Auxin-related gene families in abiotic stress response in Sorghum bicolor

Sorghum, a C4 model plant, has been studied to develop an understanding of the molecular mechanism of resistance to stress. The auxin-response genes, auxin/indole-3-acetic acid (Aux/IAA), auxin-response factor (ARF), Gretchen Hagen3 (GH3), small auxin-up RNAs, and lateral organ boundaries (LBD), are involved in growth/development and stress/defense responses in Arabidopsis and rice, but they have not been studied in sorghum. In the present paper, the chromosome distribution, gene duplication, promoters, intron/exon, and phylogenic relationships of Aux/IAA, ARF, GH3, and LBD genes in sorghum are presented. Furthermore, real-time PCR analysis demonstrated these genes are differently expressed in leaf/root of sorghum and indicated the expression profile of these gene families under IAA, brassinosteroid (BR), salt, and drought treatments. The SbGH3 and SbLBD genes, expressed in low level under natural condition, were highly induced by salt and drought stress consistent with their products being involved in both abiotic stresses. Three genes, SbIAA1, SbGH3-13, and SbLBD32, were highly induced under all the four treatments, IAA, BR, salt, and drought. The analysis provided new evidence for role of auxin in stress response, implied there are cross talk between auxin, BR and abiotic stress signaling pathways.     

Construction of a dense comparative map between human chromosome 1p36-->p35 and swine chromosome 6 by using human sequence-tagged sites

Construction of a comprehensive comparative map between swine and human chromosomes is a prerequisite, in order to select candidate swine genes for traits from the human genome database as well as to understand the evolutionary process of the two species. The present study attempted to use 910 sequence-tagged sites (STSs) localized in human chromosome (HSA) 1p36-->p35 (35 Mbp) for radiation hybrid (RH) mapping to swine chromosomes (SSCs). Out of the 910 STSs subjected to amplification of swine orthologues, primer pairs for 13 STSs were found to amplify the respective orthologues and the STSs were assigned to SSCs. Eleven STSs were assigned to SSC6 in the same order as that in HSA1: SSC6cen-(SHGC-150)-(A006H31)-(X82877)-(A007E03)-(IB404)-(stGDB:371372)-(stSG31658)-(A009Q18)-(stSG14201/A009C01)-(H08335)-qter. One of the remaining two STSs, WI-20819, was assigned to SSCX, and the other, R91D18R, was not linked to any first-generation markers of the IMpRH map with a lod score greater than 3.     

Soluble expression, purification and functional identification of a disulfide-rich conotoxin derived from Conus litteratus

Conotoxins are a diverse array of small peptides mostly with multiple disulfide bridges. These peptides become an increasing significant source of neuro-pharmacological probes and drugs as a result of the high selectivity for ion channels and receptors. Usually, the analogue of natural conotoxins is produced by means of chemical synthesis. Here, we present a simple and fast strategy of producing disulfide-rich conotoxins via recombinant expression. By fused with thioredoxin and His tag, a novel O-superfamily conotoxin lt7a was successfully expressed in Escherichia coli and purified, resulting in a high yield of recombinant lt7a about 6 mg/l. The purity of target protein is up to 95% as identified by HPLC results. Whole cell patch-clamp recording revealed that the new conotoxin blocked voltage-sensitive sodium channels in rat dorsal root ganglion neurons, indicating it might be a novel microO-conotoxin.     

基于ITS序列分析探讨杜鹃属映山红亚属的组间关系

以叶状苞亚属的叶状苞杜鹃为外类群,以杜鹃属映山红亚属（subg.Tsutsusi)2组12种杜鹃和羊踯躅亚属（subg.Pentanthera）3种4种杜鹃的ITS区（包括5.8S rDNA)的序列了系统学分析。3个亚属的ITS区序长度范围为642－645bp。排序后ITS区的序列长度为653个位点,gap做缺失处理时,变异位点和信息位点分别占6．58％和3．68％。运用PAUP4．0软件分析,获得15个最简树,步长为75,一致性指数（CI）和维持性指数（RI）值分别为0．9333和0．9515,利用15个最简约树获取严格一致树,结果表明：1）映山红亚属为一单系类群,其内部支持率为81％;2）不支持将R.ashiroi独立成假映山红组,也不支持将R.tashiroi并入映山红组,而支持将R.tashiroi并入轮生叶组中的观点;3）支持将R.tsusiophyllum并入映山红组中的观点;4）大字杜鹃的系统位置还需进一步的研究。     

