Flavonoids ofBignoniaceae from the “cerrado” and their possible taxonomic significance

Flavones and glycosides of flavones and flavonols were obtained from leaves of five species ofBignoniaceae from the cerrado, a savanna ecosystem of Central and Southeast Brazil. A predominance of flavonol glycosides was observed in all samples investigated. Flavones were often found in species of tribeTecomeae and rarely inBignonieae. The species of the former yielded derivatives of 6-hydroxyluteolin. No 6-oxygenated compounds were found in species ofBignonieae. The results point to the flavonoid chemistry evolution ofBignoniaceae following a path of simplification. More complex chemical profiles characterize the more woodyTecomeae rather than the more advancedBignonieae.     

Neuromuscular Tone: Concepts of the “Moscow Motor Control School” from N.A. Bernstein until Today

Human Physiology - The notions on neuromuscular tone are discussed up from the time of N.A.Bernstein, who regarded it as level A, Rubro-Spinal Level of Paleokinetic Regulations in his book On the...     

Three reciprocally monophyletic mtDNA lineages elucidate the taxonomic status of Grant’s gazelles

The intraspecific phylogeography of Grant’s gazelles Nanger granti was assessed with mitochondrial DNA control region sequences. Samples of 177 individuals from 17 Kenyan and Tanzanian populations were analysed. Three highly divergent, reciprocally monophyletic lineages were found, with among group net nucleotide distances of 8–12%. The three lineages—notata, granti and petersii—grouped populations according to their geographic origin, encompassing populations in the north, southwest, and east, respectively. The mtDNA lineages reflected distinct evolutionary trajectories, and the data are discussed in reference to the four currently recognised subspecies. We suggest Grant’s gazelles be raised to the superspecies Nanger (granti) comprising three taxonomic units corresponding to the three mtDNA lineages. There was no evidence of gene flow between the notata and granti lineages, despite their geographic proximity, suggesting reproductive isolation. These constitute evolutionary significant units within the adaptive evolutionary framework. Due to its restricted geographic distribution and genetic and morphological distinctiveness, we suggest the petersii lineage be raised to the species Nanger (granti) petersii within the Grant’s gazelles superspecies.     

What is the taxonomic status of East Asian otter species based on molecular evidence?: focus on the position of the Japanese otter holotype specimen from museum

The Japanese otter (Lutra nippon), once inhabited in most islands of Japan, is now considered as an extinct species. Although the Japanese otter is regarded as a distinct species from the Eurasian otter (L. lutra), its phylogeny and taxonomic status are based on limited information on morphological and genetic data, and thus further clarification is required. Here, we assessed the phylogenetic relationship among the genus Lutra and taxonomic status of L. nippon by using the complete sequences of cytochrome b gene of its holotype. The present phylogenic trees supported that the genus Lutra specimens largely formed monophyletic group, with L. sumatrana as a basal to other Lutra species. Within Lutra species, L. nippon was distantly related with L. lutra. The European otter population of L. l. lutra were clustered together with its subspecies, L. l. chinensis rather than the same subspecies, Korean otter population. The discrepancy between the genetic data and traditional taxonomy justifies the necessity of reexamination of the current subspecific classification system of Eurasian otters. Level of genetic divergence between the holotype of L. nippon and L. lutra was two to three-fold lower than those among the other sister species of the Lutrinae. Based on the level of divergence between the L. nippon and L. lutra, and insufficient evidence of morphological difference between them, it is suggested that designation of Japanese otter as a separate species from L. lutra will be reconsidered.     

Behaviour in culture of isolated protoplasts from “Paul's scarlet” rose suspension culture cells

Summary Protoplasts were enzymatically isolated from Paul's scarlet rose suspension culture cells. They were cultured in medium similar to that used to culture the cells from which they were isolated with the addition of sucrose as an osmotic stabiliser. They were studied by light and electron microscopy and their changes in size and number per culture were recorded. Expansion was greater when the protoplasts were cultured in medium plus 12% sucrose than with 24% sucrose. Budding was observed. In medium plus 12% sucrose about 45% of the protoplasts divided but in medium plus 24% sucrose far fewer divided. Cytokinesis was abnormal: the phragmoplast disappeared soon after cytokinesis began and the cell plate became a groove and then a fibril-lined or filled tongue which progressed across the vacuole, unconnected by strands to other parts of the protoplast. The wall regenerated after several days culture in medium plus 12% sucrose fluoresced with calcofluor. The wall regenerated in medium with 24% sucrose fluoresced usually only after several weeks culture. Cytokinesis hastened formation of a wall fluorescing with calcofluor. In the electron microscope the wall was seen to contain fibrils and non-fibrillar material. The latter was the minor component in medium plus 12% sucrose but was usually the major component in medium plus 24% sucrose. The growth in plasmolysing and nonplasmolysing medium of the cells from which protoplasts are isolated was also studied.It appears that loss of the wall alters the potential of protoplasts to expand and possibly also to regenerate a wall and to divide. Wall regeneration is initially linked with expansion and cytokinesis. Osmotic pressure of the external medium is also an important factor.This work formed part of a thesis by one of us (R.S.P.) approved for the degree of Ph. D. in the University of Nottingham. The work was supported by the Agricultural Research Council.     

