MBg-2 Gene concept

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,第,2,章,基因的概念,Concept of the Gene,True-False Question,All gene products are polypeptides.,Answer:,False.,Some genes produce functional,RNAs,as the terminal genetic product (e.g., ribosomal and transfer RNA genes).,经典的基因概念,基因概念的演变与发展,基因的分子结构,基因概念的多样性,1866. -1926.,经典的基因概念,早期的基因概念,融合遗传理论,（,Blending inheritance,）,子代具有父，母双亲的性状,母本体液,父本体液,+,B.C.460 - 370,Hippocrates,Ancient Greece physician,希波克拉底（古希腊名医）,获得的性状是由环境影响,(,非遗传物质的改变,),物种,加强和完善对环境的适应,逐渐转变为新种,新性状一旦获得,便能遗传给后代,获得性遗传理论,Inheritance of acquired characters,Jean-,Baptiste,de Lamarck 1744-1829,泛生论假说,（,Hypothesis of the Pangenesis,）,Panger,C. Darwin,1868,种质论,(W,eismann,老鼠尾巴切割实验,切割,22,代,第,23,代仍有尾巴,),（,Theory of,germplasm,Weismann,1883.,）,Germplasm,Somatoplasm,（体细胞）,Root, Stem, Leaf,Somatoplasm,Germplasm,Germplasm,1834-1914,遗传因子假说,(Hypothesis of the inherited factor,G. J. Mendel,1866.,),生物性状由遗传因子控制,亲代传给子代的是遗传因子,(,A,a,.),遗传因子在体细胞内成双,(,AA,aa,),在生殖细胞内为单（,A,a,）,杂合子体细胞内具有成双的遗传因子,(,Aa,),等位的遗传因子独立分离,非等位遗传因子间自由组合地分配到配子中,Theory of the gene,基因是染色体上的实体,基因象链珠,(bead),一样，孤立地呈,线状地排列在染色体上,基因是,(Three in one),；,功能,(functional unit),突变,(mutation unit),交换,(cross-over unit),“,三位一体,”,的,最小的,不可分割的,基本的,遗传单位,(1926,T. H. Morgan,),基因概念的,演变与发展,分子生物学史的第一个重要发现,One gene,One enzyme,The one gene-one enzyme hypothesis is the idea that genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn affects a single step in a metabolic pathway.,It is often considered the first significant result in what came to be called molecular biology. Although it has been extremely influential, the hypothesis was recognized soon after its proposal to be an oversimplification.,Even the subsequent reformulation of the one gene-one polypeptide hypothesis is now considered too simple to describe the relationship between genes and proteins.,1941,年，,George Beadle,和,Edward Tatum,Neurospora,crassa,（,粉色面包霉菌,）,提出的“,one gene one enzyme,”,的假说,（,获得,1958,年,Nobel,奖,）,说明了基因的生化作用本质是控制酶的合成,G. Beadle & E. Tatum,生物化学和遗传学之间的联合迈出的第一步，也是分子生物学的第一个重要发现,基因的位置效应,Position effect,Bar eye,Position effect,Dosage effect,Duplication,Wild type,16A,780,个,68,个,45,个,chromosome,Sturtevent,385,个,（,Ww in,euchromatin,常染色质）,（,W gene be silenced,in heterochromatin,异染色质,),W,W,w,w,Ww,Red eye,Ww,white eye,Position effect,Why ?,Epigenetics,!,Epigenetics,表观遗传学,Epigenetics is the study of heritable changes in phenotype (appearance) or gene expression caused by mechanisms other than changes in the underlying DNA sequence, hence the name,epi-,(Greek: over, above),-genetics,.,These changes may remain through cell divisions for the remainder of the cells life and may also last for multiple generations. However, there is no change in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organisms