The detection of apple chlorotic leafspot virus by a modified procedure of enzyme-linked immunosorbent assay (ELISA)

The technique of enzyme-linked immunosorbent assay (ELISA) was modified to enable detection of apple chlorotic leafspot virus (CLSV) both in herbaceous hosts and in several naturally infected fruiting and ornamental woody host species. Some of the characteristics of the modified method as used with different virus-host combinations are described.     

The Nuclear Envelope of Amoeba proteus During Mitosis as Studied With a Monoclonal Antibody Against a Membrane-Associated Protein

. The behavior of nuclear envelopes during mitosis in Amoeba proteus was studied by means of indirect immunofluo-rescence staining using a monoclonal antibody against a 220-kD membrane-associated protein of amoebae in conjunction with DAPI staining of chromatin. The antibody selectively recognized antigens on nuclear envelopes during interphase but did not react with the nuclear membranes during mitosis until after cytokinesis had been completed. Thus, it appeared that the membrane-associated protein reacting with the monoclonal antibody and normally present on the nuclear membranes was absent from fragmented nuclear membranes or nuclear membranes that were continuous but did not have the honey-comb lamina. The findings suggested that the 220-kD nuclear-membrane protein may be involved in the dissolution and reformation of the honey-comb lamina during mitosis in amoebae.     

Interspecies Relationships in the Paramecium aurelia Complex: Acid Phosphatase Variation1

ABSTRACT. Up to five zones of acid phosphatase activity appear in gels after electrophoresis of detergent-treated extracts from 13 of the 14 species of the Paramecium aurelia complex. The overall pattern is somewhat similar for all species: differences in intensity and mobility of individual zones permit the grouping of these sibling species into eight groups. All 14 species can be identified using the procedure of enzyme electrophoresis, although two of them are more similar than is usually the case. Problems of misclassification are discussed in terms of the nature and frequency of variants. With the judicious choice of enzymes used to screen new stocks, these problems can be circumvented. Species relationships are updated using 11 enzymes. A dendrogram constructed from the matrix of genetic distances shows four clusters of species: (i) P. biaurelia, P. triaurelia; (ii) P. primaurelia, P. pentaurelia, P. sexaurelia, P. novaurelia; (iii) P. septaurelia, P. undecaurelia, P. tredecaurelia, P. quadecaurelia; and (iv) P. tetraurelia, P. octaurelia, P. decaurelia, P. dodecaurelia. Distances between the species are large, on the order of the differences between Drosophila species. The species are characterized by an extraordinary lack of geographical differentiation and great morphological similarity, which contrasts strongly with the molecular differentiation.     

A comparison,by sweep sampling,of the arthropod fauna of secondary vegetation in Michigan,England and Costa Rica

• 1 Six 800-sweep samples of English and Michigan (“old field”) secondary vegetation arthropods are compared with Costa Rican samples taken in the same way.
• 2 Parasitic Hymenoptera and spiders accounted for a larger proportion of the arthropod fauna in the mid-latitude than the tropical samples.
• 3 In one English field, the seasonal change in insect numbers was 88% of that recorded over all the seasonal and elevational changes examined in Costa Rica. Furthermore, the difference in the total dry weights of the arthropod fauna between December and July was similar to the difference found between the wet and dry seasons in tropical secondary vegetation (also similar to the difference between day and night values during the dry season).
• 4 Aphids and Psyllidae were far more abundant in the English site than in the Costa Rican mainland sites.
• 5 In mid-summer, the English field had far more arthropods in it than did any of the tropical sites sampled.

     

Diversity of Culturable Bacteria Isolated from Highland Barley Cultivation Soil in Qamdo,Tibet Autonomous Region

The soil bacterial communities have been widely investigated. However, there has been little study of the bacteria in Qinghai-Tibet Plateau, especially about the culturable bacteria in highland barley cultivation soil. Here, a total of 830 individual strains were obtained at 4°C and 25°C from a highland barley cultivation soil in Qamdo, Tibet Autonomous Region, using fifteen kinds of media. Seventy-seven species were obtained, which belonged to 42 genera and four phyla; the predominant phylum was Actinobacteria (68.82%), followed by Proteobacteria (15.59%), Firmicutes (14.29%), and Bacteroidetes (1.30%). The predominant genus was Streptomyces (22.08%, 17 species), followed by Bacillus (6.49%, five species), Micromonospora (5.19%, four species), Microbacterium (5.19%, four species), and Kribbella (3.90%, three species). The most diverse isolates belonged to a high G+C Gram-positive group; in particular, the Streptomyces genus is a dominant genus in the high G+C Gram-positive group. There were 62 species and 33 genera bacteria isolated at 25°C (80.52%), 23 species, and 18 genera bacteria isolated at 4°C (29.87%). Meanwhile, only eight species and six genera bacteria could be isolated at 25°C and 4°C. Of the 77 species, six isolates related to six genera might be novel taxa. The results showed abundant bacterial species diversity in the soil sample from the Qamdo, Tibet Autonomous Region.     