A review on the “in vitro” culture of freshwater mussels (Unionoida)

Many Unionoida are considered to be extinct, endangered, or of special concern. These bivalves have complex life cycle stages that limit successful culture. In nature, the larvae (glochidia) of these bivalves must successfully parasitize a host (mainly fish) in order to metamorphose into juveniles. The two artificial methods used to obtain juvenile freshwater mussels in laboratory are either by induced attachment to host fish or by in vitro culture of glochidia. This article is focused on the in vitro method that represents a novel and alternative process to fish infestation, offering the ability to obtain larger numbers of juveniles without the need for host fishes and reducing the overall costs of propagation. In vitro culture requires a medium which fulfills the nutritional needs of each glochidia species and avoids microbial contamination. Recently, this methodology has presented excellent results with survival and transformation rates up to 94% using host fish plasma. High efficiencies on growth, and survival rates (84%) of juvenile freshwater bivalve Hyriopsis myersiana (Lea, 1856) up to 120 days were obtained when reared in adequate recirculating aquacultural systems using a very specific diet. More research is still needed to demonstrate successful propagation, mainly concerning the media nutritional composition to increase glochidia transformation and juvenile quality.     

In vitro culture of glochidia of the threatened freshwater mussel Unio crassus Philipsson 1788 – the dilution problem

We applied in vitro techniques in culturing glochidia of the thick-shelled river mussel Unio crassus, seriously threatened European species. Glochidia were freshly isolated from a gravid female. The sterile phase of the cultures was terminated at different time points to assess the optimal length of this phase. We imitated the process of juvenile excision from a fish host by diluting the culture with water at regular time intervals. The metamorphosed juveniles that survived until the end of the experiment and started growing their shells were observed for 24–27 days from the start of the culture in samples diluted for the first time between days 13 and 17. Long-lasting cultures usually became infected and died, whereas in those that were terminated too early, glochidia were unable to develop further in clean water. The transfer of juveniles from an artificial medium to pure water should be done gradually, through a series of dilutions, so that the larvae have the opportunity to feed on the diluted medium after metamorphosis. Only individuals with an active foot capable of operating outside the shell were ready to inhabit water and forage on solid food from the external environment.     

Production of cucumber fruits from the culture of ‘Marketmore-76’ plantlets

A procedure to produce fruits from cultured shoot tips of Cucumis sativus L. cultivar Marketmore-76 in vitro is described. Four-week-old shoot tips, derived from sterile germinated seedlings on a MS medium, were cultured in a 3.8-1 Mason jar using an automated plant culture system. Tips readily generated roots, leaves and flowers after another 4 to 8 weeks in culture. Administration of compressed air at a 300 ml/min flow rate for 30 min 10 or 15 times a day induced the development of parthenocarpic fruits from flowers. Fruits, up to 170 mm long by 35 mm diameter, were obtained within 30 to 45 d after flower opening.Abbreviations APCS automated plant culture system - BA N-(phenylmethyl)-1H-purin-6-amine - BM basal medium - cv cultivar - MS Murashige and Skoog - NAA 1-naphthaleneacetic acid     

Microbial diversity and the “lower-limit” problem of biodiversity

Science is now studying biodiversity on a massive scale. These studies are occurring not just at the scale of larger plants and animals, but also at the scale of minute entities such as bacteria and viruses. This expansion has led to the development of a specific sub-field of “microbial diversity”. In this paper, I investigate how microbial diversity faces two of the classical issues encountered by the concept of “biodiversity”: the issues of defining the units of biodiversity and of choosing a mathematical measure of diversity. I also show that the extension of the scope of biodiversity to microbial entities such as viruses and many other not-clearly-alive entities raises yet another foundational issue: that of defining a “lower-limit” of biodiversity.     

Strategic procurement of fish by the pumé: A South American “fishing culture”

Information is presented on fishing effort, efficiency, techniques, and catch composition for Pumé men, women, and children along with a conceptual model of fishing as a food procurement strategy. The Pumé are a native lowland South American group living in the topical savanna region of southwestern Venezuela characterized by seasonal flooding. Results are discussed in relation to the Pumé environmental and social situation, and briefly compared with results from other lowland South American groups.     

