1株产酸碱指示剂的真菌的鉴定

采用形态学和分子生物学鉴定的方法,对1株产生酸碱指示剂的真菌进行鉴定.结果表明,该菌株的子囊壳呈球形或卵形,单生或聚生,子囊孢子双胞,无色,椭圆形,分隔处稍缢缩,无性态为串珠镶孢.通过该菌株rDNA ITS的PCR扩增和序列测定,与NCBI网站进行同源性比对分析,结果表明待测菌株与藤仓赤霉菌(Gibberella fujikuroi)同源性为100％,确定该菌株为蘑仓赤霉菌.     

广东省地方鸡线粒体遗传多样性与母系起源

系统评估地方鸡的遗传变异水平并追溯其母系起源, 可为保护利用优质家禽种质资源库提供科学依据。本研究测定了广东省和邻省共12个地方鸡品种的线粒体DNA D-loop序列, 分析品种间的遗传距离与系统关系, 并构建单倍型系统发生树和中介网络图。360份样品共检测到60个突变位点, 均为转换。定义了85种单倍型, 归属于单倍型类群A、B、C和E, 在12个鸡品种中均有分布, 其中B是优势单倍型类群(187个, 51.94%), E次之(76个, 21.11%)。B02 和C01是优势单倍型(85个, 23.61%; 48个, 13.33%), 为12个鸡品种共有; E03位居第三(35个, 9.72%), 杏花鸡、黄郎鸡和宁都三黄鸡未见此单倍型。杏花鸡集中分布在单倍型类群B, 惠阳胡须鸡和中山沙栏鸡则主要分布在单倍型类群E; 怀乡鸡的单倍型数量最多, 中山沙栏鸡的最少。广东地方鸡品种间遗传距离为0.012-0.015, 单倍型多样性0.805 ± 0.047至0.949 ± 0.026, 核苷酸多样性0.0102 ± 0.0017至0.0138 ± 0.0009。邻接树和中介网络图将85种单倍型划分为进化枝A、B、C和E, 广东省与邻省地方鸡单倍型的地理分布模式相似。中性检验显示广东地方鸡未经历明显的群体历史扩张。结果表明广东地方鸡处于较好的保护状态, 遗传多样性水平较高, 品种的形成受到邻省和北方家鸡的影响, 东南亚红原鸡对广东地方鸡也有重要的遗传贡献。     

运用PDB中的同源信息提高NetTurnP的蛋白质β转角预测精度

β转角作为一种蛋白质二级结构类型在蛋白质折叠、蛋白质稳定性、分子识别等方面具有重要作用．现有的β转角预测方法,没有将PDB等结构数据库中先前存在的同源序列的结构信息映射到待预测的蛋白质序列上．PDB存储的结构已超过70 000,因此对一条新确定的序列,有较大可能性从PDB中找到其同源序列．本文融合PDB中提取的同源结构信息(对每一待测序列,仅使用先于该序列存储于PDB中的同源信息)与NetTurnP预测,提出了一种新的β转角预测方法BTMapping,在经典的BT426数据集和本文构建的数据集EVA937上,以马修斯相关系数表示的预测精度分别为0.56、0.52,而仅使用NetTurnP的为0.50、0.46,以Q_total表示的预测精度分别为81.4%、80.4%,而仅使用NetTurnP的为78.2%、77.3%．结果证实同源结构信息结合先进的β转角预测器如NetTurnP有助于改进β转角识别．BTMapping程序及相关数据集可从http://www.bio530.weebly.com获得．     

Genetic Variation and Evolution of the <Emphasis Type="Italic">Pi9</Emphasis> Blast Resistance Locus in the AA Genome <Emphasis Type="Italic">Oryza</Emphasis> Species

The rice nucleotide-binding site–leucine-rich repeat (NBS-LRR)-encoding resistance (R) gene Pi9 confers broad-spectrum resistance to the fungal pathogen Magnaporthe oryzae. The Pi9 locus comprises many NBS-LRR-like genes and is an ancient locus that is highly conserved in cultivated and wild rice species. To understand the genetic variation and molecular evolutionary mechanism of the Pi9 alleles in different rice species, we studied five AA genome Oryza species including two cultivated rice species (Oryza sativa and Oryza glaberrima) and three wild rice species (Oryza nivara, Oryza rufipogon, and Oryza barthii). A 2.9-kb fragment spanning the NBS-LRR core region of the Pi9 gene was amplified and sequenced from 40 accessions. Sequence comparison revealed that the Pi9 alleles had an intermediate-diversified nucleotide polymorphism among the AA genome Oryza species. Sequence variations were more abundant in the LRR region than in the NBS region, indicating that the LRR region has played a more important role for the evolution of the Pi9 alleles. Furthermore, positive selection was found to be the main force promoting the divergence of the Pi9 alleles, especially in the LRR region. Our results reveal the characteristics and evolutionary dynamics of the Pi9 alleles among the two cultivated and three wild rice species.     

Using a yeast two-hybrid system to identify FTCD as a new regulator for HIF-1α in HepG2 cells

HIF-1α is implicated in hepatocellular carcinoma (HCC) pathologies. Here, we screened a human liver cDNA library for HIF-1α-interacting partners using a yeast two-hybrid system. We identified 53 genes, including formiminotransferase cyclodeaminase (FTCD), which was confirmed by co-immunoprecipitation. Moreover, our data indicated that HIF-1α mediated the effects of hypoxia on FTCD induction via binding to the hypoxia-responsive elements of the FTCD promoter. Knockdown of FTCD reduced the effects of HIF-1α in hypoxia and enhanced chemosensitivity in HepG2 cells. Our findings suggested crosstalk between FTCD and HIF signaling and promoted HCC progression, thus implicating FTCD as a therapeutic target for HCC.     

洞庭湖区社鼠脏器重量的比较

对洞庭湖区社鼠(Niviventer confucianus)野外自然种群脏器的重量指标进行了测定,并比较了其在年龄组、性别、季节及生境间的差异。结果表明,社鼠内脏(心、肺、肝、脾、肾脏)随着年龄组的增加,重量有明显的增加,其重量与体重有极其显著的相关性。两性间的脏器重量指标没有显著性差异。脏器季节变化的共同特征是夏季脏器重量较低,四季间比较,仅有心脏重量有显著的季节变化。生境间心脏和肾脏重量的变化相对较大,达显著水平。参与繁殖与未参与繁殖的雌鼠相比,心、肺、肝、肾脏的各项指标均较高,脾脏则相反,但均未有显著性差异。总的来看,洞庭湖社鼠种群的脏器指标相对稳定,尽管重量指标随着年龄组而增加,受性别、季节、生境及繁殖行为的影响相对较小。     

外源金属硫蛋白对奶牛抗热应激调控及SOD基因表达的影响

将28头泌乳奶牛随机分成A、B、C、D 4组,分别按每头0 (对照)、6.0、12.0和16.0 mg剂量静脉注射经生理盐水溶解的Zn-MT,以探讨外源性金属硫蛋白(MT)对奶牛抗热应激的调控作用及其机理.结果表明：B、C和D组的脉搏、呼吸频率及血清MDA含量均显著(P＜0.05或P＜0.01)低于A组;4%标准乳产量、血液GSH-PX活性、红细胞SOD活性、血清MT含量、奶MT含量及SOD基因表达水平均显著(P＜0.05或P＜0.01)高于A组;C和D组的上述各项指标又优于(P＜0.05或P＞0.05)B组;外源性MT的调控效果以注射后第30天表达最佳.说明MT是一种能够有效调控奶牛热应激能力的生理活性物质,且在奶牛体内表现出一定的剂量效应和时间效应.