Name: how cells set the division plane
Uploaded: 2021-04-07T12:12:02.000Z
Duration: 2 min 13 s
Channel: JoVE

K12 Standards

Next Generation Science Standards

High School

Life Science

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms: Structures and Processes

HS-LS1-4

Determining the Plane of Cell Division

分裂する細胞がその細胞分裂面を正確に決定することは、染色体の良好な分離と細胞質内容物の娘細胞への分布に不可欠です。
動物では、分裂面は分離された染色体の間の細胞赤道に位置し、その位置は後期に決定されます。有糸分裂紡錘体を形成する微小管は、細胞皮質と相互作用し、切断溝を特定する上で決定的な役割を果たします。
細胞分裂面の決定を説明するために、アストラル刺激モデル、極性リラクゼーションモデル、および中心紡錘体刺激モデルの3つの異なるモデルが使用されます。
アストラル刺激モデルでは、アストラル微小管の放射状配列が赤道皮質と相互作用し、卵割溝の形成を誘導します。
極性緩和モデルでは、アストラル微小管が細胞極に抑制性シグナルを送り、それによって両極での切断溝の形成を抑制します。これにより、細胞赤道での皮質収縮が起こります。
後期が始まると、分離された染色体の間に存在する極間微小管は、中央紡錘体とも呼ばれる重なり合う逆平行微小管に再配置されます。中心紡錘体刺激モデルでは、中央紡錘体が赤道皮質での切断溝形成を刺激します。 
一般的なコンセンサスは、3つのプロセスすべてが一緒に作用して細胞分裂の平面を決定するというものです。この多面的なアプローチにより、システムはタンパク質濃度や細胞サイズの変動に応答し、細胞分裂の精度を高めることができます。
各方法の寄与度は、細胞の種類とサイズによって異なります。例えば、C.エレガンスの胚では、アストラル微小管の大規模な配列が存在するため、細胞分裂面の決定においてより積極的な役割を果たす可能性があります。

<ol>
	<li>細胞の分子生物学、アルバーツ、第6版。997-999ページ。</li>
	<li>分子細胞生物学、ロディッシュ、第8版。ページ - 903。</li>
	<li>Geelen, Danny. "The Positioning of the Division Plane Is Determined by a Cortical Division Site at the Plasma Membrane." バイオテクノロジーと持続可能な農業 2006 年以降, pp. 121-124.スプリンガー、ドルドレヒト、2007年。</li>
	<li>「出芽酵母、分裂酵母、動物細胞における細胞質分裂の比較分析」 Current Biology 14, no. 18 (2004): R806-R818.</li>
	<li>「Saccharomycesのセプチン足場と劈開面」 Cell 84, no. 2 (1996): 187-190.</li>
	<li>「Mid1/アニリンと分裂酵母におけるサイトカインシスの空間的調節」 Cytoskeleton 69, no. 10 (2012): 764-777.</li>
	<li>「初期のC.エレガンス胚における切断面の決定」 遺伝学の年次レビュー 42 (2008):389-411。</li>
</ol>

細胞分裂面の決定

細胞分裂面の位置決めは、発生および細胞分化中、特に有糸分裂中には、その面が2つの娘細胞のサイズを決定するために不可欠であるため、重要なステップです。細胞分裂面は染色体分離面に対して垂直ですが、生物の種類が異なれば、その形態や機能に合わせて異なる細胞分裂機構を持っています。

動物細胞

動物細胞では、細胞膜の下の領域である細胞皮質から始まる細胞分裂面に沿って分裂溝が形成されます。有糸分裂紡錘体は、細胞分裂面の決定において決定的な役割を果たします。したがって、紡錘体の軸が変化すると、分裂面が変化する可能性があります。この戦略は、Caenorhabditis elegansなどの一部の真核生物が対称細胞分裂から非対称細胞分裂に切り替えるために使用されます。対称的な細胞分裂は2つの同一の娘細胞を生成し、同じ種類の細胞を多く含む組織を成長させるためによく使用されます。対照的に、非対称分裂は2つの同一ではない娘細胞を生成するため、細胞の多様性を生み出します。たとえば、神経上皮細胞は、最初は対称的な分裂を経てその数を増やします。その後、非対称分裂を利用して親細胞に似た娘細胞を生成し、ニューロンを分化させます。

