Recovery of plants from “Near-Lethal” stress

This study reports on the dieback and recovery of red-osier dogwood, Cornus sericea L. plants from near-lethal (NL, sublethal) stress after varying lengths of post-stress environment (PSE). Intact dormant stems were subjected to 47° C for one hour during either October, November or December, and then placed into either constant 0° C or 23° C (dark condition) or kept under natural conditions at Corvallis, OR. Plants exposed to NL-heat stress in October died prior to 9 weeks of 0° C PSE, while none of the plants from other PSE treatments showed signs of injury. For plants exposed to NL-heat stress during November and December, stemdieback occurred at 0° C after 12 and 15 weeks, respectively. None of the plants from the other PSE treatments were injured. Post-stress temperatures of 0° or 5° C following NL-heat in October were lethal while temperatures above 10° C allowed recovery. Post-stress exposure to 0° C injured excised stems within 48 h, whereas irreversible damage to whole plants occurred by two weeks. Dormant plants exposed in October to other stresses, e.g., freezing temperature and hydrogen cyanamide, at NL dosages showed that these stresses also caused plant dieback at 0° C and little or no dieback at 23° C PSE.Abbreviations NL Near-Lethal - PSE Post-Stress Environment     

Recovery of transgenic plants from “escape” shoots

The problem of escapes is well known to those investigating the regeneration of transgenic shoots from transformed callus. Shoots can pass various tests and assays for transformation, and are then scored as transgenic, but the progeny do not express the transferred trait and do not contain the T-DNA. Explanations for these enigmatic escapes include instability of the T-DNA, genomic rearrangements during meiosis, or merely non-rigorous selection or identification assays giving rise to spuriously positive scorings. At least some shoots, however, are likely to simply be chimeric, containing both transformed and non-transformed cell lines. In this case, the transformed cells are responsible for the positive selection and scoring on tests, but either do not contribute to the germ line (resulting in no transgenic progeny) or contribute to only a portion of the germ line (resulting in many fewer positive segregants than expected). We describe two methods which we used to recover fully transgenic plants from apparent escapes. One method involved analyzing more progeny than would normally be necessary (to identify minority transgenic contribution to the cell line). The other method, (to recover transgenic plants from primary selectants with no transgenic contribution to the germ line) involved regenerating new shoots from leaf tissue used in a selection assay to score the initial shoot as a positive transgenic.     

Removal of “Podon” polyphemoides from the genus podon

Summary It is argued that Podon polyphemoides does not belong in the genus Podon, since the only similarity with the other species in this genus is the body outline, a characteristic of minor importance in generic distinction in the Polyphemoidea. The new name Pleopis polyphemoides is proposed.

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Resumen Se argumenta que Podon polyphemoides no debe colocarse más en el genero Podon, ya que solamente tiene similitud con las otras especies de este género en la configuración del cuerpo, una caracteristica de menor importancia en la distinción del Orden Polyphemoidea. Se propone el nombre nuevo Pleopis polyphemoides.

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Based on part of a dissertation, titled The Cladocera of the North Atlantic and the North Sea: Biological and Ecological Studies, and submitted in partial fulfillment of the requirements for the Ph.D. degree at McGill University, Montreal, Canada.     

