小麦杂交种与亲本发育早期种子的基因表达差异及其与杂种优势关系的初步研究

为深入探讨小麦杂种优势形成的分子机理,选取3个冬小麦品种(系)为一组亲本,3个为另一组亲本,配制了正反交18个杂交组合,以授粉后6d的杂交和自交种子为材料,应用mRNA差异显示技术(DDRT—PCR)研究了小麦杂交当代种子与其亲本自交种子基因的表达差异,并与杂种优势进行相关分析。为降低DDRT—PCR技术假阳性的不利影响,对每个引物组合均作了两次PCR扩增,在处理数据时,仅统计能重复出现的条带。结果发现：杂交种和亲本之间的基因表达模式有8类共15种：(1)单亲沉默型(2种),(2)单亲一致型(2种),(3)正交或反交沉默型(2种),(4)正交或反交特异型(2种),(5)正交或反交单亲一致型(4种),(6)杂交种特异型(1种),(7)双亲共沉默型(1种),(8)表达一致型(1种)。分析发现,小麦杂交种和亲本间存在显著的表达差异。在差异表达类型中,杂交种特异型和双亲共沉默型比例最低。对上述15种表达模式与杂种优势进行相关分析,结果表明,表达一致型与各产量性状杂种优势之间的相关均不显著,说明杂种优势是由某些有表达差异的基因造成。9个产量性状均能检测到一种以上与其显著或极显著相关的基因表达模式,有些性状受正负相关效应的共同影响;沉默型(包括单亲沉默型、正交或反交沉默型和双亲共沉默型)和正交或反交单亲一致型在杂种优势形成中发挥重要作用。这些研究表明,在种子发育早期,基因的差异表达与杂种优势形成之间可能存在较为复杂的关系。     

玉米杂种与亲本穗分化期功能叶基因差异表达与杂种优势

为探讨玉米杂种优势的分子机理,以10个玉米自交系及其组配的38个杂交种为材料,利用cDNA-AFLP技术,分析杂种与亲本在玉米雌穗小穗分化期功能叶片的基因差异表达类型与主要农艺性状的杂种表现及杂种优势的关系。研究表明：（1）杂种的基因相对于其双亲,存在质和量的表达差异,其中质的差异表达类型包括：单亲沉默表达,双亲沉默表达,亲本显性表达和杂种特异表达等类型。（2）在雌穗小穗分化期,同一差异表达类型中不同杂交组合间差异很大;从总体平均看,杂种特异表达类型占25.22%,亲本显性表达类型占21.46%,双亲沉默表达类型占8.27%,单亲沉默表达类型占33.49%。（3）单亲沉默表达与株高的杂种表现呈显著正相关;双亲沉默表达与穗粗的杂种优势呈显著负相关,显性表达与行粒数和单株粒重的杂种优势呈显著负相关,其余表达类型与所有农艺性状杂种表现及杂种优势均不相关,并对结果进行了讨论。     

小麦杂种及其亲本苗期叶片家族基因差异表达及其与杂种优势关系的初步研究

为探讨小麦杂种优势形成的分子机理,以一套双列杂交组合的苗期叶片为材料,利用mRNA差异显示技术分析了杂种及其亲本间MADS－box、G－ box、Ser/Thr蛋白激酶、EIF－4A、ARF1基因家族共5类家族基因在杂交种和亲本之间的表达差异。并与杂种性状表现和杂种优势进行了相关分析。结果发现,除ARF1家族基因外,其余家族基因在杂种和亲本间存在显著的表达差异,差异表达类型可概括为4种：（1）双亲共沉默;（20单亲表达沉默;（3）杂种特异表达;（4）单亲表达一致。分析发现,MADS－box、G－box和EIF－4A家族基因在杂种和亲本间的差异表达模式相似,均以单亲特异表达和种特异表达类型所占比例最高。相关分析结果表明,以上所有家族基因的总体差异表达程度与所有性状的杂种表现均不相关,MADS－box家族基因中杂种特异表达类型与小穗数、单株产量和单穗产量杂种优势呈显著正相关,双亲共沉默类型与小穗数、千粒重和单穗产量杂种优势呈显著负相关,另外,EIF－4A家族基因中单亲表达一致型与单穗产量杂种优势呈显著正相,但双亲共沉默类型与小穗数和单穗产量杂种优势呈显著负相关,对于G－box基因家族而言,仅小穗数杂种优势和双亲共沉默类型成显著负相关,而蛋白激酶家族基因的各种差异类型与性状杂种优势的相关分析均不显著。这些研究表明,调控基因的差异表达与杂种优势形成有密切关系。     

