Trichome

thcscience_admin

Amitosis, also known as karyostenotic, direct cell division, or binary fission, represents a mode of asexual cell division predominantly observed in prokaryotes. This process is distinct from other cell division mechanisms such as mitosis and meiosis, primarily because it bypasses the complexities associated with the mitotic apparatus, such as spindle formation. Additionally, amitosis does not involve the condensation of chromatin into distinct chromosomes before the division of the cell occurs, simplifying the process of cellular replication.

Several instances of cell division formerly thought to be "non-mitotic", such as the division of some unicellular eukaryotes, may actually occur by the process of "closed mitosis", which is different from open or semi-closed mitotic processes, all of which involve mitotic chromosomes and are classified by nuclear envelope. Amitosis can also effect on the distribution of human lactic acid dehydrogenase isoenzyme which is present in almost all body tissue. Example of amitosis is spermatogenesis. When in the process of amitosis the cell membrane will not divide.

There are two or more nuclei which are called dinucleated and multinucleated cells respectively. Sometimes it is also formed by fusion of the cell. Amitosis differs fundamentally from mitosis without cytokinesis, yet still shares some similarities between amitosis and cell fusion. Amitosis can result in near haploid nuclei, which is not possible through mitosis or cell fusion.[1]

The mitotic index declines from 2.2% at day ten to 0.3% at day thirty during postnatal life. Delayed fixation yields degenerated prophase and telophase nuclei only. [2]

Processes[edit]

Amitosis is the division of cells in the interphase state usually accomplished by a simple constriction into two sometimes unequal halves without any regular segregation of genetic material.[3] As a result, this process leads to random distribution of parental chromosomes in the subsequent daughter cells, in contrast to mitosis, which involves precise distribution of chromosomes in the resulting daughter cells. This phenomenon does not involve maximal condensation of chromatin into chromosomes, a molecular event that is observable by light microscopy when sister chromatids line up in pairs along the metaphase plate. While amitosis has been reported in ciliates, its role in mammalian cell proliferation is still unconfirmed. The discovery of copy number variations (CNVs) in mammalian cells within an organ[4] has challenged the assumption that every cell in an organism must inherit an exact copy of the parental genome to be functional. Instead of CNVs stemming from errors in mitosis, such variations could have arisen from amitosis, and may even be beneficial to the cells. Furthermore, ciliates possess a mechanism for adjusting copy numbers of individual genes during amitosis of the macronucleus.[5]

Discovery[edit]

Amitosis was first described in 1880 by Walther Flemming, who also described mitosis and other forms of cell division.[6] Initially it was common for biologists to think of cells having both the capability to divide mitotically and amitotically.[7]

Functional role[edit]

Additional reports of non-mitotic proliferation as well as insights into its underlying mechanisms have emerged from extensive work with polyploid cells. Multiple copies of the genome in a cell population may be involved in the cell's adaptation to the environment.[8]

Polyploid cells are frequently "reduced" to diploid cells by amitosis.[9] Naturally occurring polyploid placental cells have been observed to produce nuclei with diploid or near-diploid complements of DNA. Such nuclei, derived from polyploid placental cells, receive one or more copies of a microscopically identifiable region of the chromatin. This particular amitotic process can actually result in representative transmission of chromatin. In rat polyploid trophoblasts, the nuclear envelope of the giant nucleus is involved in this subdivision.[10] Polyploid cells may also be key to the survival processes underlying chemotherapy resistance in certain cells.

It has been reported that following treatment of cultured cells with mitosis-inhibiting chemicals (similar to those used in certain chemotherapeutic protocols), a small population of induced polyploid cells survived. Eventually, this population gave rise to "normal" diploid cells by the formation of polyploid chromatin bouquets that return to an interphase state, before separating into several secondary nuclei.[11] Controlled autophagic degradation of DNA as well as the production of nuclear envelope-limited sheets[12] accompany the process.[13] Since this process of depolyploidization involves mitotic chromosomes, it conforms to the broad definition of amitosis.