Chitosomes from the wall-less “slime” mutant of Neurospora crassa

Cell-free extracts from the wall-less slime mutant of Neurospora crassa and the mycelium of wild type exhibit similar chitin synthetase properties in specific activity, zymogenicity and a preferential intracellular localization of chitosomes. The yield of chitosomal chitin synthetase from sline cells was essentially the same irrespective of cell breakage procedure (osmotic lysis or ballistic disruption) —an indication that chitosomes are not fragments of larger membranes produced by harsh (ballistic) disruption procedures. The plasma membrane fraction, isolated from slime cells treated with concanavalin A, contained only a minute portion of the total chitin synthetase of the fungus. Most of the activity was in the cytoplasmic fraction; isopycnic sedimentation of this fraction on a sucrose gradient yielded a sharp band of chitosomes with a buoyant density=1.125 g/ cm³. Approximately 76% of the total chitin synthetase activity of the slime mutant was recovered in the chitosome band. Because of their low density, chitosomes could be cleanly separated from the rest of the membranous organelles of the fungus. Apparently, the lack of a cell wall in the slime mutant is not due to the absence of either chitosomes or zymogenic chitin synthetase.Abbreviations Con A concanavalin A - d buoyant density in g/cm³ - GlcNAc N-acetyl-D-glucosamine - MES 2-[N-morpholino]ethanesulfonic acid - UDP-GlcNAc uridine diphosphate N-acetyl-D-glucosamine     

The Origin of Chinese Traditional Drug “Shuigaoben” from Hubei

A new variety of Ligusticum L. (Umbelliferae), L. sinense var. hupehense collected from Hubei province, is described in this paper.. Cytological investigation shows that the new plant is a diploid, with the karyotypic formula 2n=22=14m+ 8sm. The parameters of chromosomes and the idiogram are given. The comparison of ARC (arm ratio curve) diagram between the new variety andL. sinense is also given.     

Determination of “active” cytochrome P-450 from relaxation kinetics of product formation

We estimate the active part of cytochrome P-450, which is involved in a special substrate transformation, by measuring the initial change of the production rate as a function of the relaxation transitions between two different steady states of the reaction cycle of cytochrome P-450 using the light-reversibility of the carbon monoxide inhibition. The kinetic data of such relaxations are interpreted within a model cycle, which reduces the reaction cycle to three steps. The estimation of the rate constant of the first reduction step, derived from model simulation of the production rate, is confirmed by independent experimental study of the reduction kinetics.An application of our model to the O-deethylation of 7-ethoxycoumarin reveals that — in a time average — 10%–15% of the spectroscopically detectable cytochrome P-450 is involved in that transformation.Abbreviations Cyt. P-450 microsomal cytochrome P-450 - 7-EC 7-ethoxycoumarin     

A problem of taxonomic status of “banana cricket” from culture of the Moscow Zoo insectarium

The “banana cricket” is one of the preferred laboratory objects used for studying general and applied biological problems. However, the exact identity of this form remains obscure. Correct identification of the insects maintained in culture is vital for the correct prediction of the properties of the object in question and comparative studies. Analysis of acoustic signals showed that the banana cricket from the Moscow Zoo culture did not belong to the Gryllus assimilis (F.) group as it was assumed earlier. Analysis of acoustic signals and genitalia revealed similarity between the banana cricket and insects from the culture maintained at the Institute of Evolutionary Physiology and Biochemistry (IEPhB, St. Petersburg), which were supposed to be Gryllus argentinus (Sauss.). The calling songs and genitalia of crickets from both cultures differed from those of G. argentinus. Thus, the banana cricket and Gryllus sp. from the IEPhB culture belong to the same species but the exact identity of that species has not been yet determined.     

Properties of “enkephalinase” from rat kidney: Comparison of dipeptidyl-carboxypeptidase and endopeptidase activities

The “enkephalinase” i.e. the metallopeptidase cleaving the Gly³-Phe⁴ amide bond of enkephalins from rat kidney was studied in its membrane-bound form as well as in a highly purified preparation. It seems identical or very close to three other enzyme activities: “enkephalinase” from cerebral membranes, an endopeptidase from bovine pituitary and the “neutral endopeptidase” from rabbit kidney. Specificity constants of substrates were higher for peptides with a free terminal carboxylate as compared to amidified or typical endopeptidase substrates which were also cleaved. The dipeptidyl carboxypeptidase specificity of “enkephalinase” is attributable to the presence of a critical arginine residue in its active site.     

