Uber die Ernährung der Arbeitermade vonApis Mellifica L., insbesondere in der Altersperiode

Zusammenfassung der Ergebnisse Verf. sucht in dieser Arbeit experimentell zu klären, wie die Bienen das Mischfutter zusammensetzen, mit welchem sie die Arbeitermaden in der Altersperiode füttern.Nachdem es sich in früheren Versuchen ergeben hatte, daß bei einer Fütterung lediglich mit Pollen+Honig+Aqua dest. keine Verpuppung zustande kommt, ein Futtersaftzusatz demnach unerläßlich ist, verwendete Verf. bei seinen Brutschrankversuchen die drei von ihm, nachgewiesenen Futtersaftarten: 1.) den Arbeiterfuttersaft, 2.) den Königinjungmaden-Futtersaft, 3.) den Königinaltmaden-Futtersaft. Der Erwartung entsprechend, wurde die Metamorphose durch 3.) am stärksten gefördert, dagegen durch 1.) verhindert. Die Verpuppung einiger mit 2.) gefütterten Maden war ein unerwartetes Ergebnis.Verf. weist nach, daß die biologische Bedeutung des Futterwechsels des Überganges zur Mischfutterernährung, vor allem in der Änderung der Futtersaftqualität liegt, weil diese erst die Metamorphose ermöglicht, ferner, daß die Mitverwendung von Pollen und Honig keine determinative Bedeutung hat, vielmehr dem ebenfalls wichtigen Zwecke dient, unter Einsparung von Futtersaft alle Maden auf ein Gewicht zu bringen, bei welchem sie verwandlungsfähig sind.

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Summary The bee-larvae, in their early state, are fed, with pure jelly till they weigh approx. 35 mg. This is, as to its quality, not identical with the jelly for the queen-larvae. Yet with the jelly for queen-young-larvae, which serves to predetermine the female larva for a queen (v.Rhein, 1951), it has in common, that it is only good for the larva in its early state. By this characteristic it differs from the jelly for the queen-old-larvae, by which the predetermined larvae are determined queens; by means of this latter very young worker-larvae can be bred in thermostates. The results are, however, since those are not predetermined, either normal workers or medium forms with more or less enlarged ovaries and spermatic vessels (v.Rhein, 1933). This observation proves, that, for determining the larva for a worker, no pure pollen is necessary.This pollen is found, as it is well known, aside honey, in the mixed food, which is received by the bee-larvae from their hatching-nurses in their later state. That this food also contains jelly was already supposed byRösch (1925). I was able to proof this thesis by way of experiment. I began to feed larvae after their early stage with a mixture of pollen, honey, aqua dest. in relation 32065. Although the larvae grew normally and even reached a weight of 214 mg (norm:approx. 158 mg), they all died before excrementing (v.Rhein, 1933). During the years 1953 and 1954 I was able to solve this problem by adding to the just mentioned mixture in different test-groups 100 and 200 mg jelly for worker-young-larvae, jelly for queen-young-larvae and jelly for queen-old-larvae; the addition of water was decreased, corresponding to the used quantity of jelly, to 670 respectively to 570 mg. The result was as follows:Table (see German text).Thus we can conclude, that the jelly is the most suitable as additional food, for queen-old-larvae while the jelly is not suitable at all for worker-young-larvae.The chrysalis, arised from this experiment, were, judged from the morphologie and anatomic point of view, normal chrysalis of workers, except one chrysalis originated from a particular heavy larva (238 mg), which showed enlarged ovaries (74 ovaries in the average).

