鄱阳湖水生维管束植物生物量及其合理开发利用的初步建议

用4种不同的计算方法测定了鄱阳湖水生维管束植物的生物量。根据22个断面,199个采集点,398个样方的测定结果,得出鄱阳湖水生维管束植物的年生产量为431.76万吨(湿重),即相当于5.44×10~(-15)焦耳(能量)。其中,马来眼子菜、苦草和黑藻等3种合计约占总生物量的71.46%。全湖可供草食性鱼类食用的水生维管束植物约占总量的86.9%。文中还对4个植物带和9个群丛生物量的分布规律进行了讨论。提出了人工增殖草食性鱼类,调整湖中植被组成,保护和种植水生经济植物等合理开发利用鄱阳湖水生植物资源的初步建议。     

痛觉的脑功能成像研究进展

本文综述了近年来关于痛觉功能性脑成像的研究进展,痛觉的感觉辨别成分似与外侧丘脑、初级和次级躯体感觉区及岛叶皮层有关,而伤害性信息的认知－注意过程则与顶叶后部和前额中皮层有关。扣带回的不同部分调节着痛觉认知和情感的不同方面。文章最后对临床各种疼痛特别是神经源性痛病人的成像研究进行了分析。     

The fragile X mental retardation syndrome protein interacts with novel homologs FXR1 and FXR2.

Fragile X Mental Retardation Syndrome is the most common form of hereditary mental retardation, and is caused by defects in the FMR1 gene. FMR1 is an RNA-binding protein and the syndrome results from lack of expression of FMR1 or expression of a mutant protein that is impaired in RNA binding. The specific function of FMR1 is not known. As a step towards understanding the function of FMR1 we searched for proteins that interact with it in vivo. We have cloned and sequenced a protein that interacts tightly with FMR1 in vivo and in vitro. This novel protein, FXR2, is very similar to FMR1 (60% identity). FXR2 encodes a 74 kDa protein which, like FMR1, contains two KH domains, has the capacity to bind RNA and is localized to the cytoplasm. The FXR2 gene is located on human chromosome 17 at 17p13.1. In addition, FMR1 and FXR2 interact tightly with the recently described autosomal homolog FXR1. Each of these three proteins is capable of forming heteromers with the others, and each can also form homomers. FXR1 and FXR2 are thus likely to play important roles in the function of FMR1 and in the pathogenesis of the Fragile X Mental Retardation Syndrome.     

植物DNA甲基化及胁迫诱导的变异

DNA中碱基的化学修饰近年来一直是生命科学领域研究的热点之一。DNA甲基化是一种常见的表观遗传现象,它能在不改变DNA序列的前提下改变遗传表型。各种胁迫因素能诱导植物DNA甲基化产生变异,但其应答胁迫机制仍然未知。本文对植物DNA甲基化研究进展进行了综述,结合本课题组的研究结果,对7Li离子束注入、~(60)CO-γ射线诱变诱导产生的DNA甲基化变异进行了报道,以期为DNA甲基化可能参与涉及植物的表型可塑性提供一定的依据。     

香港岛黄桐森林群落分析

 香港岛以黄桐(Endospermum chinense)等为优势的森林群落,具有较多的热带植物区系和较复杂的群落结构,是我国南亚热带低地常绿阔叶林的代表类群。     

Confounding from cryptic relatedness in haplotype-based association studies

Cryptic relatedness was suggested to be an important source of confounding in population-based association studies (PBAS). The impact of cryptic relatedness on the performance of haplotype phase inference and haplotype-based association tests is not clear. In this study, we used the Hapmap genetic data to simulate a set of related samples. We evaluated the accuracy of haplotype phase inferred by PHASE 2.1 and calculated the power, type I error rates, accuracy and positive prediction value (PPV) of haplotype frequency-based association tests (HFAT) and haplotype similarity-based association tests (HSAT) under various scenarios, considering relatedness levels, disease models and sample sizes. Cryptic relatedness appeared to slightly increase the accuracy of haplotype phase inference. We observed significant negative effect of cryptic relatedness on the performance of HFAT and HSAT. Ignoring cryptic relatedness may increase spurious association results in haplotype-based PBAS.     

马铃薯StSnRK2.1基因克隆与生物信息学分析

SnRK2基因对植物的逆境胁迫具有重要的调节作用,以马铃薯‘陇薯3号’(Solanum tuberosum)为试材,采用RT-PCR方法从马铃薯试管苗中克隆得到1个SnRK2.1基因cDNA,命名为StSnRK2.1,提交GenBank注册,注册号为JX280911。通过生物信息学分析,该基因开放阅读框全长1 008 bp,编码335个氨基酸。预测蛋白质分子量约为37.77 kD,等电点为5.37,蛋白质二级结构预测α-螺旋42.39%,延伸链16.42%,β-折叠7.46%,无规卷曲33.73%,具有疏水性,为膜内蛋白。亚细胞定位显示该基因出现在细胞质及微体中的可能性较大。肽链可能有7处丝氨酸磷酸化位点,2处苏氨酸磷酸化位点,以及3处酪氨酸磷酸化位点,因此推测该基因在植物抗逆中有重要的作用。     

DcR3/TR6 modulates immune cell interactions

DcR3/TR6, a secreted protein, is a member of TNF receptor family. Its ligands include FasL, LIGHT, and TL1A, all TNF family members. TR6 can interfere with FasL- or LTbetaR-mediated apoptosis; it can also inhibit T-cell costimulation by blocking the two-way signaling between TR2 and LIGHT, and the one-way signaling from TL1A to DR3. In this study, we discovered that TR6 was secreted by peripheral blood mononuclear cells (PBMC) stimulated by T-cell mitogens. It inhibited actin polymerization of T cells upon mitogen stimulation, and repress T-cell pseudopodium formation, which is known to be important for cell-cell interaction. As a consequence, T-cell aggregation stimulated by alloantigens, anti-CD3 or PHA was suppressed by either soluble or solid phase TR6-Fc. This result suggests that TR6 might regulate T-cell interaction with other cells such as antigen-presenting cells (APC) or their fellow T cells by preventing them from forming inseparable cell clusters, which are undesirable for the progression of immune responses.