南瓜雌蕊与自花及远缘花粉的相互作用

南瓜柱头表面经去垢剂、蛋白酶及Con A处理后花粉不能萌发或花粉管生长受阻,Con A能专一地与柱头表面结合。柱头块加入培养液可促进花粉萌发。不同的远缘花粉授粉后在雌蕊不同部位受阻。在成熟南瓜雌蕊提取液中检测到血凝活性,凝集素可能参与雌蕊对远缘花粉的抑制。     

Temporal changes in the migration phenology of turtle doves Streptopelia turtur in Britain, based on sightings from coastal bird observatories

Using daily counts of birds seen at six coastal bird observatories in southern and eastern England, we explored the migration phenology of turtle doves during the period 1963 to 2000. Annual totals increased threefold up to the late 1970s then decreased again, in accordance with the BTO Common Birds Census (CBC) index of abundance. Median annual spring arrival and autumn departure dates of turtle doves were not related to abundance (CBC index) or mean temperature in spring or summer respectively. Although median annual spring arrival date has not altered over the 38-year period, median annual autumn departure date has become earlier by 8 days. This has resulted in a shortening of the breeding season by 12 days, which ties in with a reduction in average number of nesting attempts per pair observed by a recent autecological study. It is possible that breeding turtle doves are now out of phase with peaks in food availability. This may have resulted in reduced breeding performance and earlier termination of the breeding season, and may have partly contributed to the decline of the species.     

球体蛛在我国首次发现及一新种记述（蜘蛛目：球体蛛科）

球体蛛在我国首次被发现,本文记述了产于我国海南的纳尔蛛属一新种,定名为华纳尔蛛Wendilgarda sinensis sp. nov.,模式标本保存在河北教育学院生物系。     

中国皿蛛科——新纪录属及天山前延首蛛的重描述（蜘蛛目：皿蛛科）

本文记述我国皿蛛科一新纪录属:前延首蛛届Archaraeoncus Tanasevitch 1987,并对天山前延首蛛A.tianshanicus(Hu et Wu,1989)n.comb.重新作了描述,本种的雌蛛系首次发现。本文还对Araeoncus tianschanica Hu et Wu 1989原学名命名的原始拚缀作了改正。文中测量数据均以mm为单位。     

中国皿蛛科蜘蛛一新属和一新种记述(蛛形纲:蜘蛛目)

本文记述采自新疆的皿蛛科蜘蛛一新届——颚齿蛛属Maxillodens gen.nov.及其一新种——鞭状颚齿蛛M.flageuatus sp.nov。     

Wlds-mediated protection of dopaminergic fibers in an animal model of Parkinson disease

Parkinson disease (PD) is characterized by the progressive degeneration of substantia nigra dopaminergic neurons projecting to the striatum. Since the deficit in striatal dopamine is the main cause of PD symptoms, it appears critical to preserve axon terminals. Significant axon protection from peripheral nerve Wallerian degeneration is observed in Wlds mice, a phenotype conferred by a spontaneous dominant mutation. To assess any Wlds-mediated rescue of dopamine fibers in a PD model, the nigrostriatal pathway of Wlds mice was lesioned with 6-hydroxydopamine (6-OHDA), a catecholaminergic neurotoxin. Following 6-OHDA injection in the medial forebrain bundle, Wlds mice showed remarkable dopamine fiber protection in the striatum. Drug-induced rotational behavior confirmed the nigrostriatal fiber ability to release dopamine, although revealing an abnormal neurotransmitter control presumably due to disrupted axonal transport. Following 6-OHDA injection in the midstriatum, only a protection trend was observed. Strikingly, no protection of Wlds nigral dopaminergic cell bodies was obtained following either nigrostriatal lesion. Besides showing subtle differences in the degeneration process between subcellular compartments, the reported Wlds-mediated protection of the dopamine axon terminals in an animal model of PD may lead to the understanding of mechanisms underlying axon loss and to the development of new therapeutic approaches.     

Comparative proteome analysis of Helicobacter pylori

Helicobacter pylori, the causative agent of gastritis, ulcer and stomach carcinoma, infects approximately half of the worlds population. After sequencing the complete genome of two strains, 26695 and J99, we have approached the demanding task of investigating the functional part of the genetic information containing macromolecules, the proteome. The proteins of three strains of H. pylori, 26695 and J99, and a prominent strain used in animal models SS1, were separated by a high-resolution two-dimensional electrophoresis technique with a resolution power of 5000 protein spots. Up to 1800 protein species were separated from H. pylori which had been cultivated for 5 days on agar plates. Using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) peptide mass fingerprinting we have identified 152 proteins, including nine known virulence factors and 28 antigens. The three strains investigated had only a few protein spots in common. We observe that proteins with an amino acid exchange resulting in a net change of only one charge are shifted in the two-dimensional electrophoresis (2-DE) pattern. The expression of 27 predicted conserved hypothetical open reading frames (ORFs) and six unknown ORFs were confirmed. The growth conditions of the bacteria were shown to have an effect on the presence of certain proteins. A preliminary immunoblotting study using human sera revealed that this approach is ideal for identifying proteins of diagnostic or therapeutic value. H. pylori 2-DE patterns with their identified protein species were added to the dynamic 2D-PAGE database (http://www.mpiib-berlin.mpg.de/2D-PAGE/). This basic knowledge of the proteome in the public domain will be an effective instrument for the identification of new virulence or pathogenic factors, and antigens of potentially diagnostic or curative value against H. pylori.     

Yeast sphingolipids do not need to contain very long chain fatty acids

Synthesis of VLCFAs (very long chain fatty acids) and biosynthesis of DHS (dihydrosphingosine) both are of vital importance for Saccharomyces cerevisiae. The bulk of VLCFAs and DHS are used for ceramide synthesis by the Lag1p (longevity-assurance gene 1)/Lac1p (longevity-assurance gene cognate 1)/Lip1p (Lag1p/Lac1p interacting protein) ceramide synthase. LAG1 and LAC1 are redundant but LIP1 is essential. Here we show that 4Delta (lag1Deltalac1Deltaypc1Deltaydc1Delta) cells devoid of all known endogenous ceramide synthesis pathways are unviable but can be rescued by the expression of Lass5, a mouse LAG1 homologue. Ceramide synthase activity of 4Delta.Lass5 cells only utilizes C16 and C18 fatty acids and does not require the help of Lip1p, an essential cofactor of Lag1p/Lac1p. HPLC-electrospray ionization-MS/MS analysis demonstrated that in IPCs (inositolphosphorylceramides) of 4Delta.Lass5, the very long chain fatty acids (C26 and C24) account for <1% instead of the normal >97%. Notwithstanding, IPCs incorporated into glycosylphosphatidylinositol anchors of 4Delta.Lass5 show normal mobility on TLC and the ceramide- and raft-dependent traffic of Gas1p (glycophospholipid-anchored surface protein) from endoplasmic reticulum to Golgi remains almost normal. Moreover, the biosynthesis of C24:0 fatty acids remains essential. Thus, C(24:0) and dihydrosphingosine are both necessary for survival of yeast cells even if they utilize C16 and C18 fatty acids for sphingolipid biosynthesis.