fbpx
Wikipedia

Cell division

September 28, 2023

Not to be confused with cellular differentiation.

Cell division is the process by which a parent cell divides into two daughter cells.[1] Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing. In eukaryotes, there are two distinct types of cell division: a vegetative division (mitosis), producing daughter cells genetically identical to the parent cell, and a cell division that produces haploid gametes for sexual reproduction (meiosis), reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells.[2] In cell biology, mitosis (/maɪˈtoʊsɪs/) is a part of the cell cycle, in which, replicated chromosomes are separated into two new nuclei. Cell division gives rise to genetically identical cells in which the total number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of interphase (during which the DNA replication occurs) and is often followed by telophase and cytokinesis; which divides the cytoplasm, organelles, and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components. The different stages of mitosis all together define the mitotic (M) phase of animal cell cycle—the division of the mother cell into two genetically identical daughter cells.[3] Meiosis undergoes two divisions resulting in four haploid daughter cells. Homologous chromosomes are separated in the first division of meiosis, such that each daughter cell has one copy of each chromosome. These chromosomes have already been replicated and have two sister chromatids which are then separated during the second division of meiosis. [4] Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle. Both are believed to be present in the last eukaryotic common ancestor.

Cell division in prokaryotes (binary fission) and eukaryotes (mitosis and meiosis). The thick lines are chromosomes, and the thin blue lines are fibers pulling on the chromosomes and pushing the ends of the cell apart.
The cell cycle in eukaryotes: I = Interphase, M = Mitosis, G0 = Gap 0, G1 = Gap 1, G2 = Gap 2, S = Synthesis, G3 = Gap 3.

Prokaryotes (bacteria and archaea) usually undergo a vegetative cell division known as binary fission, where their genetic material is segregated equally into two daughter cells, but there are alternative manners of division, such as budding, that have been observed. All cell divisions, regardless of organism, are preceded by a single round of DNA replication.

For simple unicellular microorganisms such as the amoeba, one cell division is equivalent to reproduction – an entire new organism is created. On a larger scale, mitotic cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. Mitotic cell division enables sexually reproducing organisms to develop from the one-celled zygote, which itself is produced by fusion of two gametes, each having been produced by meiotic cell division.[5][6] After growth from the zygote to the adult, cell division by mitosis allows for continual construction and repair of the organism.[7] The human body experiences about 10 quadrillion cell divisions in a lifetime.[8]

The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be cleanly divided between progeny cells.[9] A great deal of cellular infrastructure is involved in ensuring consistency of genomic information among generations.[10][11][12]

In bacteria Edit

 
Divisome and elongasome complexes responsible for peptidoglycan synthesis during lateral cell-wall growth and division.[13]

Bacterial cell division happens through binary fission or sometimes through budding. The divisome is a protein complex in bacteria that is responsible for cell division, constriction of inner and outer membranes during division, and remodeling of the peptidoglycan cell wall at the division site. A tubulin-like protein, FtsZ plays a critical role in formation of a contractile ring for the cell division.[14]

In eukaryotes Edit

See also: Alternation of generations

Cell division in eukaryotes is more complicated than in prokaryotes. If the chromosomal number is reduced, eukaryotic cell division is classified as meiosis (reductional division). If the chromosomal number is not reduced, eukaryotic cell division is classified as mitosis (equational division). A primitive form of cell division, called amitosis, also exists. The amitotic or mitotic cell divisions are more atypical and diverse among the various groups of organisms, such as protists (namely diatoms, dinoflagellates, etc.) and fungi.

Forms of mitosis (of karyokinesis step) in eukaryotes
  •  

    closed
    intranuclear
    pleuromitosis

  •  

    closed
    extranuclear
    pleuromitosis

  •  

    closed
    orthomitosis

  •  

    semiopen
    pleuromitosis

  •  

    semiopen
    orthomitosis

  •  

    open
    orthomitosis

In the mitotic metaphase (see below), typically the chromosomes (each containing 2 sister chromatids that developed during replication in the S phase of interphase) align themselves on the metaphase plate. Then, the sister chromatids split and are distributed between two daughter cells.

In meiosis I, the homologous chromosomes are paired before being separated and distributed between two daughter cells. On the other hand, meiosis II is similar to mitosis. The chromatids are separated and distributed in the same way. In humans, other higher animals, and many other organisms, the process of meiosis is called gametic meiosis, during which meiosis produces four gametes. Whereas, in several other groups of organisms, especially in plants (observable during meiosis in lower plants, but during the vestigial stage in higher plants), meiosis gives rise to spores that germinate into the haploid vegetative phase (gametophyte). This kind of meiosis is called sporic meiosis.

Phases of eukaryotic cell division Edit

 
The phases (ordered counter-clockwise) of cell division (mitosis) and the cell cycle in animal cells.

Interphase Edit

Interphase is the process through which a cell must go before mitosis, meiosis, and cytokinesis.[15] Interphase consists of three main phases: G1, S, and G2. G1 is a time of growth for the cell where specialized cellular functions occur in order to prepare the cell for DNA replication.[16] There are checkpoints during interphase that allow the cell to either advance or halt further development. One of the checkpoint is between G1 and S, the purpose for this checkpoint is to check for appropriate cell size and any DNA damage . The second check point is in the G2 phase, this checkpoint also checks for cell size but also the DNA replication. The last check point is located at the site of metaphase, where it checks that the chromosomes are correctly connected to the mitotic spindles.[17] In S phase, the chromosomes are replicated in order for the genetic content to be maintained.[18] During G2, the cell undergoes the final stages of growth before it enters the M phase, where spindles are synthesized. The M phase can be either mitosis or meiosis depending on the type of cell. Germ cells, or gametes, undergo meiosis, while somatic cells will undergo mitosis. After the cell proceeds successfully through the M phase, it may then undergo cell division through cytokinesis. The control of each checkpoint is controlled by cyclin and cyclin-dependent kinases. The progression of interphase is the result of the increased amount of cyclin. As the amount of cyclin increases, more and more cyclin dependent kinases attach to cyclin signaling the cell further into interphase. At the peak of the cyclin, attached to the cyclin dependent kinases this system pushes the cell out of interphase and into the M phase, where mitosis, meiosis, and cytokinesis occur.[19] There are three transition checkpoints the cell has to go through before entering the M phase. The most important being the G1-S transition checkpoint. If the cell does not pass this checkpoint, it results in the cell exiting the cell cycle.[20]

