羟基脲(Hydroxyurea)对细胞周期与珠蛋白基因表达的影响(简报)

已有许多证据表明羟基脲能增加镰状细胞贫血及β-地贫病人的胎儿型血红蛋白(HbF)的合成。最近,有人报道羟基脲也能使一些患有β-地贫病人的β-珠蛋白基因表达增加。K562细胞是人红白血病细胞株,它只能表达胚胎型(ε-)与胎儿型(γ-)珠蛋白基因,而不能表达成年型(β-)珠蛋白基因。因此,K562     

自发性高血压大鼠中枢血管紧张素Ⅱ的变化对中枢肾上腺素和去甲肾上腺素含量的影响

自发性高血压大鼠中枢肾上腺能递质含量异常,然其原因仍不清楚。本工作发现:12周龄易卒中型自发性高血压大鼠(SHRSP)脑桥,下丘脑后部、尾核中去甲肾上腺素(NE)含量及延髓、下丘脑前部,下丘脑后部中肾上腺素(E)含量均高于同龄 Wista Kyoto 大鼠(WKY),SHRSP 中枢 AⅡ含量亦明显高于同龄 WKY;向8周龄 SHRSP 和 WKY 侧脑室慢性灌注巯甲丙脯氨酸,不仅降低动脉血压及各脑区AⅡ含量,亦使中枢 NE 及 E 水平下降,但巯甲丙脯氨酸对 SHRSP 的影响远较对 WKY 明显。结果提示:SHRSP 中枢肾上腺能递质含量增加可能与 SHRSP 中枢 AⅡ量含量升高以及 SHRSP 中枢 AⅡ对中枢肾上腺能递质的促释放调节机制明显易化有关。     

Conditional QTL mapping of protein content in wheat with respect to grain yield and its components

Grain protein content in wheat (Triticum aestivum L.) is generally considered a highly heritable character that is negatively correlated with grain yield and yield-related traits. Quantitative trait loci (QTL) for protein content was mapped using data on protein content and protein content conditioned on the putatively interrelated traits to evaluate possible genetic interrelationships between protein content and yield, as well as yield-related traits. Phenotypic data were evaluated in a recombinant inbred line population with 302 lines derived from a cross between the Chinese cultivar Weimai 8 and Luohan 2. Inclusive composite interval mapping using IciMapping 3.0 was employed for mapping unconditional and conditional QTL with additives. A strong genetic relationship was found between protein content and grain yield, and yield-related traits. Unconditional QTL mapping analysis detected seven additive QTL for protein content, with additive effects ranging in absolute size from 0.1898% to 0.3407% protein content, jointly accounting for 43.45% of the trait variance. Conditional QTL mapping analysis indicated two QTL independent from yield, which can be used in marker-assisted selection for increasing yield without affecting grain protein content. Three additional QTL with minor effects were identified in the conditional mapping. Of the three QTLs, two were identified when protein content was conditioned on yield, which had pleiotropic effects on those two traits. Conditional QTL mapping can be used to dissect the genetic interrelationship between two traits at the individual QTL level for closely correlated traits. Further, conditional QTL mapping can reveal additional QTL with minor effects that are undetectable in unconditional mapping.     

中国元三甲螨属六新纪录种(甲螨亚目,元三甲螨科)

记述中国元三甲螨属6新纪录种:双元三甲螨Oribotritia anceps NiedbaΙa,2000、狭元三甲螨Oribotritia angusta Mahunka,1982、亚洲元三甲螨Oribotritia asiatica Hammer,1977、父岛元三甲螨Oribotritia chichijimensis Aoki,1980、大元三甲螨Oribotritia gigas Bayoumiet Mahunka,1979、尼泊尔元三甲螨Oribotritia nepalensis NiedbaΙa,2000,并给出了6新纪录种的特征图。研究标本除注明保存在波兰亚当密茨凯维奇大学动物分类与生态学系(DATE)外,其余均保存在中国科学院动物研究所国家动物博物馆。     

新生大鼠大脑皮层神经元胞体ATP激活的离子通道及其特性

用膜片箝技术的细胞贴附式和内面向外式,在机械分离的新生ＳＤ大鼠的大脑皮层神经元上,记录到ＡＴＰ激活的离子通道。此通道的电导为３２ｐＳ,对Ｎａ~＋,Ｋ~＋和Ｃｓ~＋无选择性通透,而对Ｃｌ~－不通透。通道开放时间分布直方图多数需用双指数拟合,少数可用单指数拟合;通道关闭时间分布直方图均需用双指数拟合。通道的平均开放时间和开放概率均不依赖于膜电位;但通道的开放概率随着激动剂ＡＴＰ浓度的增加而增大。当电极内液无ＡＴＰ时,无通道电流。六烃季胶和美加明不能阻断此通道。上述结果表明,新生大鼠的大脑皮层神经元胞体可能存在ＡＴＰ激活的离子通道。     

A diverse metaphyte assemblage from the Neoproterozoic black shales of South China

A fossil assemblage of diverse megascopic benthic algae is well preserved on bedding planes in black siliceous shales of the Neoproterozoic Lantian Formation (upper Sinian) at Lantian village, Xiunng county, Anhui Province, South China. Based on morphological differences, 12 taxa are recognized. Most specimens show both a holdfast and a vegetative thallus, some with dichotomous branching, which reveals that they are multicellular benthic algae. Each type presents a certain morphological appearance, e.g., spheroidal - Chuaria sp., filamentous - Doushantuophyton rigidulum , fan-like - Flabellophyton lantianensis. Four to six different benthic forms and more than 15 individuals are well preserved on the same bed with an area less than 150 cm². These confirm that a great morphological evolutionary radiation of seaweeds took place no later than the Lantian epoch, with an absolute age around 570 Ma. Growth cycles in Flabellophyton strigata n.sp. reveal that periodical events, such as seasonal variations, occurred in that epoch. A benthic assemblage consisting of three differentiated macroscopic remains is similar to the Miaohe Biota reported from the Doushantuo Formation of the Yangtze Gorges 1200 km away, allowing biostratigraphic correlation of both of these Neoproterozoic Formations.     