The Active and the Inactive Form of the hAT1 Receptor Have an Identical Ligand-Binding Environment: An MPA Study on a Constitutively Active Angiotensin II Receptor Mutant

Several models of activation mechanisms were proposed for G protein-coupled receptors (GPCRs), yet no direct methods exist for their elucidation. The availability of constitutively active mutants has given an opportunity to study active receptor conformations within acceptable limits using models such as the angiotensin II type 1 (AT₁)¹ receptor mutant N111G-hAT₁ which displays an important constitutive activity. Recently, by using methionine proximity assay, we showed for the hAT₁ receptor that TMD III, VI, and VII form the ligand-binding pocket of the C-terminal amino acid of an antagonistic AngII analogue. In the present contribution, we investigated whether the same residues would also constitute the ligand-binding contacts in constitutively activated mutant (CAM) receptors. For this purpose, the same Met mutagenesis strategy was carried out on the N111G double mutants. Analysis of 43 receptors mutants in the N111G-hAT₁ series, photolabeled and CNBr digested, showed that there were only subtle structural changes between the wt-receptor and its constitutively active form.     

寄主植物挥发物对梨小食心虫受孕雌虫的引诱作用初探

梨小食心虫Grapholita molesta(Busck),是一种世界性的蛀果害虫。利用产卵选择试验研究了15种寄主植物挥发物对梨小食心虫受孕雌虫的产卵引诱活性。室内试验表明:受孕雌虫对不同挥发物的产卵选择趋性不同,其中对叶醇和己酸丁酯表现出明显的产卵选择趋性。为验证寄主挥发物对受孕雌虫的实际诱捕效果,进行了田间诱捕试验。结果发现,挥发物中己酸丁酯、苯甲腈、叶醇、E-2-己烯醛以及乙酸己酯诱捕到的雌虫均为受孕雌虫,显著高于空白对照及其他物质,其中己酸丁酯的平均诱捕量最多,苯甲腈次之,E-2-己烯醛、乙酸己酯这两种物质的平均诱捕量分别为第三、第四,叶醇的诱捕量低于乙酸己酯,其余物质的诱捕量均较低。综合室内及田间试验结果发现,寄主植物挥发物对受孕雌虫的引诱作用也随它们之间的作用距离表现出一定的差异性。     

生物信息学软件研究的可视化分析

以Web of Science数据库为数据来源,利用Cite Space和UCINET软件对发表在Nucleic Acids Research期刊上有关生物信息学软件研究的文献做了可视化分析,揭示了该领域的研究力量、作者团队与高被引作者、知识基础、期刊分布、研究热点与前沿,为生物信息学软件的研究和发展提供必要的参考依据。     

MUSCARINIC ACETYLCHOLINE RECEPTOR SUBTYPE mRNAs IN THE HUMAN AND RAT VESTIBULAR PERIPHERY

The expression of the five muscarinic acetylcholine receptor (mAChR) subtypes (m1–m5) in the vestibular end-organs and in the primary afferent vestibular ganglia of the human and rat was studied using RT-PCR from the two tissue populations from both species. In the human, although all five mAChR subtypes were expressed in brain, only the m1, m2, and m5 mAChR subtypes were amplified from both the vestibular ganglia and the vestibular end-organs, while in the rat, all five mAChR subtypes were expressed. These data suggest that the efferent cholinergic axo-dendritic and axo-somatic synapses have a muscarinic component and that there are pharmacologic implications for patients with vestibular dysfunction.     

BRYOZOAN MUD-MOUNDS FROM THE UPPER ORDOVICIAN JIFARAH (DJEFFARA) FORMATION OF TRIPOLITANIA, NORTH-WEST LIBYA

Abstract:  A bryozoan fauna from carbonate mud-mounds is described from subsurface well cores from the Upper Ordovician (Lower Ashgill) Jifarah (Djeffara) Formation of Tripolitania, north-west Libya. Among a diverse assemblage dominated by trepostomes, nine species of bryozoans are identified, including Jifarahpora libyensis gen. et sp. nov. Delicate and robust branching, encrusting and nodular bryozoan growth forms are all common. The bryozoan-rich limestones are mostly mudstones and wackestones, with bafflestone and floatstone textures, but the mounds apparently lack organic framework and microbial fabrics. Regional geophysical data indicate rapid thickness changes between wells, where mound complexes locally up to 100 m thick had limited topographic relief over the surrounding sea floor. The mounds formed in a high-latitude, cool-water carbonate belt that extended widely across the northern margin of Gondwana. Quaternary analogues from the Great Australian Bight suggest that these early Ashgill mounds may have developed in slope environments during an episode of glacial lowstand that preceded the late Ashgill, Hirnantian glacial event.