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1.
The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.  相似文献   

2.
In behavioural experiments and histological investigations we could demonstrate that the previously widespread generalization that females of the social parasite genus Bombus subgenus Psithyrus do not possess wax glands is not justified. Wax pieces that accumulated on the abdomina of Bombus vestalis, B. sylvestris, and B. bohemicus females which were prevented from self-grooming provided the first evidence for wax production in these species. A histological analysis of epithelial tissues confirmed the existence of epithelial wax glands. Received 17 September 2007; revised 12 March and 2 July 2008; accepted 4 July 2008.  相似文献   

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Summary  Eleven species comprising the Madagascan genus Vaughania are subsumed within the large pantropical genus Indigofera. Six new combinations are made; the remaining species were originally described in Indigofera.  相似文献   

5.
Genome sequence analysis of Xanthomonas oryzae pv. oryzae has revealed a cluster of 12 ORFs that are closely related to the gum gene cluster of Xanthomonas campestris pv. campestris. The gum gene cluster of X. oryzae encodes proteins involved in xanthan production; however, there is little experimental evidence supporting this. In this study, biochemical analyses of xanthan produced by a defined set of X. oryzae gum mutant strains allowed us to preliminarily assign functions to most of the gum gene products: biosynthesis of the pentasaccharide repeating unit for GumD, GumM, GumH, GumK, and GumI, xanthan polymerization and transport for GumB, GumC, GumE, and GumJ, and modification of the pentasaccharide repeating unit for GumF, GumG, and GumL. In addition, we found that the exopolysaccharides are essential but not specific for the virulence of X. oryzae. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. Sang-Yoon Kim and Jeong-Gu Kim contributed equally to this work.  相似文献   

6.
Summary   Funastrum rupicola Goyder, a new species of Apocynaceae: Asclepiadoideae from Bolivia, is described and illustrated. The conservation status of this species is assessed.  相似文献   

7.
Field observations and inoculation experiments revealed that Uromyces appendiculatus var. azukicola has an autoecious and macrocyclic life cycle and produces spermogonia, aecia, uredinia, and telia on Vigna angularis var. angularis and V. angularis var. nipponensis. From inoculation experiments, it was suggested that this rust fungus has different host relationships from other varieties. Morphological examinations revealed that the characteristics of urediniospores and teliospores are different among varieties, although aeciospores are morphologically similar to each other.Contribution no. 182, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan  相似文献   

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Mycobacterium austroafricanum IFP 2012, which grows on methyl tert-butyl ether (MTBE) and on tert-butyl alcohol (TBA), the main intermediate of MTBE degradation, also grows on a broad range of n-alkanes (C2 to C16). A single alkB gene copy, encoding a non-heme alkane monooxygenase, was partially amplified from the genome of this bacterium. Its expression was induced after growth on n-propane, n-hexane, n-hexadecane and on TBA but not after growth on LB. The capacity of other fast-growing mycobacteria to grow on n-alkanes (C1 to C16) and to degrade TBA after growth on n-alkanes was compared to that of M. austroafricanum IFP 2012. We studied M. austroafricanum IFP 2012 and IFP 2015 able to grow on MTBE, M. austroafricanum IFP 2173 able to grow on isooctane, Mycobacterium sp. IFP 2009 able to grow on ethyl tert-butyl ether (ETBE), M. vaccae JOB5 (M. austroaafricanum ATCC 29678) able to degrade MTBE and TBA and M. smegmatis mc2 155 with no known degradation capacity towards fuel oxygenates. The M. austroafricanum strains grew on a broad range of n-alkanes and three were able to degrade TBA after growth on propane, hexane and hexadecane. An alkB gene was partially amplified from the genome of all mycobacteria and a sequence comparison demonstrated a close relationship among the M. austroafricanum strains. This is the first report suggesting the involvement of an alkane hydroxylase in TBA oxidation, a key step during MTBE metabolism.  相似文献   