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Résumé Les larves des Abeilles reçoivent une alimentation particulière jusqu'à ce qu'elles atteignent un poids de 35 mg environ. La gelée qui sert de base à cette alimentation n'est pas qualitativement identique à la gelée royale; le seul caractère commun à ces deux substances est de ne convenir qu'aux très jeunes larves. Ce caractère les sépare de la gelée servie aux vieilles larves de reines grâce à laquelle les larves prédéterminées achèvent leur détermination: cette gelée en effet, peut permettre d'élever complètement de jeunes larves d'ouvrières dans un thermostat. Comme ces larves n'ont pas été prédéterminées, on obtient soit des ouvrières normales, soit des formes intermédiaires, avec ovaires et vésicules séminales plus ou moins hypertrophiés (von Rhein, 1933). Cette observation prouve que le pollen à l'état brut n'est pas indispensable à la détermination d'une larve ouvrière; pourtant on en trouve dans le miel et dans la nourriture mixte servie aux larves d'Abeilles âgées par les nourrices. Depuis longtemps, on a émis l'hypothèse (Resch, 1925) que cette nourriture mixte renferme aussi de la gelée royale. J'ai réussi à en fournir la preuve expérimentale. A la fin de la première phase de l'existence des larves (phase de jeunesse), j'ai commencé à les alimenter avec du pollen, du miel et de l'eau distillée mélangés dans les proportions suivantes: 3/20/65. Les larves se développèrent normalement et atteignirent un poids de 214 mg (le poids normal est d'environ 158 mg), mais elles mouraient toutes avant la défécation (von Rhein, 1933). En 1953 et 1954, je trouvais la solution du problème en ajoutant dans plusieurs groupes expérimentés, au mélange sus-mentionné, 100 ou 200 mg de gelée de jeunes larves d'ouvrières, de gelée de jeunes larves de reines, de gelée de vieilles larves de reines; en même temps, l'apport d'eau correspondant à la quantité de gelée utilisée était réduit respectivement à 670 et 570 mg. Le résultat était le suivant:Tableau (texte allemand).On peut conclure de ce tableau que la gelèe des vieilles larves de reines est la plus propre à servir de nourriture complémentaire; la gelée des jeunes larves d'ouvrières y est totalement impropre. Les nymphes obtenues à la suite de l'expérience étaient, du point de vue morphologique et anatomique, des nymphes normales d'ouvrières, excepté une particulièrement lourde (238 mg), qui présentait des ovaires hypertrophiés (74 avarioles en moyenne).

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Durchgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft.     

假苍耳的生活史进程中几种生理生化指标的变化

本文试图从生理生化的角度对假苍耳(Iva xanthifolia)生活史进程中可溶性糖类、赤霉素、单宁以及黄酮的变化进行探讨。通过对假苍耳在生长发育期间几种生理生化指标的测定, 结果表明, 在假苍耳生活史进程的不同阶段, 其体内各种代谢产物的含量基本都在种子或芽阶段具有最高含量。此外, 不同发育阶段可溶性还原糖含量的变化规律相似: 芽>花序>苗>成株>种子。除在花序和苗阶段没有测到海藻糖, 其他各阶段海藻糖的含量变化如下: 芽>成株>种子。另外, 只有在种子阶段检测到棉子糖, 其含量为15.43 mg.g-1。赤霉素含量的变化规律如下: 种子＞芽≈苗≈花序＞成株。单宁含量的变化趋势: 种子＞成株＞苗＞芽＞花序。黄酮含量的变化趋势: 种子＞芽＞成株≈花序＞苗。值得注意的是, 当单宁/黄酮的比值接近1时, 植物体内需要的单宁和黄酮的含量则相对较低; 相反, 当单宁/黄酮的比值接近0时, 植物体内需要的单宁和黄酮的含量则较高。     

Isoform-specific Prolongation of Kv7 (KCNQ) Potassium Channel Opening Mediated by New Molecular Determinants for Drug-Channel Interactions

Kv7 channels, especially Kv7.2 (KCNQ2) and Kv7.3 (KCNQ3), are key determinants for membrane excitability in the brain. Some chemical modulators of KCNQ channels are in development for use as anti-epileptic drugs, such as retigabine (D-23129, N-(2-amino-4-(4-fluorobenzylamino)-phenyl)), which was recently approved for clinical use. In addition, several other compounds were also reported to potentiate activity of the Kv7 channels. It is therefore of interest to investigate compound-channel interactions, so that more insights may be gained to aid future development of therapeutics. We have conducted a screen of 20,000 compounds for KCNQ2 potentiators using rubidium flux combined with atomic absorption spectrometry. Here, we report the characterization of a series of new structures that display isoform specificity and induce a marked reduction of deactivation distinct from that of retigabine. Furthermore, KCNQ2(W236L), a previously reported mutation that abolishes sensitivity to retigabine, remains fully sensitive to these compounds. This result, together with mutagenesis and other studies, suggests that the reported compounds confer a unique mode of action and involve new molecular determinants on the channel protein, consistent with the idea of recognizing a new site on channel protein.     