Prophase Edit

Prophase is the first stage of division. The nuclear envelope is broken down in this stage, long strands of chromatin condense to form shorter more visible strands called chromosomes, the nucleolus disappears, and microtubules attach to the chromosomes at the disc-shaped kinetochores present in the centromere.[21] Microtubules associated with the alignment and separation of chromosomes are referred to as the spindle and spindle fibers. Chromosomes will also be visible under a microscope and will be connected at the centromere. During this condensation and alignment period in meiosis, the homologous chromosomes undergo a break in their double-stranded DNA at the same locations, followed by a recombination of the now fragmented parental DNA strands into non-parental combinations, known as crossing over.[22] This process is evidenced to be caused in a large part by the highly conserved Spo11 protein through a mechanism similar to that seen with topoisomerase in DNA replication and transcription.[23]

Metaphase Edit

In metaphase, the centromeres of the chromosomes align themselves on the metaphase plate (or equatorial plate), an imaginary line that is at equal distances from the two centrosome poles and held together by complexes known as cohesins. Chromosomes line up in the middle of the cell by microtubule organizing centers (MTOCs) pushing and pulling on centromeres of both chromatids thereby causing the chromosome to move to the center. At this point the chromosomes are still condensing and are currently one step away from being the most coiled and condensed they will be, and the spindle fibers have already connected to the kinetochores.[24] During this phase all the microtubules, with the exception of the kinetochores, are in a state of instability promoting their progression toward anaphase.[25] At this point, the chromosomes are ready to split into opposite poles of the cell toward the spindle to which they are connected.[26]

Anaphase Edit

Anaphase is a very short stage of the cell cycle and it occurs after the chromosomes align at the mitotic plate. Kinetochores emit anaphase-inhibition signals until their attachment to the mitotic spindle. Once the final chromosome is properly aligned and attached the final signal dissipates and triggers the abrupt shift to anaphase.[25] This abrupt shift is caused by the activation of the anaphase-promoting complex and its function of tagging degradation of proteins important toward the metaphase-anaphase transition. One of these proteins that is broken down is securin which through its breakdown releases the enzyme separase that cleaves the cohesin rings holding together the sister chromatids thereby leading to the chromosomes separating.[27] After the chromosomes line up in the middle of the cell, the spindle fibers will pull them apart. The chromosomes are split apart while the sister chromatids move to opposite sides of the cell.[28] As the sister chromatids are being pulled apart, the cell and plasma are elongated by non-kinetochore microtubules.[29]

Telophase Edit

Telophase is the last stage of the cell cycle in which a cleavage furrow splits the cells cytoplasm (cytokinesis) and chromatin. This occurs through the synthesis of a new nuclear envelope that forms around the chromatin gathered at each pole. The nucleolus reforms as the chromatin reverts back to the loose state it possessed during interphase.[30][31] The division of the cellular contents is not always equal and can vary by cell type as seen with oocyte formation where one of the four daughter cells possess the majority of the duckling.[32]

Cytokinesis Edit

The last stage of the cell division process is cytokinesis. In this stage there is a cytoplasmic division that occurs at the end of either mitosis or meiosis. At this stage there is a resulting irreversible separation leading to two daughter cells. Cell division plays an important role in determining the fate of the cell. This is due to there being the possibility of an asymmetric division. This as a result leads to cytokinesis producing unequal daughter cells containing completely different amounts or concentrations of fate-determining molecules.[33]

In animals the cytokinesis ends with formation of a contractile ring and thereafter a cleavage. But in plants it happen differently. At first a cell plate is formed and then a cell wall develops between the two daughter cells.[citation needed]

In Fission yeast (S. pombe) the cytokinesis happens in G1 phase [34]

Variants Edit

 
Image of the mitotic spindle in a human cell showing microtubules in green, chromosomes (DNA) in blue, and kinetochores in red

Cells are broadly classified into two main categories: simple non-nucleated prokaryotic cells and complex nucleated eukaryotic cells. Due to their structural differences, eukaryotic and prokaryotic cells do not divide in the same way. Also, the pattern of cell division that transforms eukaryotic stem cells into gametes (sperm cells in males or egg cells in females), termed meiosis, is different from that of the division of somatic cells in the body. Image of the mitotic spindle in a human cell showing microtubules in green, chromosomes (DNA) in blue, and kinetochores in red.[citation needed]

 
Cell division over 42. The cells were directly imaged in the cell culture vessel, using non-invasive quantitative phase contrast time-lapse microscopy.[35]

In 2022, scientists discovered a new type of cell division called asynthetic fission found in the squamous epithelial cells in the epidermis of juvenile zebrafish. When juvenile zebrafish are growing, skin cells must quickly cover the rapidly increasing surface area of the zebrafish. These skin cells divide without duplicating their DNA (the S phase of mitosis) causing up to 50% of the cells to have a reduced genome size. These cells are later replaced by cells with a standard amount of DNA. Scientists expect to find this type of division in other vertebrates.[36]

