安徽师范大学：《细胞生物学》课程教学课件（讲稿）Chapter 7 Nucleus Section 3 Chromosome

Nuclear.envelopexNuclearpoChapter 7 Nucleuspl.nucleiPrefaceuclearmiatrxNucleopsm Size: 5-10μum(high animal); 5-20μm(High plant)Volume ratio of nucleus to cytoplasm:l:10 (9) Shape:Spherical or ovalDNA and associatedproteins (chromatin) Contain:4 subunitsendoolasmicreticulumnucleolus·Nuclear Envelope Chromatincentrosome?NucleolusmicrotubuleintermediateNuclearMatrix (nuclearskeleton)filamentsnuclearlaminanuclearporeouter nuclear membranenuclear envelope1uminner nuclear membrane

Size: 5-10µm(high animal); 5-20µm(High plant)  Volume ratio of nucleus to cytoplasm: 1:10 (9)  Shape: Spherical or oval  Contain: 4 subunits • Nuclear Envelope • Chromatin • Nucleolus • Nuclear Matrix (nuclear skeleton) Preface Chapter 7 Nucleus pl. nuclei

OuternuclearmembraneNuciearenvelopNuclearlaminaInnernuclearmembraneNucleolusPerinuclearspaceChromatinRibosomesSectionl. Nuclear envelopeI.NuclearmembraneII.Nuclearporecomplex(NPC)I.NuclearlaminaSection2.ChromatinSection3.ChromosomeNuclearporesCYTOSOLSection4.Nucleolus &Nuclear Matrix/skeletonRoughER

Section1. Nuclear envelope I. Nuclear membrane II. Nuclear pore complex (NPC) III. Nuclear lamina Section2. Chromatin Section3. Chromosome Section4. Nucleolus & Nuclear Matrix/skeleton

Section 3. Chromosome梁色单体I. Structure随体1. Four types: see the right短臂(p)II+次缝痕着丝粒主继痕）1长臂(g)12. Main subunits:亚端着丝粒端着丝粒中着丝粒亚中着丝粒2.1 Centromere:染色体染色体染色体染色体Centrosome(1) Definition: The highly constricted region of achromosome that is the position at which thepair of chromatids are held together.Primaryconstriction（主痕）

I. Structure Section 3. Chromosome 1. Four types: see the right 2. Main subunits: 2.1 Centromere: Primary constriction (主缢痕) (1) Definition: The highly constricted region of a chromosome that is the position at which the pair of chromatids are held together. Centrosome

(2) Function:EServe both as linker sites of sister chromatids, and as attachment sites艺①②formicrotubulesofthemitoticspindle（有丝分裂纺锤体微管）A美(3) Composition:CentromereDNA,Centromereassociatedproteins

(2) Function: Serve both as linker sites of sister chromatids, and as attachment sites for microtubules of the mitotic spindle. (3) Composition:  Centromere DNA;  Centromere associated proteins. ① ② （有丝分裂纺锤体微管）

(4)Subunits:3主要+1次要inner-outer①Pairing domain:Theinteraction siteforMetaphasechromatids(sisterchromatids)Includetwotypesofproteins:INCENP(innercentromereproteins):CLIP(chromatidlinkingproteins) These two types of proteins are responsible for the paring of chromatids配对结构域中央结构域着丝粒动粒结构域（主缢痕）y染色体臀着丝粒的结构域组织

(4) Subunits: 3主要+1次要 inner outer ① Pairing domain:  The interaction site for Metaphase chromatids (sister chromatids).  Include two types of proteins: INCENP (inner centromere proteins); CLIP (chromatid linking proteins).  These two types of proteins are responsible for the paring of chromatids

配对结构域②Centraldomain:中央结构域Composed ofhighlyrepeated satelliteDNA动粒结构域(CentromereDNA)③kinetochoredomain（动粒/着丝点）PlusendofmicrotubuleswhereKinetochoreSubunitsareaddedorlostOuterkinetochoreplate口Innerplate（内板）DyneinMiddlespace/interzone（中间间隙）Microtubule口Outerplate（外板）CentramericMicrotubuleheterochromatir(microtubule)Fibrous+MTcoronaFibrouscorona：coronafiber（微管蛋白）(纤维冠）Inner plateCENP-EInterzoneOuterplateCoronafiber(b)(c)

③ kinetochore domain:  Composed of highly repeated satellite DNA. ② Central domain： (Centromere DNA) (动粒/着丝点)  Inner plate（内板）  Middle space/interzone (中间间隙)  Outer plate（外板） (microtubule) ④ Fibrouscorona: corona fiber（微管蛋白） （纤维冠）

Centromere formationeLeLR配对结构城H动粒结构←着丝粒DNAD卖店A中央结构城福A

着丝粒DNA 配对结构域 中央结构域 动粒结构域 Centromere formation

次缢痕2.2 Secondary constriction:P280,282M主痕浅染缢缩？由于染色体DNA上基因转录，折叠晚了。导致折叠压缩程度不高，吸附染料较少。(没有跟上大部队)着丝粒蛋白特异标记什么基因？

2.2 Secondary constriction: 次缢痕 着丝粒蛋白特异标记 浅染缢缩？ 由于染色体DNA上基 因转录，折叠晚了。 导致折叠压缩程度不 高，吸附染料较少。 (没有跟上大部队) 主缢痕 什么基因？ P280,282

某些次继痕是rRNA(5srRNA除外)基因的所在部位。则次缢痕与间期细胞核内核仁形成有关（组织者）。故，这些次缢痕又称核仁组织区(nucleolarorganizingregion，NOR）。次痕可作为染色体的“鉴定标记”rRNA基因?ForthereasonthattherRNA(excluding5srRNA)genesare(5srRNA外)locatedhereandtheyareinvolvedinribosomesbiogenesis.These secondary constrictionsarealsocalledas NOR28S、18S和5.8SC

 For the reason that the rRNA (excluding 5srRNA) genes are located here and they are involved in ribosomes biogenesis.  These secondary constrictions are also called as NOR.  某些次缢痕是rRNA(5srRNA除外)基因的所在部位。  则次缢痕与间期细胞核内核仁形成有关（组织者）。 故，这些次缢痕又称核仁组织区(nucleolar organizing region，NOR) 。  次缢痕可作为染色体的“鉴定标记”。 rRNA基因？ (5srRNA外) 28S、18S和5.8S

satellite2.3 Satellite:随体secondaryconstriction（次继痕）(nucleolar organizing region, NOR) A spherical segment at the end of a chromosome.Primaryconstriction（主痕）(centromere)

2.3 Satellite: 随体  A spherical segment at the end of a chromosome. secondary constriction (次缢痕) (nucleolar organizing region, NOR) (centromere) Primary constriction (主缢痕) satellite