Separation of chitosomes and secretory vesicles from the “slime” variant of Neurospora crassa

Cells from the slime variant of Neurospora crassa were broken in isotonic conditions by use of triethanolamine buffer plus EDTA. After removal of large membranous structures by low-speed centrifugation, chitosomes and secretory vesicles were separated by means of gel filtration, precipitation of membranous contaminants with Concanavalin A, and centrifugation in sucrose or glycerol gradients. Polypeptidic composition of fractions enriched in secretory vesicles or chitosomes was found to be distinct. By these criteria we concluded that chitosomes and secretory vesicles represent different populations of microvesicles. Both microvesicular populations appeared free of endoplasmic reticulum and vacuolar contaminants as demonstrated by determination of appropriate enzymatic markers.Abbreviations ER Endoplasmic reticulum - UDP-GlcNAc uridine-5-diphosphate N-acetyl glucosamine - GlcNAc N-acetyl glucosamine - SDS sodium dodecyl sulfate - PMSF phenyl methyl sulfonyl fluoride - EDTA ethylene diamino tetraacetic acid Investigador Nacional de Mexico. On leave from the Centro de Investigacion y Estudios Avanzados (IPN), and the Universidad de Guanajuato, Gto., Mexico     

Analysis of chemical constituents from Polygonatum cyrtonema after “Nine-Steam-Nine-Bask” processing

Seven new compounds, known as polygonatine N₁‒N₇ (1‒7), and a known compound (8) were isolated from the ‘Nine-Steam-Nine-Bask’ processing product of Polygonatum cyrtonema Hua. The compounds’ structures were determined by spectroscopic analysis. All compounds were tested for dipeptidyl peptidase-4 (DPP-4) inhibition, glucose transport, and anti-inflammatory activities. Compound 8 suppressed NO production with an IC₅₀ of 35.4 μM.     

Drugs of plant origin from the “Carlo Erba” collection of the Botanical Museum in Portici “Orazio Comes”

Phytochemistry Reviews - The aim of this paper is to illustrate the origin and composition of a collection of 192 plant drugs, based on archival documents from 1932 to 1940. This unique collection...     

Application of “spider-web” mode in discovery and identification of Q-markers from Xuefu Zhuyu capsule

BackgroundThe selection of quality control indicators in a complex system is a key scientific issue for the study of Chinese materia medica (CMM), which is directly related to its safety and efficacy. In order to scientifically understand and control the quality of CMM, quality marker (Q-marker) has been recently raised as a new concept, which provided a novel research idea for the quality control and evaluation of CMM.PurposeBy a new and integrated “spider-web” mode, Q-markers of Xuefu Zhuyu capsule (XZC) were comprehensively uncovered, conducing to great improvement of quality control of XZC.MethodsMainly established by three dimensions derived from six variables including content, stability and activity, “spider-web” mode was constructed to evaluate Q-marker property of candidate compounds by taking regression area of the tested compounds into account.ResultsThe candidate compounds with larger regression area were preferentially adopted as Q-markers, which should possess the satisfactorily integrated properties of content, stability and activity. Six compounds, naringin, isoliquiritin, paeoniflorin, protocatechuic acid, neohesperidin and ferulic acid, were identified and preferred as Q-markers of XZC.ConclusionBased on “spider-web” mode, Q-markers from Xuefu Zhuyu capsule were successfully screened, which would substantially perform quality control of XZC and prove the feasibility of “spider-web” mode in solving the selection of quality control indicators from compound formulae.     

“Spontaneous” Release of Type C Viruses from Clonal Lines of “Spontaneously” Transformed Balb/3T3 Cells

I wish to report that clonal lines of spontaneously transformed Balb/c 3T3 cells can spontaneously release high titres of type C virus in conditions where the untransformed cells do not release type C virus. Further, the spontaneously transformed clones of random-bred Swiss cells, such as 3T6 and 3T12 and an SV40 transformed 3T3 clone have inducible type C viruses, while in the same conditions complete virus production is not detected in the untransformed 3T3 cells. The results suggest that the control of endogenous type C virus information is altered in transformed cells.     