genes to behave (or express themselves) differently.,拟等位基因概念的提出,（,pseudo alleles,）,Multiple alleles,a1,A a2,a3,A,a1,a2,a1a1 a2a2,a1a2 ( no wild type ),野生型基因,A,向不同方向发生突变形成不同的等位基因,a1, a2, a3 .,又总称为复等位基因,multiple alleles.,But !,W,w,-,w,a,red eye (,w.t,),X,w,-,X,wa,X,w,-,Y,X,w,-,Y,X,w,-,X,w,-,X,w,-,X,w,-,Y,X,wa,X,w,-,X,wa,X,wa,Y,?,1/1000,W.T,red eye,white eye (,mut,),amygdaloid,eye (,mut,),in Drosophila,migd.lid,杏仁色,紧密连锁,（交换率极低）,功能相同,（表型相似）,Pseudo Alleles,A1,A2,a1 a2,W,.t,Mut,.,A1,a2,a1,A2,(,mut,),(,mut,),When two mutations in the same,cistron,give rise to different phenotypes in the,cis,and trans conditions respectively, called,(A),Pseudoalleles,(B) Pseudogene,(C),Pseudogamy,(D) None of the above,(Answer: A),拟等位基因：紧密连锁，控制同一性状的,非等位基因,! ? !,pseudo alleles,是基因内的突变体,.,Processed,pseudogenes,arise from integration of reverse transcribed mRNAs. When reverse transcriptase is present in a cell, mRNA molecules can be copied into,dsDNA,. In rare instances, these DNA molecules can integrate into the genome creating,pseudogenes,. Because,introns,are rapidly removed from newly transcribed,RNAs,these,pseudogenes,have the common characteristic of lacking,introns,. This distinguishes the,pseudogene,from the copy of the gene from which it was derived. In addition,pseudogenes,lack the appropriate promoter sequences,to direct their transcription as these are not part of the mRNA from which they are derived.,Pseudogene,Pseudogenes,are dysfunctional relatives of known genes that have lost their protein-coding ability or are otherwise no longer expressed in the cell.,顺反子理论,Theory of cistron,(S.,Benzer 1955),对经典的基因概念的,第一次重要修正与发展,Strptococcum,pneumonice,DNA as genetic material,1941. Beadle & Tatum,N,e,ur,o,spora,crassa,One gene -one enzyme,1944 Oswald Avery (Canada),Jacob & Monod,Escherichia coli,Lactose,operon,1955.,S.Benzer,E. coli,T4 phage,Cistron,理论基础,Theory of,cistron,Mut.T4,rII,: rII107, rII105, rII51, rII47(400),Phage,E.coli,B,E.coli,k12,Plaque,W.t,T4,Mut.T4,rII,白,小,边缘模糊,白,小,边缘模糊,大,园,边缘清晰,！,Seymour,Benzer,1955,Cis,: Latin: on this or the near side of.,Trans,: Latin: across, beyond, crossing, on the other side.,Cistron,and,cis,-trans complementation test, mutations in two,cistrons,and can complement one another, and produce wild-type phenotype. A and B represent two,cistrons,or two genes., mutations in the same,cistron,do not complement one another, and produce no wild-type phenotype. A and B represent two,cistrons,or two genes.,顺反子假说,（,Theory of,cistron,）,Cistron,是基因的同义词,在一个顺反子内，有若干个突变单位,突变子,(,muton,),在一个顺反子内，有若干个交换单位,交换子（,recon,）,基因是一个具有特定功能的，完整的，不可分割的,最小的遗传单位,基因内可以较低频率发生基因内的重组，交换,pseudo alleles,是基因内的突变体,mut1 X mut2,W.t,是基因内发生交换的结果,cistron,概念的提出,是对经典的基因概念的动摇,是对,pseudo alleles,概念的修正,three in one,one,in