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Control of organ size is the product of coordinated cell division and expansion. In plants where one of these pathways is perturbed, organ size is often unaffected as compensation mechanisms are brought into play. The number of founder cells in organ primordia, dividing cells, and the period of cell proliferation determine cell number in lateral organs. We have identified the Antirrhinum FORMOSA (FO) gene as a specific regulator of floral size. Analysis of cell size and number in the fo mutant, which has increased flower size, indicates that FO is an organ-specific inhibitor of cell division and activator of cell expansion. Increased cell number in fo floral organs correlated with upregulation of genes involved in the cell cycle. In Arabidopsis the AINTEGUMENTA (ANT) gene promotes cell division. In the fo mutant increased cell number also correlates with upregulation of an Antirrhinum ANT-like gene (Am-ANT) in inflorescences that is very closely related to ANT and shares a similar expression pattern, suggesting that they may be functional equivalents. Increased cell proliferation is thought to be compensated for by reduced cell expansion to maintain organ size. In Arabidopsis petal cell expansion is inhibited by the BIGPETAL (BPE) gene, and in the fo mutant reduced cell size corresponded to upregulation of an Antirrhinum BPE-like gene (Am-BPE). Our data suggest that FO inhibits cell proliferation by negatively regulating Am-ANT, and acts upstream of Am-BPE to coordinate floral organ size. This demonstrates that organ size is modulated by the organ-specific control of both general and local gene networks. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

12.
We developed molecular diagnostic assays for the detection of Streptococcus pyogenes (GAS) and Streptococcus dysgalactiae subsp. equisimilis (SDSE), two streptococcal pathogens known to cause both pharyngitis and more invasive forms of disease in humans. Two real-time PCR assays coupled with an internal control were designed to be performed in parallel. One assay utilizes a gene target specific to GAS, and the other utilizes a gene target common to the two species. Both assays showed 2–3 orders of magnitude improved analytical sensitivity when compared to a commercially available rapid antigen test. In addition, when compared to standard culture in an analysis of 96 throat swabs, the real-time PCR assays resulted in clinical sensitivity and specificity of 91.7 and 100%, respectively. As capital equipment costs for real-time PCR can be prohibitive in smaller laboratories, the real-time PCR assays were converted to a low-density microarray format designed to function with an inexpensive photopolymerization-based non-enzymatic signal amplification (NESA™) method. S. pyogenes was successfully detected on the low-density microarray in less than 4 h from sample extraction through detection.  相似文献   

13.
The entire (e) locus of tomato (Solanum lycopersicum L.) controls leaf morphology. Dominant E and recessive e allele of the locus produce pinnate compound and complex reduced leaves. Previous research had indicated that SlIAA9, an Aux/IAA gene, was involved in tomato leaf morphology. Down-regulation of SlIAA9 gene by antisense transgenic method decreased the leaf complex of tomato and converted tomato compound leaves to simple leaves. The leaf morphology of these transgenic lines was similar with leaf morphology of tomato entire mutant. In this paper, we report that a single-base deletion mutation in the coding region of SlIAA9 gene results in tomato entire mutant phenotypes.  相似文献   

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The Indo-Pacific marine atherinid fishes Atherinomorus forskalii (Rüppell, 1838), Atherinomorus lacunosus (Forster, 1801), and Atherinomorus pinguis (Lacepède, 1803) are redescribed as valid species based on the types and non-type specimens collected throughout the Indo-Pacific. They are similar to each other chiefly in having a wide midlateral band (almost the same or greater than the midlateral scale width), large mouth (posterior tip of upper jaw reaching to or beyond a vertical through anterior margin of pupil), and no distinct tubercle at the posterior end of the dentary. All three species are distinguishable from congeners by those characters. The three species have long been confused with each other or synonymized erroneously as a single species. Atherinomorus forskalii, known from the Red Sea and eastern Mediterranean, differs from Atherinomorus lacunosus and Atherinomorus pinguis in having conspicuous, large endopterygoid teeth, forming obvious tooth ridges. Atherinomorus lacunosus, widely distributed in almost the entire Indo-Pacific, from East Africa to Tonga, north to southern Japan, and south to northern Australia, differs from Atherinomorus pinguis in having a wider midlateral band (the lower margin reaching to almost the center of the fourth scale row at level of the anal fin origin vs. the lower margin reaching to the ventral end of the third scale row in Atherinomorus pinguis) and more numerous midlateral scales (40–44 vs. 38–41 in Atherinomorus pinguis). Atherina morrisi Jordan and Starks, 1906, Hepsetia pinguis mineri Nichols and Roemhild, 1951, Pranesus capricornensis Woodland, 1961, Pranesus maculatus Taylor, 1964, and Pranesus pinguis ruppelli Smith, 1965, are regarded as junior synonyms of Atherinomorus lacunosus. Atherinomorus pinguis is also widely distributed in the Indo-West Pacific, from East Africa to northern Australia and north to southern Japan. Atherina pectoralis Valenciennes, 1835, is considered a junior synonym of Atherinomorus pinguis. Supplementary material to this paper is available in electronic format at  相似文献   