Merging Maddenia with the morphologically diverse Prunus (Rosaceae)

Maddenia (Rosaceae) has been distinguished from Prunus on the basis of its tepaloid perianth and one‐ to two‐carpellate gynoecium. These distinctive morphological traits nonetheless overlap with several Prunus spp. Maddenia has previously been shown to be nested within Prunus, more specifically within a clade containing members of subgenera Laurocerasus and Padus, but its phylogenetic position within that clade has not been defined precisely. This study clarifies the position of Maddenia within Prunus through phylogenetic analyses of nuclear ribosomal internal transcribed spacer (ITS) and plastid ndhF sequences, with an expanded sampling of tropical species of subgenus Laurocerasus and the inclusion of three Maddenia spp. The monophyly of Maddenia is supported by both the ITS and ndhF analyses, but both datasets support the inclusion of Maddenia in Prunus. All trees from the ITS analysis and some trees from the ndhF analysis also support a close alliance of Maddenia with a clade comprising temperate species of subgenera Laurocerasus and Padus. On the basis of these results, all recognized species of Maddenia are herein formally transferred to Prunus, which requires four new combinations and one new name: Prunus fujianensis (Y.T.Chang) J.Wen, comb. nov. ; Prunus himalayana J.Wen, nom. nov. ; Prunus hypoleuca (Koehne) J.Wen, comb. nov. ; Prunus hypoxantha (Koehne) J.Wen, comb. nov. ; and Prunus incisoserrata (T.T.Yü & T.C.Ku) J.Wen, comb. nov. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 236–245.     

Systematic placement and biogeographical relationships of the monotypic genera Gypothamnium and Oxyphyllum (Asteraceae: Mutisioideae) from the Atacama Desert

Gypothamnium and Oxyphyllum (Asteraceae) are two monotypic genera endemic to the Atacama Desert of northern Chile. We performed a phylogenetic analysis using published sequences of the plastid rbcL and ndhF genes, the trnL‐trnF region and the nuclear ribosomal internal transcribed spacer (ITS) to assess the systematic placement of the two genera within Mutisioideae. On the basis of the phylogenetic results, we constructed area cladograms to explore the biogeographical relationships and origin of the genera. The phylogenetic analysis showed that Gypothamnium is closely related to Aphylloclados, Plazia, Urmenetia, Lycoseris and Onoseris, whereas Oxyphyllum is closely related to Leucheria, Moscharia, Polyachyrus and, with low support, Jungia. These results do not differ substantially from those proposed in previous treatments based on morphological characters. The biogeographical analysis suggests that Gypothamnium in the coastal Atacama Desert is related to taxa that are currently distributed in eastern subtropical South America and in the Puna. Oxyphyllum may have originated from central Chile and other areas in southern South America, but its sister group (Leucheria + Polyachyrus) also reaches the Puna and the coastal Atacama Desert. Both groups show ancestral affinities with elements currently distributed in north‐western South America and Mesoamerica. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 32–51.     

Evolutionary process of a tetranucleotide microsatellite locus in Acipenseriformes

The evolutionary dynamics of the tetra-nucleotide microsatellite locus Spl-106 were investigated at the repeat and flanking sequences in 137 individuals of 15 Acipenseriform species, giving 93 homologous sequences, which were detected in 11 out of 15 species. Twenty-three haplotypes of flanking sequences and three distinct types of repeats, type I, type II and type III, were found within these 93 sequences. The MS-Align phylogenetic method, newly applied to microsatellite sequences, permitted us to understand the repeat and flanking sequence evolution of Spl-106 locus. The flanking region of locus Spl-106 was highly conserved among the species of genera Acipenser, Huso and Scaphirhynchus, which diverged about 150 million years ago (Mya). The rate of flanking sequence divergence at the microsatellite locus Spl-106 in sturgeons is between 0.011% and 0.079% with an average at 0.028% per million years. Sequence alignment and phylogenetic trees produced by MS-Align showed that both the flanking and repeat regions can cluster the alleles of different species into Pacific and Atlantic lineages. Our results show a synchronous evolutionary pattern between the flanking and repeat regions. Moreover, the coexistence of different repeat types in the same species, even in the same individual, is probably due to two duplication events encompassing the locus Spl-106 that occurred during the divergence of Pacific lineage. The first occured before the diversification of Pacific species (121–96 Mya) and led to repeat types I and II. The second occurred more recently, just before the speciation of A. sinensis and A. dabryanus (69–10 Mya), and led to repeat type III. Sequences in the same species with different repeat types probably corresponds to paralogous loci. This study sheds a new light on the evolutionary mechanisms that shape the complex microsatellite loci involving different repeat types.