one,等位基因（,Allele, Allomorph,）概念的发展,Pseudo allele,Allele,同一,座位,存在的两个以上,不同状态,的基因,其总和称,之为复等位基因（,multiple alleles,）（,A, a1, a2.,）,全同等位基因,(,homoallele,),非全同等位基因,(,heteroallele,),Allele,具有相对差异的,DNA,区域,TAAAG,T,AAT,TAAAG,C,AAT,(,非全同等位基因,),site,Gene locus,Mut,a1,Mut,a2,W.t,A,Mut,a1,Mut,a2,ATTC,T,GAGCT,ATTC,G,GAGCT,ATTC,A,GAGCT,ATTC,G,GAGCT,ATTC,A,GAGCT,(mut2),ATTC,A,GAGCT,ATTC,G,GAGCT,(mut1),全同等位基因,在同一基因座位,(,locus,),中，同一突变位点（,site,）向不同方向发生突变所形成的等位基因,(,homoallele,),非全同等位基因,；在同一基因座位（,locus,）中，不同突变位点（,site,）发生突变所形成的等位基因。,(,heteroallele,),site,Gene locus,Mut,a1,Mut,a2,site,W.t,A,Mut,a1,Mut,a2,ATTCTGAGCT,TTC,G,GAGCT,ATTCTGAG,A,T,ATTC,G,GAGCT,ATTC,G,GAG,A,T,(,mut,),ATTCTGAG,A,T,ATTCTGAGCT,(,W.t,),Summary,Benzer,关于顺反子理论的提出不仅将基因的 “三位一体,”,的经典概念修正为基因的 “一位一体,”,概念,而且,动摇或否定了 “拟等位基因,”,的概念,认为拟等位基因实际上是基因内不同位点的突变体,是复等位基因的不同成员,.,同时将 “在同一基因座位,(locus),中,同一突变位点向不同方向发生突变所形成的等位基因” 称为全同等位基因,(,homoallele,).,将“在同一基因座位中,不同突变位点发生突变所形成的等位基因” 称为非全同等位基因,(,heteroallele,).,Gene locus,In the diploid cells of an organism, there can be _ different,allele(s,) of a given single-copy nuclear gene.,Only one,One or two,One, two, three or four,Many,ANSWER: One or two,In a population, there can be _,allele(s,) of a given single-copy nuclear gene.,Only one,One or two,One, two, three or four,Many,ANSWER: Many,Question,a,b,c,d,e,The diagrams represent stages in cell division by mitosis. (only one chromosome is represented). What is the correct sequence of events?,(d),d b a c e,(c),b a d c e,(,b,) b a c e d,(a),a b c d e,Next slide,The chromosomes shorten and thicken (,b,),after,they have appeared in the nucleus (,b,). Similarly at the end of cell division, the chromosomes extend and become less visible (,d,),after,the cell divides (,e,),No,Yes,This is the correct sequence,The cell does not start to divide (,d,) until the,chromatids,have separated (,c,). Also, cell constriction (,e,) precedes cell division (,d,),No,No,Cell division (d) does not take place until the,chromatids,have appeared (b) and separated (c). Also, cell constriction (e) precedes cell division (d),操纵子理论,(Lactose,operon,1961. Jacob, Monod ),Lac.,Operon,Lactose,I P O Z Y A,z,y,a,生物体性状的表现往往具有,上位性互作,的遗传效应,某一基因功能的表现,是若干基因组成的信息表达的整体行为,one gene one function,(,Ribozyme,Abzyme,（抗体酶）,rDNA,tDNA,.),o,ne gene one enzyme,tDNA,rDNA, polymer,one gene one peptide,（缩氨酸）,transcribed, translatable gene,( Z,Y,A ),transcribed but non-translatable gene,(,tDNA,rDNA, small RNA. ),Non- transcribed, non-translatable gene,( promoter, operator ),基因的类型,cis,action factor,(,基因表达调控因子,:,顺式作用因子,),Affects the activity only of DNA sequences on its own molecular of DNA, this property usually implies that the factor does not code for protein,通过核苷酸自身的特异二级结构控制与它紧密连锁的结构基因的表达,一般不编码蛋白质,(,无基因产物的,DNA,功能区,), trans action