Nucleolar localization and circadian regulation of Per2S,a novel splicing variant of the Period 2 gene

In this work, we show for the first time that a second splicing variant of the core clock gene Period 2 (Per2), Per2S, is expressed at both the mRNA and protein levels in human keratinocytes and that it localizes in the nucleoli. Moreover, we show that a reversible perturbation of the nucleolar structure acts as a resetting stimulus for the cellular clock. Per2S expression and periodic oscillation upon dexamethasone treatment were assessed by qRT-PCR using specific primers. Western blot (WB) analysis using an antibody against the recombinant human PER2 (abRc) displayed an intense band at a molecular weight of ~55 kDa, close to the predicted size of Per2S, and a weaker band at the expected size of Per2 (~140 kDa). The antibody raised against PER2 pS662 (abS662), an epitope absent in PER2S, detected only the higher band. Immunolocalization studies with abRc revealed a peculiar nucleolar signal colocalizing with the nucleolar marker nucleophosmin, whereas with abS662 the signal was predominantly diffuse all over the nucleus and partially colocalized with abRc in the nucleolus. The analysis of cell fractions by WB confirmed the enrichment of PER2S and the presence of PER2 in the nucleolar compartment. Finally, a pulse (1 h) of actinomycin D (0.01 μg/ml) induced reversible nucleolar disruption, PER2S de-localization and circadian synchronization of clock and Per2S genes. Our work represents the first evidence that the Per2S splicing isoform is a clock component expressed in human cells localizing in the nucleolus. These results suggest a critical role for the nucleolus in the process of circadian synchronization in human keratinocytes.     

抑郁症发生与氧化应激关系研究进展

就近年来关于抑郁痘发生与线粒体功能,一氧化氮、丙二醛和炎性介质水平,环氧化酶、超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶表迭和活性的关系作一综述介绍。     

Influence of social experience on sexual readiness of male house crickets,Acheta domestica

Summary MaleAcheta domestica were deprived of social experience at three different life stages and mated as 2-or 3-day adults. Those deprived from the egg stage were found to copulate morereadily than males which had social experience.The data were taken from a thesis submitted in partial fulfillment of the requirements for the Ph. D. degree at the City University of New York.     

Superoxide dismutase 1 is positively selected to minimize protein aggregation in great apes

Positive (adaptive) selection has recently been implied in human superoxide dismutase 1 (SOD1), a highly abundant antioxidant protein with energy signaling and antiaging functions, one of very few examples of direct selection on a human protein product (exon); the molecular drivers of this selection are unknown. We mapped 30 extant SOD1 sequences to the recently established mammalian species tree and inferred ancestors, key substitutions, and signatures of selection during the protein’s evolution. We detected elevated substitution rates leading to great apes (Hominidae) at ~1 per 2 million years, significantly higher than in other primates and rodents, although these paradoxically generally evolve much faster. The high evolutionary rate was partly due to relaxation of some selection pressures and partly to distinct positive selection of SOD1 in great apes. We then show that higher stability and net charge and changes at the dimer interface were selectively introduced upon separation from old world monkeys and lesser apes (gibbons). Consequently, human, chimpanzee and gorilla SOD1s have a net charge of ?6 at physiological pH, whereas the closely related gibbons and macaques have ?3. These features consistently point towards selection against the malicious aggregation effects of elevated SOD1 levels in long-living great apes. The findings mirror the impact of human SOD1 mutations that reduce net charge and/or stability and cause ALS, a motor neuron disease characterized by oxidative stress and SOD1 aggregates and triggered by aging. Our study thus marks an example of direct selection for a particular chemical phenotype (high net charge and stability) in a single human protein with possible implications for the evolution of aging.     

Glutathione peroxidase, superoxide dismutase and catalase in the red blood cells of GSH-normal and GSH-deficient sheep

Levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase were measured in the red blood cells of glutathione(GSH)-normal and GSH-deficient sheep. There were no significant differences in any of the 3 enzyme activities measured in the 2 groups of sheep. Also, there was no relationship between GSH level and the enzyme activity. These results suggest that inspite of large differences in GSH levels, the red blood cells from GSH-normal and GSH-deficient Merino sheep appear to have similar response to oxidative stress against which GSH is credited to play a major role.     