Degradation Edit

Multicellular organisms replace worn-out cells through cell division. In some animals, however, cell division eventually halts. In humans this occurs, on average, after 52 divisions, known as the Hayflick limit. The cell is then referred to as senescent. With each division the cells telomeres, protective sequences of DNA on the end of a chromosome that prevent degradation of the chromosomal DNA, shorten. This shortening has been correlated to negative effects such as age-related diseases and shortened lifespans in humans.[37][38] Cancer cells, on the other hand, are not thought to degrade in this way, if at all. An enzyme complex called telomerase, present in large quantities in cancerous cells, rebuilds the telomeres through synthesis of telomeric DNA repeats, allowing division to continue indefinitely.[39]

History Edit

 
Kurt Michel with his phase-contrast microscope

A cell division under microscope was first discovered by German botanist Hugo von Mohl in 1835 as he worked over the green alga Cladophora glomerata.[40]

In 1943, cell division was filmed for the first time[41] by Kurt Michel using a phase-contrast microscope.[42]

See also Edit

References Edit

  1. ^ Martin EA, Hine R (2020). A dictionary of biology (6th ed.). Oxford: Oxford University Press. ISBN 9780199204625. OCLC 176818780.
  2. ^ Griffiths AJ (2012). Introduction to genetic analysis (10th ed.). New York: W.H. Freeman and Co. ISBN 9781429229432. OCLC 698085201.
  3. ^ "10.2 The Cell Cycle - Biology 2e | OpenStax". openstax.org. Retrieved 2020-11-24.
  4. ^ Gilbert, Scott F. (2000), "Meiosis", Developmental Biology. 6th edition, Sinauer Associates, retrieved 2023-09-08
  5. ^ Gilbert SF (2000). "Spermatogenesis". Developmental Biology (6th ed.).
  6. ^ Gilbert SF (2000). "Oogenesis". Developmental Biology (6th ed.).
  7. ^ Maton, Anthea (1997). Cells : building blocks of life (3rd ed.). Upper Saddle River, N.J.: Prentice-Hall. pp. 70–74. ISBN 978-0134234762. OCLC 37049921.
  8. ^ Quammen D (April 2008). "Contagious Cancer". Harper's Magazine. ISSN 0017-789X. Retrieved 2019-04-14.
  9. ^ Golitsin, Yuri N.; Krylov, Mikhail C. C. (2010). Cell division : theory, variants, and degradation. New York: Nova Science Publishers. p. 137. ISBN 9781611225938. OCLC 669515286.
  10. ^ Fletcher, Daniel A.; Mullins, R. Dyche (28 January 2010). "Cell mechanics and the cytoskeleton". Nature. 463 (7280): 485–492. Bibcode:2010Natur.463..485F. doi:10.1038/nature08908. ISSN 0028-0836. PMC 2851742. PMID 20110992.
  11. ^ Li, Shanwei; Sun, Tiantian; Ren, Haiyun (27 April 2015). "The functions of the cytoskeleton and associated proteins during mitosis and cytokinesis in plant cells". Frontiers in Plant Science. 6: 282. doi:10.3389/fpls.2015.00282. ISSN 1664-462X. PMC 4410512. PMID 25964792.
  12. ^ Hohmann, Tim; Dehghani, Faramarz (18 April 2019). "The Cytoskeleton—A Complex Interacting Meshwork". Cells. 8 (4): 362. doi:10.3390/cells8040362. ISSN 2073-4409. PMC 6523135. PMID 31003495.
  13. ^ Hugonnet JE, Mengin-Lecreulx D, Monton A, den Blaauwen T, Carbonnelle E, Veckerlé C, et al. (October 2016). "Escherichia coli". eLife. 5. doi:10.7554/elife.19469. PMC 5089857. PMID 27767957.
  14. ^ Cell Division: The Cycle of the Ring, Lawrence Rothfield and Sheryl Justice, CELL, DOI
  15. ^ Marieb EN (2000). Essentials of human anatomy and physiology (6th ed.). San Francisco: Benjamin Cummings. ISBN 978-0805349405. OCLC 41266267.
  16. ^ Pardee AB (November 1989). "G1 events and regulation of cell proliferation". Science. 246 (4930): 603–8. Bibcode:1989Sci...246..603P. doi:10.1126/science.2683075. PMID 2683075.
  17. ^ Molinari M (October 2000). "Cell cycle checkpoints and their inactivation in human cancer". Cell Proliferation. 33 (5): 261–74. doi:10.1046/j.1365-2184.2000.00191.x. PMC 6496592. PMID 11063129.
  18. ^ Morgan DO (2007). The cell cycle : principles of control. London: New Science Press. ISBN 9780199206100. OCLC 70173205.
  19. ^ Lindqvist A, van Zon W, Karlsson Rosenthal C, Wolthuis RM (May 2007). "Cyclin B1-Cdk1 activation continues after centrosome separation to control mitotic progression". PLOS Biology. 5 (5): e123. doi:10.1371/journal.pbio.0050123. PMC 1858714. PMID 17472438.
  20. ^ Paulovich AG, Toczyski DP, Hartwell LH (February 1997). "When checkpoints fail". Cell. 88 (3): 315–21. doi:10.1016/S0092-8674(00)81870-X. PMID 9039258. S2CID 5530166.
  21. ^ Schermelleh L, Carlton PM, Haase S, Shao L, Winoto L, Kner P, et al. (June 2008). "Subdiffraction multicolor imaging of the nuclear periphery with 3D structured illumination microscopy". Science. 320 (5881): 1332–6. Bibcode:2008Sci...320.1332S. doi:10.1126/science.1156947. PMC 2916659. PMID 18535242.
