乌兰巴托-锡林浩特样带草地植被特征与水热因子的关系

2012年夏季,研究人员对蒙古高原长约1100km的乌兰巴托—锡林浩特草地样带开展考察,获取了46个样地的物种数量、地上生物量等数据;基于全球GHCN(全球历史气象网络)数据集,提取了样带夏季(6—8月)月均温度和降水总量;继而根据自然地理和行政区边界,将草地样带大致分成北部(蒙古国乌兰巴托—蒙古国艾日格)、中部(蒙古国艾日格—中国苏尼特左旗)和南部(中国苏尼特左旗—中国锡林浩特),开展了分析。研究表明:(1)样带夏季平均温度的空间分布形态呈现明显的倒"U"型分布,南北两端温度较低,中部温度较高;夏季降水量在空间上的分布形态则与之相反,呈现南北两端降水量较高,中部降水量较低的正"U"型分布;(2)样带上植物物种数量、地上生物量的空间分布形态均呈现正"U"型分布,即在生态景观类型为典型温性草原的样带南部和北部地区,其生物多样性、地上生物量明显好于呈现为温性荒漠草原、温性荒漠景观的样带中部地区。(3)相关分析体现了大尺度(高原样带尺度)上植被特征与水热环境因子间的关系:植物物种数量、地上生物量与夏季月均温度均呈现负相关,而与夏季降水总量则呈现正相关关系。(4)偏相关分析反映了局地小尺度上植被特征与水热环境因子间的关系:温度和降水要素对于植物物种数量、地上生物量均呈现正相关。     

丹参的研究现状与应用前景

本文从丹参的药用资源、化学成分、药理作用和制剂等药物学方面以及丹参的组织培养、有效成分积累的调控、品种改良和选育等开发应用方面对近期有关丹参的研究进行了综述,力图阐述丹参的研究现状和应用前景.     

Effects of UV-B radiation on ingestion, fecundity, population dynamics and antioxidant enzyme activities of Schmackeria inopinus (Copepoda Calanoida)

Effects of enhanced ultraviolet B (UV-B, 280-320 nm) on copepods have gained particular attention in recent years. In this study, we investigated the effects of UV-B radiation on ingestion, fecundity, population dynamics and antioxidant enzyme activities of copepod Schmackeria inopinus exposed to varying doses of UV-B irradiance. Artificial UV-B radiation resulted in an increased mortality of nauplii, copepodites and adults with increasing UV-B doses. Nauplii and copepodites were more sensitive to UV-B radiation than adults, and adult males had a higher UV-B radiation susceptivity in comparison with adult females. Both ingestion rates and proportion of gravid females decreased with the increase of UV-B doses; and at the same time, we also observed that adult females had higher ingestion rates as compared with adult males. In comparison with the control, the abundance of the treatment significantly decreased. Antioxidant enzyme (GPx and GR) activities attained a significant increase at lower UV-B radiation doses when compared to the control, but declined at higher UV-B doses. These results suggested that enhanced UV-B radiation might change the species composition of copepods. Our study also showed that antioxidant enzymes might protect S. inopinus against UV-induced oxidative damage.     

Genetic polymorphisms in AURKA,BRCA1, CCNE1 and CDK2 are associated with ovarian cancer susceptibility among Chinese Han women

IntroductionCentrosome aberrations and cell-cycle deregulation have important implications for ovarian cancer development. The AURKA, BRCA1, CCNE1 and CDK2 genes play pivotal roles in centrosome duplication and cell-cycle regulation.MethodsUsing a haplotype-based analysis, this study aimed to investigate whether genetic polymorphisms in these four genes may contribute to ovarian cancer susceptibility. A total of 22 single nucleotide polymorphisms (SNPs) in these four genes were genotyped in 287 cases of ovarian serous cystadenocarcinomas and 618 age-matched cancer-free controls from the Chinese Han population, and then haplotype blocks were reconstructed according to our genotyping data and linkage disequilibrium (LD) status of these SNPs.ResultsFor AURKA, we found that haplotype GA [rs6064391 (T→G) + rs911162 (G→A)] was strongly associated with decreased ovarian cancer risk (adjusted OR = 0.31, 95% CI = 0.15–0.63, P = 0.0012). For BRCA1, we found that haplotype CGTAG was associated with decreased ovarian cancer risk (adjusted OR = 0.64, 95% CI = 0.41–0.98, P = 0.0417). Moreover, women harboring homozygous GA/CGTAG haplotypes showed the lowest risk (OR = 0.12, 95% CI = 0.02–0.94, P = 0.0438). In CCNE1, the SNPs rs3218035 and rs3218042 were significantly associated with increased ovarian cancer risk (rs3218035: adjusted OR = 5.20, 95% CI = 1.85–14.52, P = 0.0017; rs3218042: adjusted OR = 4.98, 95% CI = 1.75–14.19, P = 0.0027). For CDK2, no significant association was found.ConclusionsThis study indicates that genetic polymorphisms of AURKA, BRCA1 and CCNE1 may affect ovarian cancer susceptibility in Chinese Han women.     