A novel amino-oligosaccharide isolated from the culture of Streptomyces strain PW638 is a potent inhibitor of α-amylase

A novel amino-oligosaccharide, named SF638-1, was isolated from the culture filtrate of the Streptomyces strain PW638. Its chemical structure was determined by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and two-dimensional nuclear magnetic resonance spectroscopy. The novel compound was a mixed inhibitor of human pancreatic α-amylase, with a K_i value in the same order of magnitude as that of the α-amylase inhibitor, acarbose. SF638-1 inhibited starch hydrolysis and glucose transfer in vitro, and suppressed postprandial blood glucose elevation in vivo. These results suggest that SF638-1 may be a potent antidiabetic agent.     

An integrative assessment of the taxonomic status of putative hybrid leopard frogs (Anura: Ranidae) from the Chortís Highlands of Central America,with description of a new species

Integrative taxonomy seeks to approach the complex topic of species diagnosis using independent, complementary lines of evidence. Despite their ubiquity throughout North and Central America, taxonomy of the American leopard frogs (Anura: Ranidae: Rana: subgenus Pantherana) remains largely unresolved, and this is arguably nowhere truer than in the Central American country of Honduras, where there are two nominal species, the taxonomy of which remains unresolved. Leopard frogs from several mountainous areas along the continental divide in Honduras have previously been considered putative hybrids between Rana brownorum and R. cf. forreri, as opposed to two alternate hypotheses: one that they represent a high-altitude eco-morph of a single widespread species that included both lowland forms, or a second that there is an undescribed highland species distinct from either of the recognized lowland forms. We examine this set of hypotheses using three independent lines of evidence. First, we used species distribution modelling to examine potential geographic isolation of the highland form and the two putative parental lowland species, and found strong ecological separation between the highland and lowland forms. Second, mitochondrial and nuclear DNA supports the distinction of the highland form from both putative parental species, with mtDNA data refuting the hypothesis that representatives of either species may represent a matrilineal founder. Morphologically, the highland form is significantly smaller than, and otherwise readily differentiated from, both R. brownorum and R. cf. forreri, as well as all other Rana found in Honduras and adjacent areas. As a result, we formally describe the highland leopard frog as a new species.

http://zoobank.org/urn:lsid:zoobank.org:pub:BE53F587-3618-4433-9651-E495808E5474     

A review of criticisms of phylogenetic nomenclature: is taxonomic freedom the fundamental issue?

The proposal to implement a phylogenetic nomenclatural system governed by the PhyloCode), in which taxon names are defined by explicit reference to common descent, has met with strong criticism from some proponents of phylogenetic taxonomy (taxonomy based on the principle of common descent in which only clades and species are recognized). We examine these criticisms and find that some of the perceived problems with phylogenetic nomenclature are based on misconceptions, some are equally true of the current rank-based nomenclatural system, and some will be eliminated by implementation of the PhyloCode. Most of the criticisms are related to an overriding concern that, because the meanings of names are associated with phylogenetic pattern which is subject to change, the adoption of phylogenetic nomenclature will lead to increased instability in the content of taxa. This concern is associated with the fact that, despite the widespread adoption of the view that taxa are historical entities that are conceptualized based on ancestry, many taxonomists also conceptualize taxa based on their content. As a result, critics of phylogenetic nomenclature have argued that taxonomists should be free to emend the content of taxa without constraints imposed by nomenclatural decisions. However, in phylogenetic nomenclature the contents of taxa are determined, not by the taxonomist, but by the combination of the phylogenetic definition of the name and a phylogenetic hypothesis. Because the contents of taxa, once their names are defined, can no longer be freely modified by taxonomists, phylogenetic nomenclature is perceived as limiting taxonomic freedom. We argue that the form of taxonomic freedom inherent to phylogenetic nomenclature is appropriate to phylogenetic taxonomy in which taxa are considered historical entities that are discovered through phylogenetic analysis and are not human constructs.     

A small variance in the antigenicity but not function of recombinant β-lactoglobulin purified from the culture supernatant of transformed yeast cells

We purified recombinant bovine -lactoglobulin (r-LG) from the culture supernatant of transformed yeast and investigated whether r-LG maintained the functional ability and antigenicity of native -LG. Immunostaining following gel electrophoresis and reversed-phase high-performance liquid chromatography confirmed that r-LG was purified homogeneously. r-LG showed almost the same retinol-binding ability as native -LG purified from bovine milk. However, affinities of two anti--LG monoclonal antibodies (mAbs) to r-LG were different from those to native -LG, although three other mAbs bound these two proteins equally. Since our panel of five mAbs has been previously shown to be able to detect structural changes occurring in -LG, this variance in antigenicity can be attributed to conformational differences between r-LG and native -LG. Then, we studied which step in the production and purification procedure was responsible for altering the antigenicity of r-LG. Bovine milk native -LG was added to several steps in this procedure and purified in the same manner as r-LG. The results suggested that incubation in the yeast culture had adverse effects on maintaining the antigenicity of this recombinant protein. We conclude from these results that even if no difference between the native and recombinant proteins can be detected by functional analysis, some subtle conformational change which can be distinguished by mAbs may be incorporated into the recombinant protein during its production and ultimately cause a different immune reaction in vivo.Abbreviations -LG, -lactoglobulin; r-LG, recombinant -LG; PBS, phosphate-buffered saline; PBS-Tween, PBS containing 0.05% Tween 20; ELISA, enzyme-linked immunosorbent assay.     