  22. ^ Lewontin RC, Miller JH, Gelbart WM, Griffiths AJ (1999). "The Mechanism of Crossing-Over". Modern Genetic Analysis.
  23. ^ Keeney S (2001). Mechanism and control of meiotic recombination initiation. Current Topics in Developmental Biology. Vol. 52. Elsevier. pp. 1–53. doi:10.1016/s0070-2153(01)52008-6. ISBN 9780121531522. PMID 11529427.
  24. ^ "Researchers Shed Light On Shrinking Of Chromosomes". ScienceDaily. Retrieved 2019-04-14.
  25. ^ a b Walter P, Roberts K, Raff M, Lewis J, Johnson A, Alberts B (2002). "Mitosis". Molecular Biology of the Cell (4th ed.).
  26. ^ Elrod S (2010). Schaum's outlines : genetics (5th ed.). New York: Mcgraw-Hill. p. 8. ISBN 9780071625036. OCLC 473440643.
  27. ^ Brooker AS, Berkowitz KM (2014). "The roles of cohesins in mitosis, meiosis, and human health and disease". Cell Cycle Control. Methods in Molecular Biology. Vol. 1170. New York: Springer. pp. 229–66. doi:10.1007/978-1-4939-0888-2_11. ISBN 9781493908875. PMC 4495907. PMID 24906316.
  28. ^ "The Cell Cycle". www.biology-pages.info. Retrieved 2019-04-14.
  29. ^ Urry LA, Cain ML, Jackson RB, Wasserman SA, Minorsky PV, Reece JB (2014). Campbell Biology in Focus. Boston (Massachusetts): Pearson. ISBN 978-0-321-81380-0.
  30. ^ Dekker J (2014-11-25). "Two ways to fold the genome during the cell cycle: insights obtained with chromosome conformation capture". Epigenetics & Chromatin. 7 (1): 25. doi:10.1186/1756-8935-7-25. PMC 4247682. PMID 25435919.
  31. ^ Hetzer MW (March 2010). "The nuclear envelope". Cold Spring Harbor Perspectives in Biology. 2 (3): a000539. doi:10.1101/cshperspect.a000539. PMC 2829960. PMID 20300205.
  32. ^ Gilbert SF (2000). "Oogenesis". Developmental Biology (6th ed.).
  33. ^ Guertin DA, Trautmann S, McCollum D (June 2002). "Cytokinesis in eukaryotes". Microbiology and Molecular Biology Reviews. 66 (2): 155–78. doi:10.1128/MMBR.66.2.155-178.2002. PMC 120788. PMID 12040122.
  34. ^ The Cell, G.M. Cooper; ed 2 NCBI bookshelf, The eukaryotic cell cycle, Figure 14.7
  35. ^ . Internet archive. Archived from the original on 29 June 2013.
  36. ^ Chan KY, Yan CC, Roan HY, Hsu SC, Tseng TL, Hsiao CD, et al. (April 2022). "Skin cells undergo asynthetic fission to expand body surfaces in zebrafish". Nature. 605 (7908): 119–125. doi:10.1038/s41586-022-04641-0. PMID 35477758. S2CID 248416916.
  37. ^ Jiang H, Schiffer E, Song Z, Wang J, Zürbig P, Thedieck K, et al. (August 2008). "Proteins induced by telomere dysfunction and DNA damage represent biomarkers of human aging and disease". Proceedings of the National Academy of Sciences of the United States of America. 105 (32): 11299–304. Bibcode:2008PNAS..10511299J. doi:10.1073/pnas.0801457105. PMC 2516278. PMID 18695223.
  38. ^ Cawthon RM, Smith KR, O'Brien E, Sivatchenko A, Kerber RA (February 2003). "Association between telomere length in blood and mortality in people aged 60 years or older". Lancet. 361 (9355): 393–5. doi:10.1016/S0140-6736(03)12384-7. PMID 12573379. S2CID 38437955.
  39. ^ Jafri MA, Ansari SA, Alqahtani MH, Shay JW (June 2016). "Roles of telomeres and telomerase in cancer, and advances in telomerase-targeted therapies". Genome Medicine. 8 (1): 69. doi:10.1186/s13073-016-0324-x. PMC 4915101. PMID 27323951.
  40. ^ Biographie, Deutsche. "Mohl, Hugo von - Deutsche Biographie". www.deutsche-biographie.de (in German). Retrieved 2019-04-15.
  41. ^ Masters BR (2008-12-15). "History of the Optical Microscope in Cell Biology and Medicine". Encyclopedia of Life Sciences. John Wiley & Sons, Ltd. doi:10.1002/9780470015902.a0003082. ISBN 978-0470016176.
  42. ^ ZEISS Microscopy (2013-06-01), Historic time lapse movie by Dr. Kurt Michel, Carl Zeiss Jena (ca. 1943), archived from the original on 2021-11-07, retrieved 2019-04-15

Further reading Edit

  • Morgan HI. (2007). "The Cell Cycle: Principles of Control" London: New Science Press.
  • J.M.Turner Fetus into Man (1978, 1989). Harvard University Press. ISBN 0-674-30692-9
  • McDougal, W. Scott, et al. Campbell-Walsh Urology Eleventh Edition Review. Elsevier, 2016.
  • The from the (Gall JG, McIntosh JR, eds.) contains commentaries on and links to seminal research papers on mitosis and cell division. Published online in the Image & Video Library of The American Society for Cell Biology
  • The Image & Video Library 2011-06-10 at the Wayback Machine of The American Society for Cell Biology contains many videos showing the cell division.
  • The Cell Division of the Cell Image Library
  • Images : Calanthe discolor Lindl. - Flavon's Secret Flower Garden
  • Tyson's model of cell division and a Description on BioModels Database
  • WormWeb.org: Interactive Visualization of the C. elegans Cell Lineage - Visualize the entire set of cell divisions of the nematode C. elegans