factor,(,基因表达调控因子：反式作用因子,),Affects the activity of any gene located on genome by its translated product.,通过扩散自身表达产物（酶，调节蛋白）控制其他基因的表达,可转录，可翻译调节蛋白的,DNA,功能区,可通过互补测验体系确定其功能区域,DNA is a main genetic material,Hershey,lambdar,phage cycle,Watson & Crick,DNA double helix,RII,DNA,SIII,1928 Griffith 1944 Avery O.T,DNA,是主要的遗传物质,DNA,编码两类遗传信息,II,类；特定,DNA seq. +,特定蛋白质,/,核酸结合,基因表达的指令,gene on,/,off,I,类；,DNA seq. RNA seq. (,codon,),aa,seq. protein,phenotype (central dogma),内在信息,内,外,(,信号分子,),结合信息,ORF only Helix ,Nt,seq,.,遗传信息存在于模版链,三维空间结构,/,DNA,序列,的一级结构上,(IR, Box,paracodon,),三联体密码,空间，调控密码,(,key & lock,),简并,(degeneration),简并,(degeneration),Wobble,Iso,-acceptor,（同功受体）,cis,1 trans 2,cis,2,trans 1,cis,1,trans 3,cis,3,I,类,II,类,expression by,specific binding,aa,base,DNA RNA protein,DNA,作为遗传物质的优点,(,自然选择的优势,),储存遗传信息量大,1kb DNA,序列,4,1000,种遗传信息,核糖的,2 OH,脱氧,在水中的稳定性高于,RNA,可以突变,方便修复,以求不断进化,以求稳定遗传,A / T, C / G,互补,双螺旋结构,复制,转录,遗传稳定,DNA,中如有,U,潜在的遗传危险,?,错配修复系统,倾向除,U,插,C,G/C G/U,G/C,DNA,中有,T,无,U,无后顾之忧,DNA,扩增,进化, DNA,中有,T,无,U,是进化的结果,C U,突变,错配修复系统不能识别两种,U,，难以对突变进行修复,基因的分子结构,Nucleic Acid (,NA,),Polynucleotide chain (,poly,Nt,),Nucleotide,(,Nt,),basic unit,Mono-phosphate (,Mp,),Nucleoside (,Ns,),Deoxy,-ribose,脱氧核糖,(,Ribose,),Base,Purin,e,(,pu,),Pyrimidine,(,py,),Ade,n,ine (A) Thymine (T),Guanine (G),Uracil,(U),Cytosine (C),基因是,DNA,分子的片段,DNA,1. Double helix,Bases,(,碱基,),:,DNA,adenine(A,),guanine(G,) are,purines,;,cytosine(C,),thymine(T,) are,pyrimidines,RNA, ,uracil,(U),Nucleotides:,base + sugar + phosphate = nucleotides,(,核苷酸,),The nucleoside 5-triphosphates (,NTPs,or,dNTPs,) are respectively the building blocks of polymeric RNA and DNA,Nucleosides,: base + sugar = nucleoside,(,核苷,),RNA:,ribonucleosides,or just nucleosides;,DNA: 2-deoxyribonucleosides or just,deoxynucleosides,Phosphodiester,bonds,: covalent linkage of a phosphate group between the,(,磷酸二脂键,),5-hydroxyl of a ribose and the 3-hydroxyl of the next. At neutral pH, each phosphate group has a single negative charge.,Nucleic acids are thus highly charged polymers.,DNA/RNA sequence,: The nucleic acid sequence is the sequence of bases,A, C, G, T/U in the DNA/RNA chain. The sequence is,conventionally written from the free 5- to the free 3- end,of the molecule,5- ATTAGCTC- 3(DNA) , 5- AUAGCUUGA-3 (RNA),DNA double helix,DNA,是右手螺旋,(,right-handed double helix,),。,双螺旋包括两条多核苷酸链,.,磷酸,-,核糖骨架,(back-bone),在外侧，含氮碱基层状排列在双螺旋内部。,两条多核苷酸链的碱基通过氢键,(,hydrogen bonding,),互作。,双螺旋每一圈有,10,个碱基对,(,base pairs,),，长度为,34 Angstroms,，螺旋 的直径,20 Angstroms,。,双螺旋的两条链是反向平行互补的,(,anti-parallel and complementary,),。,双螺旋有两种不同的沟,:,major grooves,and minor grooves,。