Experimental approach for target selection of wild wine yeasts from spontaneous fermentation of “Inzolia” grapes

The aim of this research was the study of indigenous yeasts isolated from spontaneous fermentation of Inzolia grapes, one of the most widespread native white grapes in Sicily (Italy). The use of selective medium for the isolation and the screening for sulphur dioxide tolerance were useful for the first selection among 640 isolates. The yeasts characterized by high SO₂ tolerance were identified at species level by restriction analysis of ITS region; although the majority of isolates were identified as S. cerevisiae, some non-Saccharomyces yeasts were found. Forty-seven selected yeasts, both S. cerevisiae and non-Saccharomyces yeasts, were characterized for genetic and technological diversity. The genetic polymorphism was evaluated by RAPD-PCR analysis, whereas the technological diversity was analyzed by determining the main secondary compounds in the experimental wines obtained by inoculating these yeasts. Both the molecular and metabolic profiles of selected yeasts were able to clearly discriminate S. cerevisiae from non-Saccharomyces yeasts. This research was useful for the constitution of a collection of selected indigenous yeast strains, including S. cerevisiae and non-Saccharomyces species possessing interesting enological traits. This collection represents a source of wild yeasts, among of which it is possible to select indigenous starters able to maintain the specific organoleptic characteristics of Inzolia wine.     

Morphology and Mechanics of Daughter Cells “Delaminating” from the Ventricular Zone of the Developing Neocortex