September 28, 2023
cell, division, confused, with, cellular, differentiation, process, which, parent, cell, divides, into, daughter, cells, usually, occurs, part, larger, cell, cycle, which, cell, grows, replicates, chromosome, before, dividing, eukaryotes, there, distinct, type. Not to be confused with cellular differentiation Cell division is the process by which a parent cell divides into two daughter cells 1 Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome s before dividing In eukaryotes there are two distinct types of cell division a vegetative division mitosis producing daughter cells genetically identical to the parent cell and a cell division that produces haploid gametes for sexual reproduction meiosis reducing the number of chromosomes from two of each type in the diploid parent cell to one of each type in the daughter cells 2 In cell biology mitosis maɪˈtoʊsɪs is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei Cell division gives rise to genetically identical cells in which the total number of chromosomes is maintained In general mitosis division of the nucleus is preceded by the S stage of interphase during which the DNA replication occurs and is often followed by telophase and cytokinesis which divides the cytoplasm organelles and cell membrane of one cell into two new cells containing roughly equal shares of these cellular components The different stages of mitosis all together define the mitotic M phase of animal cell cycle the division of the mother cell into two genetically identical daughter cells 3 Meiosis undergoes two divisions resulting in four haploid daughter cells Homologous chromosomes are separated in the first division of meiosis such that each daughter cell has one copy of each chromosome These chromosomes have already been replicated and have two sister chromatids which are then separated during the second division of meiosis 4 Both of these cell division cycles are used in the process of sexual reproduction at some point in their life cycle Both are believed to be present in the last eukaryotic common ancestor Cell division in prokaryotes binary fission and eukaryotes mitosis and meiosis The thick lines are chromosomes and the thin blue lines are fibers pulling on the chromosomes and pushing the ends of the cell apart The cell cycle in eukaryotes I Interphase M Mitosis G0 Gap 0 G1 Gap 1 G2 Gap 2 S Synthesis G3 Gap 3 Prokaryotes bacteria and archaea usually undergo a vegetative cell division known as binary fission where their genetic material is segregated equally into two daughter cells but there are alternative manners of division such as budding that have been observed All cell divisions regardless of organism are preceded by a single round of DNA replication For simple unicellular microorganisms such as the amoeba one cell division is equivalent to reproduction an entire new organism is created On a larger scale mitotic cell division can create progeny from multicellular organisms such as plants that grow from cuttings Mitotic cell division enables sexually reproducing organisms to develop from the one celled zygote which itself is produced by fusion of two gametes each having been produced by meiotic cell division 5 6 After growth from the zygote to the adult cell division by mitosis allows for continual construction and repair of the organism 7 The human body experiences about 10 quadrillion cell divisions in a lifetime 8 The primary concern of cell division is the maintenance of the original cell s genome Before division can occur the genomic information that is stored in chromosomes must be replicated and the duplicated genome must be cleanly divided between progeny cells 9 A great deal of cellular infrastructure is involved in ensuring consistency of genomic information among generations 10 11 12 Contents 1 In bacteria 2 In eukaryotes 3 Phases of eukaryotic cell division 3 1 Interphase 3 2 Prophase 3 3 Metaphase 3 4 Anaphase 3 5 Telophase 3 6 Cytokinesis 4 Variants 5 Degradation 6 History 7 See also 8 References 9 Further readingIn bacteria Edit nbsp Divisome and elongasome complexes responsible for peptidoglycan synthesis during lateral cell wall growth and division 13 Bacterial cell division happens through binary fission or sometimes through budding The divisome is a protein complex in bacteria that is responsible for cell division constriction of inner and outer membranes during division and remodeling of the peptidoglycan cell wall at the division site A tubulin like protein FtsZ plays a critical role in formation of a contractile ring for the cell division 14 In eukaryotes EditSee also Alternation of generations This section is missing information about asynthesic division in zebra fish skin cells Please expand the section to include this information Further details may exist on the talk page April 2022 Cell division in eukaryotes is more complicated than in prokaryotes If the chromosomal number is reduced eukaryotic cell division is classified as meiosis reductional division If the chromosomal number is not reduced eukaryotic cell division is classified as mitosis equational division A primitive form of cell division called amitosis also exists The amitotic or mitotic cell divisions are more atypical and diverse among the various groups of organisms such as protists namely diatoms dinoflagellates etc and fungi Forms of mitosis of karyokinesis step in eukaryotes nbsp closed intranuclear pleuromitosis nbsp closed extranuclear pleuromitosis nbsp closed orthomitosis nbsp semiopen pleuromitosis nbsp semiopen orthomitosis nbsp open orthomitosis In the mitotic metaphase see below typically the chromosomes each containing 2 sister chromatids that developed during replication in the S phase of interphase align themselves on the metaphase plate Then the sister chromatids split and are distributed between two daughter cells In meiosis I the homologous chromosomes are paired