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1.
A novel category of variable tandem repeats (VNTR) called mycobacterial interspersed repetitive units (MIRUs) has been identified for Mycobacterium ulcerans (n = 39), M. marinum (n = 27), and one related organism. Fifteen MIRU loci were identified in the genome of M. marinum and were used to genotype M. ulcerans, M. marinum, and an M. marinum-like organism that is considered a possible missing link between M. marinum and M. ulcerans. Seven MIRU loci were polymorphic, and locus-specific PCRs for four of these loci differentiated seven M. ulcerans genotypes, four M. marinum genotypes, and a unique genotype for the missing link organism. The seven M. ulcerans genotypes were related to six different geographic origins of isolates. All isolates from West and Central Africa, including old and recent isolates, belonged to the same genotype, emphasizing the great spatiotemporal homogeneity among African isolates. Unlike the M. ulcerans genotypes, the four M. marinum genotypes could not be clearly related to the geographic origins of the isolates. According to MIRU-VNTR typing, all M. ulcerans and M. marinum isolates of American origin were closely related, suggesting a common American ancestor for these two pathogenic species on the American continents. MIRU typing has significant potential value for discriminating between reoccurrence and reinfection for M. ulcerans disease.  相似文献   

2.
The present study investigated how direction of hand movement, which is a well-described parameter in cerebral organization of motor control, is incorporated in the somatotopic representation of the manual effector system in the human primary motor cortex (M1). Using functional magnetic resonance imaging (fMRI) and a manual step-tracking task we found that activation patterns related to movement in different directions were spatially disjoint within the representation area of the hand on M1. Foci of activation related to specific movement directions were segregated within the M1 hand area; activation related to direction 0° (right) was located most laterally/superficially, whereas directions 180° (left) and 270° (down) elicited activation more medially within the hand area. Activation related to direction 90° was located between the other directions. Moreover, by investigating differences between activations related to movement along the horizontal (0°+180°) and vertical (90°+270°) axis, we found that activation related to the horizontal axis was located more anterolaterally/dorsally in M1 than for the vertical axis, supporting that activations related to individual movement directions are direction- and not muscle related. Our results of spatially segregated direction-related activations in M1 are in accordance with findings of recent fMRI studies on neural encoding of direction in human M1. Our results thus provide further evidence for a direct link between direction as an organizational principle in sensorimotor transformation and movement execution coded by effector representations in M1.  相似文献   

3.
The cocultivation of a lung cell line from the Southeast Asian mouse Mus cervicolor with cells from heterologous species has resulted in the isolation of two new distinct type C viruses. Both viruses are endogenous to M. cervicolor and are present in multiple copies in the cellular DNA of these mice. One of the viruses, designated M. cervicolor type CI, replicates readily in the SIRC rabbit cell line and is antigenically related to the infectious primate type C viruses isolated from a woolly monkey (simian sarcoma-associated virus) and gibbon apes (gibbon ape leukemia virus). This virus is also closely related by both immunological and nucleic acid hybridization criteria to a type C virus previously isolated from a second Asian murine species, Mus caroli. The isolation of the M. cervicolor type C I virus thus provides further evidence that the infectious primate type C viruses originated by trans-species infection of primates by an endogenous virus of mice. The second virus, designated M. cervicolor type C II, replicates well in various cell lines derived from the laboratory mouse Mus musculus. While antigenically related to type C viruses derived from M. musculus, the M. cervicolor type C II virus isolate can be readily distinguished from standard murine leukemia viruses. Both new type C viruses from M. cervicolor are unrelated to the previously described retrovirus (M432) isolated from the same Mus species. The DNA of M. cervicolor therefore contains multiple copies of at least three distinct classes of endogenous viral genes. An examination of the cellular DNA of other rodent species for nucleic acid sequences related to the genomes of both M. cervicolor type C I and II reveals that both viruses have been highly conserved evolutionarily, and that other species of rodents, such as laboratory mice and rats, contain endogenous virogenes related to those in the DNA of M. cervicolor.  相似文献   

4.
Pairing of X and Y chromosomes at meiotic prophase and the G- and C-banding patterns and nucleolar organizer region (NOR) distribution were analyzed in Microtus kikuchii. M. kikuchii is closely related to M. oeconomus and M. montebelli, karyologically and systematically. The formation of a synaptonemal complex between the X and Y chromosomes at pachytene and end-to-end association at diakinesis--metaphase I are only observed in three species in the genus Microtus; M. kikuchii, M. oeconomus, and M. montebelli. All the other species that have been studied so far have had asynaptic X-Y chromosomes. These data confirm that M. kikuchii, M. oeconomus, and M. montebelli are very closely related, and support the separation of asynaptic and synaptic groups on the phylogenetic tree.  相似文献   