Cajanol,a novel anticancer agent from Pigeonpea [Cajanus cajan (L.) Millsp.] roots,induces apoptosis in human breast cancer cells through a ROS-mediated mitochondrial pathway

Cajanol (5-hydroxy-3-(4-hydroxy-2-methoxyphenyl)-7-methoxychroman-4-one) is an isoflavanone from Pigeonpea [Cajanus cajan (L.) Millsp.] roots. As the most effective phytoalexin in pigeonpea, the cytotoxic activity of cajanol towards cancer cells has not been report as yet. In the present study, the anticancer activity of cajanol towards MCF-7 human breast cancer cells was investigated. In order to explore the underlying mechanism of cell growth inhibition of cajanol, cell cycle distribution, DNA fragmentation assay and morphological assessment of nuclear change, ROS generation, mitochondrial membrane potential (ΔΨm) disruption, and expression of caspase-3 and caspase-9, Bax, Bcl-2, PARP and cytochrome c were measured in MCF-7 cells. Cajanol inhibited the growth of MCF-7 cells in a time and dose-dependent manner. The IC₅₀ value was 54.05 μM after 72 h treatment, 58.32 μM after 48 h; and 83.42 μM after 24 h. Cajanol arrested the cell cycle in the G2/M phase and induced apoptosis via a ROS-mediated mitochondria-dependent pathway. Western blot analysis showed that cajanol inhibited Bcl-2 expression and induced Bax expression to desintegrate the outer mitochondrial membrane and causing cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascade, and active-caspase-3 was involved in PARP cleavage. All of these signal transduction pathways are involved in initiating apoptosis. To the best of our knowledge, this is the first report demonstrating the cytotoxic activity of cajanol towards cancer cells in vitro.     

Expression of BjMT2, a metallothionein 2 from Brassica juncea, increases copper and cadmium tolerance in Escherichia coli and Arabidopsis thaliana, but inhibits root elongation in Arabidopsis thaliana seedlings

The protective function of a plant type-2 metallothionein was analysed after expression in Escherichia coli and in Arabidopsis thaliana seedlings. BjMT2 from Brassica juncea was expressed in E. coli as a TrxABjMT2 fusion protein. After affinity chromatography and cleavage from the TrxA domain, pure BjMT2 protein was obtained which strongly reacted with the thiol reagent monobromobimane. Escherichia coli cells expressing the TrxABjMT2 fusion were more tolerant to Cu2+ and Cd2+ exposure than control strains. Likewise, when BjMT2 cDNA was expressed in A. thaliana under the regulation of the 35S promoter, seedlings exhibited an increased tolerance against Cu2+ and Cd2+ based on shoot growth and chlorophyll content. Analysis of transiently transformed cells of A. thaliana and tobacco leaves by confocal laser scanning microscopy (CLSM) revealed exclusive cytosolic localization of a BjMT2::EGFP (enhanced green fluorescent protein) fusion protein in control and heavy metal-exposed plant cells. Remarkably, ectopic expression of BjMT2 reduced root growth in the absence of heavy metal exposure, whereas in the presence of 50 or 100 microM Cu2+ root growth in control and transgenic lines was identical. The results indicate that in A. thaliana, root and shoot development are differentially affected by ectopic expression of BjMT2.     

Newly-formed photosynthates and the respiration rate of girdled stems of Korean pine (Pinus koraiensis Sieb. et Zucc.)

A stem-girdling experiment was carried out on an evergreen conifer, the Korean pine (Pinus koraiensis Sieb. et Zucc.), in mid summer in Northeast China. A 50 % higher respiration rate at the upper part of the stem was observed 3 d after stem girdling, and a stable higher rate (1.2–2.8 times) one week later. However, no higher soluble sugar or starch contents were found in the upper bark of the girdled stems in measurements over three weeks. These findings indicate that most of the newly-formed photosynthates were consumed by the high respiratory activity; this is also implied by the strong correlation between the photosynthetic photon flux over the canopy (PPF) and respiration at the upper parts of girdled stems. Moreover, the maximum PPF and cumulative PPF one day before measurement (PPFmax-Y and CPPF-Y, respectively) were closely correlated with the respiratory difference between the upper and the lower parts, but no such correlation was found with the instantaneous PPF (PPF-I) and cumulative PPF on the current day from sunrise to measured time point (CPPF-C). This shows that photosynthates newly formed by canopy needles need at least one day for transportation in order to increase the stem respiration at tree breast height.     

