稳定;65℃水浴促进了DNA从包裹的多糖中溶解释放,但2～3次水浴使大片段的DNA降解。结论:DNA保存在TE缓冲溶液中非常稳定;65℃水浴尽管可提高DNA的提取量,但会使DNA发生降解。因此,一般情况下对DNA不要进行水浴促溶。     

皱边石杉内生真菌DNA提取有效方法比较

目的:优化确定适用于皱边石杉内生真菌DNA提取的有效方法,并评价其效果。方法:运用氯化苄改良法、CTAB改良法分别提取皱边石杉内生真菌菌丝体DNA。结果:氯化苄改良法可从17个内生真菌菌丝体中均获得了高质量的DNA,除5、13、14号生长缓慢的内生真菌其菌丝体DNA浓度≤60ng/μL,其余样品的DNA浓度均≥200ng/μL。而CTAB改良法仅适宜于平板培养菌落生长迅速、菌落疏松,发酵培养菌丝体产量高的1、2、3、9、10、12号菌株。结论:氯化苄改良法是适宜于皱边石杉内生真菌DNA提取的理想方法。     

山东省玉米矮花叶病毒的生物学特性及基因组全序列测定

对山东省玉米矮花叶病毒原分离物(SD)进行了寄主范围、血清学等普通生物学鉴定,测定了该病毒的基因组核苷酸全序列。该病毒基因组RNA由9596个核苷酸组成(不包括3’—polyA的长度),整个基因组按一个ORF编码一个3063个氨基酸的多聚蛋白。序列比较表明,该病毒分离物(SD)与玉米矮花叶病河南分离物(HN,EMBL登录号：AF94510)核苷酸全序列同源性最高,为98．2％,与已报道的甘蔗花叶病毒(SCMV)7个分离物同源性也高达79．5％-98．2％,但与玉米矮花叶病毒保加利亚分离物(MDMV—B8,AJ001691)和高梁花叶病毒萧山甘蔗分离物(SrMV—XoS,AJ310197)的同源性仅为67．8％和69．3％,与约翰逊草花叶病毒(226920,JGMV)差异最大。系统进化树分析也表明,该病毒与SCMV分离物位于同一进化簇,而与MDMV进化关系很远。     

Cloning the Deleted DNA Fragment from a Deletion Mutant of Planetree by Genomic Subtraction

A novel type of mutant of planetree (Platanus occidentalis L. ), which was produced via γ-ray irradiation, does not form lower buds yet its vegetative organs grow normally. Genetic analysis showed that this was clue to the deletion of DNA fragments in the mutant genome. Through genomic subtraction technique, a 2.0 kb DNA segment (pBS 2.0) was isolated, which is only present in wild planetree genome, but is absent in mutant genome.     

苹果属植物树皮组织总蛋白提取及分离方法的建立

为了建立适于苹果属植物树皮组织总蛋白提取的技术方法, 以8年生华月苹果(Malus domestica)树枝条为试材, 通过比较不同提取方法(TCA-丙酮沉淀法(A)、甲醇/醋酸铵沉淀法(B)和改良的Tris-酚抽提方法(C))并优化提取条件, 确立了最适提取及分离方法为改良的Tris-酚抽提方法。在2-DE分离时, 该方法所获得的样品图谱中蛋白点总数为993个, 明显多于TCA-丙酮沉淀(418个)和甲醇醋酸铵沉淀(674个)方法, 并且与其它两种方法相比, 该方法获得的图谱背景更清晰, 蛋白点聚焦效果更好。此外, 经过3个梯度上样量的图谱分离效果比较, 确定了800 μg为本研究中2-DE分析的理想上样量。另外, 为了验证该提取及分离方法的可行性, 进一步对蛋白质表达谱中的部分蛋白点进行了质谱分析, 且这些蛋白点均得到了成功鉴定。该研究通过优化总蛋白提取方法及样品上样量等条件, 获得了理想的双向电泳分离图谱, 为苹果属植物树皮组织材料的蛋白质组学研究奠定了基础。     

Identification and Genome Characterization of the First Sicinivirus Isolate from Chickens in Mainland China by Using Viral Metagenomics