高丹草杂种和亲本叶片基因差异表达研究

以4份高粱不育系和5种类型苏丹草为亲本,按照NCⅡ设计配制成20个杂交组合,分析各组合及亲本的表型值和中亲及超亲优势并筛选出8个优势强的组合为试材,利用cDNA-AFLP技术,分析杂种与亲本苗期叶片基因差异表达类型与主要产量性状的杂种表现及杂种优势的关系。研究表明:(1)12对引物共扩增出315条TDFs,杂种与亲本间基因表达类型有:单亲表达一致一型(P1F1型)和二型(P2F1型)、杂种特异表达类型(F1型)、单亲表达沉默一型(P1型)和二型(P2型)、双亲共沉默类型(P1P2型)和杂种亲本表达一致型(P1F1P2型)7种。(2)在差异展示类型与产量构成因素的相关分析中,有效分蘖数与P1F1型(0.726**)呈极显著正相关,单株鲜重与P1P2型(0.659*)、叶长与P2型(0.647*)呈显著正相关,成株期叶片数与F1型(-0.81**)呈极显著负相关。在与中亲优势相关分析中发现,单株鲜重与P1(0.695*)、P2(0.637*)呈显著正相关,单株鲜重与P1F1P2型(0.743**)呈极显著正相关,叶宽与P1P2型(-0.619*)呈显著负相关。在与超亲优势进行相关分析后发现,穗长与P2F1型(0.732**)呈极显著正相关,叶宽与P2F1型(-0.731**)以及P1P2型(-0.731**)呈极显著负相关。(3)差异展示类型P1F1、P2F1、P1和P2是显性效应类型,共占总检测的91.4%。差异展示类型F1和P1P2表现超显性,共占总检测的4.8%,说明各个性状的杂种表现主要受到的是(超)显性效应影响。(4)对8个与高丹草杂种优势相关的TDFs进行回收及BLAST分析均得到同源核苷酸,并且找到7个同源蛋白,这些蛋白质在控制植物生长发育方面具有重要作用。(5)将克隆测序获得差异片段的核苷酸序列,采用半定量RT-PCR进行了验证。本研究为进一步揭示高丹草杂种优势的分子机制和提高高丹草强优势组合的筛选效率以及种质资源的创建提供依据。     

盛花期抗虫杂交棉及其亲本叶片基因表达差异与杂种优势

采用DDRT-PCR技术,以棉花盛花期项尖叶片cDNA为材料,对上海生物工程公司合成的专用于基因差异显示分析的3个锚定引物和全套26个随机引物进行筛选,最后选择了15个扩增差异带丰富的随机引物。采用3个锚定引物和这15个随机引物组成的45对引物组合对24个抗虫棉杂交组合及其10亲本盛花期叶片cDNA进行扩增和差显,2次扩增重复率达70．1％,表明在扩增过程中存在较高的假阳性,通过重复PCR扩增,统计稳定扩增的条带,可减少假阳性干扰。根据基因表达方式,将其划分5种模式：MI为双亲表达沉默,双亲出现条带而杂种没有条带;M2为单亲表达沉默,带仅出现在亲本之一,包括仅母本有带而父本和杂种无带和仅父本有带而母本和杂种无带2种表达方式：M3为杂种特异表达,带仅出现在杂种,双亲无带;M4为单亲表达一致,带在双亲之一和杂种中出现,而在另一亲本中不出现,包括母本、杂种中有带而父本无带和父本、杂种中有带而母本无带2种方式;M5为基因表达一致,带在双亲和杂种中均出现。差显表达模式比例与产量性状和杂种优势分析表明：M4与所有产量性状均呈正相关,并且与单位面积铃数相关达显著水平,其他各种模式与杂种产量性状表型值均未达到显著水平;M2与单位面积铃数杂种优势呈显著负相关,M3与皮棉产量杂种优势呈显著正相关。上述结果表明,盛花期叶片中的基因显性表达和杂种特异表达有利于产量形成和杂种优势发挥。     

鸡瘦蛋白受体(OBR)基因内含子8单核苷酸多态性与体脂性状的相关研究

以东北农业大学高低脂双向选择系的第 6世代肉鸡为材料 ,鸡 7周龄时测定体重和腹脂重等屠体性状。根据鸡瘦蛋白受体基因内含子 8的序列 (GenBank登陆号 :AF2 2 2 783 )设计引物 ,用直接测序的方法检测多态性位点 ,用PCR SSCP的方法进行基因型分析 ,建立适合的统计模型对多态性位点产生的基因型与生长和体组成性状进行相关分析。结果表明 ,在第 50 0和 659位碱基同时发生了T—C、G—A突变。经最小二乘分析 ,3种基因型在腹脂重和腹脂率上差异显著 (P <0 0 5) ,BB型个体腹脂重和腹脂率显著高于AB型 (P <0 0 5) ,极显著地高于AA型个体 (P <0 0 1) ;3种基因型在肝重上差异显著 (P <0 0 5) ,且AA基因型个体的肝重显著低于AB和BB基因型个体。初步推断OBR基因可能是影响鸡脂肪性状的主效基因或与主效基因连锁 ,推测可以利用这个多态位点对鸡的体脂性状进行标记辅助选择     