酵母

出芽酵母（Saccharomyces cerevisiae）などの出芽酵母では、細胞分裂の平面はセプチンタンパク質によってG1期に決定されます。細胞質分裂は、出芽酵母細胞の首領域に分裂溝を形成することによって達成されます。ただし、有糸分裂装置は細胞分裂面の決定には何の役割も果たしません。対照的に、Schizosaccharomyces pombeなどの分裂酵母では、間期核の位置がG2期の細胞分裂面の位置を決定します。間期では、Mid1タンパク質は主に核に局在します。しかし、有糸分裂中に、Mid1は核から細胞皮質に輸送され、そこでアクトミオシンリングの構成要素を細胞の内側領域に補充します。これにより、最終的に、母細胞が2つの同様のサイズの娘細胞に分裂します。

植物

ほとんどの植物細胞では、細胞が有糸分裂を開始する前に、細胞分裂の平面が決定されます。 前前期バンドは親細胞の赤道に沿って形成され、細胞分裂の面を示します。 前前期バンドは、微小管とF-アクチンから構成されるリング状の構造です。それは隔膜形成体と呼ばれる微小管束を生じさせ、細胞プレートの拡張と位置決めのための構造的足場を提供します。

細胞分裂面の位置決めは、発生および細胞分化中、特に平面が...

Education

JoVE Core

Molecular Biology

分子生物学

Unit 2

ユニット2

Cell Division

細胞分裂

KEY TERMS AND CONCEPTS

主要用語と概念

how cells set the division plane

How cells set the division plane during cell division affects daughter cell size and, in many cases, cell fate. The plane of division is perpendicular to the plane of chromosome segregation. Different organisms use different cues to place it, based on their shape and needs.

In animal cells, the cleavage furrow forms along the division plane from the cell cortex, the area just below the plasma membrane. The mitotic spindle is the main guide for this position. If the spindle axis changes, the division plane can change as well. Some eukaryotes, such as Caenorhabditis elegans, use this shift to move from symmetric division to asymmetric division.

Symmetric cell division makes two identical daughter cells and is often used to build tissues with many of the same cell type. Asymmetric division makes two different daughter cells and increases cell diversity. Neuroepithelial cells first divide symmetrically to raise their numbers. They later divide asymmetrically to form a daughter cell like the parent cell and another that will become a neuron.

In budding yeast, such as Saccharomyces cerevisiae, septin proteins decide the plane of division during the G1 phase. The cell then completes cytokinesis by forming a cleavage furrow at the bud neck. In this yeast, the mitotic apparatus does not set the division plane.

In fission yeast, such as Schizosaccharomyces pombe, the interphase nucleus helps decide where the division plane will form during the G2 phase. The Mid1 protein stays mainly in the nucleus during interphase. During mitosis, Mid1 moves to the cell cortex and recruits actomyosin ring components to the middle of the cell. This lets the mother cell divide into two similar-sized daughter cells.

In most plant cells, the division plane is set before the cell enters mitosis. A preprophase band forms along the cell equator and marks where division will occur. This ring-like structure contains microtubules and F-actin. It helps form the phragmoplast, which supports cell plate growth and placement.

How Cells Set the Division Plane

mitosis and cytokinesis

Mitosis and Cytokinesis Stages

Mitosis and cytokinesis are the two main steps of cell division. Mitosis is the process that divides the nucleus, while cytokinesis splits the rest of the cell. During mitosis, the cell’s genetic material is separated into two sets. This helps form two new nuclei with the same genetic information. Cytokinesis then completes division by separating the cytoplasm, which creates two daughter cells. These stages work together to make cell division possible in growing and repairing tissues.

duplication of chromatin structure

Chromatin Rebuilding During DNA Replication

Chromatin rebuilding during DNA replication helps cells copy DNA and pass on chromosome structure to daughter cells. During cell division, the genome must be disrupted and then reassembled across the whole chromosome. This process allows chromatin to be inherited, rebuilt, and maintained in new cells. The basic unit of chromatin is the nucleosome. A nucleosome contains DNA wrapped around an octamer of histone proteins, with short linker DNA between neighboring nucleosomes. The histone proteins...

