Situation of brucellosis in the regions of Stavropol Territory affected by the flood of 2002

The emergency situation caused by inundations and high floods on the rivers in the affected regions exerts no direct influence on brucellosis morbidity among humans. Still the urgent evacuation of agricultural animals in connection with the natural calamity, their displacement and regrouping give grounds to prognosticate the deterioration of the epizootic situation in this infection in a number of regions of the territory where no sufficient veterinary surveillance has been ensured.     

Expression of CMS in zygotic and apozygotic progenies of sugar beet Beta vulgaris L

Zygotic and apozygotic progenies of sugar beet exhibit high phenotypic variation with respect to cytoplasmic male sterility (CMS). There are progenies with completely sterile, semisterile, semifertile, and fertile pollen. The proportions of semifertile and fertile plants in zygotic and apozygotic progenies varied from zero to 28% and from zero to 17.8%, respectively. Comparison of the phenotypic distributions in zygotic and apozygotic progenies did not reveal significant differences in the CMS expression, although the latter is determined by the maternal S-plasmotype and both maternal and paternal (pollinator) genotypes in zygotic progenies and only by the maternal S-plasmotype and genotype in apozygotic progenies. It has been hypothesized that the instability of the CMS expression in apozygotic progenies is determined by epigenetic variation in the activities of the genes that control the maintenance of the pollen-grain sterility. Inactivated dominant alleles Rf1(0) and Rf2(0) in homozygous state may function as sterility maintenance genes, whereas activation of these alleles during ontogeny results in a partial or complete restoration of pollen-grain fertility. It was demonstrated that pollen fertility of mother plants with S cytoplasm did not affect the CMS expression in two sib progenies. Conversely, in two other progenies, the proportion of fertile plants was significantly higher in the sib progenies of mother plants with fertile pollen and S cytoplasm (inheritance of epigenetic variation).     

Structural and transcriptional variation of mitochondrial DNA in pollen-sterile agamospermous sugar beet (Beta vulgaris L.) progeny

The cytoplasm status according to mitochondrial sequence tags was determined in agamospermous sugar beet progenies characterized by unstable manifestation of cytoplasmic male sterility. The detected variations in the ratios of homologous sequences related to the N and S mtDNA types did not correlate with pollen phenotypes of the plants. Polymerase chain reaction allowed semiquantitative evaluation of these variations and their detection. A cDNA corresponding to a hitherto unknown minor RNA and containing a consensus sequence of dicotyledonous plant promoters was detected by mtRNA display. Probable sources of CMS variability in agamospermous sugar beet progenies are discussed.     

Epiplastome variation of the number of chloroplasts in stomata guard cells of sugar beet (Beta vulgaris L.)

In stomata guard cells of sugar beet, variation in the number of chloroplasts was studied in successive generations: (1) hybrid generation; (2) generation yielded by uniparental apozygotic seed reproduction; (3) generation obtained after seed treatment with a colchicine solution; (4) generation obtained after seed treatment with 5-azacytidine. As compared to hybrid generation, uniparental seed reproduction increases the average number of chloroplasts in stomata guard cells (from 13.5 to 15.0) and decreases distribution variance of this trait by a factor of 3 to 4. Colchicine increases both average number of chloroplasts in stomata guard cells (from 13.5 to 18.2) and distribution variance (about twice). 5-Azacytindine reduces the number of chloroplasts in cells (from 15.0 to 12.9) but enhances distribution variance (about 1.5 times). Variation in the number of chromosomes in stomata cells is related to myxoploidy in meristem tissue, on the one hand, and to the rate of cell division, on the other. Uniparental seed reproduction is suggested to enhance the number of organelles per cell due to high myxoploidy in cell populations, which is typical of inbred plants. Colchicine blocks spindle division and sharply increases the level of myxoploidy in cell populations and the number of organelles per cell. 5-Azacytidine hypomethylates chromosome DNA, increases the rate of cell divisions, and reduces the number of organelles per cell. The described changes in the number of chloroplasts are inherited in cell lineage ("cell hereditary memory") and successive sporophyte generations.     

