Utilization of the guanylyltransferase and methyltransferases of vaccinia virus to modify and identify the 5′-terminals of heterologous RNA species

Enzymes extracted from purified vaccinia virus particles were used to catalyze the guanylylation (i.e. capping) and/or methylation of heterologous RNA species containing two or three phosphates or the structure m⁷G(5′)pppN at their 5′-terminals. This procedure provides a novel and specific method of labeling the 5′-terminals with $\text{[}{}^{\mathrm{\alpha -32}}\text{P]GTP}$ or S-adenosyl-[methyl-³H]methionine. Analysis of the RNAs of satellite tobacco necrosis virus and tobacco mosaic virus that were modified in this manner indicated that the original 5′-terminal sequences were (p)ppApGpPy and m⁷G(5′)pppGpU, respectively, which were enzymatically converted to m⁷G(5′)pppA^mpGpPy and m⁷G(5′)pppG^mpU.     

Sampling design and the shape of species–area curves on the regional scale

Species–area relationships (SARs) are one of the fundamental patterns in ecology. However, how the way they were constructed influences resulting SAR shapes has gained astonishingly little attention. We use data of the distribution atlas of Polish butterflies to compare SARs constructed from four different designs: adding up species numbers of independent areas (species accumulation curves using contiguous and non-contiguous areas), using a nested design, and comparing species numbers of independent areas of different sizes. It appeared that the way of constructing SARs influences the outcome. We attribute this influence to the pronounced faunal dissimilarities of more distant areas (spatial species turnover). The nested design resulted in significantly higher slopes and lower intercepts of power function SARs than the other designs. SARs from all four sampling designs showed a pronounced downward curvature on small spatial scales. Only the nested design predicted species densities correctly. The implications of these results for the use of SARs in bioconservation are discussed.     

Identifying and characterizing the most significant β-glucosidase of the novel species Aspergillus saccharolyticus

The newly discovered fungal species Aspergillus saccharolyticus was found to produce a culture broth rich in β-glucosidase activity. In this present work, the main β-glucosidase of A.?saccharolyticus responsible for the efficient hydrolytic activity was identified, isolated, and characterized. Ion exchange chromatography was used to fractionate the culture broth, yielding fractions with high β-glucosidase activity and only 1 visible band on an SDS-PAGE gel. Mass spectrometry analysis of this band gave peptide matches to β-glucosidases from aspergilli. Through a polymerase chain reaction approach using degenerate primers and genome walking, a 2919 bp sequence encoding the 860 amino acid BGL1 polypeptide was determined. BGL1 of A.?saccharolyticus has 91% and 82% identity with BGL1 from Aspergillus aculeatus and BGL1 from Aspergillus niger , respectively, both belonging to Glycoside Hydrolase family 3. Homology modeling studies suggested β-glucosidase activity with preserved retaining mechanism and a wider catalytic pocket compared with other β-glucosidases. The bgl1 gene was heterologously expressed in Trichoderma reesei QM6a, purified, and characterized by enzyme kinetics studies. The enzyme can hydrolyze cellobiose, p-nitrophenyl-β-d-glucoside, and cellodextrins. The enzyme showed good thermostability, was stable at 50?°C, and at 60?°C it had a half-life of approximately 6?h.     

Habitat requirements of Cardaminopsis petraea — Rare and relict species of the Czech Republic

Vegetation with Cardaminopsis petraea was sampled by phytosociological relevés at almost all the known Czech sites, and characterized by indicator values, influence of potential direct solar irradiation, and bedrock type with the aid of multivariate methods. It has been declared that C. petraea prefers open natural or seminatural drier to mesophilous habitats without some preference to the bedrock. It occupies habitats with various slopes, but it prefers more extreme slants and northerly exposed slopes. The classification and ordination methods showed clear distinction between Moravian and Bohemian habitats. Apart from other types, in Bohemia this species occurs uniquely in acidophilous rock communities, whereas in Moravia it grows uniquely within calcareous grasslands. Relictness of the species was discussed in relation to the specific site conditions (light supply, disturbance regime, and geographical isolation) and to the occurrence of other rare taxa and habitats. Occurrence on some man-made habitats was also observed.     

Do species evenness and plant density influence the magnitude of selection and complementarity effects in annual plant species mixtures?

