鸟类核型研究XⅣ.鸻形目14种

本文报道了(行鸟)形目14种鸟的核型,并发现该目种类间染色体数目变异很大,由石(行鸟)的2n=40至沙锥的2n=98不等。这种变异是由原始的2n=80核型通过两种方式形成的:在(行鸟)小目中,小染色体相互融合而造成染色体数目的减少;在鹬小目中,大染色体的着丝点分离而造成染色体数目的增加。     

巨型艾美耳球虫孢子化卵囊cDNA文库的构建

为构建巨型艾美耳球虫(Eimeria maxima)孢子倾卵囊cDNA表灰文库,从E.maxima孢子化卵囊中提取总RNA,以总RNA为模板、λTriplex2TM为栽体,利用SMARTTM cDNA文库构建试剂盒构建全长cDNA表达文库.经测定构建的E.maxima cDNA表达文库的原始文库容量为1×106 pfu/ml,扩增后的文库滴度为5×1010pfu/ml,重组率为95%,插入片断主要集中在0.5～1kb之间.根据已知序列设计引物,能从文库中扩增出编码E.maxima免疫球蛋白重链结合蛋白的基因序列片段.结果 表明所构建的E.maxima cDNA表达文库质量良好,为克隆、筛选E.maxima的功能性基因奠定了基础.     

锌指核酸内切酶:基因操作的有力工具

针对动植物进行基因靶向操作的技术,是解析基因功能、研究疾病,以及农业经济生产中一个有用的工具。至今,基因靶向操作主要是通过在胚胎干细胞(embryonic stem cell,ES cell)中进行同源重组或者是体细胞核转移的方法进行,但同源重组方法由于需要ES细胞而被限制在个别物种,而核转移方法存在核去分化、效率低、成本高的缺陷。近几年,一种基于锌指核酸内切酶(zinc-finger nuclease,ZFN)基因靶向修饰的新技术被应用于包括植物、果蝇、爪蟾、斑马鱼和大鼠等不同物种的基因操作。通过胚胎注射ZFN的质粒或是mRNA可以有效地定靶并迅速地在内源基因上引起可遗传的突变。ZFN介导基因靶向敲除的可行性,使得那些无法获得ES细胞和克隆技术支持的物种的基因靶向修饰成为可能。     

夜间增温对稻田甲烷排放的影响及其高光谱估算

昼夜不对称增温是全球气候变化的主要特征之一,有关夜间增温对稻田甲烷(CH_4)排放影响的报道尚不多见。通过田间模拟试验,研究了被动式夜间增温下水稻田CH_4排放及高光谱的特征,并用高光谱数据对稻田甲烷排放进行定量模拟。田间试验设夜间增温(NW)和对照处理(CK),夜间增温即在整个水稻生育期的夜间(19:00—6:00)用铝箔反射膜覆盖水稻冠层。结果表明,夜间增温显著促进水稻拔节期和抽穗期-灌浆期CH_4排放。水稻冠层近红外光谱反射率表现为,在分蘖期和拔节期时,NWCK;而在抽穗-灌浆期和成熟期时,CKNW。水稻冠层光谱反射率、一阶导数光谱及光谱特征值均与CH_4排放通量显著相关,相关系数最大可达0.8(P0.01),其中以"蓝边面积"(SD_b)构成的二次多项式模型模拟精度和检验精度综合最佳,决定系数R~2分别为0.70和0.72。研究结果对稻田CH_4排放通量遥感监测的可行性提供了理论依据和技术支持。     

Genetic diversity and population structure of Chinese <Emphasis Type="Italic">Lentinula edodes</Emphasis> revealed by InDel and SSR markers

Genetic diversity and population structure of 88 Chinese Lentinula edodes strains belonging to four geographic populations were inferred from 68 Insertion-Deletion (InDel) and two simple sequence repeat (SSR) markers. The overall values of Shannon’s information index and gene diversity were 0.836 and 0.435, respectively, demonstrating a high genetic diversity in Chinese L. edodes strains. Among the four geographic populations, the Central China population displayed a lower genetic diversity. Multiple analyses resolved two unambiguous genetic groups that corresponded to two regions from which the samples were collected—one was a high-altitude region (region 1) and the other was a low-altitude region (region 2). Results from analysis of molecular variance suggested that the majority of genetic variation was contained within populations (74.8 %). Although there was a strong genetic differentiation between populations (F _ST ?=?0.252), the variability of ITS sequences from representative strains of the two regions (<3 %) could not support the existence of cryptic species. Pairwise F _ST values and Nei’s genetic distances showed that there were relatively lower genetic differentiations and genetic distances between populations from the same region. Geographic distribution could play a vital role in the formation of the observed population structure. Mycelium growth rate and precocity of L. edodes strains displayed significant differences between the two regions. Strains from region 2 grew faster and fructified earlier, which could be a result of adaptation to local environmental factors. To the best of our knowledge, this was the first study on the genetic structure and differentiation between populations, as well as the relationship between genetic structure and phenotypic traits in L. edodes.     