before being separated and distributed between two daughter cells On the other hand meiosis II is similar to mitosis The chromatids are separated and distributed in the same way In humans other higher animals and many other organisms the process of meiosis is called gametic meiosis during which meiosis produces four gametes Whereas in several other groups of organisms especially in plants observable during meiosis in lower plants but during the vestigial stage in higher plants meiosis gives rise to spores that germinate into the haploid vegetative phase gametophyte This kind of meiosis is called sporic meiosis Phases of eukaryotic cell division EditThis section relies excessively on references to primary sources Please improve this section by adding secondary or tertiary sources Find sources cell division eukaryotic news newspapers books scholar JSTOR July 2017 Learn how and when to remove this template message nbsp The phases ordered counter clockwise of cell division mitosis and the cell cycle in animal cells Interphase Edit Interphase is the process through which a cell must go before mitosis meiosis and cytokinesis 15 Interphase consists of three main phases G1 S and G2 G1 is a time of growth for the cell where specialized cellular functions occur in order to prepare the cell for DNA replication 16 There are checkpoints during interphase that allow the cell to either advance or halt further development One of the checkpoint is between G1 and S the purpose for this checkpoint is to check for appropriate cell size and any DNA damage The second check point is in the G2 phase this checkpoint also checks for cell size but also the DNA replication The last check point is located at the site of metaphase where it checks that the chromosomes are correctly connected to the mitotic spindles 17 In S phase the chromosomes are replicated in order for the genetic content to be maintained 18 During G2 the cell undergoes the final stages of growth before it enters the M phase where spindles are synthesized The M phase can be either mitosis or meiosis depending on the type of cell Germ cells or gametes undergo meiosis while somatic cells will undergo mitosis After the cell proceeds successfully through the M phase it may then undergo cell division through cytokinesis The control of each checkpoint is controlled by cyclin and cyclin dependent kinases The progression of interphase is the result of the increased amount of cyclin As the amount of cyclin increases more and more cyclin dependent kinases attach to cyclin signaling the cell further into interphase At the peak of the cyclin attached to the cyclin dependent kinases this system pushes the cell out of interphase and into the M phase where mitosis meiosis and cytokinesis occur 19 There are three transition checkpoints the cell has to go through before entering the M phase The most important being the G1 S transition checkpoint If the cell does not pass this checkpoint it results in the cell exiting the cell cycle 20 Prophase Edit Prophase is the first stage of division The nuclear envelope is broken down in this stage long strands of chromatin condense to form shorter more visible strands called chromosomes the nucleolus disappears and microtubules attach to the chromosomes at the disc shaped kinetochores present in the centromere 21 Microtubules associated with the alignment and separation of chromosomes are referred to as the spindle and spindle fibers Chromosomes will also be visible under a microscope and will be connected at the centromere During this condensation and alignment period in meiosis the homologous chromosomes undergo a break in their double stranded DNA at the same locations followed by a recombination of the now fragmented parental DNA strands into non parental combinations known as crossing over 22 This process is evidenced to be caused in a large part by the highly conserved Spo11 protein through a mechanism similar to that seen with topoisomerase in DNA replication and transcription 23 Metaphase Edit In metaphase the centromeres of the chromosomes align themselves on the metaphase plate or equatorial plate an imaginary line that is at equal distances from the two centrosome poles and held together by complexes known as cohesins Chromosomes line up in the middle of the cell by microtubule organizing centers MTOCs pushing and pulling on centromeres of both chromatids thereby causing the chromosome to move to the center At this point the chromosomes are still condensing and are currently one step away from being the most coiled and condensed they will be and the spindle fibers have already connected to the kinetochores 24 During this phase all the microtubules with the exception of the kinetochores are in a state of instability promoting their progression toward anaphase 25 At this point the chromosomes are ready to split into opposite poles of the cell toward the spindle to which they are connected 26 Anaphase Edit Anaphase is a very short stage of the cell cycle and it occurs after the chromosomes align at the mitotic plate Kinetochores emit anaphase inhibition signals until their attachment to the mitotic spindle Once the final chromosome is properly aligned and attached the final signal dissipates and triggers the abrupt shift to anaphase 25 This abrupt shift is caused by the activation of the anaphase promoting complex and its function of tagging degradation of proteins important toward the metaphase anaphase transition One of these proteins that is broken down is securin which through its breakdown releases the enzyme separase that cleaves the cohesin rings holding together the sister chromatids thereby leading to the chromosomes separating 27 After the chromosomes line up in the middle of the cell the spindle fibers will pull them apart The chromosomes are split apart while the sister chromatids move to opposite sides of the cell 28 As the sister chromatids