cohesins

Cohesins in Meiosis and Genetic Disorders

Cohesin protein complexes act like molecular glue that keeps sister chromatids together. They are important in both mitosis and meiosis. In mitosis, cohesin complexes are removed from chromosomes before anaphase begins. Meiosis has two rounds of chromosome separation. Meiosis I separates homologous chromosomes, while Meiosis II separates sister chromatids. This process produces four daughter cells. The Meiosis I cohesin complex is made of four subunits: Smc1, Smc3, Rec8, and Scc3. Rec8...

condensins

How Condensins Shape Mitotic Chromosomes

Condensins shape chromosomes during mitosis, the stage when a cell divides. These large protein complexes use ATP, the cell’s energy molecule, to help turn loose post-interphase DNA into compact, separate chromosomes. They organize and segregate chromosomal DNA so it can be passed on correctly. Plant and animal cells contain two condensin complexes: condensin I and condensin II. Each complex has five subunits. Two are SMC, or Structural Maintenance of Chromosomes, subunits. One is a kleisin...

the mitotic spindle

How the Mitotic Spindle Separates Chromosomes

The mitotic spindle is a microtubule-based structure that helps separate chromosomes during cell division. It forms in eukaryotic cells and moves sister chromatids to opposite ends of the parent cell. This leaves each new cell nucleus with the correct genetic material. A bipolar spindle has two poles, and that shape is important for chromosome segregation. In many animal cells, two centrosomes are present when mitosis begins. Each centrosome helps organize a circular set of microtubules at one...

centrosome duplication

Centrosome Duplication in the Cell Cycle

Centrosome duplication is a key part of the animal cell cycle. The centrosome is the main microtubule organizing center, or MTOC, in animal cells. It contains two cylindrical centrioles at its core. Each centriole has nine sets of three microtubules held together by proteins. The two centrioles sit at right angles and are surrounded by the pericentriolar matrix, or PCM, a shapeless protein cloud. Duplication starts early in the cell cycle so each daughter cell can receive a centrosome after...

microtubule instability

Microtubule Growth and Shrinkage

Microtubules are hollow, cylindrical filaments in the cell. They are about 25 nm wide and can range from 200 nm to 25 μm in length. Their main building blocks are GTP-bound tubulin subunits that form αβ-heterodimers, which then assemble into protofilaments. These protofilaments join by lateral bonds to create stable microtubule cylinders. Microtubules are highly dynamic because they repeatedly assemble and break down. They can even grow on one end while shrinking on the other at the same time.

spindle assembly

How the Mitotic Spindle Forms

The mitotic spindle forms through centrosome-mediated, chromatin-mediated, and microtubule-mediated pathways. These pathways often work at the same time. Together, they build a strong spindle apparatus for cell division. In most cells, centrosomes are the main sites where microtubules begin to grow. During the G2 to prophase transition, centrosomes mature and make more microtubules. The growing microtubules extend from both centrosomes, and their plus-ends search for chromosomes by attaching...

attachment of sister chromatids

Kinetochore-Microtubule Binding in Mitosis

Kinetochore-microtubule binding helps chromosomes line up and separate during mitosis. After the nuclear envelope breaks down, condensed chromosomes are exposed to the bipolar microtubules of the mitotic spindle. The kinetochore is a large, disc-shaped protein complex at the centromere region of each sister chromatid, and it serves as the microtubule binding site. Usually, the plus-end of a single microtubule inserts into the kinetochore. In some cases, a kinetochore first makes lateral...

forces acting on chromosomes

Chromosome Movement During Mitosis

Chromosome movement during mitosis depends on several small forces that act at different times and positions in the cell. In prometaphase, these forces help chromosomes move to the equatorial plane and line up at the metaphase plate. Because the forces change with location and stage, chromosome behavior also changes as mitosis continues. Microtubules and motor proteins create two main kinds of force on chromosomes: poleward force and anti-poleward force, also called polar-ejection force.