Sonic hedgehog signaling pathway in vertebrate epithelial appendage morphogenesis: perspectives in development and evolution

Vertebrate epithelial appendages are elaborate topological transformations of flat epithelia into complex organs that either protrude out of external (integument) and internal (oral cavity, gut) epithelia, or invaginate into the surrounding mesenchyme. Although they have specific structures and diverse functions, most epithelial appendages share similar developmental stages, including induction, morphogenesis, differentiation and cycling. The roles of the SHH pathway are analyzed in exemplary organs including feather, hair, tooth, tongue papilla, lung and foregut. SHH is not essential for induction and differentiation, but is involved heavily in morphogenetic processes including cell proliferation (size regulation), branching morphogenesis, mesenchymal condensation, fate determination (segmentation), polarizing activities and so on. Through differential activation of these processes by SHH in a spatiotemporal-specific fashion, organs of different shape and size are laid down. During evolution, new links of developmental pathways may occur and novel forms of epithelial appendages may emerge, upon which evolutionary selections can act. Sites of major variations have progressed from the body plan to the limb plan to the epithelial appendage plan. With its powerful morphogenetic activities, the SHH pathway would likely continue to play a major role in the evolution of novel epithelial appendages.     

Level of marker enzymes in spermatogenesis on administration of PGF2 alpha in rats.

Intraperitoneal administration of PGF 2 alpha in rats significantly increased testicular acid phosphatase (p less than 0.05), decreased hyaluronidase (p less than 0.05), whereas the activities of 5'-nucleotidase, N-acetyl-B-glucosaminidase, B-galactosidase and uridine diphosphatase remained unaffected.     

MPTP慢性帕金森病小鼠海马内氧化应激与细胞凋亡蛋白的表达

目的 观察 MPTP慢性帕金森病小鼠海马氧化应激指标及细胞凋亡相关蛋白的表达.方法 应用MPTP制备慢性帕金森病模型,观察行为学改变,Morris水迷宫实验,检测模型组和对照组小鼠海马内超氧化物歧化酶（SOD）、还原型谷胱甘肽（GSH）及丙二醛（MDA）舍量变化,以及免疫组织化学方法、RT-PCR方法、Western blot方法检测海马Bax和Bel-2蛋白表达.结果 慢性帕金森病模型小鼠行为学特点为震颤、活动减少;水迷宫实验结果提示认知功能降低;与对照组海马比较：模型组海马SOD、GSH含量均下降,而MDA含量升高（P〈0.05）;模型组海马Bax蛋白表达增高,而Bel-2蛋白表达下降（P〈0.05）.结论 氧化应激在慢性帕全森病认知功能障碍发病机制中起重要作用,而Bax和Bcl-2蛋白参与了氧化应激诱导海马神经元凋亡的调控过程.     

Oenocytes of poultry liceLipeurus lawrensis tropicalis Peters (Phthiraptera: Ischnocera)

Summary Oenocytes ofLipeurus lawrensis tropicalis Peters, an ischnoceran Mallophaga (Sens. Lat. Phthiraptera) occur either singly or in clusters of 2–6, and do not exhibit any changes in the different stages of nymphs and adults of the 2 sexes.Acknowledgment. Thanks are due to Head of the Zoology Department Banaras Hindu University, for laboratory facilities and to State Council of Science and Technology, U.P. for financial assistance under the grant No.SCST/4779/BHU (43)/77     

Oviposition rhythm of individualDrosophila melanogaster

Summary Individually-housedDrosophila melanogaster show a gradual bimodal rise in egg production with a major crest shortly after dusk. The crest drifts toward noon after 2 to 3 days. The rhythm is hourglass.I thank L. Cutkomp for the use of his facilities and material help during the initial stages of this study.     

Insecticidal effects of essential oils. A study of the effects of essential oils extracted from eleven Greek aromatic plants on Drosophila auraria.

Effects of the essential oils (EOs) extracted from eleven aromatic plants belonging to the Lamiaceae family (common in the Greek flora) were examined upon three different developmental stages of Drosophila auraria. All of the EOs examined exhibited insecticidal effects, either by preventing egg hatching, or by causing the death of larvae and adult flies. In several cases, malformation and/or prohibition of puparium formation was also observed.     

Über die Aktivitätssteigerung mikrobieller Neuraminidasen bei niedrigen Wasserstoffperoxid-Konzentrationen

Summary The activity of bacterial neuraminidases can be influenced by H₂O₂ secreted by some organisms. Thus, at low H₂O₂ concentrations (0.002–0.01%), an increase of neuraminidase activities was observed, whereas at concentrations 0.1% the enzyme activities were destroyed.     