During the development of the murine neocortex, time-lapse imaging and microsurgical experiments demonstrate that distinct mechanical forces may be acting on the migration of delaminating daughter cells. Bipolar daughter cells transform into a unipolar morphology as they detach from the inner ventricular surface along the embryonic cerebral wall. Twisting and stretching of their distally remaining pial process establishes a spring-like mechanism that efficiently pulls the soma of these transforming cells to the outer pial surface. The significance of this physical contraction observed in transforming bipolar cells is highlighted when compared to the migration of pin-like daughter cells that lack a pial process. While bipolar and pin-like cells each initially appear epithelial with a ventricular process integrated into the adherence junction meshwork at the ventricular surface, the pin-like cells instead show a transient adventricular somal movement. Consequently, pin-like cells exit from the ventricular zone much more slowly than bipolar cells. Thus, these contrasting movements of daughter cells suggest that differential pulling forces may act separately on their pial and ventricular processes as they delaminate from the telencephalic germinal zone.Key words: cerebral cortex, neuroepithelium, delamination, mechanical force, neuronal migration, slice cultureThe molecular mechanisms of cell migration that ultimately forms the brain should be studied based on the precise understanding of the morphology and behavior of the migrating cells. While within the outer part of the embryonic cerebral wall that subsequently matures into the cerebral cortex how neurons move has been progressing (reviewed in refs. ^1–6), the beginning of a neuron''s life, i.e., birth and start of migration, is not fully understood. This is because live observation of the birth of neurons, i.e., mitosis of their progenitor cells (Fig. 1, left), in the intact neuroepithelia or in the cerebral walls taken from mammalian embryos has only recently become possible.^7–9 In these and other three-dimensional time-lapse studies, it was commonly observed that daughter cells generated at the ventricular (or apical) surface of the neuroepithelium had integrated their processes into the surface.^8,10–17 This phenomenon was not surprising at all when the daughter cells were thought to behave as progenitor cells that had been well known to join the apical junctional meshwork.¹⁸ For neocortical daughter cells to differentiate and migrate towards the pial (or basal) side, however, it was rather unexpected. Differentiating cells were generally thought to be free from the ventricular surface from the very beginning of their life. Many of these apically-connected daughter cells that I observed (steps 1–2 in Fig. 1) then retracted their ventricular process (step 3) and migrated towards the pial side (step 4),^{8,12–14,16,17,24} indicating that they were committed to the neuronal lineage. Although it is still possible that a certain type of daughter cell is produced without inheriting the apex of its progenitor cell and does not join the junctional meshwork,^7,19,20 we should recognize that for many daughter cells to migrate towards the pial side, “delamination” (or de-epithelialization) from the neuroepithelium or the ventricular zone (VZ) (step 3) is an important initial task.²¹Open in a separate windowFigure 1Two types of “departure” exhibited by daughter cells in the mouse neocortical primordium. A pin-like cell (type A) and a bipolar cell (type B) are similar in their initial connection (steps 1–2) to the ventricular surface, i.e., their birth place (left), but they differ in somal movement during which they retract a ventricular process (step 3). Forces likely to be acting in the pial and ventricular processes are illustrated.Two different patterns of “delamination” have been captured so far in the mid-embryonic mouse cerebral wall. The first pattern is exhibited by cells that do not have a pial process (“type A” in Fig. 1; Supplemental Movie 1). These cells move the soma abventricularly while extending their ventricular process (steps 1–2), thereby taking a pin-like morphology.^13,14,17 After retracting their ventricular process (step 3), these cells transform into a multipolar morphology in the subventricular zone (SVZ) and in the intermediate zone (IZ), zones basal to the VZ, and then either divide there to give rise to neuronal pairs^13,14,22 or migrate further basally to fully differentiate into young neurons.^9,13,17,23 We find that the majority of pin-like cells during process retraction (step 3) show a somal movement towards the ventricular surface,¹⁷ and we speculate that this phenomenon may be explained by a contraction-like mechanism (green arrows) that involves microtubules within the shortening ventricular process and the centrosome at the tip of the process, as well as the actomyosin system. How such an adventricular somal movement stops and changes to an abventricular movement to SVZ (step 4) remains unknown.In contrast, the second pattern of delamination (“type B” in Fig. 1; Supplemental Movie 2) is exhibited by the bipolar cells that connect to the ventricular and pial surfaces (reflecting the inheritance of the pial process from the parent cell) and transform into a unipolar shape by releasing their ventricular connection.^8,14,24 During this bipolar-to-unipolar (B-U) transformation (step 3), the soma moves abventricularly (without any retardation or reverse movement as in the pin-like cells) and the pial process forms coils or a hairpin loop, raising the possibility that the pial process had been twisted and stretched (at step 2) such that a spring-like mechanism pulls the soma when the stretch is released by ventricular detachment (step 3).Indeed, it is now possible to observe with high-magnification confocal microscopic and scanning electron microscopic examinations exactly such process twisting (at step 2). Moreover, transection of a ventricular process using fine glass capillaries (at step 2; at the level of IZ or SVZ) results in the retraction of cut ends and the buckling of the pial processes. This result, together with the fact that B-U transforming cells exit from VZ much more quickly than pin-like cells, strongly suggests that the pial process-mediated spring-like mechanism contributes to the abventricular somal movement of this type of delaminating cell.²⁴ It is likely that the force generated within the pial process (magenta arrows) is greater than within the ventricular process (green arrows). Passive stretching of the pial process (steps 1–2) may be due to cell crowding in the progressively thickening cerebral wall. How the process becomes twisted needs to be examined further (reviewed in ref. ²⁵), although process transection experiments in the presence of cytoskeletal inhibitors suggest that intermediate filaments, rather than microtubules and actomyosin, are the major contributor to the process twisting.²⁴ Additionally, live observation of a newly growing pial process (not illustrated in Fig. 1) suggests that it may rotationally extend like a screw.²⁴These results tell us that the mechanical properties of cells migrating in vivo brain tissues must be further examined. It is necessary to establish 3D experimental systems in which the length and tension of elongated cells, as well as pressures exerted on these cells, can be manipulated so that the significance of these physical parameters on histogenetic behaviors can directly be assessed.