Approaching the taxonomic affiliation of unidentified sequences in public databases – an example from the mycorrhizal fungi

Background  

During the last few years, DNA sequence analysis has become one of the primary means of taxonomic identification of species, particularly so for species that are minute or otherwise lack distinct, readily obtainable morphological characters. Although the number of sequences available for comparison in public databases such as GenBank increases exponentially, only a minuscule fraction of all organisms have been sequenced, leaving taxon sampling a momentous problem for sequence-based taxonomic identification. When querying GenBank with a set of unidentified sequences, a considerable proportion typically lack fully identified matches, forming an ever-mounting pile of sequences that the researcher will have to monitor manually in the hope that new, clarifying sequences have been submitted by other researchers. To alleviate these concerns, a project to automatically monitor select unidentified sequences in GenBank for taxonomic progress through repeated local BLAST searches was initiated. Mycorrhizal fungi – a field where species identification often is prohibitively complex – and the much usedITSlocus were chosen as test bed.     

Identity of the active site flavin-peptide fragments from the human “A”-form and the bovine “B”-form of monoamine oxidase

The monoamine oxidase present in the mitochondria of human placenta was verified to be the clorygyline sensitive or A form. This property was not abolished following extensive phospholipase treatment and Triton X-100 extraction. Proteolytic digestion of the partially purified enzyme using trypsin and chymotrypsin and isolation of a peptide containing the covalently linked flavin coenzyme permitted determination of the amino acid composition and sequence of the flavin region of the catalytic site of the enzyme. The structure of the flavin peptide was found to be identical to that of the bovine liver enzyme which is clorgyline insensitive, hence, the B form. The flavin peptide segment of mitochondrial monoamine oxidase is thus conserved between the two forms and among mammalian species.     

A “coupled” subchondral bone-articular cartilage tissue culture system for the study of cartilage proteoglycan metabolism

Summary Current evidence suggests that interactions between the subchondral bone and the articular cartilage of mammalian diarthrodial joints may occur through the action of bone-associated peptide factors. However, there is no suitable organ culture model for studying these interactions. This study defines a long-term tissue culture system where the articular cartilage is coupled to the adjacent subchondral bone obtained from the proximal ends of bovine metacarpals. Autoradiography done over 3 mo., by utilizing [³⁵S]SO₄ incorporation into cartilage proteoglycan (PG) and a procedure for cutting non-decalcified bone, demonstrated similar numbers of silver grains over chondrocytes in all cartilage zones, including the bone-cartilage interface. Newly synthesized PG (NSPG) from the cartilage of the “coupled” system over a 3-wk period was primarily of large hydrodynamic size (Kav of 0.34). Comparable bovine articular and nasal cartilage slice systems, incubated for short periods of time, yielded similar and somewhat larger NSPG, respectively. Labeled chondroitin sulphate PG accumulating in the medium of primary chondrocyte monolayer cultures, derived from the cartilage of the coupled system at 0, 1, 2, and 3 wk, revealed two polydisperse subpopulations (Kav of 0.30 to 0.38 and 0.51 to 0.68). We conclude that this coupled bone-cartilage system is viable for prolonged periods, is suitable for studies on the metabolism of articular cartilage PGs, and seems to have some advantages over the cultured articular cartilage slice system.     

A mathematical model of the interactions in the mixed culture of invertebrates and algae in the “producer–consumer” aquatic biotic cycle

This paper presents a mathematical model of interactions between two herbivorous invertebrates (ciliate Paramecium caudatum and rotifer Brachionus plicatilis) and two planktonic algae (Chlorella vulgaris and Scenedesmus quadricauda) spatially segregated in two compartments of a chemostat–type experimental microcosm system. The model mimics a producer–consumer aquatic biotic cycle, describing the dynamics of the mixed culture of ciliates and rotifers, as consumer compartment, feeding on the mixed algal culture, as producer compartment, under N-limiting conditions. We experimentally found that metabolites of the alga Scenedesmus produce an adverse effect on the reproduction of ciliate Paramecium. Taking this effect into account improved the behavior of the model, the results of which came into qualitative agreement with the experimental results. Both our experimental and modeling approaches demonstrated that, even in conditions of a spatially–segregated producer-consumer biotic cycle, species coexistence is impossible either in the mixed algal culture or in the mixed invertebrate culture. Scenedesmus excluded Chlorella, whereas Brachionus excluded Paramecium.