separation of sister chromatids

Anaphase Start and Chromatid Release

Anaphase starts when sister chromatids are released from one another and pulled toward opposite spindle poles. Before that happens, cohesion along the chromosomal arms is reduced from prophase to metaphase, which helps the sister chromatids resolve. A residual cohesin link still holds them together until the metaphase-to-anaphase transition. This leftover connection helps prevent early separation and reduces the risk of aneuploidy, or the wrong number of chromosomes, in daughter cells. At the...

the spindle assembly checkpoint

How Cells Safeguard Chromosome Separation

The spindle assembly checkpoint helps cells safeguard chromosome separation during anaphase. It acts as a molecular surveillance system. The checkpoint checks whether the steps needed for chromosome segregation are complete before the cell moves on. Many proteins work together to control this checkpoint. If mutations affect these proteins, a cell may enter anaphase too early. Chromosomes can then separate before the needed steps are finished. When this happens, the daughter cells may receive...

anaphase a and b

Chromatid Movement by Microtubule Forces

Chromatid movement during anaphase depends on microtubule forces at the spindle. Kinetochore microtubules grow from the spindle poles, and their plus ends attach to kinetochores on sister chromatids. The kinetochore protein complex Ndc80 makes low-affinity links with the microtubule plus end.

the contractile ring

How Cells Build the Contractile Ring

Contractile rings are built from microfilaments and help separate daughter cells during cytokinesis. This ring forms as the cell cycle moves forward, but the exact timing and coordination with other cell cycle events are still not fully understood. RhoA, a small GTPase in the Ras superfamily, controls contractile ring assembly and function. The inactive form of RhoA is bound to GDP. A guanine nucleotide exchange factor, or Rho-GEF, is located in the cortex region, where the next cell division...

determining the plane of cell division

How cells set the division plane during cell division affects daughter cell size and, in many cases, cell fate. The plane of division is perpendicular to the plane of chromosome segregation. Different organisms use different cues to place it, based on their shape and needs. In animal cells, the cleavage furrow forms along the division plane from the cell cortex, the area just below the plasma membrane. The mitotic spindle is the main guide for this position. If the spindle axis changes, the...

the phragmoplast

How Plant Cells Build a New Wall

Plant cells build a new wall during cytokinesis with help from the phragmoplast. This plant structure forms from the central spindle and related cell parts as the cell finishes dividing. In animal cells, the comparable structure is the midbody, but in plants the phragmoplast expands outward to guide new wall formation. The mature phragmoplast has a donut-like shape. It has an outer leading region, a middle transition zone, and an inner lagging region. New microtubules are assembled...

distribution of cytoplasmic content

How Organelles Are Split During Cytokinesis

Cytokinesis splits a cell’s chromosomes and organelles into two daughter cells. Before cell division, organelles grow and divide. They cannot be made from scratch, so each daughter cell must inherit at least one copy to survive. Many details of this organelle sorting process are still not fully known. The cytoplasm contains organelles, salts, proteins, and water. Small organelles such as peroxisomes and lysosomes can be shared by simple diffusion. Because cells contain many copies of these...

anaphase promoting complex

APC Activates Chromosome Separation

The anaphase-promoting complex, or APC, helps control cell cycle progression by destroying specific proteins at the right time. These proteins are tagged with ubiquitin by ubiquitin ligases and then broken down by the proteasome. The SCF (Skp1/Cullin/F-box) complex and APC are two major ubiquitin ligases involved in this process. SCF stays active throughout the cell cycle, but APC turns on during the metaphase-to-anaphase transition. APC becomes active when Cdc20 or Cdh1 binds to it. These...

key terms and concepts

Learn how animal cells, yeast, and plant cells position the division plane using the spindle, septins, nucleus, and preprophase band.

How Cells Set the Division Plane | JoVE K12

molecular biology

JoVE Core 分子生物学は、明確で簡潔なアニメーション ビデオ レッスンを通じて細胞の分子プロセスを紹介します。さらに、科学者の実際のビデオでは、これらの概念の応用が現代の研究室での実際の実験を通じて実証されています。

new-york-state-science-learning-standards

New York State Science Learning Standards

Inheritance and Variation of Traits

HS-LS1-4.

