MC1R germline variants confer risk for BRAF-mutant melanoma

Germline variants in MC1R, the gene encoding the melanocortin-1 receptor, and sun exposure increase risk for melanoma in Caucasians. The majority of melanomas that occur on skin with little evidence of chronic sun-induced damage (non-CSD melanoma) have mutations in the BRAF oncogene, whereas in melanomas on skin with marked CSD (CSD melanoma) these mutations are less frequent. In two independent Caucasian populations, we show that MC1R variants are strongly associated with BRAF mutations in non-CSD melanomas. In this tumor subtype, the risk for melanoma associated with MC1R is due to an increase in risk of developing melanomas with BRAF mutations.     

A variant of the HTRA1 gene increases susceptibility to age-related macular degeneration

Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss in the developed world and has a strong genetic predisposition. A locus at human chromosome 10q26 affects the risk of AMD, but the precise gene(s) have not been identified. We genotyped 581 AMD cases and 309 normal controls in a Caucasian cohort in Utah. We demonstrate that a single-nucleotide polymorphism, rs11200638, in the promoter region of HTRA1 is the most likely causal variant for AMD at 10q26 and is estimated to confer a population attributable risk of 49.3%. The HTRA1 gene encodes a secreted serine protease. Preliminary analysis of lymphocytes and retinal pigment epithelium from four AMD patients revealed that the risk allele was associated with elevated expression levels of HTRA1 mRNA and protein. We also found that drusen in the eyes of AMD patients were strongly immunolabeled with HTRA1 antibody. Together, these findings support a key role for HTRA1 in AMD susceptibility and identify a potential new pathway for AMD pathogenesis.     

牦牛CAPN1基因部分序列的SNPs研究

本研究采用PCR-SSCP技术,设计了2对引物分别对牦牛钙激活蛋白酶基因内含子8、外显子9、内含子9和外显子10部分序列以及第12内含子和13外显子部分序列进行单核苷酸多态性分析.结果表明:与牛基因序列(AF252504S2)相比,牦牛基因在10 581bp处发生了G→A转换,位于第12内含子,表现出3种基因型,其中A、B基因频率分别为0.698 9和0.301 1,AA、AB和BB基因型频率分别为0.475 1、0.447 5和0.077 3,遗传杂合度(He)和多态信息含量(PIC)分别为0.420 9和0.332 3;在5 837bp处发生G→T的转换,位于第9内含子,表现出3种基因型,A、B基因频率分别为0.908 8和0.091 2,AA、AB和BB基因型频率分别为0.828 7、0.160 2和0.011 1,遗传杂合度(He)多态信息含量(PIC)分别为0.165 7和0.152 0;牦牛在这2个位点上处于Hardy-Weinberg平衡状态.     

四种不同植物病原真菌与多菌灵抗药性相关基因突变的比较

克隆了小麦赤霉病菌（Fusarium graminearum）、油菜菌核病菌（Scherotinia sclerotiorum）、辣椒炭疽病菌（Cal-letotrichum gloeosporiodies）和番茄灰霉病菌（Botrytis cinerea）4种病原菌的9个菌株的β－微管蛋白基因、进而与典型模式菌粗糙麦孢霉（Neurospora crassa）进行序列比较，结果表明，4种病原真菌β－微管蛋白序列与粗糙表孢霉具高度同源性；油菜菌核病菌、辣椒炭疽病菌和番茄灰霉病菌的β－微管蛋白198位氨基酸由Glu突变为Ala，是导致上述病原菌产生对多菌灵（MBC）抗药性的主要原因；突变位点和突变类型与其他抗多菌灵真菌一致，且与乙霉威（NPC）之间存在明显负交互抗性。但小麦赤霉病MBC^S和MBC^R菌株的β－微管蛋白序列完全一样，且与NPC之间不存在负交互抗性，有关小麦赤霉病菌产生抗药性的机制有待于进一步的研究。     

猪FoxN1基因转录变异体亚细胞定位研究

Fox N1基因主要表达于胸腺上皮细胞和皮肤角质细胞,在胸腺发育、T细胞增殖、毛发生长、指甲发育等方面发挥重要作用。Fox N1基因存在多种转录变异体,人类Fox N1基因已发现18种转录变异体。转录变异体的存在使基因差异表达和蛋白质多样性存在可能。为深入研究转录变异体生物学功能,研究将前期发现的猪Fox N1基因3种转录变异体分别连入p EGFP-N1载体内,构建各自融合蛋白,转入猪PK15细胞,利用荧光显微镜观察转录变异体亚细胞定位情况。结果表明,p EGFP-N1空载体转染表达绿色荧光蛋白在PK15细胞核和细胞质均匀分布,而重组载体p EGFP-N1-Fox N1(a/b/c)表达的融合蛋白仅在细胞核内均匀分布。结果可为3种转录变异体后续功能研究奠定基础。     