Current literature[edit]

There are also multiple reports of amitosis occurring when nuclei bud out through the plasma membrane of a polyploid cell. Such a process has been shown to occur in amniotic cells transformed by a virus[14] and in mouse embryo fibroblast lines exposed to carcinogens.[15] A similar process called extrusion has been described for mink trophoblasts, a tissue in which fissioning is also observed.[16] Asymmetric cell division has also been described in polyploid giant cancer cells and low eukaryotic cells and reported to occur by the amitotic processes of splitting, budding, or burst-like mechanisms.[17] Similarly, two different kinds of amitosis have been described in monolayers of Ishikawa endometrial cells.[18]

An example of amitosis particularly suited to the formation of multiple differentiated nuclei in a reasonably short period of time has been shown to occur during the differentiation of fluid-enclosing hemispheres called domes from adherent Ishikawa endometrial monolayer cells during an approximately 20-hour period.[19][20] During the initial stages of differentiation, particularly within the first 6 hours, aggregates of nuclei from monolayer syncytia undergo a unique process where they become enveloped in mitochondrial membranes. These resulting structures, known as mitonucleons, experience an elevation due to the formation of vacuoles around them. This phenomenon indicates a distinct cellular organization and differentiation process, highlighting the complex interactions between cellular structures during development.[21][22] Over the next 4 to 5 hours, chromatin from these aggregated nuclei becomes increasingly pycnotic, eventually undergoing karyolysis and karyorrhexis in the now-elevated predome structures.[23] In other systems, such changes accompany apoptosis but not in the differentiating Ishikawa cells, where the processes appear to accompany changes in DNA essential for the newly created, differentiated dome cells. Finally, the chromatin filaments emerging from these processes form a mass from which dozens of dome nuclei are amitotically generated[24] over a period of approximately 3 hours with the apparent involvement of nuclear envelope-limited sheets.[25]

Scientific literature not only affirms the involvement of amitosis in cell proliferation, but also explores the existence of more than one amitotic mechanism capable of producing "progeny nuclei" without the involvement of "mitotic chromosomes." A form of amitosis involves fissioning, a nucleus splitting in two without the involvement of chromosomes, which has been reported to occur in placental tissues and in cells grown from such tissues in rats,[26] as well as in human and mouse trophoblasts.[27][28] Amitosis by fissioning has also been reported in mammalian liver cells[29] and human adrenal cells.[30] Chen and Wan[31] reported amitosis in rat liver and presented a mechanism for a four-stage amitotic process whereby chromatin threads are reproduced and equally distributed to daughter cells as the nucleus splits in two. In Mac amitosis of Tetrahymena we required γ-tubulin-mediated MT assembly[32]

In other studies, examination of fetal guts during development (5 to 7 weeks), colonic adenomas, and adenocarcinomas has revealed nuclei that appear as hollow bells encased in tubular syncytia. These structures can either divide symmetrically by an amitotic nuclear fission process, forming new "bells", or undergo fission asymmetrically, resulting in one of seven other nuclear morphotypes, five of which appear to be specific to development since they are rarely observed in adult organisms.[33]

The current body of literature suggests that amitosis may be involved in cellular development in humans,[34] likely during the fetal and embryonic phases of development when the majority of these cells are produced.

When the intestinal stem cells (ISCs) in fruit flies' guts are seriously reduced, they use a cool trick called amitosis to fix the problem. Instead of the usual way cells divide, where a spindle structure helps split the cell, they do it differently. Cells in another part of the gut, called enterocytes, reduce their number of chromosomes without going through the normal division process. This helps replace the lost ISCs, keeping the gut functioning properly. It's like the gut has a backup plan to make sure everything stays in balance!