普通小麦不同优势杂交种及其亲本苗期根系基因的差异表达

为探讨小麦 (TriticumaestivumL .)杂种优势形成的分子机理 ,选用普通小麦品种 (系 ) 3338、6 5 5 4和 2 410TD及其强优势杂种A(3338× 6 6 5 4)和无优势杂种B(2 410TD× 6 5 5 4) ,采用mRNA差异显示技术 ,对生长至三叶一心的根系 (初生根 )基因表达差异进行了比较研究。结果发现 ,小麦杂种一代苗期根系基因表达较亲本明显不同 ,表现为数量水平和质量水平上的差异 ,且差异表达基因的数目远高于我们以苗期叶片为材料的研究结果 ,表明小麦杂交种与其亲本间的基因差异表达与所研究的组织和器官有关。比较分析发现 ,在强优势杂种组合A中 ,超亲表达和偏高亲表达基因所占比例均明显高于无优势杂种组合B。以家族特异基因替代随机引物进行的差异显示结果表明 ,MADS_box家族基因在小麦杂交种和亲本苗期根系中存在着显著的表达差异 ,且差异表达类型以杂种特异表达和亲本基因在杂种一代沉默为主 ,说明MADS_box家族基因可能与小麦的杂种优势形成具有重要关系。对杂种和亲本基因表达差异与杂种优势的关系进行了分析和讨论     

香菇杂交子农艺性状与差异基因表达类型的相关性研究

以香菇(Lentinula edodes)4个菌株为亲本组成3个杂交组合,采用单孢菌株配对获得杂交子,观察锁状联合鉴别出真正的杂交子,测定杂交子及其亲本的农艺性状。在每个杂交组合中分别各选取3个杂交子,研究杂交子和亲本在子实体发育阶段差异基因表达情况。结果表明:杂交子共有4种基因表达类型:双亲沉默型(W1型),单亲沉默型(W2型),杂交子特异表达型(W3型),单亲表达型(W4型)。香菇杂交子农艺性状与基因差异表达类型的相关性分析表明:菌盖厚与双亲沉默型(W1型)呈极显著负相关,而菌柄长与单亲沉默型(W2型)呈显著负相关。     

鸡Myostatin基因单核苷酸多态性与骨骼肌和脂肪生长的关系

肌肉生长抑制素是控制骨骼肌生长发育的重要细胞因子. 采用PCR-SSCP 和DNA测序的方法检测了Myostatin基因单核苷酸多态性, 利用CAU资源家系对所发现的Myostatin单核苷酸多态性与屠体重、胸肌重、腿肌重、肝重和腹脂重等性状进行了关联分析. 结果表明, P60/61位点基因型(AA, BB和AB型)对12周龄腹脂重、腹脂率、初生重、胸肌率有影响(P < 0.05): AA型腹脂重显著高于BB型(P < 0.05); AA和AB型腹脂率显著高于BB型(P < 0.05); AA型的初生重显著高于BB型(P < 0.05); AA型胸肌率显著高于AB型(P < 0.05). P80/P81位点基因型(CC, DD和CD型)与胸肌重(P < 0.05)和胸肌率(P < 0.01)相关: CC型与DD型之间的胸肌重差异显著(P < 0.05), CC型的胸肌重较高; CC型与DD型之间的胸肌率差异极显著(P < 0.01), CC型和CD型之间差异显著(P < 0.05), CC型比CD和DD型的胸肌率高, 而CD型的胸肌率也比DD型的高(P < 0.05). P93/94位点基因型(EF和EE型)与胸肌率有显著相关(P < 0.05): EF型比EE型具有更高的胸肌率. 研究表明, Myostatin基因的功能不但与骨骼肌的生长发育有关, 而且, 更重要的是可能参与脂肪的代谢与沉积.     