鹅Caspase-1 基因的克隆与序列分析

为系统了解鹅炎症系统,用Trizol法提取马岗鹅脾脏总RNA,采用兼并引物RT-PCR方法克隆了马岗鹅Caspase-1基因并进行了系统的生物信息学分析。测序结果显示,go-Caspase-1基因完整ORF区长813 bp,编码270个氨基酸(Gen Bank序列号为MG463109)。同源性分析显示,go-Caspase-1基因序列与鸭、鸡等禽类的同源性较高,与其他物种的差异较大。蛋白质功能结构域分析显示,不同物种间Caspase-1蛋白的Caspase结构域高度相似。蛋白三维结构预测比较显示,go-Caspase-1蛋白空间结构与鸡和人的Caspase-1主体结构相似。     

不同品种鸡BTN1基因序列差异分析

【目的】BTN1基因位于MHC家族的BF/BL核心区域,研究其SNPs和InDels对提高鸡抗病性有重要意义.【方法】以NCBI中Gallus gallus BTN1基因序列为参照,利用MEGA6.06软件对26个品种鸡的BTN1基因序列比较分析,筛选出与抗病性有关的InDels、SNPs和氨基酸变化,并对26个品种鸡的BTN1基因序列进行聚类分析.【结果】在Exon5和Exon17上各有1个SNPs位点,且为错义突变.SNPs位点主要发生在Intron10、Intron13、Intron18、Intron22和Intron23上.‘雪山草鸡’和‘安卡红鸡’等抗病性强、适应性强的品种鸡在Exon17上发生错义突变;与抗病性较强的‘安卡红鸡’相比,‘来航鸡’在Exon5上存在一个错义突变.【结论】BTN1的Exon5和Exon17上SNPs位点对抗病性具有一定的影响,为家禽的抗病育种研究提供参考依据.     

花烟草NaD1基因的表达及其启动子序列分析

花烟草(Nicotiala alata)的花中存在的植物防御素Nicotiala alata defensin 1(NaD1),对多种致病性真菌具有防御活性,在天然防御免疫系统中发挥着重要作用.本研究分别对花烟草根、茎、叶、花组织部分以及伸根期、旺长期、成熟期发育阶段叶片中NaD1基因的表达量进行qRT-PCR定量检测...     

Common sequence polymorphisms shaping genetic diversity in Arabidopsis thaliana

The genomes of individuals from the same species vary in sequence as a result of different evolutionary processes. To examine the patterns of, and the forces shaping, sequence variation in Arabidopsis thaliana, we performed high-density array resequencing of 20 diverse strains (accessions). More than 1 million nonredundant single-nucleotide polymorphisms (SNPs) were identified at moderate false discovery rates (FDRs), and approximately 4% of the genome was identified as being highly dissimilar or deleted relative to the reference genome sequence. Patterns of polymorphism are highly nonrandom among gene families, with genes mediating interaction with the biotic environment having exceptional polymorphism levels. At the chromosomal scale, regional variation in polymorphism was readily apparent. A scan for recent selective sweeps revealed several candidate regions, including a notable example in which almost all variation was removed in a 500-kilobase window. Analyzing the polymorphisms we describe in larger sets of accessions will enable a detailed understanding of forces shaping population-wide sequence variation in A. thaliana.     

牦牛PIT-1基因第5、6外显子部分序列的克隆测序

利用PCR方法扩增了麦洼牦牛PIT-1基因第5、6外显子的部分序列,扩增片段长度为1 285 bp,克隆到PND-18载体中进行测序,结果牦牛与普通牛的PIT-1基因有97%的同源性,共有28处不同,其中在内含子5的347处有18个碱基的缺失,565处有4个碱基的插入;外显子6有一个碱基突变,并导致氨基酸由普通牛的Thr变为牦牛的Arg。对61头麦洼牦牛和30头九龙牦牛PIT-1基因部分序列进行PCR-RFLP分析,均未检测到多态性。     

牦牛α1-珠蛋白基因的克隆和序列分析

根据α-珠蛋白基因起始密码子上游及终止密码子下游的保守序列设计引物，以牦牛基因组DNA为模板克隆并测定了α-珠蛋白基因序列。结果表明，所测的氨基酸序列与牦牛α-珠蛋白链的氨基酸序列完全相同，即为牦牛α1-珠蛋白基因，长706bp，编码141个氨基酸。通过与其他物种的同源性比较，发现牦牛α1-珠蛋白基因的核苷酸序列与黄牛和水牛的同源性分别为99．71％和98．58％，与山羊、绵羊、人和马的同源性只有96．0：3％、95．57％、68．55％和51．13％；氨基酸序列与黄牛和水牛的同源性分别为99．29％和96．45％，与山羊、绵羊、人和马的同源性只有92．90％、91．49％、87．23％和87．23％，说明牛亚科α-珠蛋白基因在进化上高度保守。同时发现第254位的碱基A为牦牛α1-珠蛋白基因所特有。牦牛的两个α1-珠蛋白基因长度相等，都为706bp，且间距为2．47kb，距离比山羊的远。     