References[edit]

  1. ^ Kuhn, E. M.; Therman, E.; Susman, B. (1991). "Amitosis and endocycles in early cultured mouse trophoblast". Placenta. 12 (3): 251–261. doi:10.1016/0143-4004(91)90006-2. PMID 1754574.
  2. ^ Pfitzer, P. (1980). "Amitosis: A Historical Misinterpretation?". Pathology, Research and Practice. 167 (2–4): 292–300. doi:10.1016/S0344-0338(80)80059-8. PMID 7433237.
  3. ^ Tippit, D. H.; Pickett-Heaps, J. D. (1976-07-01). "Apparent amitosis in the binucleate dinoflagellate Peridinium Balticum". Journal of Cell Science. 21 (2): 273–289. doi:10.1242/jcs.21.2.273. ISSN 0021-9533. PMID 987046.
  4. ^ O'Huallachain, M.; Karczewski, K. J.; Weissman, S. M.; Urban, A. E.; Snyder, M. P. (2012-10-30). "Extensive genetic variation in somatic human tissues". Proceedings of the National Academy of Sciences. 109 (44): 18018–18023. Bibcode:2012PNAS..10918018O. doi:10.1073/pnas.1213736109. ISSN 0027-8424. PMC 3497787. PMID 23043118.
  5. ^ Prescott, D. M. (June 1994). "The DNA of ciliated protozoa". Microbiological Reviews. 58 (2): 233–267. doi:10.1128/MMBR.58.2.233-267.1994. ISSN 0146-0749. PMC 372963. PMID 8078435.
  6. ^ Macklin, C. C. (June 1916). "Amitosis in Cells Growing in Vitro". The Biological Bulletin. 30 (6): 445–[466]–1. doi:10.2307/1536358. ISSN 0006-3185. JSTOR 1536358.
  7. ^ Holland, Nicholas (2021), "Vicenzo Colucci's 1886 memoir, Intorno alla rigenerazione degli arti e della coda nei tritoni, annotated and translated into English as: Concerning regeneration of the limbs and tail in salamanders", The European Zoological Journal, 88: 837–890, doi:10.1080/24750263.2021.1943549, S2CID 238904520
  8. ^ Duncan, Andrew W.; Taylor, Matthew H.; Hickey, Raymond D.; Hanlon Newell, Amy E.; Lenzi, Michelle L.; Olson, Susan B.; Finegold, Milton J.; Grompe, Markus (2010-10-07). "The ploidy conveyor of mature hepatocytes as a source of genetic variation". Nature. 467 (7316): 707–710. Bibcode:2010Natur.467..707D. doi:10.1038/nature09414. ISSN 1476-4687. PMC 2967727. PMID 20861837.
  9. ^ Zybina, T.G.; Zybina, E.V.; Kiknadze, I.I.; Zhelezova, A.I. (2001). "Polyploidization in the Trophoblast and Uterine Glandular Epithelium of the Endotheliochorial Placenta of Silver Fox (Vulpes fulvus Desm.), as Revealed by the DNA Content". Placenta. 22 (5): 490–498. doi:10.1053/plac.2001.0675. PMID 11373160.
  10. ^ Zybina, Eugenia V.; Zybina, Tatiana G. (July 2008). "Modifications of nuclear envelope during differentiation and depolyploidization of rat trophoblast cells". Micron. 39 (5): 593–606. doi:10.1016/j.micron.2007.05.006. ISSN 0968-4328. PMID 17627829.
  11. ^ Erenpreisa, Jekaterina; Salmina, Kristine; Huna, Anda; Kosmacek, Elizabeth A.; Cragg, Mark S.; Ianzini, Fiorenza; Anisimov, Alim P. (July 2011). "Polyploid tumour cells elicit paradiploid progeny through depolyploidizing divisions and regulated autophagic degradation". Cell Biology International. 35 (7): 687–695. doi:10.1042/CBI20100762. ISSN 1095-8355. PMID 21250945. S2CID 130498.
  12. ^ Olins, A. L.; Buendia, B.; Herrmann, H.; Lichter, P.; Olins, D. E. (1998-11-25). "Retinoic acid induction of nuclear envelope-limited chromatin sheets in HL-60". Experimental Cell Research. 245 (1): 91–104. doi:10.1006/excr.1998.4210. ISSN 0014-4827. PMID 9828104.