普通小麦不同优势杂交种及其亲本苗期根系基因的差异表达

为探讨小麦(Triticum aestivum L.)杂种优势形成的分子机理,选用普通小麦品种(系)3338、6554和2410TD及其强优势杂种A(3338×6654)和无优势杂种B(2410TD×6554),采用mRNA差异显示技术,对生长至三叶一心的根系(初生根)基因表达差异进行了比较研究.结果发现,小麦杂种一代苗期根系基因表达较亲本明显不同,表现为数量水平和质量水平上的差异,且差异表达基因的数目远高于我们以苗期叶片为材料的研究结果,表明小麦杂交种与其亲本间的基因差异表达与所研究的组织和器官有关.比较分析发现,在强优势杂种组合A中,超亲表达和偏高亲表达基因所占比例均明显高于无优势杂种组合B.以家族特异基因替代随机引物进行的差异显示结果表明,MADS-box家族基因在小麦杂交种和亲本苗期根系中存在着显著的表达差异,且差异表达类型以杂种特异表达和亲本基因在杂种一代沉默为主,说明MADS-box家族基因可能与小麦的杂种优势形成具有重要关系.对杂种和亲本基因表达差异与杂种优势的关系进行了分析和讨论.     

History of Modern Chromosomal Analysis. Differential Staining of Plant Chromosomes

Differential staining methods found extensive use in karyotype studies of many plant and animal species and provide for reliable identification of all chromosomes of the organism. Below we describe the most widespread methods and history of their advent. In addition, we discuss specific structure of the chromosomes and possible mechanisms responsible for differential segmentation.     

差异显示技术及其研究进展

差异显示技术是分离差异表达基因的重要方法与手段,同其它研究基因差异表达的方法如RDA,SSH,SAGE相比,差异显示技术是其中使用频率较高的方法。该技术自1992年创立以来,经过各国研究者不断完善与改进,现已大大克服以往诸多不足,扩大了应用领域。本文就差异显示技术的原理及主要优缺点作以简要概述,并着重就引物设计、降低假阳性、鉴定差异表达基因及差异显示技术的衍生技术这4个方面的研究进展作以详尽介绍。     

Multiomics analysis on DNA methylation and the expression of both messenger RNA and microRNA in lung adenocarcinoma

Lung adenocarcinoma (LUAD) poses a significant threat to public health worldwide, while the genetic and epigenetic abnormalities involved in the oncogenesis of LUAD remains unknown. This study aimed to identify and validate key genes during the development and progression of LUAD by multiomics analysis. First, Empirical Analysis of Digital Gene Expression Data in R (EdgeR) was used to identify differentially regulated genes between normal samples and LUAD samples. Then significance analysis of microarrays (SAM) was used to identify differentially methylated genes and regulated microRNAs (miRNAs) between normal samples and LUAD samples. Following that, Kyoto Encyclopedia of Genes and Genomes (KEGG)-enrichment analysis was used to analyze the function that these genes enriched in. A total of 4,816 genes, 419 miRNAs, and 4,476 methylated genes that were significantly differentially expressed corresponding to the normal tissues in LUAD were obtained, and some of the pathways these genes enriched in were the same. Moreover, 255 genes differentially methylated and expressed at the same time were also found, and these 255 genes were the target genes of the miRNAs differentially expressed in LUAD. Finally, nine genes (BRCA1, COL1A1, ESR1, FGFR2, HNF4A, IGFBP3, MET, MMP3, and PAK1) network analysis, and two of which were found to be related to the survival of LUAD patients. In summary, a total of nine genes that may play important roles in the development of LUAD were identified, and two (PAK1 and FGFR2) of them can be served as prognostic biomarkers for LUAD patients. The genes found in this study played different roles in the tumor progression of LUAD, indicating these genes may be considered as potential target genes for LUAD treatment.     

喉癌差异表达cDNA序列的分离与初步鉴定

分离和克隆人喉癌中新的相关基因将有助于提示喉癌的易感性与癌变机制。运用ｍＲＮＡ差异显示法对２例成人喉癌组织及配对癌旁正常组织的基因表达进行研究,分离到３５个差异显示片段;用反向Ｎｏｒｔｈｅｒｎ点杂交筛选到６个差异片段,经克隆、测序和匹配分析,得１２条不同ｃＤＮＡ序列,其中４条为新基因序列,另外８条与已知基因高度同源。将１２条ｃＤＮＡ序列固定在膜上,用来自喉癌和配对正常组织的总ｃＤＮＡ探针与其杂交和     