Insecticidal effects of essential oils. A study of the effects of essential oils extracted from eleven Greek aromatic plants onDrosophila auraria

Effects of the essential oils (EOs) extracted from eleven aromatic plants belonging to the Lamiaceae family (common in the Greek flora) were examined upon three different developmental stages ofDrosophila auraria. All of the EOs examined exhibited insecticidal effects, either by preventing egg hatching, or by causing the death of larvae and adult flies. In several cases, malformation and/or prohibition of puparium formation was also observed.     

Possible relationship between packed sperm volume and egg mass in domestic fowl

Summary Packed sperm volume (PSV) values of male chickens have been observed to parallel the daily egg mass values of laying hens. Selection progress was greater when selection was for PSV and egg mass than for egg mass alone.     

Short cerebral ischemia and subsequent reperfusion and treatment with stobadine.

Lipid peroxidation and activities of antioxidative enzymes were studied in the brain cortex after short (15 min) cerebral ischemia and reperfusion (10 min) in rats. Conjugated dienes (CD) and thiobarbituric acid-reactive substances (TBARS) were significantly elevated in the group of rats with ischemia followed by reperfusion in comparison to the ischemic animals. Superoxide dismutase (SOD) activity significantly increased in the group of animals with ischemia and reperfusion. No significant changes in the activities of glutathione peroxidase (GP) were observed. Stobadine administered before ischemia or before reperfusion decreased the level of TBARS. Stobadine probably prevents malondialdehyde (MDA) formation from hydroperoxide or might elevate the activity of aldehyde dehydrogenase. In contradiction to the findings after long-lasting (4 h) ischemia and subsequent reperfusion, no decrease in the concentration of CD or in the activity of SOD or GP was found.     

Fitness traits associated with the red back phenotype in the migratory grasshopper,Melanoplus sanguinipes

Summary The dominantly inherited variant, red back, in the migratory grasshopper,Melanoplus sanguinipes, is rare in nature. The present study illustrates that is this probably due, in part, to the trait's association (either through pleiotropy of the red back gene,Pro and/or closely linked fitness loci) with lower egg hatchability, greater developmental time, greater mortality during later stages, and a greater tendency to have an extra instar.A part of an M.Sc. thesis of F. R. H. Hodson, University of Regina (1985).Financial assistance from the Natural Sciences and Engineering Research Council (A0485) is greatfully acknowledged. Address reprint requests to W.C.     

Effect of starvation and refeeding on catalase and superoxide dismutase activities in skeletal and cardiac muscles from 12-month-old rats

Summary Catalase and superoxide dismutase (SOD) activities were determined in muscles from 12-month-old rats after severe starvation and after subsequent refeeding. Catalase increased in most muscles after starvation and decreased after refeeding, while SOD remained unchanged.This research was supported by the Science and Education Administration of the U.S. Department of Agriculture under grant No. 5901-0410-8-0014-0 from the Competitive Grants Office. We thank Dr Craig Frisk for advice in the care of the animals.Scientific Journal Series No. 11, 191, Minnesota Agricultural Experiment Station.     

Differential lethality following treatment with ionizing radiations of various energies in Drosophila

Male and female gametes of Drosophila were treated with various doses of ionizing radiations: X-rays at different energy, and gamma-rays from 2 sources given singly and in 2 temporal sequences. The induced lethality was assessed in successive developmental stages by scoring the number of eggs, larvae and adults. The results clearly show that the effects of various radiations appear in terms of difference among developmental stages and/or between treated sexes/genotypes. It is suggested that the various energies affect different gene functions which are not completely independent, as supported by the non-additive effects of the two temporal sequences.     

Level of marker enzymes in spermatogenesis on administration of PGF2a in rats

Summary Intrapertioneal administration of PGF_2a in rats significantly increased testicular acid phosphatase (p<0.05), decreased hyaluronidase (p<0.05), whereas the activities of 5-nucleotidase, N-acetyl-B-glucosaminidase, B-galactosidase and uridine diphosphatase remained unaffected.Acknowledgment. We are grateful to Dr D. Sundaresan, for his interest in the study and to Mr B. M. Sharma for technical assistance.