Leucine-rich repeat C4 protein is involved in nervous tissue development and neurite outgrowth, and induction of glioma cell differentiation

LRRC4, leucine-rich repeat C4 protein, has been identified in human （GenBank accession No. AF196976）, mouse （GenBank accession No. DQ177325）, rat （GenBank accession No. DQ119102） and bovine （GenBank accession No. DQ 164537） with identical domains. In terms of their similarity, the genes encoding LRRC4 in these four mammalian species are orthogs and therefore correspond to the same gene entity. Based on previous research, and using in situ hybridization, we found that LRRC4 had the strongest expression in hippocampal CA1 and CA2, the granule cells of the dentate gyrus region, the mediodoral thalamic nucleus, and cerebella Purkinje cell layers. Using a P19 cell model, we also found that LRRC4 participates in the differentiation of neuron and glia cells. In addition, extracellular proteins containing both an LRR cassette and immunoglobulin domains have been shown to participate in axon guidance. Our data from neurite outgrowth assays indicated that LRRC4 promoted neurite extension of hippocampal neurons, and induced differentiation of glioblastoma U251 cells into astrocyte-like cells, confirmed by morphology observation and glial fibrillary acidic protein expression.     

鹿衔草化学成分的研究：羟基肾叶鹿蹄草甙的结构鉴定

从鹿衔草（Ｐｙｒｏｌａ ｃａｌｌｉａｎｔｈａ Ｈ．Ａｎｄｒｅｓ）分离得到两个化合物。经光谱分析,确定其中１个化合物为新化合物,命名为羟基肾叶鹿蹄草甙（１, ｈｙｄｒｏｘｙｌｒｅｎｉｆｏｌｉｎ）,另一化合物为儿茶素（３）。     

TLR4 signaling-induced heme oxygenase upregulation in the acute lung injury: role in hemorrhagic shock and two-hit induced lung inflammation

Resuscitated hemorrhagic shock is believed to promote the development of acute lung injury (ALI) by priming the immune system for an exaggerated inflammatory response to a second trivial stimulus. This work explored effects of TLR4 on hemorrhage-induced ALI and “second-hit” responses, and further explore the mechanisms involved in “second-hit” responses. Expression of HO-1, IL-10, lung W/D and MPO markedly increased at nearly all time-points examined in HSR/LPS group as compared with sham/LPS group in WT mice. In HSR/LPS mice, the induced amount of IL-10 and the expressions of HO-1 of WT mice were significantly higher compared with TLR-4d/d. This study provides in vivo evidence that pulmonary infections after LPS instillation contribute to local tissue release of pro-inflammatory mediators after HSR systemic. Activation of TLR4 might induce HO-1 expression and HO-1 modulates proinflammatory responses that are triggered via TLR4 signaling.     

武汉东湖浮游病毒的丰度及多样性

运用透射电镜及荧光显微技术 ,对富营养化的武汉东湖中浮游病毒丰度及多样性进行了研究。电镜观察和计数结果显示 ,东湖中浮游病毒的丰度达到 10 8个 /mL。荧光显微镜计数结果约是电镜计数结果的 2 72倍 ,差异极显著 (P <0 0 1)。在东湖超富营养区的水样中观察到了多种与各种病毒形态类似的颗粒 ,其中大部分与噬菌体和噬藻体类似 ,具多种形态的尾部和六边形头部。还有一些线状、杆状、子弹形等形态的病毒粒子。研究结果显示东湖水环境中的浮游病毒不仅丰度极高 ,而且种类丰富。提示浮游病毒在东湖水环境和水生态系统中可能扮演重要角色。