The dynamic systems approach to control and regulation of intracellular networks

Systems theory and cell biology have enjoyed a long relationship that has received renewed interest in recent years in the context of systems biology. The term 'systems' in systems biology comes from systems theory or dynamic systems theory: systems biology is defined through the application of systems- and signal-oriented approaches for an understanding of inter- and intra-cellular dynamic processes. The aim of the present text is to review the systems and control perspective of dynamic systems. The biologist's conceptual framework for representing the variables of a biochemical reaction network, and for describing their relationships, are pathway maps. A principal goal of systems biology is to turn these static maps into dynamic models, which can provide insight into the temporal evolution of biochemical reaction networks. Towards this end, we review the case for differential equation models as a 'natural' representation of causal entailment in pathways. Block-diagrams, commonly used in the engineering sciences, are introduced and compared to pathway maps. The stimulus-response representation of a molecular system is a necessary condition for an understanding of dynamic interactions among the components that make up a pathway. Using simple examples, we show how biochemical reactions are modelled in the dynamic systems framework and visualized using block-diagrams.     

不同抗逆性菠萝品种的差异基因和差异代谢物分析

该研究对2个不同抗逆性的菠萝品种PZ2(抗逆性较差)和PZ3(抗逆性强)进行转录组和代谢组比较分析,以探索品种间抗逆性差异的分子生理机制,为菠萝抗性育种提供理论依据。(1)转录组结果显示,以PZ2为对照,在2个品种间共筛选到1 667个差异表达基因,上调和下调的差异表达基因分别为770个和897个;其中筛选到20个与抗逆性相关的差异表达基因,包括WRKY和MYB转录因子基因以及ASR3、SOD1、POD48、HSP20、GSTF1、GSTU17等基因。(2)代谢组分析表明,以PZ2为对照,在2个品种间共筛选到208个差异代谢物,含量上调和下调的差异代谢物分别为98个和110个,其中22种差异代谢物与抗逆性相关,包括氨基酸及其衍生物、脂类、黄酮类、糖类和糖苷等。(3)qRT PCR分析验证表明,所选的8个差异表达基因在菠萝品种PZ2与PZ3中的差异表达趋势与转录组测序中差异基因表达水平变化趋势基本一致。(4)关联分析表明,差异表达基因和差异代谢物共同富集的通路有类黄酮生物合成,苯丙素生物合成,莨宕烷、哌啶和吡啶丙酸盐生物合成,半胱氨酸与蛋氨酸代谢等4条。研究发现,抗逆性强的菠萝品种的非生物逆境反应相关基因、抗氧化酶基因、逆境响应结构基因和调控基因的表达水平高于抗逆性较差的品种,且黄酮类、氨基酸衍生物类及木脂素、脂质等代谢物的含量也高于抗逆性较差的品种。     

Identification and characterisation of imprinted genes in the mouse.

Imprinted genes are expressed specifically from one or other parental allele. Over 70 are now known, and about one-half of these are expressed from the paternal allele and one-half from the maternal allele. Most imprinted genes are clustered within imprinting regions of the mouse genome, regions which are associated with abnormal phenotypes when inherited uniparentally. Imprinted genes have been identified from surveys based on differential expression or differential methylation according to parental origin, as well as analyses of candidate genes, mutants and imprinted gene clusters. Many imprinted genes affect growth and development, and more than 25 per cent determine non-coding RNAs that may have a function in controlling imprinted gene expression.     

Intermediate variables in the explanation of differential fertility: Results of a village study in rural Java

A tendency for fertility to be higher among middle-class women than among lower-class women has been found in all the recent sources of data on fertility levels and patterns in Indonesia. After briefly reviewing these findings, this article presents the results of a community study in rural Java which systematically investigates the positive relation between fertility and socioeconomic status, focusing on the so- called intermediate variables (first inventoried by Davis and Blake in 1956) which directly determine fertility. Differential patterns of marital stability, secondary sterility, and the practice of postpartum abstinence in particular were found to contribute to the contrasts in fertility levels observed. The use of modern contraceptives, a recent innovation at the time of the study, was found to a greater extent among middle-class women, and may prove to be an important determinant of future patterns of fertility and fertility differentials.This article is based on a study of fertility patterns undertaken in Yogyakarta during 1972–1973. The research was funded by the Australian National University. A complete account of the research findings is contained in Hull (1975), and a detailed analysis of the topics discussed here can be found in Hull (1976).     

Periodicity computation of generalized mathematical biology problems involving delay differential equations

In this paper, we consider a low initial population model. Our aim is to study the periodicity computation of this model by using neutral differential equations, which are recognized in various studies including biology. We generalize the neutral Rayleigh equation for the third-order by exploiting the model of fractional calculus, in particular the Riemann–Liouville differential operator. We establish the existence and uniqueness of a periodic computational outcome. The technique depends on the continuation theorem of the coincidence degree theory. Besides, an example is presented to demonstrate the finding.