are being pulled apart the cell and plasma are elongated by non kinetochore microtubules 29 Telophase Edit Telophase is the last stage of the cell cycle in which a cleavage furrow splits the cells cytoplasm cytokinesis and chromatin This occurs through the synthesis of a new nuclear envelope that forms around the chromatin gathered at each pole The nucleolus reforms as the chromatin reverts back to the loose state it possessed during interphase 30 31 The division of the cellular contents is not always equal and can vary by cell type as seen with oocyte formation where one of the four daughter cells possess the majority of the duckling 32 Cytokinesis Edit The last stage of the cell division process is cytokinesis In this stage there is a cytoplasmic division that occurs at the end of either mitosis or meiosis At this stage there is a resulting irreversible separation leading to two daughter cells Cell division plays an important role in determining the fate of the cell This is due to there being the possibility of an asymmetric division This as a result leads to cytokinesis producing unequal daughter cells containing completely different amounts or concentrations of fate determining molecules 33 In animals the cytokinesis ends with formation of a contractile ring and thereafter a cleavage But in plants it happen differently At first a cell plate is formed and then a cell wall develops between the two daughter cells citation needed In Fission yeast S pombe the cytokinesis happens in G1 phase 34 Variants Edit nbsp Image of the mitotic spindle in a human cell showing microtubules in green chromosomes DNA in blue and kinetochores in redCells are broadly classified into two main categories simple non nucleated prokaryotic cells and complex nucleated eukaryotic cells Due to their structural differences eukaryotic and prokaryotic cells do not divide in the same way Also the pattern of cell division that transforms eukaryotic stem cells into gametes sperm cells in males or egg cells in females termed meiosis is different from that of the division of somatic cells in the body Image of the mitotic spindle in a human cell showing microtubules in green chromosomes DNA in blue and kinetochores in red citation needed nbsp Cell division over 42 The cells were directly imaged in the cell culture vessel using non invasive quantitative phase contrast time lapse microscopy 35 In 2022 scientists discovered a new type of cell division called asynthetic fission found in the squamous epithelial cells in the epidermis of juvenile zebrafish When juvenile zebrafish are growing skin cells must quickly cover the rapidly increasing surface area of the zebrafish These skin cells divide without duplicating their DNA the S phase of mitosis causing up to 50 of the cells to have a reduced genome size These cells are later replaced by cells with a standard amount of DNA Scientists expect to find this type of division in other vertebrates 36 Degradation EditMulticellular organisms replace worn out cells through cell division In some animals however cell division eventually halts In humans this occurs on average after 52 divisions known as the Hayflick limit The cell is then referred to as senescent With each division the cells telomeres protective sequences of DNA on the end of a chromosome that prevent degradation of the chromosomal DNA shorten This shortening has been correlated to negative effects such as age related diseases and shortened lifespans in humans 37 38 Cancer cells on the other hand are not thought to degrade in this way if at all An enzyme complex called telomerase present in large quantities in cancerous cells rebuilds the telomeres through synthesis of telomeric DNA repeats allowing division to continue indefinitely 39 History Edit nbsp Kurt Michel with his phase contrast microscopeA cell division under microscope was first discovered by German botanist Hugo von Mohl in 1835 as he worked over the green alga Cladophora glomerata 40 In 1943 cell division was filmed for the first time 41 by Kurt Michel using a phase contrast microscope 42 See also EditCell fusion gametic fusion Cell growth Cyclin dependent kinase Labile cells cells that constantly divide Mitotic catastropheReferences Edit Martin EA Hine R 2020 A dictionary of biology 6th ed Oxford Oxford University Press ISBN 9780199204625 OCLC 176818780 Griffiths AJ 2012 Introduction to genetic analysis 10th ed New York W H Freeman and Co ISBN 9781429229432 OCLC 698085201 10 2 The Cell Cycle Biology 2e OpenStax openstax org Retrieved 2020 11 24 Gilbert Scott F 2000 Meiosis Developmental Biology 6th edition Sinauer Associates retrieved 2023 09 08 Gilbert SF 2000 Spermatogenesis Developmental Biology 6th ed Gilbert SF 2000 Oogenesis Developmental Biology 6th ed Maton Anthea 1997 Cells building blocks of life 3rd ed Upper Saddle River N J Prentice Hall pp 70 74 ISBN 978 0134234762 OCLC 37049921 Quammen D April 2008 Contagious Cancer Harper s Magazine ISSN 0017 789X Retrieved 2019 04 14 Golitsin Yuri N Krylov Mikhail C C 2010 Cell division theory variants and degradation New York Nova Science Publishers p 137 ISBN 9781611225938 OCLC 669515286 Fletcher Daniel A Mullins R Dyche 28 January 2010 Cell mechanics and the cytoskeleton Nature 463 7280 485 492 Bibcode 2010Natur 463 485F doi 10 1038 nature08908 ISSN 0028 0836 PMC 2851742 PMID 20110992 Li Shanwei Sun Tiantian Ren Haiyun 27 April 2015 The functions of the cytoskeleton and associated proteins during mitosis and cytokinesis in plant cells Frontiers in Plant Science 6 282 doi 10 3389 fpls 2015 00282 ISSN 1664 462X PMC 4410512 PMID 25964792 Hohmann Tim Dehghani Faramarz 18 April 2019 The Cytoskeleton A Complex Interacting Meshwork Cells 8 4 362 doi 10 3390 cells8040362 ISSN 2073 4409 PMC 6523135 PMID 31003495 Hugonnet JE Mengin Lecreulx D Monton A den Blaauwen T Carbonnelle E Veckerle C et al October 2016 Escherichia coli eLife 5 doi 10 7554 elife 