Acquisition of lethal doses of Beauveria bassiana conidia by western flower thrips, Frankliniella occidentalis, exposed to foliar spray residues of formulated and unformulated conidia

Secondary acquisition of Beauveria bassiana conidia was recorded on the whole bodies and selected body parts of second-instar nymphs and adult female western flower thrips exposed to foliar spray residues of three differently formulated conidial preparations, for 24 h. Conidia were formulated in emulsifiable oil or with clay (wettable powder), or were essentially unformulated conidia (technical grade powder suspended in water with a surfactant). Formulation had no significant effect on dose acquisition and no effect on virulence of acquired conidia. The mean nymphal LC50/LD50 was 116 conidia/mm2 and 52conidia/insect, respectively; the values for adults were 19 conidia/mm2 and 5conidia/insect. Greatest numbers of conidia were recorded on the legs and abdomens of nymphs and on the legs, wings, and thoraces of adults. As would be expected, numbers of conidia acquired increased with residue concentration (application rate). However, an inverse relationship was noted between acquisition rate (conidia acquired/total conidia applied) and residue concentration. The mechanism underlying this response was not determined. However, there was no indication that any body parts (e.g., tarsi) became saturated with spores, which suggests that either the thrips were repelled by the conidial residues or that as the concentrations of conidia on the substrate increased, conidia somehow became more difficult to acquire. Slopes of the LC probit regressions were lower than those of the LD regressions (mean 1.14 vs 1.78), suggesting that the low slopes often obtained in fungal pathogen assays could be partly an artifact of unequal rates of dose acquisition at low vs high application rates.     

Peripheral benzodiazepine receptors in potatoes (Solanum tuberosum)

The peripheral benzodiazepine receptor (PBR), an internal protein of the mammalian mitochondrial membrane, is involved in several metabolic functions such as steroidogenesis, oxidative phosphorylation, and regulation of cell proliferation. Here we report the presence of PBRs in parenchymal and meristematic tissues of potato (Solanum tuberosum). PBRs are heterogeneously distributed in potato and are highly expressed in meristematic cells. In particular the receptor protein is mainly localised in the meristematic nuclear subcellular preparation. This 30-36 kDa protein, which corresponds to PBR, is increased, indeed, in meristematic compared to the parenchymal tissue. This suggests an involvement of this receptor in the regulation of cell plant growth. In addition, the demonstration that PBRs are also present in vegetables supports the hypothesis of a highly conserved receptor system during phylogenesis.     

Localization of β1-Adrenergic Receptors in the Cochlea and the Vestibular Labyrinth

Sympathetic activation in a “fight or flight reaction” may put the sensory systems for hearing and balance into a state of heightened alert via β₁-adrenergic receptors (β₁-AR). The aim of the present study was to localize β₁-AR in the gerbil inner ear by confocal immunocytochemistry, to characterize β₁-AR by Western immunoblots, and to identify β₁-AR pharmacologically by measurements of cAMP production. Staining for β₁-AR was found in strial marginal cells, inner and outer hair cells, outer sulcus, and spiral ganglia cells of the cochlea, as well as in dark, transitional and supporting cells of the vestibular labyrinth. Receptors were characterized in microdissected inner ear tissue fractions as 55 kDa non-glycosylated species and as 160 kDa high-mannose-glycosylated complexes. Pharmacological studies using isoproterenol, ICI-118551 and CGP-20712A demonstrated β₁-AR as the predominant adrenergic receptor in stria vascularis and organ of Corti. In conclusion, β₁-AR are present and functional in inner ear epithelial cells that are involved in K⁺ cycling and auditory transduction, as well as in neuronal cells that are involved in auditory transmission.     

PTSD样情感行为异常大鼠杏仁核Caspase 9的改变

目的观察创伤后应激障碍(PTSD)样行为异常大鼠杏仁核神经元Caspase 9表达变化,有望揭示PTSD的部分发病机制。方法采用国际认定的SPS方法刺激建立大鼠PTSD模型,取成年健康雄性Wistar大鼠60只,随机分为SPS模型的1d、4d、7d组及正常对照组,采用免疫荧光法、免疫印迹和逆转录-聚合酶链式反应检测大鼠杏仁核Caspase 9的表达变化。结果SPS刺激后大鼠杏仁核神经元细胞内Caspase 9于1d开始逐渐升高,7d时表达最多;Caspase 9 mRNA的变化与之相一致。结论海马Caspase 9的表达变化,可能是PTSD大鼠情感行为异常的重要病理生理基础之一。     

