Exchange of Proton and Major Elements in Two-Layer Canopies Under Acid Rain in a Subtropical Evergreen Forest in Central-South China

Canopy exchanges of H^＋ and N （NH4^＋-N, NO3^--N） and other major ions were evaluated and quantified In twolayer canopies based on throughfall measurements in Shaoshan Forest during the period 2000-2002, central-south China, The collected annual rainfall, throughfall, and sub-throughfall were 1 401, 1 191, and 1 084 mm/year, respectively. Fifteen percent and 8% of rainfall （or 9% of throughfall） were intercepted by the top canopy and sub-canopy layers, respectively, The foliar leaching of base cations from the top canopy was significantly higher than that from the sub-canopy, and the latter accounted for 25% of the former. The uptake of H^＋ and NH4^＋ was significantly higher in the top canopy than in the sub-canopy, indicating that the canopy buffering capacity in the top canopy was stronger than the sub-canopy; Mg^2＋ can be absorbed from water flux on the sub-canopy foliar surfaces to compensate for the Mg deficit in the forest soil during the growing season,     

WNT10A Plays an Oncogenic Role in Renal Cell Carcinoma by Activating WNT/β-catenin Pathway

Renal cell carcinoma (RCC) is a malignancy with poor prognosis. WNT/β-catenin signaling dysregulation, especially β-catenin overactivation and WNT antagonist silencing, is associated with RCC carcinogenesis and progression. However, the role of WNT ligands in RCC has not yet been determined. We screened 19 WNT ligands from normal kidney and RCC cell lines and tissues and found that WNT10A was significantly increased in RCC cell lines and tissues as compared to that in normal controls. The clinical significance of increase in WNT10A was evaluated by performing an immunohistochemical association study in a 19-year follow-up cohort comprising 284 RCC and 267 benign renal disease (BRD) patients. The results of this study showed that WNT10A was dramatically upregulated in RCC tissues as compared to that in BRD tissues. This result suggests that WNT10A, nuclear β-catenin, and nuclear cyclin D1 act as independent risk factors for RCC carcinogenesis and progression, with accumulative risk effects. Molecular validation of cell line models with gain- or loss-of-function designs showed that forced WNT10A expression induced RCC cell proliferation and aggressiveness, including higher chemoresistance, cell migration, invasiveness, and cell transformation, due to the activation of β-catenin-dependent signaling. Conversely, WNT10A siRNA knockdown decreased cell proliferation and aggressiveness of RCC cells. In conclusion, we showed that WNT10A acts as an autocrine oncogene both in RCC carcinogenesis and progression by activating WNT/β-catenin signaling.     

UV-B辐射对窄叶野豌豆生长繁殖的影响

采用增补和滤除掉部分自然UV-B辐射的模拟试验,研究了增强和近环境UV-B辐射对高寒草甸一年生牧草窄叶野豌豆生长和繁殖的影响.结果表明:增补UV-B辐射处理后,窄叶野豌豆的株高、生物量、分配向果实的生物量、总花数和种子百粒重均显著下降,花期延迟,开花集中度和繁殖成功率有所提高,而种子产量无显著变化.相对于减弱UV-B辐射处理,近环境UV-B辐射使窄叶野豌豆的株高先降后升,分配向果实的生物量减少,花期、花数和种子产量无显著变化,种子百粒重减小.增强和近环境UV-B辐射对窄叶野豌豆的生长和繁殖有一定的抑制作用,且增强UV-B辐射的影响更大.     

枯草杆菌脂肪水解酶LipA和LipB

源自枯草杆菌的分泌型脂肪水解酶LipA及LipB已经被克隆、表达并表征. 它们的分子结构特点、催化机理也已经被深入研究. 枯草杆菌脂肪水解酶因为具有较好的食品工业及化学工业等方面的应用潜力,已经吸引了越来越多的关注. 通过定向进化及高通量筛选的方法对酶分子进行改造,提高其热稳定性及立体选择性是近年的研究热点. 结合国外及本研究组的工作,本文对LipA和LipB的生化性质、结构特点以及采用基因工程突变的方法进行分子改造等方面的研究进展做一简要综述. 另外,对其中一些研究论文做了简要的评价,并提出对未来工作的展望.     

Labeled microRNA pull-down assay system: an experimental approach for high-throughput identification of microRNA-target mRNAs

We developed a simple, direct and cost-effective approach to search for the most likely target genes of a known microRNA (miRNA) in vitro. We term this method ‘labeled miRNA pull-down (LAMP)’ assay system. Briefly, the pre-miRNA is labeled with digoxigenin (DIG), mixed with cell extracts and immunoprecipitated by anti-DIG antiserum. When the DIG-labeled miRNA and bound mRNA complex are obtained, the total cDNAs are then subcloned and sequenced, or RT–PCR-amplified, to search for the putative target genes of a known miRNA. After successfully identifying the known target genes of Caenorhabditis elegans miRNAs lin-4 and let-7 and zebrafish let-7, we applied LAMP to find the unknown target gene of zebrafish miR-1, which resulted in the identification of hand2. We then confirmed hand2 as a novel target gene of miR-1 by whole-mount in situ hybridization and luciferase reporter gene assay. We further validated this target gene by microarray analysis, and the results showed that hand2 is the top-scoring among 302 predicted putative target genes. We concluded that LAMP is an experimental approach for high-throughput identification of the target gene of known miRNAs from both C. elegans and zebrafish, yielding fewer false positive results than those produced by using only the bioinformatics approach.     

中条山区蝶类考察初报

对山西中条山皇姑幔附近原始森林的蝶类进行了初步调查,获得７科６７种。该地区蝶类包括东洋区东份及古北区成份,其中主要种群为古北界区系成份,其地理分布区系属于华北区系,东洋区系则包括西南及华中成份,其侵入途径可能有两条：一是从秦岭山脉进入,二是从华中区,沿着山西、河北和河南三省交界地区进入中条山脉,由此表明山西东洋区系成份分界是中条山。     

Comparative Studies on the Allelopathic Effects of Ulva pertusa Kjellml, Corllina pilulifera Postl et Ruprl, and Sargassum thunbergii mertl O. Kuntze on Skeletonema costatum （Grev.）Cleve

In the present study, we evaluated the allelopathic effects of three macroalgae, namely Ulva pertusa Kjellml, Corallina pilufifera Postl et Ruprl, and Sargassum thunbergii Mertl O. Kuntze, on the growth of the microalga Skeletonema costaturn （Grev.） Creve using culture systems in which the algae coexisted. The effects of the macroalgal culture medium filtrate on S. costatum were also investigated. Moreover, isolated co-culture systems were built to confirm the existence of allelochemicals and preclude growth inhibition by direct contact. The coexistence assay data demonstrated that the growth of S. costaturn was strongly inhibited when fresh tissues, dry powder and aqueous extracts were used; the allelochemicals were lethal to S. costatum at relatively higher concentrations. The effects of the macroalgal culture medium filtrate on the microalga showed both species specificity and complexity. The inhibitory effect of fresh macroalgal tissue and culture medium filtrate on the microalga was due to the alleochemicals released by the macroalgae. The results of the present study show that the allelopathic effects of macroalgae on the microalga are complex. The present study could shed light onto the basis of the interaction between macro- and microalgae.