  13. ^ Erenpreisa, Jekaterina; Ivanov, Andrey; Cragg, Mark; Selivanova, Galina; Illidge, Timothy (March 2002). "Nuclear envelope-limited chromatin sheets are part of mitotic death". Histochemistry and Cell Biology. 117 (3): 243–255. doi:10.1007/s00418-002-0382-6. ISSN 0948-6143. PMID 11914922. S2CID 7261907.
  14. ^ Walen, Kirsten H. (February 2002). "The origin of transformed cells. studies of spontaneous and induced cell transformation in cell cultures from marsupials, a snail, and human amniocytes". Cancer Genetics and Cytogenetics. 133 (1): 45–54. doi:10.1016/s0165-4608(01)00572-6. ISSN 0165-4608. PMID 11890989.
  15. ^ Sundaram, Meenakshi; Guernsey, Duane L.; Rajaraman, Murali M.; Rajaraman, Rengaswami (February 2004). "Neosis: a novel type of cell division in cancer". Cancer Biology & Therapy. 3 (2): 207–218. doi:10.4161/cbt.3.2.663. ISSN 1538-4047. PMID 14726689.
  16. ^ Isakova, G. K.; Shilova, I. E. (July 2003). "[Frequency ratio of two forms of amitotic division of trophoblast cell nuclei in the mink blastocysts during the period of delayed implantation]". Izvestiia Akademii Nauk. Seriia Biologicheskaia (4): 395–398. ISSN 1026-3470. PMID 12942744.
  17. ^ Zhang, Dan; Wang, Yijia; Zhang, Shiwu (2014). "Asymmetric cell division in polyploid giant cancer cells and low eukaryotic cells". BioMed Research International. 2014: 432652. doi:10.1155/2014/432652. ISSN 2314-6141. PMC 4089188. PMID 25045675.
  18. ^ Fleming, Honoree (2014-12-31). Unusual characteristics of opaque Ishikawa endometrial cells include the envelopment of chromosomes with material containing endogenous biotin in the latter stages of cytokinesis (Report). PeerJ PrePrints.
  19. ^ Fleming, Honorée (1995). "Differentiation in human endometrial cells in monolayer culture: Dependence on a factor in fetal bovine serum". Journal of Cellular Biochemistry. 57 (2): 262–270. doi:10.1002/jcb.240570210. ISSN 0730-2312. PMID 7759563. S2CID 40483780.
  20. ^ Fleming, Honoree (1999). "Structure and Function of Cultured Endometrial Epithelial Cells". Seminars in Reproductive Medicine. 17 (1): 93–106. doi:10.1055/s-2007-1016215. ISSN 1526-8004. PMID 10406079. S2CID 9681391.
  21. ^ Fleming, Honoree; Condon, Rebekah; Peterson, Genevieve; Guck, Ilse; Prescott, Elizabeth; Chatfield, Kathryn; Duff, Meghan (1998-12-01). "Role of biotin-containing membranes and nuclear distribution in differentiating human endometrial cells". Journal of Cellular Biochemistry. 71 (3): 400–415. doi:10.1002/(SICI)1097-4644(19981201)71:3<400::AID-JCB9>3.0.CO;2-W. PMID 9831077. S2CID 19080155.
  22. ^ Fleming, Honoree (2016-02-09). Mitonucleons formed during differentiation of Ishikawa endometrial cells generate vacuoles that elevate monolayer syncytia: Differentiation of Ishikawa domes, Part 1 (Report). PeerJ PrePrints. doi:10.7287/peerj.preprints.1728v1.
  23. ^ Fleming, Honoree (2016-02-09). Pyknotic chromatin in mitonucleons elevating in syncytia undergo karyorhhexis and karyolysis before coalescing into an irregular chromatin mass: Differentiation of Ishikawa Domes, Part 2 (Report). PeerJ PrePrints. doi:10.7287/peerj.preprints.1729v1.
  24. ^ Fleming, Honoree (2016-02-09). Chomatin mass from previously aggregated, pyknotic, and fragmented monolayer nuclei is a source for dome cell nuclei generated by amitosis: Differentiation of Ishikawa Domes, Part 3 (Report). PeerJ PrePrints. doi:10.7287/peerj.preprints.1730v1.