5.
Three new species of Mitrephora (Blume) Hook. f. & Thomson, M. clemensiorum, M. vittata and M. woodii , are described from Sabah, Malaysia. Mitrephora clemensiorum is related to M. korthalsiana Miq., but is distinguished by having long inflorescences, long flowering and fruiting pedicels, and fruits with sessile monocarps. Mitrephora vittata is related to M. reflexa Merr., but has lanceolate, subcoriaceous leaves, and densely pubescent inflorescence rachides, flowering pedicels and bracts. Mitrephora woodii is similar to M. heyneana (Hook. f. & Thomson) Thwaites, but has smaller flowers and fruits with sessile monocarps  相似文献   

6.
Serological comparison of ten glycolytic Mycoplasma species   总被引:16,自引:6,他引:10       下载免费PDF全文
Seventeen strains of mycoplasmata representing 11 named species were compared serologically by three parameters: growth inhibition on agar, double immunodiffusion, and complement fixation. In growth-inhibition studies, a strain labeled Mycoplasma histotropicum was found related to and perhaps best classified as M. pulmonis, a relationship confirmed by double immuno-diffusion studies. A comparison of the remaining 10 species demonstrated that two pairs of species could be shown to be closely related by complement fixation and double immunodiffusion but not by growth inhibition; these were: M. granularum-M. laidlawii and M. felis-M. canis. M. pneumoniae and M. gallisepticum were the most serologically unique organisms in this study, showing very few cross-reactions with each other or other species. Overall, taxonomic groupings obtained by comparative serology appeared to correlate with the groupings obtained when the guanine plus cytosine contents of the deoxyribonucleic acid of mycoplasmata were employed as classification criteria. The group of organisms having a guanine plus cytosine content of 23 to 28% (M. canis, M. fermentans, M. hyorhinis, M. neurolyticum, and M. pulmonis) appeared to be generally serologically related. Thus the remarkable heterogeneity observed in the base composition of the deoxyribonucleic acid of order Mycoplasmatales is also reflected and apparently paralleled by a corresponding serological heterogeneity.  相似文献   

7.
The roots of M. corymbosa afford three new benzofuran derivatives very closely related to leysseralangelicate isolated from the related genus Leyssera. The aerial parts of M. glandulosa contain, besides labdanolic acid, a new cis-clerodane derivative, its structure being elucidated by spectroscopic methods and by chemical reactions. The roots of a further Macowania species closely related to M. hamata afford a new ester related to m-thymol.  相似文献   

8.
Twenty-one flavonoids were isolated from the leaves of two endemic species ofMyrceugenia on the Juan Fernandez Islands,M. fernandeziana andM. schulzei, from two related species from Brazil,M. campestris andM. rufescens, and from five species from continental Chile,M. colchaguensis, M. exsucca, M. lanceolata, M. pinifolia, andM. rufa. A phenetic analysis was used to evaluate chemical similarities.Myrceugenia campestris andM. rufescens appear most closely related to each other based on flavonoid profiles, and they are also different from the other seven species. The two endemic species in the Juan Fernandez Islands,M. fernandeziana andM. schulzei, group with the continental Chilean species. The former is most closely related toM. lanceolata, and the latter clusters withM. exsucca, although somewhat distantly. The results suggest that the two Juan Fernandez endemics are derived from two introductions from the Chilean continent and not from immigrants from the eastern side of the Andes.  相似文献   

9.
Abstract Mycoplasma gallisepticun, M. imitans and M. iowae are three morphologically similar avian Mycoplasma species, and M. gallisepticum and M. imitans have been shown to be antigenically related. Using a monoclonal antibody that binds to the previously described size- and phase-variant integral membrane surface protein PvpA of M. gallisepticum , we have identified in all three avian Mycoplasma species a 41-kDa surface antigen, which in M. gallisepticum and M. imitans was identified as peripheral membrane protein undergoing variation in expression among clonal isolates. Southern blot analysis using the pvpA gene as a probe demonstrated sequence homology with M. imitans and M. iowae genomic DNA and suggested that a pvpA -related gene that may encode the 41-kDa product exists in these two Mycoplasma species. These studies establish (i) that M. iowae is antigenically related to M. gallisepticum and M. imitans , (ii) that the three species share non-ribosomal gene sequences, and (iii) that peripheral membrane proteins contribute to Mycoplasma surface variation.  相似文献   

10.
Metahuntemannia triarticulata sp.n., M. arctica sp.n. and M. bifida sp.n. arc described. M. triurficulata and M. arctica belong to the 'spinosa' group within the genus Metahuntemannia Smirnov. From the closely related species, M. triarticulata differs in the possession of 3-segmented Enp P3, M. arctica in the segmentation of the Al, and both new species in the setation of their swimming legs P1–P5. M. hifida belongs to the 'talpa' group within Metahuntemannia and differs from the closely related species in the setation of the swimming legs P2–P4. The species relationships and the phylogeny within the genus are discussed. All species were collected at the Iceland-Faroe Ridge from depths between 435 and 2500 m.  相似文献   

