棉花耐旱相关基因的cDNA-AFLP差异显示

为鉴定棉花干旱胁迫响应基因,应用cDNA-AFLP技术,以棉花耐旱品种晋棉13号幼苗为研究对象,对干旱胁迫早期叶片基因表达进行了mRNA指纹分析。通过64对引物组合的筛选,共分离得到232个差异表达的转录衍生片段(TDFs),对其中102个TDFs进行了克隆、测序和序列分析。结果表明:45个TDFs与NCBI中已有序列同源,功能涉及信号传导、转录调控以及逆境诱导蛋白等,另有57个TDFs无同源序列或同源性低,预测其为是一些未知功能基因。     

棉花色素腺体研究进展

对棉花色素腺体的分布、发生方式、遗传学等方面的国内外研究成果进行了综述,并介绍了棉花色素腺体对植株抗性的影响及与环境因子的相互作用,指出了研究中尚待解决的一些问题．     

陆地棉色素腺体的表达与遗传的特殊规律

陆地棉种子及各部器官含有毒物质棉酚,这与棉株各部器官着生有色素腺体有关.研究结果表明:色素腺体在棉株各器官上的分布极具特殊性,有色素腺体棉与无色素腺体棉杂交后代,不同个体的不同器官色素腺体的分布具多样性,色素腺体的密度不均匀,色素腺体的表达时期不一致,各种色素腺体类型出现的频率无规律.色素腺体的遗传亦极具特殊性,难以用两对基因质量性状遗传或微效多基因数量性状遗传理论进行圆满解释.对如何提高无色素腺体类型或高色素腺体类型的中选率、减少误判提出了依据.     

棉花不同腺体类型的棉酚高效液相色谱测定及其生物特性表征

运用高效液相(HPLC)方法对新近育成的特殊和普通的无腺体陆地棉及特殊和普通的有腺体陆地棉及海岛棉等多种遗传类型品种材料的棉酚含量进行了比较研究.实验以一反向C18色谱柱为固定相,甲醇 0.5%的醋酸90∶10为流动相,流速为0.8mL·min-1,建立了分离度好、准确而快速的棉酚HPLC测定方法:其最低检测限量3×10-6g/mL-1,精密度(RSD)和准确度(RME)均小于10%,回收率为100.4%～103.2%.分析表明,不同遗传类型品种材料种子的棉酚含量差异极大.通过准确的高效液相分析展示出各种遗传类型尤其是特殊腺体类等珍贵资源.     

牙鲆感染迟钝爱德华氏菌的miRNA转录组分析

为了探究牙鲆感染迟钝爱德华氏菌过程中miRNA的分子调控机制,以牙鲆头肾组织为研究材料,分析其感染迟钝爱德华氏菌后miRNA的差异表达情况.利用高通量测序平台(Illumina HiSeq)分别对感染迟钝爱德华氏菌3 h、6 h以及未感染的牙鲆头肾组织的RNA进行转录组测序,并对数据进行生物信息学分析.将测序结果与斑马...     

陆地棉色素腺体分布的多样性与遗传的特殊性

陆地棉种子及各部器官含有毒物质棉酚,这与棉株各部器官着生有色素腺体有关．研究结果表明：色素腺体在棉株各器官上的分布极具特殊性,有色素腺体棉与无色素腺体棉杂交后代,不同个体的不同器官色素腺体的分布具多样性,色素腺体的密度不均匀,色素腺体的表达时期不一致,各种色素腺体类型出现的频率无规律．色素腺体的遗传亦极具特殊性,难于用两对基因质量性状遗传或微效多基因数量性状遗传理论进行圆满解释．对如何提高无色素腺体类型或高色素腺体类型的中选率提出了可减少误判的依据．     

小鼠囊胚发育阶段miRNA表达的研究

研究小鼠囊胚发育阶段miRNA的表达,探讨miRNA在着床前胚胎发育中的作用.采用miRNA芯片技术和RT-PCR方法,鉴定小鼠囊胚发育阶段miRNA的表达.在小鼠囊胚发育阶段共筛查到124个miRNA,其中包括与发育和细胞分化相关的miRNA let-7e、miR-125a和miR-181a.说明小鼠囊胚发育阶段表达大量的miRNA,有可能对着床前胚胎发育和分化过程起重要的调控作用.     

英汉表达差异点滴

本文从七个方面来简单地论述了英汉表达的差异，为的是提醒英语学习者要正确地掌握英汉表达的差异，从而达到准确地理解英语原文，提高笔头和口头表达能力。     

miRNA调控诱导的随机增益和双峰表达

一方面,miRNA通过加速mRNA的降解对基因表达进行后转录调控; 另一方面,最新的研究表明某些细胞中miRNA以切换的方式对mRNA进行调控.基于此,建立起一个miRNA后转录调控的基因表达模型.通过对相应化学主方程的分析求解与数值模拟,研究了miRNA调控过程中的噪声对mRNA表达的定量和定性影响.结果显示:这种随机涨落既能提高mRNA的平均表达水平(称这种现象为随机增益)又能诱导mRNA的双峰表达.研究结果表明:miRNA后转录调控是一种有效控制基因表达的机制.     