Abstract Plant species richness influences primary productivity via mechanisms that (1) favour species with particular traits (selection effect) and (2) promote niche differentiation between species (complementarity). Influences of species evenness, plant density and other properties of plant communities on productivity are poorly defined, but may depend on whether selection or complementarity prevails in species mixtures. We predicted that selection effects are insensitive to species evenness but increase with plant density, and that the converse is true for complementarity. To test predictions, we grew three species of annuals in monocultures and in three‐species mixtures in which evenness of established plants was varied at each of three plant densities in a cultivated field in Texas, USA. Above‐ground biomass was smaller in mixtures than expected from monocultures because of negative ‘complementarity’ and a negative selection effect. Neither selection nor complementarity varied with species evenness, but selection effects increased at the greatest plant density as predicted.     

Comparison of the β-lactamases ofBacteroides species

-Lactam antibiotic susceptibility and the presence of -lactamase were examined in clinical strains ofBacteroides species. All strains produced a noninducible, cell-associated cephalosporinase. Based on isoelectric focusing, molecular weight determinations, substrate profiles, and inhibition studies, it was concluded that allBacteroides strains examined produced a very similar, if not identical, -lactamase in terms of these enzymatic and physical characteristics.     

Survival and reproduction of plant species in the Qinghai–Tibet Plateau

The Qinghai–Tibet Plateau (QTP) is the highest and largest plateau in the world. It covers correspondingly wide geological, topographical, and climatic gradients, and thus hosts greater biodiversity than surrounding lowlands and other high elevation regions. Due to its extreme environmental and biological diversity, the QTP is an ideal region for studying adaptations of plant species under harsh environmental conditions at multiple evolutionary levels. Many recent ecological studies have revealed functions of distinctive morphological features of various plants in the region that improve their reproductive success. Examples include large and showy bracts, hairy inflorescences, and drooping flowers. Numerous other investigations have examined QTP plants' sexual systems, patterns of biomass allocations, and biotic interactions. This paper summarizes recent advances in understanding of morphological adaptations, plant–plant interactions, plant–pollinator interactions, floral color patterns, pollination adaptations, and resource allocation patterns of alpine plants of the QTP. The overall aim is to synthesize current knowledge of the general mechanisms of plant survival and reproduction in this fascinating region.     

The size and diversity of the soil seed banks and the light requirements of the species in sunny and shady natural communities of the Białowieża Primeval Forest

The research was conducted in two natural forest communities: Potentillo albae-Quercetum (oak forest) which allows much light to reach the forest floor and Tilio-Carpinetum typicum (hornbeam forest) which shades the herb layer heavily. The seed banks were estimated from numbers of seedlings emerging from soil samples over one growing season.(1) Our results confirm the hypothesis that persistent seed banks are mainly formed by species with high light requirements. Of the species found predominantly in the seed bank and absent from the herb layer or occurring there very rarely in both communities 83% of species and 70% of seedlings were strongly light-demanding (Ellenberg's light index 6–9). However, the results do not support the hypothesis that seed banks in natural deciduous forest communities are small, poor in species and do not reflect the species composition of herb layer.(2) The seed banks of both communities were rich in species and relatively large. Species richness in the oak forest turned out to be higher than in the hornbeam forest (51 vs 45 species/2.4 m₂), but size was smaller (2659 vs 5789 seedlings/2.4 m₂). In the oak forest the most abundant species in the seed bank was Galium boreale, but it constituted only 19% of the total number of seedlings, whereas in the hornbearn forest the dominant species, Urtica dioica, constituted 57% of the total.(3) In each community the species composition of the seed bank and the herb layer was very similar (>70%).(4) The seed bank was more diverse in the oak forest than in the hornbeam forest (H 2.34 vs 1.68).(5) The seed banks of both communities differed in the contribution of species with varied light requirements; in the sunny oak forest species with high light requirements dominated, whereas in the shady hornbeam forest both strongly and moderately light-demanding species had similar contributions.Nomenclature: Follows Ehrendorfer (1973) and Matuszkiewicz (1981).     

