TRPC1 protects dopaminergic SH-SY5Y cells from MPP＋, salsolinol,and N-methyl-（R）-salsolinol-induced cytotoxicity

Neurotoxins and alterations in Ca2＋ homeostasis have been associated with Parkinson＇s disease （PD）, but the role of store-operated Ca2＋ entry channels is not well understood. Previous studies have shown the neurotoxicity of salsolinol and 1-methyl-4-phenylpyridinium ion on SH-SY5Y cells and cytoprotection induced by transient receptor potential protein 1 （TRPC1）. In the present study, N-methyl-（R）-salsolinol was tested for its cellular toxicity and effects on TRPC1 expression. MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-dipbenyl- tetrazolium bromide） assays, DAPI （4＇,6-diamidino-2-pheny- lindole）, fluorescein isothiocyanate-Annexin-V/propidium iodide, western blot analysis, and JC-1 labeling revealed that the three indicated drugs could induce caspase-dependent, mitochondrial-mediated apoptosis. Exposure of SH-SY5Y cells to the indicated drugs resulted in a significant decrease in thapsigargin-mediated Ca2＋ influx and TRPC1 expression. Immnnocytochemistry experiments revealed that neurotoxins treatment induced TRPC1 translocation to the cytoplasm. Taken together, our results indicate that treatment with neurotoxins may alter Ca2＋ homeostasis and induce mitochondrial-mediated caspase-dependent cytotoxicity, an important characteristic of PD.     

Characterization of a Small Family (CAIII) of Microsatellite-Containing Sequences with X-Y Homology

Four X-linked loci showing homology with a previously described Y-linked polymorphic locus (DYS413) were identified and characterized. By fluorescent in situ hybridization (FISH), somatic cell hybrids, and YAC screening, the X-linked members of this small family of sequences (CAIII) all map in Xp22, while the Y members map in Yq11. These loci contribute to the overall similarity of the two genomic regions. All of the CAIII loci contain an internal microsatellite of the (CA)_n type. The microsatellites display extensive length polymorphism in two of the X-linked members as well as in the Y members. In addition, common sequence variants are found in the portions flanking the microsatellites in two of the X-linked members. Our results indicate that, during the evolution of this family, length variation on the Y chromosome was accumulated at a rate not slower than that on the X chromosome. Finally, these sequences represent a model system with which to analyze human populations for similar X- and Y-linked polymorphisms. Received: 29 July 1996 / Accepted: 15 January 1997     

球针壳属一新种和一新组合

本文报道了球针壳属(Phyllactinia)的一个新种和一个新组合,即寄生于杜鹃花科(Ericaceae)吊钟花属(ENkianthus)灯笼花(E.chinensis Franch)上的灯笼花球针壳(Phyllactiniaenkianthi z.y. zhao sp. nov.)和寄生于茶藨子科(Grossulariaceae)茶藨子(Ribes sp.)上的茶藨子球针壳(Phyllactinia ribesii(Jacz.)z. y. zhao comb. nov.)。上述新分类单位均有汉文和拉丁文描述,新分类单位与近似种有汉文讨论。     

The projections of chemically identified nerve fibres in canine ileum

Summary The projections of nerve fibres with immunoreactivity for the peptides enkephalin (ENK), gastrin-releasing peptide (GRP), neuropeptide Y (NPY), somatostatin (SOM), substance P (SP) and vasoactive intestinal peptide (VIP) were studied in canine small intestine by analysing the consequences of lesions of intrinsic and extrinsic nerves. Of peptides present in fibres supplying myenteric ganglia, GRP, SOM and VIP were in anally directed nerve pathways, whereas ENK and NPY were in orally directed pathways. Pathways ran for up to about 30 mm. SP fibres ran for short distances in both directions in the myenteric plexus. The circular muscle was supplied with ENK, NPY, SP and VIP fibres arising from the myenteric ganglia, whereas most mucosal SP and VIP fibres were deduced to arise from submucous ganglia. There were projections of fibres reactive for ENK, GRP, SOM, SP and VIP from myenteric ganglia to submucous ganglia. Antibodies to tyrosine hydroxylase were used to locate noradrenaline nerve fibres supplying the intestine; these fibres all disappeared when extrinsic nerves running through the mesentery to the small intestine were cut. It is deduced that there is an ordered pattern of projections of peptide-containing fibres in the canine intestine.     

The origin and evolution of vertebrate sex chromosomes and dosage compensation

In mammals, birds, snakes and many lizards and fish, sex is determined genetically (either male XY heterogamy or female ZW heterogamy), whereas in alligators, and in many reptiles and turtles, the temperature at which eggs are incubated determines sex. Evidently, different sex-determining systems (and sex chromosome pairs) have evolved independently in different vertebrate lineages. Homology shared by Xs and Ys (and Zs and Ws) within species demonstrates that differentiated sex chromosomes were once homologous, and that the sex-specific non-recombining Y (or W) was progressively degraded. Consequently, genes are left in single copy in the heterogametic sex, which results in an imbalance of the dosage of genes on the sex chromosomes between the sexes, and also relative to the autosomes. Dosage compensation has evolved in diverse species to compensate for these dose differences, with the stringency of compensation apparently differing greatly between lineages, perhaps reflecting the concentration of genes on the original autosome pair that required dosage compensation. We discuss the organization and evolution of amniote sex chromosomes, and hypothesize that dosage insensitivity might predispose an autosome to evolving function as a sex chromosome.     