一个与鸭繁殖性能相关卵巢差异表达基因的分离分析

本文用mRNA差异表达显示技术,分离分析了繁殖准备期金定鸭(Anas platyrhynchos domesticus)和绿头野鸭(Anas platyrhynchos)卵巢差异表达基因.通过卵巢组织RNA提取、反转录、mRNA差异显示PCR扩增、PAGE和银染检测扩增产物、差异带回收纯化、T载体连接转化和克隆测序分析,获得一个可能与鸭繁殖性能有关的卵巢差异表达基因片段,片段大小882bp.同源性分析表明,其序列与发情期羊卵巢cDNA(同源性为96%)、褐家鼠睾丸cDNA(同源性为83%)有很高的同源性.基因家族摸体分析表明,该序列的部分片段分别与Sox-5基因、转录因子USF基因、性别决定因子SRY、Cdx A基因都有90%以上的同源性典型摸体.由上述分析,我们推测该cDNA片段与鸭繁殖性状有关.     

棉花腺体形成时均一化cDNA文库的构建

为克隆筛选棉花腺体形成相关的基因,运用SMART技术构建cDNA文库.首先抽提棉花腺体形成时期的mRNA,mRNA逆转录后合成cDNA,经均一化处理后,SfiⅠ酶切,连接质粒载体,电转化,成功构建了棉花腺体形成时期的cDNA文库.经鉴定原始文库滴度为5.8×105 cfu/mL,其重组率高达94%,插入片段的平均长度约为1.4 kb.     

Effects of pigment glands and gossypol on somatic cell culture of upland cotton (Gossypium hirsutum L.)

The effects of pigment glands and gossypol on the somatic cell culture of upland cotton were studied, using the materials as follows: three pairs of glanded and glandless upland cotton near isogenic lines, TM-1, and Coker 312. The results showed that the pigment glands and gossypol contents in the explants had great inhibiting effect on the induction and growth of callus in somatic cell culture of upland cotton, and the induction rate of callus and the single callus weight of glandless cotton were much higher than those of their glanded near isogenic lines. It was easier to obtain regeneration plants from glandless cotton than from their glanded near isogenic lines. There was a significant inverse correlation between the gossypol contents in the explants and callus induction rate, with the correlation coefficient of -0.84. The vitro gossypol in the medium had some inhibiting effect on the induction and growth of callus, especially for the glandless cotton. However, a certain concentration of vitro gossypol in the medium (0.1 mg/L) was an aid to the steadiness growth of callus in glandless cotton somatic cell culture, with a high rate of embryogenic cells which was in favor of plant regeneration, and it was also relatively easy to obtain regeneration plants when they were transferred into differentiation medium with 0.1 mg/L of vitro gossypol, even for some cultivars which are difficult in somatic cell culture. In addition, the gossypol content and its variation in the seedlings and callus during culture of Coker 312 were discussed, as well as the relationship between gossypol variation in the explants and its somatic cell culture. The probability of vitro gossypol used in cotton somatic cell culture for the improvement of somatic cell culture was suggested.     

棉花细胞壁蛋白基因分离鉴定与表达分析

棉纤维起源于棉花胚珠外层表皮细胞．研究棉纤维发育,具有重要理论和实践意义．从棉纤维等组织cDNA文库中分离了186个棉花细胞壁结构蛋白基因,按照所编码的蛋白质结构特点,可将这些基因分为三类;富含脯氨酸细胞壁蛋白（Proline—rich cell wall proteins,PRPs）基因、伸展蛋白（Extensins）或者富含羟脯氨酸糖蛋白（Hydroxyproline—rich glycoprotein,HRGP）基因,富含甘氨酸蛋白（Glycine—rich proteins,GRPs）基因．采用cDNA microarray技术,比较上述基因在开花后10天的野生型棉花纤维和无絮无绒（fuzzless—lintless,fl）突变体胚珠表皮中表达谱发现,其中有7个基因在野生型纤维中特异性或高效性表达,表明它们可能与纤维发育有关．     

3个编码AP2/EREBP转录因子的基因克隆及其在棉纤维中优势表达的初步分析

从棉花cDNA文库中分离到3个编码AP2/EREBP转录因子的cDNAs序列,命名为GhAP2/EREBP1、GhAP2/EREBP2和GhAP2/EREBP3.利用Real-time RT-PCR对这3个基因表达进行分析,结果表明:GhAPZ/EREBP1和GhAP2/EREBP2在棉花纤维中优势表达,而GhAP2/EREBP3在花药中优势表达,在纤维中表达量也较高.这表明上述3个AP2/EREBP转录因子可能在棉花纤维发育过程中起调控作用.     

Primary analysis of QTG contribution to heterosis in upland cotton

In this paper, we analyzed the contribution of pure DNA factors to heterosis using quantitative trait genes (QTG) in two randomly selected strains from a recombinant inbred line of Gossypium hirsutum. According to a set of QTL mapping results, combined with analysis of DNA recombinant fragment sources in the two strains and QTL association analysis with their field traits, we hypothesize a view of “dominance + overdominance + epistasis”. That is, additive and additive epistasis may be the genetic basis of heterosis, and dominance, overdominance and epistasis may be the modes of heterosis action. Based on the heterosis results of this study, we also suggest a molecular mechanism for heterosis, and explain, in detail, with two randomly selected strains as examples. The male and female parent-derived additive epistatic QTLs of upper half mean length in LG01 and LG03 produced a trait variance of 2.99–3.52 compared with the female parent-derived loci. The trait of bolls per plant was controlled by two pairs of additive epistatic QTLs in LG02 and LG07, which were derived from both female and male parents. The QTLs were reciprocally interacted and produced a trait variance of 0.86. An initial concept of “super-hybrid cotton” was raised according to the nature of additive effect, that is genetic stability.     

Identification of genes associated with cotyledon senescence in upland cotton

Leaf senescence in plants is an essential develop- mental phase, and an understanding of senescence is important not only for pure scientific reasons, but also for practical purposes. During the last decade, a number of senescence-associated genes (SAGs) …