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Arachis correntina (Burkart) Krapov. & W.C. Gregory is a herbaceous perennial leguminous plant growing in the Northeast of the Province Corrientes, Argentina. It is important as forage. The development of new A. correntina cultivars with improved traits could be facilitated through the application of biotechnological strategies. The purpose of this study was to investigate the plant regeneration potential of mature leaves of A. correntina in tissue culture. Buds were induced from both petiole and laminae on 0.7% agar-solidified medium containing 3% sucrose, salts and vitamins from Murashige and Skoog (MS) supplemented with 0.5–25 M thidiazuron (TDZ). Shoot induction was achieved by transference of calli with buds to MS supplemented with 5 M TDZ. Fifty-four percent of the regenerated shoot rooted on MS + 5 M naphthaleneacetic acid. Histological studies revealed that shoots regenerated via organogenesis.  相似文献   

18.
Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The maximum degradation rate of MTBE was 16 mg protein h and 46 mg/g protein h for TBA. The culture transformed 77% of the total carbon to 14CO2. The estimated yield for MTBE was 0.18 g dry wt/g MTBE.  相似文献   

19.
Epigenetic modifications of histone play important roles for regulation of cell activity, such as cell division, cell death, and cell differentiation. A SET domain consisting of about 130 amino acids has lysine methyltransferase activity in the presence of the cosubstrate S-adenosyl-methionine. More than 60 SET domain-containing proteins have been predicted in various organisms. One of them, the SMYD family genes which contain a SET domain and a zinc-finger MYND domain are reported to regulate cell cycle and muscle formation. Here we examined the expression and function of smyd1 and 2 in Xenopus. smyd1 and 2 were expressed in various muscle tissues. While smyd1 expression was observed mainly in cardiac muscle and skeletal muscle, smyd2 expression was done abundantly in skeletal muscle and face region. Moreover, by loss-of-function experiments using antisense morpholino oligonucleotides, it was suggested that smyd1 and 2 related to muscle cells differentiation.  相似文献   

20.
Campoletis chlorideae Uchida (Hymenoptera: Ichneumonidae) is an important solitary larval endoparasitoid of the tomato fruit borer Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in India. The interaction between Bacillus thuringiensis subspecies kurstaki (Btk) HD-1 and C. chlorideae was studied under laboratory condition to explore their compatibility in managing H. armigera. The results had indicated that the growth and development of H. armigera was affected in a dose-dependent manner upon feeding on sublethal doses of Btk HD-1-treated diets. There were no larval survivors in lethal doses of Btk HD-1 (LC70 and LC90). The growth and survival of the parasitoid were normal when the host larvae were fed with sublethal doses or subjected to short time exposure to lethal doses of Btk HD-1. However, the parasitoid offsprings developed slowly and pupal as well as adult period, adult weight and adult emergence rate were reduced significantly if the parasitoid was developing inside a severely Bt intoxicated host larvae. There were no evident differences in longevity of parasitoid adults that were fed on honey solution containing different concentrations of Btk HD-1 as compared to adults fed only on honey solution. This indicates no direct adverse effect of Btk HD-1 on C. chlorideae. Further, the gravid female parasitoid did not discriminate Btk HD-1 intoxicated and normal H. armigera larvae for oviposition. The result implies that spore crystal formulation of Btk HD-1 can be effectively used in a synergistic manner along with existing natural or prereleased population of C. chlorideae in organic farming or as components in biointensive IPM module for managing H. armigera.  相似文献   

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