上皮性卵巢癌组织中P-AKT、P-gp的表达及其临床病理意义

目的探讨卵巢上皮癌组织中P-AKT(或称磷酸化蛋白激酶B,phosphorylated protein kinase B)和P-gp(P-glycoprotein)的表达及其与临床病理因素之间的关系。方法采用免疫组化法检测60例卵巢上皮癌组织、30例卵巢良性肿瘤组织和30例正常卵巢组织中P-AKT、P-gp的表达。结果(1)P-AKT、P-gp在上皮性卵巢癌中的阳性表达率(61.7%、50.0%)高于其在卵巢良性肿瘤组织和正常卵巢组织中的表达(13.3%、1.7%;6.7%、0),P0.05。(2)P-AKT和P-gp的异常表达均与卵巢癌的FIGO分期相关(P0.05),与组织学类型、病理分级无关。(3)P-AKT和P-gp蛋白的过表达呈显著正相关性(r=0.26,P0.05)。(4)P-AKT、P-gp阳性组的复发率(51.4%、73.3%)高于其阴性组的复发率(26.9%、30.8%),P0.05。P-AKT、P-gp阳性组的生存率(62.2%、56.7%)低于其阴性组的生存率(91.3%、90.0%)P0.05。结论:P-AKT、P-gp与上皮性卵巢癌的发展及预后有关。P-AKT可能通过作用于其下游的P-gp蛋白促进卵巢癌细胞的恶性转化及对化疗药物的耐药。     

Establishment of recombineering genome editing system in Paraburkholderia megapolitana empowers activation of silent biosynthetic gene clusters

The Burkholderiales are an emerging source of bioactive natural products. Their genomes contain a large number of cryptic biosynthetic gene clusters (BGCs), indicating great potential for novel structures. However, the lack of genetic tools for the most of Burkholderiales strains restricts the mining of these cryptic BGCs. We previously discovered novel phage recombinases Redαβ7029 from Burkholderiales strain DSM 7029 that could help in efficiently editing several Burkholderiales genomes and established the recombineering genome editing system in Burkholderialse species. Herein, we report the application of this phage recombinase system in another species Paraburkholderia megapolitana DSM 23488, resulting in activation of two silent non-ribosomal peptide synthetase/polyketide synthase BGCs. A novel class of lipopeptide, haereomegapolitanin, was identified through spectroscopic characterization. Haereomegapolitanin A represents an unusual threonine-tagged lipopeptide which is longer than the predicted NRPS assembly line. This recombineering-mediated genome editing system shows great potential for genetic manipulation of more Burkholderiales species to activate silent BGCs for bioactive metabolites discovery.     

Construction and analysis of dysregulated lncRNA-associated ceRNA network in colorectal cancer

Colorectal cancer (CRC) is one of the most frequently diagnosed digestive system cancer. The aim of the present study was to investigate the interactions among messenger RNAs (mRNAs), microRNAs (miRNAs), and long noncoding RNAs (lncRNAs) in CRC to reveal the mechanisms of CRC. Differentially expressed genes (DEGs) were identified from public gene expression data sets. One thousand eighty-one common dysregulated mRNAs in two data sets were identified. Gene function analysis and protein-protein interaction network analysis indicated that these DEGs might play important roles in CRC. LINC00365 was selected through coding- noncoding network analysis and its expression was validated upregulated in 22 paired clinical samples and four CRC cell lines. A competing endogenous RNA network composed of 70 miRNAs, nine mRNAs, and LINC00365 was constructed. Eight of nine mRNAs were validated upregulated in The Cancer Genome Atlas data set. Our results suggested that LINC00365 was an oncogene in CRC and it could regulate the expression of several mRNAs through sponging miRNAs.     

Bioinformatics analysis of the prognosis and biological significance of HMGB1, HMGB2, and HMGB3 in gastric cancer

High mobility group box (HMGB) consists primarily of HMGB1, HMGB2, and HMGB3 proteins. Although abnormal HMGB expression is associated with various tumors, the relationship with gastric cancer (GC) remains unclear. In this study, HMGB1, HMGB2, and HMGB3 expression was analyzed using the Oncomine and TCGA databases. Correlations between HMGB1, HMGB2, and HMGB3 and clinicopathological factors were analyzed. cBioPortal was used to analyze HMGB1, HMGB2, and HMGB3 genetic alterations and its gene regulation network in GC tissue. HMGB1, HMGB2, and HMGB3 expression was higher in tumor tissues than in normal tissues, especially in GC. High HMGB1, HMGB2, and HMGB3 expression may predict a poor prognosis among patients with GC (hazard ratios [HR] = 1.90; 95% confidence interval [CI]: [1.30−2.78]) and human digestive system neoplasm (HR = 1.85; 95% CI [1.64−2.10]). These findings suggest that HMGB1, HMGB2, and HMGB3 may be useful prognostic indicators for patients with GC.     

Characterization of Haemaphysalis flava (Acari: Ixodidae) from Qingling Subspecies of Giant Panda (Ailuropoda melanoleuca qinlingensis) in Qinling Mountains (Central China) by Morphology and Molecular Markers

Tick is one of important ectoparasites capable of causing direct damage to their hosts and also acts as vectors of relevant infectious agents. In the present study, the taxa of 10 ticks, collected from Qinling giant pandas (Ailuropoda melanoleuca qinlingensis) in Qinling Mountains of China in April 2010, were determined using morphology and molecular markers (nucleotide ITS2 rDNA and mitochondrial 16S). Microscopic observation demonstrated that the morphological features of these ticks were similar to Haemaphysalis flava. Compared with other Haemaphysalis species, genetic variations between Haemaphysalis collected from A. m. qinlingensis and H. flava were the lowest in ITS2 rDNA and mitochondrial 16S, with sequence differences of 2.06%–2.40% and 1.30%–4.70%, respectively. Phylogenetic relationships showed that all the Haemaphysalis collected from A. m. qinlingensis were grouped with H. flava, further confirmed that the Haemaphysalis sp. is H. flava. This is the first report of ticks in giant panda by combining with morphology and molecular markers. This study also provided evidence that combining morphology and molecular tools provide a valuable and efficient tool for tick identification.