,Major grooves: the place for gene expression regulation.,Nucleotide (,Nt,) basic unit,A portion of a DNA polynucleotide chain, showing the 3,5,phosphodiester,linkages that connect the nucleotides. Phosphate groups connect the 3 carbon of one nucleotide with the 5 carbon of the next.,The nucleotides of DNA. The structures of the different components of each of the four nucleotides are shown.,A portion of a,polyribonucleotide (RNA) chain.,Elements in red are distinct from DNA.,Distinctions between the nucleotides of RNA and DNA. A nucleotide of DNA is shown next to a nucleotide of RNA. All RNA nucleotides have the sugar ribose (instead of,deoxyribose,for DNA), which has a hydroxyl group on carbon 2 (shown in red). In addition, RNA has the,pyrimidine,base,uracil,instead of thymine. The three other bases that occur in DNA and RNA are identical.,Which of the following is a true statement regarding messenger RNA (mRNA)?,A. mRNA is single stranded while DNA is double stranded.,B. mRNA uses a,uracil,nucleotide instead of thymine but all other nucleotides are used by both nucleic acid species.,C. RNA nucleotides use a ribose sugar while DNA nucleotides use a,deoxyribose,sugar.,D. all of the above,Answer: D,核苷的构象,( conformation of nucleoside ), = C4-N9-,-,C1-O4,purin,e,pyrimidine, = C2-N1-,-,C1-O4,0,o,0,o,DNA,双螺旋结构模型,(DNA Double Helix Model),1938. W. T.,Astbury,1950. Erwin Chargaff,A + G / T + C = 1,A+T = G + C,1952.,Alexander Todd,NtNt,NtNtNt,X ray photograph of DNA,Rich AT form & rich GC form,3, 5,phosphodiester,bond,1953. Watson & Crick,Right handed B-form DNA,Double helix Model,碱基的重叠与堆积,G-C pair, held together by three hydrogen bonds,A-T pair , held together by two hydrogen bonds,1,6,2,3,4,2,The hydrogen-bonded base pairs of DNA.,The figure shows the position and length of the hydrogen bonds,between the base pairs. The covalent bonds between the atoms within each base are shown, but double and single bonds are not distinguished.,Question,In a DNA molecule, which of the molecules listed below pairs with adenine?,(d),cytosine,(c),valine,(b),guanine,(a),thymine,Next slide,thymine,Yes,adenine,No,guanine,cytosine,Guanine pairs with cytosine,No,Valine,is an amino acid and not an organic base,No,cytosine,guanine,Cytosine pairs with guanine,l,碱基顶部基团裸露在,DNA,大沟,内,l,蛋白质因子与,DNA,的特异结合依赖于,氨基酸与,DNA,间的氢键的形成,l,蛋白质因子沿,大沟,与,DNA,形成专一性,结合的机率与多样性,高于沿小沟,的结合,l,大沟的空间,更有利于与蛋白质的结合,DNA,双螺旋的结构特点,The helical structure of DNA. (a) Schematic model of the double helix. One turn of the helix (3.4 nm) spans approximately 10.5 base pairs, (b) Space-filling model of the double helix. The sugar and phosphate residues in each strand form the backbone, which are traced by the yellow, gray, and red circles, showing the helical twist of the overall molecule. The bases project inward but are accessible through major and minor grooves.,Formation of nucleotide by removal of water. The numbers of the,carbon atoms in 2-deoxyribose are labeled in red.,Right handed B-form DNA,Double helix Model,每一单链具有,5 3,极性,两条单链间以氢键连接,两条单链，极性相反，,反向平行,以中心为轴，,向右盘旋,(B-form),双螺旋中存在,大沟,( 2. 