11.
? Premise of the study: Polymorphic microsatellite markers were developed for Momordica charantia L. to investigate the genetic diversity and population structure within and between M. charantia and its four related species (Cucurbita pepo L., Luffa cylindrical L., Lagenaria siceraria L., and Cucumis sativus L.). ? Methods and Results: Using the Fast Isolation by AFLP of Sequence COntaining Repeats (FIASCO) method, 16 polymorphic microsatellite loci were identified in 36 individuals of M. charantia. Across all the M. charantia samples, the number of alleles per locus ranged from three to eight. Seven primers successfully amplified in the four related species. ? Conclusions: These markers will be useful to study population ecology and population differentiation among M. charantia species and its related species.  相似文献   

12.
Mycobacterium ulcerans and some pathogenic mycobacterial species elaborate wax A consisting of related long-chain beta-diol components (phthiocerol and related compounds) esterified by multimethyl-branched fatty acids. With the exception of M. ulcerans, wax A-containing mycobacteria also synthesize glycosylated phenol phthiocerol diester and related compounds: the so-called phenolic mycosides. In a deliberate effort to characterize this latter class of compounds in M. ulcerans, 20 strains were examined. Phenolic mycosides were found in two strains. Application of chemical analyses, including one- and two-dimensional NMR spectroscopy, allowed the structural elucidation of glycolipids identified as 3-O-methyl-alpha-L-rhamnosyl phenol phthiocerol diphthioceranate investigators. As phenolic mycosides are highly species-specific molecules, this finding stresses the close phylogenetic link between M. marinum and M. ulcerans. Incidentally, a survey of the mycolate content of M. ulcerans showed that methoxymycolate could not be detected in three strains.  相似文献   

13.
对中国草螟亚科3个近缘属:带草螟属 Metaeuchromius Bleszynski、丽草螟属Euchromius Guenée和双带草螟属 Miyakea Marumo进行了研究。该3属在中国已记录12个种,包括带草螟属Metaeuchromius两新种:黄色带草螟 M. fulvusalis sp. Nov.,模式产地广西,与褐带草螟 M. circe Bleszynski近缘;灰色带草螟 M. grisalis sp. Nov.,模式产地浙江,与云南带草螟 M. yuennanensis (Caradja)近缘。对新种给出了描述、外生殖器特征图和与近缘种的比较。并提供了带草螟属中国已知种检索表。  相似文献   

14.
The drumstick tree(Moringa oleifera Lam.) is a perennial crop that has gained popularity in certain developing countries for its high-nutrition content and adaptability to arid and semi-arid environments. Here we report a high-quality draft genome sequence of M. oleifera. This assembly represents 91.78% of the estimated genome size and contains 19,465 protein-coding genes. Comparative genomic analysis between M. oleifera and related woody plant genomes helps clarify the general evolution of this species, while the identification of several species-specific gene families and positively selected genes in M. oleifera may help identify genes related to M. oleifera's high protein content, fast-growth, heat and stress tolerance. This reference genome greatly extends the basic research on M. oleifera, and may further promote applying genomics to enhanced breeding and improvement of M. oleifera.  相似文献   

15.
Alpha 2-Macroglobulin (alpha 2 M) was isolated from plasma of the freshwater crayfish, Pacifastacus leniusculus, using ultracentrifugation, ion-exchange chromatography and gel filtration techniques. The Pacifastacus alpha 2 M molecule (P alpha 2 M) was radio-actively labeled in the thiol ester structure with iodo [14C]acetic acid in the presence of methylamine. After reduction and carboxymethylation of the protein, it was digested with trypsin. A 14C-labeled tryptic peptide was sequenced and contained an amino acid sequence very similar to other known thiol ester sequences from human alpha 2 M and related proteins. The N-terminal sequence of P alpha 2 M was related to that recently determined for lobster alpha 2 M [(1987) J. Biol. Chem. 262, 14606-14611].  相似文献   

16.
目的:筛选一株具有广谱抗菌活性的炭样小单孢菌JXNU-1中核苷类抗生素生物合成相关蛋白。方法:通过iTRAQ定量蛋白质组学技术对JXNU-1菌体生长期(36h)和产物合成期(108h)的差异蛋白进行鉴定和功能分析。结果:基于iTRAQ定量蛋白质组学技术共鉴定出炭样小单孢菌总蛋白质2390个,差异表达蛋白172个,在产物合成期(108h)表达上调76个、表达下调96个。通过蛋白GO和COG注释等功能分析,筛选出12个与抗生素合成密切相关蛋白和5个生物合成基因簇。结论:利用iTRAQ技术筛选出炭样小单孢菌JXNU-1的抗生素合成相关蛋白,为阐明该抗生素的生物合成机制奠定实验依据。  相似文献   