Influence of encapsulation on the survival of probiotics in food matrix under simulated stress conditions

The main objective of the present study was to evaluate the influence of encapsulation by extrusion technique using two hydrogels, namely; sodium alginate (Na-ALG) and whey protein isolate (WPI) on Bifidobacterium bifidium viability and stability of yoghurt under simulated gastrointestinal conditions. Probiotic bacteria (free or encapsulated) were added to yogurt for four weeks to test their viability and stability. Physicochemical and sensory analysis of yoghurt were conducted. Viability of B. bifidium in the simulated gastrointestinal conditions pH 2 and pH 7.5 was determined. Also, the efficiency of encapsulated final yield of the microcapsules was determined. With storage time, the pH of yoghurt containing encapsulated bacteria increased more than that of yoghurt containing free probiotic bacteria, resulting in a decrease in acidity. When compared to yoghurt containing encapsulated bacteria, the lactose level of yoghurt containing free probiotic bacteria decreased over time. The viscosity of yoghurt containing encapsulated WPI remained stable over the storage period, with syneresis remaining stable. The sensory properties of yoghurt containing free probiotics deteriorated over time. Cell viability was significantly reduced in yoghurt-containing free probiotics compared to other treated yoghurts. Cell viability in free probiotics yoghurt was lower than in encapsulated ones when exposed to simulated gastric and intestinal juice. In conclusion, WPI- encapsulated probiotics showed better stability over 28 days of storage in both yoghurt and gastrointestinal conditions, followed by sodium alginate.     

Pulmonary neuroendocrine cells sense succinate to stimulate myoepithelial cell contraction

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Beyond Our Original Horizons: the Tropicalization of Beverton and Holt

The extension into tropical areas of Beverton and Holt's yield per recruit approach for stock assessment represents a straightforward case of normal science, the common Kuhnian counterpart to his much rarer paradigm shifts. It is shown that the normal science which, in recent decades, has led to new methods for estimating growth, mortality and other statistics required for yield per recruit analyses in data-sparse environments, has not only enriched fisheries science and aquatic biology as a whole, but has also contributed to identify the limitations of the single-species research programme originally defined by Beverton and Holt. The most likely prospect for that programme, in the tropics and elsewhere, is to become a component of the multispecies, or rather ecosystem approach that is emerging, and to which Beverton and Holt will have contributed many of the concepts, and much of the rigour.     

马铃薯Y病毒pipo基因的分子变异及结构特征分析

为揭示马铃薯Y病毒(Potato virus Y, PVY) pipo基因的分子变异和结构特征, 文章根据文献报道的马铃薯Y病毒属(Potyvirus) pipo 基因保守区序列设计一对简并引物, 从感染PVY的马铃薯病叶中克隆获得pipo基因的cDNA全长序列, 分析其核苷酸序列和氨基酸序列的特征, 并基于氨基酸序列使用贝叶斯法重建了Potyvirus的系统发育树。结果显示：20个PVY分离物成功扩增出预期大小(约235 bp)的特异性片段, 其核苷酸序列与已报道的其它PVY 株系的pipo基因核苷酸序列一致性均在92%以上; 5′端均含有典型的G1-2A6-7 基序(motif), 无碱基插入/缺失, 所有的核苷酸变异都是碱基置换, 共发现13个多态性位点, 其中4个简约信息位点, 9个单一变异位点, 表明该基因高度保守, 但不同分离物也存在一定的分子变异; PIPO蛋白理论等电点11.26~11.62, 无信号肽和跨膜区, 是可溶的亲水性蛋白; 整个蛋白含有3个保守区, 其中位于10~59aa的基序最为保守。该蛋白主要定位于线粒体中, 可能是线粒体导肽。系统发育分析结果显示, 源于PVY不同株系优先相聚成簇, 而向日葵褪绿斑驳病毒(Sunflower chlorotic mottle virus, SuCMoV)与辣椒重花叶病毒(Pepper severe mosaic virus, PepSMV)的亲缘关系较PVY相比更近, 与前人的结果相一致, 表明PIPO蛋白可以作为研究Potyvirus系统发育关系的新的分子标记。     

Y‐chromosome evidence supports widespread signatures of three‐species Canis hybridization in eastern North America

There has been considerable discussion on the origin of the red wolf and eastern wolf and their evolution independent of the gray wolf. We analyzed mitochondrial DNA (mtDNA) and a Y‐chromosome intron sequence in combination with Y‐chromosome microsatellites from wolves and coyotes within the range of extensive wolf–coyote hybridization, that is, eastern North America. The detection of divergent Y‐chromosome haplotypes in the historic range of the eastern wolf is concordant with earlier mtDNA findings, and the absence of these haplotypes in western coyotes supports the existence of the North American evolved eastern wolf (Canis lycaon). Having haplotypes observed exclusively in eastern North America as a result of insufficient sampling in the historic range of the coyote or that these lineages subsequently went extinct in western geographies is unlikely given that eastern‐specific mtDNA and Y‐chromosome haplotypes represent lineages divergent from those observed in extant western coyotes. By combining Y‐chromosome and mtDNA distributional patterns, we identified hybrid genomes of eastern wolf, coyote, gray wolf, and potentially dog origin in Canis populations of central and eastern North America. The natural contemporary eastern Canis populations represent an important example of widespread introgression resulting in hybrid genomes across the original C. lycaon range that appears to be facilitated by the eastern wolf acting as a conduit for hybridization. Applying conventional taxonomic nomenclature and species‐based conservation initiatives, particularly in human‐modified landscapes, may be counterproductive to the effective management of these hybrids and fails to consider their evolutionary potential.