Morphological and karyotypic analysis of five blackfly species of the genus Cnetha (Diptera: Simulidae): description of the novel species from the Dzhrvezhskiĭ canyon in Armenia

Morphological and karyotypical features of a new blackfly species Cnetha akopi sp. n. from Armenia are described. Comparative analysis of the new species and four closely related endemic species from Caucasus is performed. Photographic maps of polythene chromosomes are provided.     

Can behavioral and personality traits influence the success of unintentional species introductions?

Unintentional species invasions are instigated by human-mediated dispersal of individuals beyond their native range. Although most introductions fail at the first hurdle, a select subset pass through each stage of the introduction process (i.e., transport, introduction, establishment and spread) to become successful invaders. Efforts to identify the traits associated with invasion success have predominately focused on deliberate introductions, which essentially bypass the initial introduction stage. Here, we highlight how behavior influences the success or failure of unintentional species introductions across each stage of the introduction process, with a particular focus on transportation and initial establishment. In addition, we emphasize how recent advances in understanding of animal personalities and individual-level behavioral variation can help elucidate the mechanisms underlying the success of stowaways.     

The myth of “minima” and “maxima”, the species of Physalis in the Indian Subcontinent

The status of the names, Physalis minima L. and P. maxima Mill. (Solanaceae), and their alleged presence on the Indian subcontinent are discussed. The issues of nativity and identity of Linnaean Physalis minima are long-debated while the use of the name P. maxima Mill. and its report from India are recent. The available evidence indicates that the name “P. minima L.” is misapplied to two different elements, viz., P. angulata L. and P. lagascae Roem. & Schult. The name Physalis minima L. may be rejected as nomen confusum, for which the paper provides the primary information. As on today, it is submerged under the synonymy of P. angulata L. The correct name for the widely known P. minima is P. lagascae. The name “P. maxima Mill.” applied to the escape and naturalized weed in the Indian subcontinent and elsewhere is to be substituted by P. pruinosa L., a name misapplied to P. grisea (Waterf.) M. Martínez.     

Anatomy and uses of the mature leaves of three species of Sabal (Arecaceae) of the Yucatan, México

This paper describes the leaf anatomy of Sabal mauritiiformis (Karst.) Griseb. & H. Wendl., Sabal mexicana Mart. and Sabal yapa Wright ex Becc., three of the four most representative species of the Yucatán Península, in Mexico. These species are locally used: in the roofing of traditional homes, as food (fruits and apical buds), and in the production of hats, brooms and handicrafts. Leaf samples were collected in secondary growth of lower montane rainforest in the state of Quintana Roo and in two home gardens in the state of Yucatán. Herbarium samples were obtained, and samples of blade and petiole were fixed in formaline-acetic acid-alcohol. Cross incisions were made on the blade and petiole, and were dyed with safranin and toluidine blue O. The results show that S. mauritiiformis and S. yapa are morphologically alike: both are tall, slim palm trees; the leaf in S. mauritiiformis is a shorter palm-like structure compared with the other two species. The shape of the main nerve, as seen in cross section, is rectangular in the three species. The hastula in the three species is acuminate and adaxial. The foliar anatomic structure is similar in the three species, although there are some differences. The adaxial an abaxial epidermis of the blade consist of one layer and, superficially, the anticlinal walls are straight; the stomata are intercostal, of the tetracytic type, present on both surfaces in S. mexicana and S. yapa and only on the abaxial surface on S. mauritiiformis. The hypodermis is one layer thick in S. yapa and in S. mexicana and two layers thick in S. mauritiiformis. In the three species the palisade parenchyma consists of several undefined strata as the cells are similar-in shape and size--to the cells in the spongy parenchyma, so there is no marked difference between these strata and the spongy parenchyma seems almost continuous. Both fibrous and vascular bundles are distributed between the hypodermis and the palisade parenchyma; the fiber bundles can be found towards the abaxial surface while the vascular and fiber bundles are located towards the adaxial surface. The fibers, in the three species, are elongated, with the pointed tips, undivided and unseptated. One to three wide vessels of metaxilem can be seen in the vascular bundles, those in S. yapa being the widest in diameter. The vascular bundles are surrounded by thick fiber sheaths which come in pairs. The anatomic structure of the petiole is similar to that of the blade, and is characterized by the many vascular and fiber bundles dispersed in the parenchymatous tissue, and which are very resistant. The histological structure of the blade and petiole reflects strength and flexibility, qualities which make these plants adequate in the construction of roofs for rural housing and other buildings.     