17.
CA 125 has two main immunogenic areas reactive with mouse and rat monoclonal antibodies. These areas are defined by the antibodies OC 125 and M11, respectively. Antibodies related to the main groups are named OC 125-like and M 11-like antibodies. The OC 125-like antibodies can be subgrouped into four sets, whereas the M 11-like antibodies segregate into many closely related binding specificities. One M 11-like antibody, ZR38, is not fully inhibited by any other M 11-like antibody and therefore represents a distinct subgroup. A single antibody, OV 197, is related to some OC 125-like antibodies, but not to OC 125. However, OC 125 enhances binding of OV 197 to its epitope. A new antibody, 7C 12, induces conformation changes, affecting binding of some M 11-like and some OC 125-like antibodies. CA 125 exists as very large molecules that can be partly disrupted by SDS and heat. The form found in serum might be a degradation product from a larger molecule found in the abdominal and other serous cavities.  相似文献   

18.
Muscle aging is associated with changes in myeloid cell phenotype that may influence age‐related changes in muscle structure. We tested whether preventing age‐related reductions in muscle neuronal nitric oxide synthase (nNOS) would obviate age‐related changes in myeloid cells in muscle. Our findings show that muscle aging is associated with elevations of anti‐inflammatory M2a macrophages that can increase muscle fibrosis. Expression of a muscle‐specific nNOS transgene in mice prevented age‐related increases in M2a macrophages. Transgene expression also reduced expression of collagens and decreased muscle fibrosis. The nNOS transgene prevented age‐related increases in arginase‐1 but did not influence TGFβ expression, indicating that the transgene may prevent age‐related muscle fibrosis by inhibiting the arginase‐dependent profibrotic pathway. Although aged satellite cells or fibro‐adipogenic precursor (FAPs) cells also promote fibrosis, transgene expression had no effect on the expression of key signaling molecules that regulate fibrogenic activity of those cells. Finally, we tested whether increases in M2a macrophages and the associated increase in fibrosis were attributable to aging of myeloid lineage cells. Young bone marrow cells (BMCs) were transplanted into young or old mice, and muscles were collected 8 months later. Muscles of young mice receiving young BMCs showed no effect on M2a macrophage number or collagen accumulation compared to age‐matched, nontransplanted controls. However, muscles of old mice receiving young BMCs showed fewer M2a macrophages and less accumulation of collagen. Thus, the age‐related increase in M2a macrophages in aging muscle and the associated muscle fibrosis are determined in part by the age of bone marrow cells.  相似文献   

19.
Partial 16S rRNA mitochondrial gene sequences were used to infer the phylogenetic relationships among Stenocephalemys albocaudata, S. griseicauda and Myomys albipes, three closely related Ethiopian endemic murines and a selection of related species (Myomys daltoni, Praomys delectorum, Mastomys natalensis, Hylomyscus kaimosae, and Colomys goslingi) from other African regions. The obtained phylogeny confirms the close relationship between M. albipes and the two Stenocephalemys species, but it also suggests that both the genera Myomys and Stenocephalemys are paraphyletic, as M. albipes is closer to Stenocephalemys than to M. daltoni and S. griseicauda is more closely related to M. albipes than to S. albocaudata. These data, if confirmed, would argue that M. albipes should be renamed S. albipes. In conclusion, our study suggests that morphological similarity is not always a reliable measure for close genetic relationship in murines. Morphological similarity among species that evolved under similar ecological conditions can be the result of convergent evolution rather than a consequence of recent common ancestry.  相似文献   

20.
Abstract Evidence shows the presence on the chromosome of Methanobacterium wolfei of a defective prophage which, by DNA-DNA hybridization, is closely related to the virulent archaeophage ψM1 of Methanobacterium thermoautotrophicum Marburg. Partial sequencing of a M. wolfei 16S rRNA gene and phylogenetic analysis indicated that this organism is more closely related to other representatives of the genus Methanobacterium than to M. thermoautotrophicum Marburg. The chromosomal region of M. wolfei encoding the putative prophage was found to be deleted for two non-contiguous segments of the phage ψM1 genome and thus encompassed only 80 to 90% of the ψM1 DNA. The prophage region was mapped to a 30 kb restriction fragment on the physical map of the M. wolfei chromosome. A randomly chosen DNA fragment was cloned from phage ψM1 DNA, as was its homologous counterpart from the chromosome of M. wolfei . The 126-bp region present in both clones exhibited 100% sequence identity.  相似文献   

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