水貂自咬症病因RAPD遗传分析

自咬症是危害笼养水貂的一种慢性疾病, 造成水貂自咬创伤而影响其生长发育和毛皮质量。文中从遗传基因角度探讨水貂自咬症的发病原因在国内外尚属首次, 采用RAPD 技术分别对正常水貂和自咬水貂样本进行了分子水平的遗传结构分析。从100 个随机引物中筛选出26个重复性好的标记引物, 对60只水貂群体(健康与患病)进行随机扩增多态DNA(RAPD)标记研究。结果表明, 26个引物扩增出105条带, 其中29条带呈现多态, 多态率为27.62%。不同引物扩增出的DNA 片段在健康与患病水貂群体中的分布频率不同。水貂群体间相似系数为0.8471, 遗传距离(变异)指数为0.1529。引物S356(序列为CTGCTTAGGG)扩增出健康与患病水貂互不相同的条带, 如在患病水貂群体中扩增出的1000 bp左右的DNA 片段, 可初步作为区分健康和患病水貂群体的分子遗传标记, 逐渐剔除自咬水貂个体, 达到净化水貂群的目的, 减少水貂饲养业的经济损失, 为今后水貂的分子育种及其疾病的预防提供一定的理论依据。     

抗寒性小麦品种逆境下化学反应与扩散过程的热力学分析

本文以典型的冬性小麦品种及春性品种为对象，利用示踪技术，通过液闪计数据方法，测定了低温胁迫下不同品种膜脂的代谢情况。根据实验的结果，从热力学的角度对低温胁迫下生物脂膜上的化学反应及扩散过程进行了分析，阐明了植株逆境下各种反应降低的原因，丰富了逆境生理研究的内容。     

Sensitivity of 70-mer oligonucleotides and cDNAs for microarray analysis of gene expression in Arabidopsis and its related species

Synthetic oligonucleotides (oligos) represent an attractive alternative to cDNA amplicons for spotted microarray analysis in a number of model organisms, including Arabidopsis, C. elegans, Drosophila, human, mouse and yeast. However, little is known about the relative effectiveness of 60-70-mer oligos and cDNAs for detecting gene expression changes. Using 192 pairs of Arabidopsis thaliana cDNAs and corresponding 70-mer oligos, we performed three sets of dye-swap experiments and used analysis of variance (anova) to compare sources of variation and sensitivities for detecting gene expression changes in A. thaliana, A. arenosa and Brassica oleracea. Our major findings were: (1) variation among different RNA preparations from the same tissue was small, but large variation among dye-labellings and slides indicates the need to replicate these factors; (2) sources of variation were similar for experiments with all three species, suggesting these feature types are effective for analysing gene expression in related species; (3) oligo and cDNA features had similar sensitivities for detecting expression changes and they identified a common subset of significant genes, but results from quantitative RT-PCR did not support the use of one over the other. These findings indicate that spotted oligos are at least as effective as cDNAs for microarray analyses of gene expression. We are using oligos designed from approximately 26,000 annotated genes of A. thaliana to study gene expression changes in Arabidopsis and Brassica polyploids.     

植物脂肪酸脱饱和酶特性及转基因研究进展

脂肪酸代谢是有机体的基本代谢之一。植物体内首先合成的是饱和脂肪酸,然后在脂肪酸脱饱和酶作用下形成不饱和脂肪酸。目前已经从很多植物中克隆到了脂肪酸合成相关的酶,并对其功能进行了鉴定。详细介绍了近年来应用基因工程技术对植物油中不饱和脂肪酸含量和组分进行改造所取得的进展,并对其在植物抗性育种中的应用进行了展望。     

Resistance of Acta2R149C/+ mice to aortic disease is associated with defective release of mutant smooth muscle α-actin from the chaperonin-containing TCP1 folding complex

Pathogenic variants of the gene for smooth muscle α-actin (ACTA2), which encodes smooth muscle (SM) α-actin, predispose to heritable thoracic aortic disease. The ACTA2 variant p.Arg149Cys (R149C) is the most common alteration; however, only 60% of carriers have a dissection or undergo repair of an aneurysm by 70 years of age. A mouse model of ACTA2 p.Arg149Cys was generated using CRISPR/Cas9 technology to determine the etiology of reduced penetrance. Acta2^R149C/+ mice had significantly decreased aortic contraction compared with WT mice but did not form aortic aneurysms or dissections when followed to 24 months, even when hypertension was induced. In vitro motility assays found decreased interaction of mutant SM α-actin filaments with SM myosin. Polymerization studies using total internal reflection fluorescence microscopy showed enhanced nucleation of mutant SM α-actin by formin, which correlated with disorganized and reduced SM α-actin filaments in Acta2^R149C/+ smooth muscle cells (SMCs). However, the most prominent molecular defect was the increased retention of mutant SM α-actin in the chaperonin-containing t-complex polypeptide folding complex, which was associated with reduced levels of mutant compared with WT SM α-actin in Acta2^R149C/+ SMCs. These data indicate that Acta2^R149C/+ mice do not develop thoracic aortic disease despite decreased contraction of aortic segments and disrupted SM α-actin filament formation and function in Acta2^R149C/+ SMCs. Enhanced binding of mutant SM α-actin to chaperonin-containing t-complex polypeptide decreases the mutant actin versus WT monomer levels in Acta2^R149C/+ SMCs, thus minimizing the effect of the mutation on SMC function and potentially preventing aortic disease in the Acta2^R149C/+ mice.