Characteristics of Life

Biology is a natural science that studies life and living organisms, including their structure, function, development, interactions, evolution, ...

https://cloudfront.jove.com/files/media/science-education/science-education-thumbs/10647.jpg

Cell Structure

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What are Cells?

Cell Diversity

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Cytoplasm

The cytoplasm consists of organelles and a framework of protein scaffolds called the cytoskeleton suspended in an aqueous solution, the cytosol. The ...

The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

The Central Dogma

The DNA Helix

Nucleic Acids

DNA as a Genetic Template

Structure of a Gene

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Chromosome Structure

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Protein Families

Types of RNA

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Conservation of Protein Domains

Transcription

Transcription is the synthesis of RNA from a DNA sequence by RNA polymerase. It is the first step in producing a protein from a gene sequence. ...

Globular and Fibrous Proteins

Translation

Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes ...

Intrinsically Disordered Proteins

Ribosomes

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that ...

Protein Complex Assembly

Protein and Protein Structures

Conjugated Proteins

Proteins: From Genes to Degradation

Amyloid Fibrils

What are Proteins?

Proteins are polymers of amino acids linked together by peptide bonds. Proteins and polypeptides are interchangeably used to refer to long chains of amino ...

Ligand Binding Sites

Protein Organization

Proteins are polymers of amino acid residues. They are versatile and responsible for different cellular functions, including DNA replication, molecular ...

Protein-Protein Interfaces

Protein Folding

Proteins are chains of amino acids linked together by peptide bonds. Upon synthesis, a protein folds into a three-dimensional conformation, critical to ...

Conserved Binding Sites

Cofactors and Coenzymes

Enzymes are proteins made of amino acids. The functional group of each constituent amino acid catalyzes a wide variety of chemical reactions via ionic ...

Cooperative Allosteric Transitions

Protein Kinases and Phosphatases

GTPases and their Regulation

Covalently Linked Protein Regulators

protein-complexes-with-interchangeable-parts

Protein Complexes with Interchangeable Parts

Mechanical Protein Function

Structural Protein Function

Protein Networks

Construct an explanation based on evidence for how the structure of DNA determines the structure of proteins, which carry out the essential functions of life through systems of specialized cells. [Assessment Boundary: Assessment does not include identification of specific cell or tissue types, whole body systems, specific protein structures and functions, or the biochemistry of protein synthesis.]

HS-LS1-1

Levels of Organization

Biological organization is the classification of biological structures, ranging from atoms at the bottom of the hierarchy to the Earth&#x27;s biosphere. ...

Animal and Plant Cell Structure

Animal and plant cells not only differ in their structure, function, and mode of nutrition but also in how they reproduce, specialize, and organize into ...

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Structural Organization of the Human Body: An Overview

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Anatomy of the Intestines

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Accessory Organs

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Lipid Digestion

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Protein Digestion

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Carbohydrate Digestion

Carbohydrate digestion and metabolism break down simple and complex carbohydrates from food into saccharides (i.e., sugars) for the body to use as energy. ...

What is a Nervous System?

Overview

The nervous system is the collection of specialized cells responsible for maintaining an organism&rsquo;s internal environment and coordinating ...

The Parasympathetic Nervous System

Overview

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The Sympathetic Nervous System

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Oogenesis

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Fertilization

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What is the Skeletal System?

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An Introduction to the Zebrafish: Danio rerio

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Physiology of the Circulatory System

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Measuring Circulatory System Function in Humans
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Develop and use a model to illustrate the hierarchical organization of interacting systems that provide specific functions within multicellular organisms. [Clarification Statement: Emphasis is on functions at the organism system level such as nutrient uptake, water delivery, and organism movement in response to neural stimuli. An example of an interacting system could be an artery depending on the proper function of elastic tissue and smooth muscle to regulate and deliver the proper amount of blood within the circulatory system.] [Assessment Boundary: Assessment does not include interactions and functions at the molecular or chemical reaction level.]

HS-LS1-2

How Cells Set the Division Plane

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