19469 PMC 5089857 PMID 27767957 Cell Division The Cycle of the Ring Lawrence Rothfield and Sheryl Justice CELL DOI Marieb EN 2000 Essentials of human anatomy and physiology 6th ed San Francisco Benjamin Cummings ISBN 978 0805349405 OCLC 41266267 Pardee AB November 1989 G1 events and regulation of cell proliferation Science 246 4930 603 8 Bibcode 1989Sci 246 603P doi 10 1126 science 2683075 PMID 2683075 Molinari M October 2000 Cell cycle checkpoints and their inactivation in human cancer Cell Proliferation 33 5 261 74 doi 10 1046 j 1365 2184 2000 00191 x PMC 6496592 PMID 11063129 Morgan DO 2007 The cell cycle principles of control London New Science Press ISBN 9780199206100 OCLC 70173205 Lindqvist A van Zon W Karlsson Rosenthal C Wolthuis RM May 2007 Cyclin B1 Cdk1 activation continues after centrosome separation to control mitotic progression PLOS Biology 5 5 e123 doi 10 1371 journal pbio 0050123 PMC 1858714 PMID 17472438 Paulovich AG Toczyski DP Hartwell LH February 1997 When checkpoints fail Cell 88 3 315 21 doi 10 1016 S0092 8674 00 81870 X PMID 9039258 S2CID 5530166 Schermelleh L Carlton PM Haase S Shao L Winoto L Kner P et al June 2008 Subdiffraction multicolor imaging of the nuclear periphery with 3D structured illumination microscopy Science 320 5881 1332 6 Bibcode 2008Sci 320 1332S doi 10 1126 science 1156947 PMC 2916659 PMID 18535242 Lewontin RC Miller JH Gelbart WM Griffiths AJ 1999 The Mechanism of Crossing Over Modern Genetic Analysis Keeney S 2001 Mechanism and control of meiotic recombination initiation Current Topics in Developmental Biology Vol 52 Elsevier pp 1 53 doi 10 1016 s0070 2153 01 52008 6 ISBN 9780121531522 PMID 11529427 Researchers Shed Light On Shrinking Of Chromosomes ScienceDaily Retrieved 2019 04 14 a b Walter P Roberts K Raff M Lewis J Johnson A Alberts B 2002 Mitosis Molecular Biology of the Cell 4th ed Elrod S 2010 Schaum s outlines genetics 5th ed New York Mcgraw Hill p 8 ISBN 9780071625036 OCLC 473440643 Brooker AS Berkowitz KM 2014 The roles of cohesins in mitosis meiosis and human health and disease Cell Cycle Control Methods in Molecular Biology Vol 1170 New York Springer pp 229 66 doi 10 1007 978 1 4939 0888 2 11 ISBN 9781493908875 PMC 4495907 PMID 24906316 The Cell Cycle www biology pages info Retrieved 2019 04 14 Urry LA Cain ML Jackson RB Wasserman SA Minorsky PV Reece JB 2014 Campbell Biology in Focus Boston Massachusetts Pearson ISBN 978 0 321 81380 0 Dekker J 2014 11 25 Two ways to fold the genome during the cell cycle insights obtained with chromosome conformation capture Epigenetics amp Chromatin 7 1 25 doi 10 1186 1756 8935 7 25 PMC 4247682 PMID 25435919 Hetzer MW March 2010 The nuclear envelope Cold Spring Harbor Perspectives in Biology 2 3 a000539 doi 10 1101 cshperspect a000539 PMC 2829960 PMID 20300205 Gilbert SF 2000 Oogenesis Developmental Biology 6th ed Guertin DA Trautmann S McCollum D June 2002 Cytokinesis in eukaryotes Microbiology and Molecular Biology Reviews 66 2 155 78 doi 10 1128 MMBR 66 2 155 178 2002 PMC 120788 PMID 12040122 The Cell G M Cooper ed 2 NCBI bookshelf The eukaryotic cell cycle Figure 14 7 Phase Holographic Imaging of Cell Division Internet archive Archived from the original on 29 June 2013 Chan KY Yan CC Roan HY Hsu SC Tseng TL Hsiao CD et al April 2022 Skin cells undergo asynthetic fission to expand body surfaces in zebrafish Nature 605 7908 119 125 doi 10 1038 s41586 022 04641 0 PMID 35477758 S2CID 248416916 Jiang H Schiffer E Song Z Wang J Zurbig P Thedieck K et al August 2008 Proteins induced by telomere dysfunction and DNA damage represent biomarkers of human aging and disease Proceedings of the National Academy of Sciences of the United States of America 105 32 11299 304 Bibcode 2008PNAS 10511299J doi 10 1073 pnas 0801457105 PMC 2516278 PMID 18695223 Cawthon RM Smith KR O Brien E Sivatchenko A Kerber RA February 2003 Association between telomere length in blood and mortality in people aged 60 years or older Lancet 361 9355 393 5 doi 10 1016 S0140 6736 03 12384 7 PMID 12573379 S2CID 38437955 Jafri MA Ansari SA Alqahtani MH Shay JW June 2016 Roles of telomeres and telomerase in cancer and advances in telomerase targeted therapies Genome Medicine 8 1 69 doi 10 1186 s13073 016 0324 x PMC 4915101 PMID 27323951 Biographie Deutsche Mohl Hugo von Deutsche Biographie www deutsche biographie de in German Retrieved 2019 04 15 Masters BR 2008 12 15 History of the Optical Microscope in Cell Biology and Medicine Encyclopedia of Life Sciences John Wiley amp Sons Ltd doi 10 1002 9780470015902 a0003082 ISBN 978 0470016176 ZEISS Microscopy 2013 06 01 Historic time lapse movie by Dr Kurt Michel Carl Zeiss Jena ca 1943 archived from the original on 2021 11 07 retrieved 2019 04 15Further reading EditMorgan HI 2007 The Cell Cycle Principles of Control London New Science Press J M Turner Fetus into Man 1978 1989 Harvard University Press ISBN 0 674 30692 9 Cell division binary fission and mitosis McDougal W Scott et al Campbell Walsh Urology Eleventh Edition Review Elsevier 2016 The Mitosis and Cell Cycle Control Section from the Landmark Papers in Cell Biology Gall JG McIntosh JR eds contains commentaries on and links to seminal research papers on mitosis and cell division Published online in the Image amp Video Library of The American Society for Cell Biology The Image amp Video Library Archived 2011 06 10 at the Wayback Machine of The American Society for Cell Biology contains many videos showing the cell division The Cell Division of the Cell Image Library Images Calanthe discolor Lindl Flavon s Secret Flower Garden Tyson s model of cell division and a Description on BioModels Database WormWeb org Interactive Visualization of the C elegans Cell Lineage Visualize the entire set of cell divisions of the nematode C elegans Retrieved from https en wikipedia org w index php title Cell division amp oldid 1174504048, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.