Unlike traditional virus isolation and sequencing approaches, sequence-independent amplification based viral metagenomics technique allows one to discover unexpected or novel viruses efficiently while bypassing culturing step. Here we report the discovery of the first Sicinivirus isolate (designated as strain JSY) of picornaviruses from commercial layer chickens in mainland China by using a viral metagenomics technique. This Sicinivirus isolate, which contains a whole genome of 9,797 nucleotides (nt) excluding the poly(A) tail, possesses one of the largest picornavirus genome so far reported, but only shares 88.83% and 82.78% of amino acid sequence identity to that of ChPV1 100C ({"type":"entrez-nucleotide","attrs":{"text":"KF979332","term_id":"672942599","term_text":"KF979332"}}KF979332) and Sicinivirus 1 strain UCC001 ({"type":"entrez-nucleotide","attrs":{"text":"NC_023861","term_id":"602259859","term_text":"NC_023861"}}NC_023861), respectively. The complete 939 nt 5′UTR of the isolate strain contains at least twelve stem-loop domains (A–L), representing the highest set of loops reported within Sicinivirus genus. The conserved ''barbell-like'' structure was also present in the 272 nt 3′UTR of the isolate as that in the 3′ UTR of Sicinivirus 1 strain UCC001. The 8,586 nt large open reading frame encodes a 2,862 amino acids polyprotein precursor. Moreover, Sicinivirus infection might be widely present in commercial chicken farms in Yancheng region of the Jiangsu Province as evidenced by all the tested stool samples from three different farms being positive (17/17) for Sicinivirus detection. This is the first report on identification of Sicinivirus in commercial layer chickens with a severe clinical disease in mainland China, however, further studies are needed to evaluate the pathogenic potential of this picornavirus in chickens.     

Virulence Factors Encoded by Legionella longbeachae Identified on the Basis of the Genome Sequence Analysis of Clinical Isolate D-4968

Legionella longbeachae causes most cases of legionellosis in Australia and may be underreported worldwide due to the lack of L. longbeachae-specific diagnostic tests. L. longbeachae displays distinctive differences in intracellular trafficking, caspase 1 activation, and infection in mouse models compared to Legionella pneumophila, yet these two species have indistinguishable clinical presentations in humans. Unlike other legionellae, which inhabit freshwater systems, L. longbeachae is found predominantly in moist soil. In this study, we sequenced and annotated the genome of an L. longbeachae clinical isolate from Oregon, isolate D-4968, and compared it to the previously published genomes of L. pneumophila. The results revealed that the D-4968 genome is larger than the L. pneumophila genome and has a gene order that is different from that of the L. pneumophila genome. Genes encoding structural components of type II, type IV Lvh, and type IV Icm/Dot secretion systems are conserved. In contrast, only 42/140 homologs of genes encoding L. pneumophila Icm/Dot substrates have been found in the D-4968 genome. L. longbeachae encodes numerous proteins with eukaryotic motifs and eukaryote-like proteins unique to this species, including 16 ankyrin repeat-containing proteins and a novel U-box protein. We predict that these proteins are secreted by the L. longbeachae Icm/Dot secretion system. In contrast to the L. pneumophila genome, the L. longbeachae D-4968 genome does not contain flagellar biosynthesis genes, yet it contains a chemotaxis operon. The lack of a flagellum explains the failure of L. longbeachae to activate caspase 1 and trigger pyroptosis in murine macrophages. These unique features of L. longbeachae may reflect adaptation of this species to life in soil.Isolation of Legionella longbeachae was first reported in 1981 after isolation from patients with pneumonia in the United States (11, 59). Although L. longbeachae is not a common respiratory pathogen in either North America or Europe, where Legionella pneumophila infections are predominant, it accounts for more than 50% of legionellosis cases in Australia and is also prevalent in New Zealand and Thailand (10, 12, 60, 66, 68, 77, 93, 94). Legionnaires'' disease induced by L. longbeachae infection is clinically indistinguishable from the disease caused by L. pneumophila (65). However, L. longbeachae infections have been associated with gardening and the use of potting soil, whereas the disease caused by other species is linked to freshwater sources (4, 65). L. longbeachae can survive for up to 9 months in moist potting soil at room temperature, in contrast to other Legionella species, which inhabit natural and manmade freshwater systems worldwide (34, 83, 84).In addition to the differences in habitat, L. longbeachae differs from L. pneumophila in its virulence in murine models of infection. L. longbeachae replicates in the lungs of A/J, C57BL/6, and BALB/c mice (6), whereas most inbred mice, including C57BL/6 and BALB strains, are resistant to L. pneumophila (61). These differences in murine host susceptibility are likely due to different abilities to activate caspase 1-mediated pyroptosis in macrophages. While L. pneumophila rapidly triggers pyroptosis in C57BL/6 mouse macrophages, L. longbeachae does not do this (6).Intracellular trafficking of L. longbeachae in mammalian macrophages also follows a route distinct from that of L. pneumophila. After phagocytosis, the L. pneumophila-containing vacuole (LCV) excludes early and late endosomal markers, such as early endosomal antigen 1 (EEA1), Rab5, LAMP-1, LAMP-2, and the mannose 6-phosphate receptor (M6PR) (5, 89). In L. pneumophila the Dot/Icm type IV secretion system is required for prevention of phagosome-lysosome fusion and for intracellular replication (47). Conversely, the L. longbeachae-containing vacuole acquires the early endosomal marker EEA1 and the late endosomal markers LAMP-2 and M6PR (5). It has been suggested that L. longbeachae intracellular trafficking resembles that of the facultative intracellular pathogen Brucella abortus, since a Brucella-containing vacuole also acquires early and late endosomal markers soon after infection (5). Despite the difference in intracellular trafficking between L. longbeachae and L. pneumophila, L. longbeachae rescues Dot/Icm-deficient L. pneumophila when these two organisms coinhabit LCV (5).Results of the studies cited above indicate that L. longbeachae differs from other legionellae in terms of habitat, host specificity, and intracellular trafficking. In this paper, we describe an analysis of the sequenced and annotated genome of L. longbeachae clinical isolate D-4968 compared with published genomes of L. pneumophila strains Corby, Lens, Paris, and Philadelphia-1 (16, 17, 38). Specifically, we compared genes involved in gene regulation, protein secretion systems, and motility in order to identify genes responsible for making L. longbeachae unique among the legionellae.     