沙皮犬MC1R基因的克隆与序列分析

黑素皮质素1型受体(melanocortin 1 receptor,MC1R)基因在哺乳动物中具有调节细胞黑色素形成的作用,被认为是影响犬毛色的重要候选基因.用PCR技术对沙皮犬MC1R基因序列进行扩增,获得沙皮犬MC1R基因序列1 333 bp,包含完整的MC1R基因开放阅读框954 bp,编码317个氨基酸.该序列与鸡、鼠、犬、人等6种动物MC1R基因CDS序列有70.1％～98.3％的同源性,相应氨基酸序列的同源性达61.1％～96.9％.系统发育树分析结果表明,沙皮犬与已报道的黄金猎犬亲缘最近,与鸡的亲缘关系最远.     

环形泰勒虫suAT1基因的克隆及序列分析

以环形泰勒虫兰州株基因组为模板,经PCR扩增获得了suATI的部分基因,将该基因克隆到pMD20-T载体,对重组质粒进行PCR和双酶切鉴定及序列测定.结果表明:该基因的长度为1 377bp,编码了459个氨基酸.同源性分析结果显示:克隆序列与CenBank收录的环形泰勒虫参考核苷酸序列同源性为98.35%,氨基酸同源性...     

野生大豆盐碱胁迫响应基因GsZFP1的克隆及序列分析

盐碱胁迫是影响植物生长、发育和产量的重要因素,野生大豆是优良的非生物胁迫抗性材料。为了获得在植物渗透胁迫反应中起关键作用的功能基因,研究以耐盐碱东北野生大豆(Glycine sojaL.G07256)为试材,利用前期构建的野生大豆碱胁迫基因芯片表达谱,从中选出一个在盐碱胁迫早期上调表达,经Blast分析预测属于C2H2类型的锌指转录因子(探针号Gma.17534.1.S1_at),命名为GsZFP1。对GsZFP1基因进行芯片结果的sqRT-PCR验证,并通过同源克隆的方法克隆得到GsZFP1的cDNA序列。利用"ORF Finder"及ExPASy的ProtParam工具分析表明GsZFP1蛋白长度为325 aa,分子质量约35.14 ku,预测等电点为9.99。其锌指结构特征为Cys-X2-Cys-X3-Phe-X5-Phe-X2-His-X3-4-His,并且不含QALGGH保守结构域。该基因是野生大豆中首次被发现的不含QALGGH motif C2H2类型的锌指蛋白,并且参与到非生物胁迫反应。该结果将为研究GsZFP1基因在非生物胁迫中的功能,并为认识不含QALGGH保守结构域的C2H2类型的锌指蛋白在非生物胁迫中的作用奠定基础,为耐渗透胁迫基因工程研究提供潜在的基因资源,为植物耐渗透胁迫机理研究提供依据。     

紫草LeEXT-1基因的克隆、序列及表达分析

以硬紫草细胞为材料,采用快速扩增cDNA末端法(rapid amplification of cDNA ends,RACE)克隆了由抑制消减杂交(suppression subtractive hybridization,SSH)和cDNA芯片技术筛选获得的在黑暗条件下优先表达的LeEXT-1基因的全长cD-NA。生物信息学分析结果表明,该cDNA全长为1 077 bp,编码1个含247个氨基酸的蛋白,与编码伸展蛋白(extensin)的基因具有高度的同源性。基因表达分析结果表明,当紫草细胞从B5培养基转到M9培养基时,LeEXT-1基因在2 h内被快速诱导表达,随后又逐渐降低到一个较低的水平。该基因的克隆为进一步研究伸展蛋白在紫草宁合成调控中的作用奠定了基础。     

Chemists cluster in chicago to confer on cagey compounds

Shrink a clump of matter to a few hundred atoms, and it enters a curious netherworld. Neither ordinary solids nor conventional small molecules, such atomic clusters have unique chemical, optical, and electronic properties. Since the mid-1970s, when advances in synthesizing and analyzing clusters first enabled researchers to explore this netherworld in earnest, clusters have nucleated a sizable field. Many of its participants gathered in Chicago on 15 to 22 September for the Sixth International Symposium on Small Particles and Inorganic Clusters, the first of the series to be held in the United States. At the top of the agenda for the 300 attendees were the field's old stalwarts, various kinds of metal clusters; its current darlings, the carbon clusters known as fullerenes; and a possible future superstar, silicon clusters.