The myth of “minima” and “maxima”, the species of Physalis in the Indian Subcontinent

The status of the names, Physalis minima L. and P. maxima Mill. (Solanaceae), and their alleged presence on the Indian subcontinent are discussed. The issues of nativity and identity of Linnaean Physalis minima are long-debated while the use of the name P. maxima Mill. and its report from India are recent. The available evidence indicates that the name "P. minima L." is misapplied to two different elements, viz., P. angulata L. and P. lagascae Roem. & Schult. The name Physalis minima L. may be rejected as nomen confusum, for which the paper provides the primary information. As on today, it is submerged under the synonymy of P. angulata L. The correct name for the widely known P. minima is P. lagascae. The name "P. maxima Mill." applied to the escape and naturalized weed in the Indian subcontinent and elsewhere is to be substituted by P. pruinosa L., a name misapplied to P. grisea (Waterf.) M. Martínez.     

Is the originality of a species measurable?

In this paper, we introduce the concept of 'originality of a species within a set' in order to indicate the average rarity of all the features belonging to this species. Using a phylogenetic tree of 70 species of New World terrestrial Carnivora, we suggest measuring the originality by a probability distribution. This maximizes the expected number of features shared by two species randomly drawn from the set. By using this new index, we take account of branch lengths whereas current indices of originality focus on tree topology. As a supplement to Nee and May's optimizing algorithm, we find that originality must be one of the criteria used in conservation planning.     

Examination of the “null” model of connor and simberloff for species co-occurrences on Islands

Summary Among birds of the Bismarck Archipelago, only certain combinations of the species in a guild coexist on islands, and some species that are very similar ecologically have mutually exclusive distributions. Diamond (1975) interpreted these patterns as biologically significant, involving effects such as competition. Connor and Simberloff (1979) claimed such patterns to be not recognizably different from random, because they were scarcely distinguishable from those generated by a null distribution supposedly not incorporating competition.On examining the analysis by Connor and Simberloff, we find that it actually yields the opposite conclusion: three faunas tested have grossly non-random structures, while their test is unworkable for the fourth fauna. The method of Connor and Simberloff for generating a null distribution has many fatal weaknesses: dilution of relevant data from guilds with irrelevant data from the whole species pool; hidden incorporation of effects of competition into the constraints; inability to recognize a checkerboard, the extreme example of a distribution produced by competition; reliance on inefficient Monte Carlo simulations; severe constraints that sometimes make generation of a null distribution impossible; failure to weight species combinations; and failure to identify the direction of non-randomness or the species combinations most responsible.Finally, we use other recent studies by Simberloff and coleagues to examine the value of constructing null hypotheses in community ecology.     

The role of the Weberian Reform in European Rubus research and the taxonomy of locally distributed species – which species should we describe?

After Sudre published his treatment of European Rubi in the early 20th century, Rubus taxonomy in Europe suffered from a scholastic phase and a longer period of stagnation. The so‐called ‘Weberian Reform’ initiated the necessary revival of European batology. It rests on four major pillars: 1) mapping projects over larger areas, 2) evaluation of type material, 3) visits to loci classici, and 4) evaluation of the status of species by means of their distribution areas. Subsequently, it has become widely accepted in European batology that only species with a distribution area over 50 km should be described. Although this pragmatic species concept has been useful in making a continent‐wide overview of brambles, we argue that it is lacking a scientific basis, and should thus be rejected. There are at least four distinctive problems when treating locally distributed brambles: 1) primary hybrids, 2) locally distributed stabilised apomicts, 3) intraspecific variation in species with a larger distribution range, and 4) unstabilised swarms of hybridogenic biotypes and the derivates thereof (mainly in the montane regions). When facing the problems in Rubus systematics, we argue that all independently evolving lineages should be described as species, including apomictic lineages with very small distribution ranges, both from the mountain‐dwelling glandular series and from the lowlands. Neither primary hybrids (which are not stabilised by apomixis), nor biotypes without an independent and coherent distribution area are independently evolving lineages, and should thus not be described as species. We advocate a restrained attitude when describing new species with limited distribution areas.