Effect of the epimutagen 5-azacytidine on the structure of floral-stalk metameres in sugar beet (Beta vulgaris L)

This study is dedicated to the effect of the epimutagen 5-azacytidine on the structure of floral-stalk metameres in sugar beet Beta vulgaris L. Simple phytomeres consist of separate flowers (unianthous plants; UA phenotype), while complex metameres occur in synanthous plants (SA phenotype). Treatment of the synanthous line mcSOAN-5 dramatically reduced the number of flowers on phytomeres as early as in generation zero (A0Az0). For the first time, plants with simple phytomeres were found in this line. The proportion of plants with the SA phenotype in generation A0Az0 was 7.7%. In generation A1Az1, the tendency for reduction of the number of flowers on phytomeres persisted. The proportion of plants with simple phytomeres reached 77%; i.e., the frequency of SA phenotypes in the progeny (A1Az1) increased tenfold in comparison with the parents A0Az0. The high frequency of morphogenetic changes in the floral stalk structure under the influence of the epimutagen suggests that the variability of the UA--SA character in beet populations is of epigenetic rather than mutational nature.     

Varied diet and opportunistic foraging in the Ethiopian Bush-crow Zavattariornis stresemanni,an Endangered generalist

The Ethiopian Bush-crow Zavattariornis stresemanni is an endangered, co-operatively breeding southern Ethiopian endemic with a remarkably restricted range (c. 6 000 km²). The species’ range was recently found to be almost perfectly predicted by an envelope of cooler, drier and more seasonal climate than surrounding areas, but the proximate determinants of this range restriction remain unclear. We assessed whether specialisation in diet or foraging may restrict the range of the species by conducting foraging watches to determine prey composition, augmented by observations of opportunistic foraging techniques, and by comparing our results to previously published information on diet. Prey composition comprised a range of arthropods, such as insect larvae (62.7%), beetles (Coleoptera) (15.6%), and grasshoppers and crickets (Orthoptera) (11.8%). Prey was primarily obtained by pecks above ground (74.2%) but also frequently dug up (23.8%). Prey capture was most successful during pecks and we also found chicks were preferentially fed larger prey items over smaller ones by adults. We documented opportunistic behaviours such as nest-raiding and ox-pecking. Diet and foraging are varied and unspecialised, and therefore do not appear to explain the restricted range of the Ethiopian Bush-crow.     

红腹锦鸡肺的组织结构与微血管构筑

为了了解红腹锦鸡(Chroysolophus pictus)肺的微细结构和微血管构筑特征,为呼吸生物学研究提供形态学依据,用组织学方法和微血管铸型技术在光镜和扫描电镜下观察研究了红腹锦鸡肺的组织结构与微血管构筑情况。结果表明,红腹锦鸡肺主要由各级支气管构成,从三级支气管上呈辅射状分出许多呼吸毛细管(微气管),并相互吻合成网状,呼吸毛细管外面包围有丰富的毛细血管;红腹锦鸡肺毛细血管垂直围绕在各微气管外,并相互吻合成密集的立体微血管网;毛细血管管径4.5~7.0μm,微气管直径11~50μm。并对肺微血管构筑情况与呼吸效率的关系作了探讨。     

Olive Phenolics as c-Met Inhibitors: (-)-Oleocanthal Attenuates Cell Proliferation,Invasiveness, and Tumor Growth in Breast Cancer Models

Dysregulation of the Hepatocyte growth factor (HGF)/c-Met signaling axis upregulates diverse tumor cell functions, including cell proliferation, survival, scattering and motility, epithelial-to-mesenchymal transition (EMT), angiogenesis, invasion, and metastasis. (-)-Oleocanthal is a naturally occurring secoiridoid from extra-virgin olive oil, which showed antiproliferative and antimigratory activity against different cancer cell lines. The aim of this study was to characterize the intracellular mechanisms involved in mediating the anticancer effects of (-)-oleocanthal treatment and the potential involvement of c-Met receptor signaling components in breast cancer. Results showed that (-)-oleocanthal inhibits the growth of human breast cancer cell lines MDA-MB-231, MCF-7 and BT-474 while similar treatment doses were found to have no effect on normal human MCF10A cell growth. In addition, (-)-oleocanthal treatment caused a dose-dependent inhibition of HGF-induced cell migration, invasion and G1/S cell cycle progression in breast cancer cell lines. Moreover, (-)-oleocanthal treatment effects were found to be mediated via inhibition of HGF-induced c-Met activation and its downstream mitogenic signaling pathways. This growth inhibitory effect is associated with blockade of EMT and reduction in cellular motility. Further results from in vivo studies showed that (-)-oleocanthal treatment suppressed tumor cell growth in an orthotopic model of breast cancer in athymic nude mice. Collectively, the findings of this study suggest that (-)-oleocanthal is a promising dietary supplement lead with potential for therapeutic use to control malignancies with aberrant c-Met activity.