Analysis of the Campylobacter jejuni Genome by SMRT DNA Sequencing Identifies Restriction-Modification Motifs

Campylobacter jejuni is a leading bacterial cause of human gastroenteritis. The goal of this study was to analyze the C. jejuni F38011 strain, recovered from an individual with severe enteritis, at a genomic and proteomic level to gain insight into microbial processes. The C. jejuni F38011 genome is comprised of 1,691,939 bp, with a mol.% (G+C) content of 30.5%. PacBio sequencing coupled with REBASE analysis was used to predict C. jejuni F38011 genomic sites and enzymes that may be involved in DNA restriction-modification. A total of five putative methylation motifs were identified as well as the C. jejuni enzymes that could be responsible for the modifications. Peptides corresponding to the deduced amino acid sequence of the C. jejuni enzymes were identified using proteomics. This work sets the stage for studies to dissect the precise functions of the C. jejuni putative restriction-modification enzymes. Taken together, the data generated in this study contributes to our knowledge of the genomic content, methylation profile, and encoding capacity of C. jejuni.     

Characterization of a novel protein with homology to C-type lectins expressed by the Cotesia rubecula bracovirus in larvae of the lepidopteran host,Pieris rapae

Polydnaviruses are essential for the survival of many Ichneumonoid endoparasitoids, providing active immune suppression of the host in which parasitoid larvae develop. The Cotesia rubecula bracovirus is unique among polydnaviruses in that only four major genes are detected in parasitized host (Pieris rapae) tissues, and gene expression is transient. Here we describe a novel C. rubecula bracovirus gene (CrV3) encoding a lectin monomer composed of 159 amino acids, which has conserved residues consistent with invertebrate and mammalian C-type lectins. Bacterially expressed CrV3 agglutinated sheep red blood cells in a divalent ion-dependent but Ca2+-independent manner. Agglutination was inhibited by EDTA but not by biological concentrations of any saccharides tested. Two monomers of approximately 14 and approximately 17 kDa in size were identified on SDS-PAGE in parasitized P. rapae larvae. The 17-kDa monomer was found to be an N-glyscosylated form of the 14-kDa monomer. CrV3 is produced in infected hemocytes and fat body cells and subsequently secreted into hemolymph. We propose that CrV3 is a novel lectin, the first characterized from an invertebrate virus. CrV3 shows over 60% homology with hypothetical proteins isolated from polydnaviruses in two other Cotesia wasps, indicating that these proteins may also be C-type lectins and that a novel polydnavirus lectin family exists in Cotesia-associated bracoviruses. CrV3 is probably interacting with components in host hemolymph, resulting in suppression of the Pieris immune response. The high similarity of CrV3 with invertebrate lectins, as opposed to those from viruses, may indicate that some bracovirus functions were acquired from their hosts.     