Frameshifting in Alphaviruses: A Diversity of 3′ Stimulatory Structures

Programmed ribosomal frameshifting allows the synthesis of alternative, N-terminally coincident, C-terminally distinct proteins from the same RNA. Many viruses utilize frameshifting to optimize the coding potential of compact genomes, to circumvent the host cell's canonical rule of one functional protein per mRNA, or to express alternative proteins in a fixed ratio. Programmed frameshifting is also used in the decoding of a small number of cellular genes. Recently, specific ribosomal − 1 frameshifting was discovered at a conserved U_UUU_UUA motif within the sequence encoding the alphavirus 6K protein. In this case, frameshifting results in the synthesis of an additional protein, termed TF (TransFrame). This new case of frameshifting is unusual in that the − 1 frame ORF is very short and completely embedded within the sequence encoding the overlapping polyprotein.The present work shows that there is remarkable diversity in the 3′ sequences that are functionally important for efficient frameshifting at the U_UUU_UUA motif. While many alphavirus species utilize a 3′ RNA structure such as a hairpin or pseudoknot, some species (such as Semliki Forest virus) apparently lack any intra-mRNA stimulatory structure, yet just 20 nt 3′-adjacent to the shift site stimulates up to 10% frameshifting. The analysis, both experimental and bioinformatic, significantly expands the known repertoire of − 1 frameshifting stimulators in mammalian and insect systems.     

Up-regulation of the embryonic self-renewal network through reversible polyploidy in irradiated p53-mutant tumour cells

We have previously documented that transient polyploidy is a potential cell survival strategy underlying the clonogenic re-growth of tumour cells after genotoxic treatment. In an attempt to better define this mechanism, we recently documented the key role of meiotic genes in regulating the DNA repair and return of the endopolyploid tumour cells (ETC) to diploidy through reduction divisions after irradiation. Here, we studied the role of the pluripotency and self-renewal stem cell genes NANOG, OCT4 and SOX2 in this polyploidy-dependent survival mechanism. In irradiation-resistant p53-mutated lymphoma cell-lines (Namalwa and WI-L2-NS) but not sensitive p53 wild-type counterparts (TK6), low background expression of OCT4 and NANOG was up-regulated by ionising radiation with protein accumulation evident in ETC as detected by OCT4/DNA flow cytometry and immunofluorescence (IF). IF analysis also showed that the ETC generate PML bodies that appear to concentrate OCT4, NANOG and SOX2 proteins, which extend into complex nuclear networks. These polyploid tumour cells resist apoptosis, overcome cellular senescence and undergo bi- and multi-polar divisions transmitting the up-regulated OCT4, NANOG and SOX2 self-renewal cassette to their descendents. Altogether, our observations indicate that irradiation-induced ETC up-regulate key components of germ-line cells, which potentially facilitate survival and propagation of the tumour cell population.     

Arbuscular mycorrhizal morphology and dark septate fungal associations in medicinal and aromatic plants of Western Ghats, Southern India

We investigated roots of 107 medicinal and aromatic plants (MAPs) in the Western Ghats region of Southern India for arbuscular mycorrhizal (AM) and dark septate endophyte (DSE) associations. Of the 107 MAPs belonging to 98 genera in 52 families examined, 79 were AM and 38 harbored a DSE association. Typical Arum- and Paris-type mycorrhizas are first reported in the presumed nonmycorrhizal family Amaranthaceae. Similarly, DSE associations are recorded for the first time in nine plant families and 37 plant species. Thirty MAPs had both AM and DSE associations. The number of MAPs having Arum-type mycorrhiza was greater than those having Paris-type. This was more prominent among herbaceous plants than in trees where the Paris-type was predominant. Similarly, the Arum-type was more prevalent in annuals than in perennials. DSE associations were more frequent in herbs and perennials compared to other MAPs.     

Itatodon tatarinovi (Tegotheriidae, Mammalia), a docodont from the Middle Jurassic of Western Siberia and phylogenetic analysis of Docodonta

Itatodon tatarinovi Lopatin et Averianov, 2005 is represented by two lower molars and a lower molar fragment from the upper part of the Itat Formation (Bathonian Stage) of the Berezovskii quarry (southern Krasnoyarsk Region). Based on the presence of a pseudotalonid, bordered by the crests a-b, b-e, e-g, and a-g, Itatodon is assigned to the endemic Asian family Tegotheriidae. In this genus, the crest a-b is reduced and the thick lingual cingulid is better developed than that of other docodonts. Phylogenetic analysis of Docodonta shows paraphyly of Morganucodonta relative to docodonts and independent development of the pseudotalonid in the Tegotheriidae and the clade comprising Krusatodon, Castorocauda, Cyrtlatherium, and Dsungarodon.