2nm ),小,沟,( 1. 2nm ),影响双螺旋结构稳定性的因素,碱基堆积的棒状实体,氢键,(Hydrogen bond 46,kc,/ mol),消除,DNA,单链上磷酸基团间的静电斥力,弱键,可加热解链,氢键堆积,有序排列,(,线性,方向,),磷酸酯键,(,phosphodiester,bond 8090,kc,/ mol),0.2 mol / L Na,+,生理盐条件,强键,需酶促解链,l,碱基堆积力,(,非特异性结合力,),3.4A,( 1,kc,/ mol 0.6kc / mol ) n,(,热运动消耗,),磷酸骨架,氨基,酮基周围水分子间的有序排列,Van de,waals,force,(,1.7A/,嘌呤环与嘧啶环作用半径,),(,0.34 nm/,碱基对间距,),疏水作用力,(,Hydrophobic interaction,),不溶于水的非极性分子在水中相互联合,成串结合的疏水作用力，即为,熵,Entropy,（,S,）,DNA,分子中非极性碱基的,重叠,聚集,产生疏水作用力,成为碱基间的部分堆积力,磷酸基团间的静电斥力,碱基间的挤压、抵御使其内能增加,碱基间有,序排列的状态破坏（氢键作用力被减弱）,影响双螺旋结构稳定性的因素,氢键,(Hydrogen bond 46,kc,/ mol),磷酸酯键,(,phosphodiester,bond 8090,kc,/ mol),0.2 mol / L Na,+,生理盐条件,碱基堆积力,(,非特异性结合力,),磷酸基团间的静电斥力,碱基间的挤压、抵御使其内能增加,碱基间有,序排列的状态破坏（氢键作用力被减弱）,DNA,分子变性,( DNA,denaturation,),D.S. DNA,S.S. DNA,(,加温,极端,pH,尿素,酰胺,),变性过程的表现,S.S.,DNA,粘度降低,D.S DNA S.S DNA,粘度降低,？,溶液粘度,取决于分子流动过程中的,内摩擦和阻力,高分子溶液,普通溶液,线状分子,不规则线团,球形分子,D.S. DNA,钢性较强，结构较为舒展的,Double helix,S.S. DNA,没有氢键的支撑,由螺旋结构向折叠和线团结构转变,D.S DNA S.S DNA,粘度降低,变性过程的表现, S.S.DNA,沉降速度加快, S.S.DNA,分子的,A 260 nm UV,值上升,(,Hyperchromicity,增色效应,),1.185,1.0,1.37,OD,= OD,增加值的中点温度,(,一般为,85-95),Tm,(melting temperature),= midpoint of the temperature range over which DNA is denatured,芳香环的不断暴露,Concentration 50g/ml,Optical Density,D.S DNA A,260,= 1,S.S DNA A,260,= 1.37,dNTPs,A,260,= 1.60,l,增色效应的跳跃现象,( Jump of,Hyperchromicity,),高分子量的,DNA,分子在热变性过程中,富含,AT,区域首先发生,变性,然后逐步扩展,表现增色效应的跳跃现象,使变形过程加快,.,rich AT,rich AT,影响,Tm,值的因素,在,A, T, C, G,随机分布的情况下, GC%,含量相同的情况下,GC%,愈高, Tm,值愈大,GC%,愈低, Tm,值愈小,AT,形成变性核心，变性加快，,Tm,值小,碱基排列对,Tm,值具有明显影响（除变性核心外）,（相同碱基组成,但不同排列,堆积力的差异,）,G C,C G,5,3,5,3,T A,A T,5,3,5,3,小,大,堆积力,稳定性,Tm,值,UAA,DNA,的呼吸现象,TATA Box,大片段,D.S. DNA,分子之间比较,片段长短对,Tm,值的影响较小,与组成和排列相关,小于,100bp,的,D.S DNA,分子比较,片段愈短，,变性愈快，,Tm,值愈小,变性液中含有尿素，酰胺等,尿素，酰胺与碱基间形成氢键,改变碱基对间的氢键,Tm,值可降至,40,左右,(,变性凝胶,),盐浓度的影响,单链,DNA,主链的磷酸基团,负电荷的静电斥力,两条单链,DNA,的分离,Na,+,在磷酸基团周围形成的电子云,对静电斥力产生屏蔽作用,减弱静电斥力,Tm,当,Na,+,浓度低,屏蔽作用小,斥力加强,Tm,静电斥力,熵值（,S,）,Tm,OD A260,0.01M,0.1M,1.0M,Na,+,当,Na,+,浓度高,屏蔽作用大,斥力减弱,熵值,(S),上升,碱基溶解性降低,疏水作用力增加,强,弱,弱,强,2.3.6. DNA,分子的复性,(anneal or,renaturation,),D.S DNA,S.S DNA,Denaturation,Renaturation,复性过程依赖于单链分子间的,随机碰撞,Depends on the collision of,complementary S.S. DNA,影响,DNA,复性过程的因素,阳离子浓度,0.18 0.2M Na,+,可消除,poly-,dNt,间的静电斥力,复性反应的温度,Tm - 25 (60-65),以消除,S.S. DNA,分子内的部分二级结构,S.S. DNA,分子的长度,S.S. DNA,愈长,S.S. DNA,愈短,分子扩散愈慢,复性愈慢,分子扩散愈快,复性愈快,影响,DNA,复性过程的因素,：,DNA,分子中,dNt,的排列状况,(,随机排列,重复排列,),S.S, DNA,的初始浓度,C,0,3-ATCTATGCTGTCAT-5,5-TAGATACGACAGTA-3,5-TAGATACGACAGTA-3,3-ATCTATGCTGTCAT-5,3-ATATATATATAT-5,5-TATATATATATA-3,3-ATATATATATAT-5,5-TATATATATATA-3,5-TATATATATATA-3,3-ATATATATATAT-5,3-ATATATATATAT-5,5-TATATATATATA-3,