Preparation of Genomic DNA from a Single Species of Uncultured Magnetotactic Bacterium by Multiple-Displacement Amplification

Magnetotactic bacteria comprise a phylogenetically diverse group that is capable of synthesizing intracellular magnetic particles. Although various morphotypes of magnetotactic bacteria have been observed in the environment, bacterial strains available in pure culture are currently limited to a few genera due to difficulties in their enrichment and cultivation. In order to obtain genetic information from uncultured magnetotactic bacteria, a genome preparation method that involves magnetic separation of cells, flow cytometry, and multiple displacement amplification (MDA) using φ29 polymerase was used in this study. The conditions for the MDA reaction using samples containing 1 to 100 cells were evaluated using a pure-culture magnetotactic bacterium, “Magnetospirillum magneticum AMB-1,” whose complete genome sequence is available. Uniform gene amplification was confirmed by quantitative PCR (Q-PCR) when 100 cells were used as a template. This method was then applied for genome preparation of uncultured magnetotactic bacteria from complex bacterial communities in an aquatic environment. A sample containing 100 cells of the uncultured magnetotactic coccus was prepared by magnetic cell separation and flow cytometry and used as an MDA template. 16S rRNA sequence analysis of the MDA product from these 100 cells revealed that the amplified genomic DNA was from a single species of magnetotactic bacterium that was phylogenetically affiliated with magnetotactic cocci in the Alphaproteobacteria. The combined use of magnetic separation, flow cytometry, and MDA provides a new strategy to access individual genetic information from magnetotactic bacteria in environmental samples.Magnetotactic bacteria synthesize nanosized intracellular magnetic particles, also referred to as magnetosomes, by accumulating iron ions from the environment. Since the first report on the identification of magnetotactic bacteria (2), the morphological and phylogenetic diversity of these organisms has been observed in various aquatic environments (12, 25, 27, 30). However, bacterial strains available in pure culture are currently limited to a few genera. Desulfovibrio magneticus strain RS-1 is the only isolate of magnetotactic bacteria that is classified among the Deltaproteobacteria (13, 23), while Magnetospirillum spp., marine magnetic vibrio strain MV-1, and “Magnetococcus strain MC-1” are phylogenetically affiliated within the Alphaproteobacteria group (24, 27). This limitation is mainly because not much is known about their metabolic requirements, culturing conditions, and obligate coculture requirements.Isolation and enrichment of magnetotactic bacteria are generally conducted by applying a magnetic field to a container containing a sediment sample from the environment. The capillary racetrack method is a highly selective enrichment technique that separates magnetotactic bacteria from other contaminants (31). The magnetic separation method that involves the use of a large glass apparatus is efficient and suitable for analyzing samples containing more than 100 ml of sediment and water (12, 16). These techniques have been applied to investigate community structure and phylogenetic diversity of uncultured magnetotactic bacteria in the environment based on 16S rRNA analyses (3, 7, 26, 29). In a recent study, DNA isolation enabling gene cloning was examined by magnetically collecting a large number of magnetotactic cells from environmental samples, and two gene fragments, probably containing parts of magnetosome islands (MAIs) derived from magnetotactic bacteria of the Alphaproteobacteria, were identified (12). However, this approach allows only for sequence gene information to be obtained from a heterogeneous bacterial community in the sample.Multiple displacement amplification (MDA) can generate microgram quantities of high-quality DNA sample from a few femtograms of DNA template (5, 6). We previously revealed that MDA is a powerful tool for whole-genome amplification from the metagenome of an uncultured bacterial community (32). Studies have been conducted to determine the efficacy of MDA for analyzing genomic DNA preparations from a limited number of bacterial cells (14, 17, 21, 22, 28). Complete genomic sequencing of an uncultured gut symbiont in termites has been achieved using MDA products amplified from approximately 1,000 cells (9). Partial genome sequencing using MDA products from a single uncultured cell has also been reported (17, 22). Such targeted genome analyses using MDA products from a single cell or genetically identical microorganisms is advantageous because it allows the assignment of individual genes to the corresponding microorganisms.In this study, an improved genome preparation method involving racetrack purification and flow cytometry followed by MDA was investigated by using a small number of uncultured magnetotactic bacteria. This method can be used for the identification of new genes from rare magnetotactic bacteria in environmental samples.     

洋葱细胞质雄性不育系70及其保持系71基因组DNA的RAPD分析

采用RAPD技术,对洋葱细胞质雄性不育系70及其保持系71的基因组DNA的多态性进行分析。结果表明,在被检测的100条随机引物中,46条引物具有扩增产物,5条引物扩增出多态性条带。对这5条引物进行重复筛选和单株验证,只有G02扩增出的多态性片段,且表现稳定。推测该标记与育性有关。     

Genomic Relationships between Enterococcus faecium Strains from Different Sources and with Different Antibiotic Resistance Profiles Evaluated by Restriction Endonuclease Analysis of Total Chromosomal DNA Using EcoRI and PvuII

Forty-seven Enterococcus faecium strains from different sources were evaluated by restriction endonuclease analysis (REA) of total chromosomal DNA. Strains from chicken, pork, and humans were clearly divided into separate clusters, whereas strains from different countries, strains with different antibiotic resistance profiles, or clinical and healthy-subject strains were not.