A New Link to Mitochondrial Impairment in Tauopathies

Tauopathies like the "frontotemporal dementia with Parkinsonism linked to chromosome 17" (FTDP-17) are characterized by an aberrant accumulation of intracellular neurofibrillary tangles composed of hyperphosphorylated tau. For FTDP-17, a pathogenic tau mutation P301L was identified. Impaired mitochondrial function including disturbed dynamics such as fission and fusion are most likely major pathomechanisms of most neurodegenerative diseases. However, very little is known if tau itself affects mitochondrial function and dynamics. We addressed this question using SY5Y cells stably overexpressing wild-type (wt) and P301L mutant tau. P301L overexpression resulted in a substantial complex I deficit accompanied by decreased ATP levels and increased susceptibility to oxidative stress. This was paralleled by pronounced changes in mitochondrial morphology, decreased fusion and fission rates accompanied by reduced expression of several fission and fusion factors like OPA-1 or DRP-1. In contrast, overexpression of wt tau exhibits protective effects on mitochondrial function and dynamics including enhanced complex I activity. Our findings clearly link tau bidirectional to mitochondrial function and dynamics, identifying a novel aspect of the physiological role of tau and the pathomechanism of tauopathies.     

Peripheral Mitochondrial Dysfunction in Alzheimer’s Disease: Focus on Lymphocytes

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease. Today, AD affects millions of people worldwide and the number of AD cases will increase with increased life expectancy. The AD brain is marked by severe neurodegeneration like the loss of synapses and neurons, atrophy and depletion of neurotransmitter systems in the hippocampus and cerebral cortex. Recent findings suggest that these pathological changes are causally induced by mitochondrial dysfunction and increased oxidative stress. These changes are not only observed in the brain of AD patients but also in the periphery. In this review, we discuss the potential role of elevated apoptosis, increased oxidative stress and especially mitochondrial dysfunction as peripheral markers for the detection of AD in blood cells especially in lymphocytes. We discuss recent not otherwise published findings on the level of complex activities of the respiratory chain comprising mitochondrial respiration and the mitochondrial membrane potential (MMP). We obtained decreased basal MMP levels in lymphocytes from AD patients as well as enhanced sensitivity to different complex inhibitors of the respiratory chain. These changes are in line with mitochondrial defects obtained in AD cell and animal models, and in post-mortem AD tissue. Importantly, these mitochondrial alterations where not only found in AD patients but also in patients with mild cognitive impairment (MCI). These new findings point to a relevance of mitochondrial function as an early peripheral marker for the detection of AD and MCI.     

Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

Bone tissue has an exceptional quality to regenerate to native tissue in response to injury. However, the fracture repair process requires mechanical stability or a viable biological microenvironment or both to ensure successful healing to native tissue. An improved understanding of the molecular and cellular events that occur during bone repair and remodeling has led to the development of biologic agents that can augment the biological microenvironment and enhance bone repair. Orthobiologics, including stem cells, osteoinductive growth factors, osteoconductive matrices, and anabolic agents, are available clinically for accelerating fracture repair and treatment of compromised bone repair situations like delayed unions and nonunions. Preclinical and clinical studies using biologic agents like recombinant bone morphogenetic proteins have demonstrated an efficacy similar or better than that of autologous bone graft in acute fracture healing. A lack of standardized outcome measures for comparison of biologic agents in clinical fracture repair trials, frequent off-label use, and a limited understanding of the biological activity of these agents at the bone repair site have limited their efficacy in clinical applications.     

A Large Insertion in bHLH Transcription Factor BrTT8 Resulting in Yellow Seed Coat in Brassica rapa

Yellow seed is a desirable quality trait of the Brassica oilseed species. Previously, several seed coat color genes have been mapped in the Brassica species, but the molecular mechanism is still unknown. In the present investigation, map-based cloning method was used to identify a seed coat color gene, located on A9 in B. rapa. Blast analysis with the Arabidopsis genome showed that there were 22 Arabidopsis genes in this region including at4g09820 to at4g10620. Functional complementation test exhibited a phenotype reversion in the Arabidopsis thaliana tt8-1 mutant and yellow-seeded plant. These results suggested that the candidate gene was a homolog of TRANSPARENT TESTA8 (TT8) locus. BrTT8 regulated the accumulation of proanthocyanidins (PAs) in the seed coat. Sequence analysis of two alleles revealed a large insertion of a new class of transposable elements, Helitron in yellow sarson. In addition, no mRNA expression of BrTT8 was detected in the yellow-seeded line. It indicated that the natural transposon might have caused the loss in function of BrTT8. BrTT8 encodes a basic/helix-loop-helix (bHLH) protein that shares a high degree of similarity with other bHLH proteins in the Brassica. Further expression analysis also revealed that BrTT8 was involved in controlling the late biosynthetic genes (LBGs) of the flavonoid pathway. Our present findings provided with further studies could assist in understanding the molecular mechanism involved in seed coat color formation in Brassica species, which is an important oil yielding quality trait.