  25. ^ Olins, A. L.; Buendia, B.; Herrmann, H.; Lichter, P.; Olins, D. E. (1998-11-25). "Retinoic acid induction of nuclear envelope-limited chromatin sheets in HL-60". Experimental Cell Research. 245 (1): 91–104. doi:10.1006/excr.1998.4210. ISSN 0014-4827. PMID 9828104.
  26. ^ Ferguson, F. G.; Palm, J. (1976-02-15). "Histologic characteristics of cells cultured from rat placental tissue". American Journal of Obstetrics and Gynecology. 124 (4): 415–420. doi:10.1016/0002-9378(76)90103-4. ISSN 0002-9378. PMID 1251862.
  27. ^ Cotte, C.; Easty, G. C.; Neville, A. M.; Monaghan, P. (August 1980). "Preparation of highly purified cytotrophoblast from human placenta with subsequent modulation to form syncytiotrophoblast in monolayer cultures". In Vitro. 16 (8): 639–646. doi:10.1007/bf02619191. ISSN 0073-5655. PMID 7419234. S2CID 20834295.
  28. ^ Kuhn, E. M.; Therman, E.; Susman, B. (May 1991). "Amitosis and endocycles in early cultured mouse trophoblast". Placenta. 12 (3): 251–261. doi:10.1016/0143-4004(91)90006-2. ISSN 0143-4004. PMID 1754574.
  29. ^ David, H.; Uerlings, I. (September 1992). "[Ultrastructure of amitosis and mitosis of the liver]". Zentralblatt für Pathologie. 138 (4): 278–283. ISSN 0863-4106. PMID 1420108.
  30. ^ Magalhães, M. C.; Pignatelli, D.; Magalhães, M. M. (April 1991). "Amitosis in human adrenal cells". Histology and Histopathology. 6 (2): 251–256. ISSN 0213-3911. PMID 1802124.
  31. ^ Chen, Y. Q.; Wan, B. K. (1986). "A study on amitosis of the nucleus of the mammalian cell. I. A study under the light and transmission electron microscope". Acta Anatomica. 127 (1): 69–76. ISSN 0001-5180. PMID 3788448.
  32. ^ Kushida, Yasuharu (February 2011). "γ-tubulin-mediated MT". Cytoskeleton (Hoboken, N.j.). 68 (2): 89–96. doi:10.1002/cm.20496. PMID 21246753.{{cite journal}}: CS1 maint: url-status (link)
  33. ^ Gostjeva, E. V.; Zukerberg, L.; Chung, D.; Thilly, W. G. (2006-01-01). "Bell-shaped nuclei dividing by symmetrical and asymmetrical nuclear fission have qualities of stem cells in human colonic embryogenesis and carcinogenesis". Cancer Genetics and Cytogenetics. 164 (1): 16–24. doi:10.1016/j.cancergencyto.2005.05.005. ISSN 0165-4608. PMID 16364758.
  34. ^ Duncan, Andrew W.; Taylor, Matthew H.; Hickey, Raymond D.; Hanlon Newell, Amy E.; Lenzi, Michelle L.; Olson, Susan B.; Finegold, Milton J.; Grompe, Markus (2010-10-07). "The ploidy conveyor of mature hepatocytes as a source of genetic variation". Nature. 467 (7316): 707–710. Bibcode:2010Natur.467..707D. doi:10.1038/nature09414. ISSN 1476-4687. PMC 2967727. PMID 20861837.

Further reading[edit]

Child CM. 1907 Amitosis as a factor in normal and regulatory growth. Anat Anz. 30: 271–97.

Coleman SJ, Gerza L, JonesCJ, Sibley CP, Aplin JD, Heazell AEP. 2013. Syncytial nuclear

Fleming H. 1995 Differentiation in human endometrial cells in monolayer culture: Dependence on a factor in fetal bovine serum J.Cell Biochem. 57:262-270.

Fleming H, Condon R, Peterson G, Guck I, Prescott E, Chatfield K, Duff M. 1998. Role of biotin-containing membranes and nuclear distribution in differentiating human endometrial cells. Journal of Cellular Biochemistry. 71(3): 400–415.

Fleming H. 1999 Structure and function of cultured endometrial epithelial cells. Semin Reprod Endocrinol.17(1):93-106.

Fleming H. 2014 Unusual characteristics of opaque Ishikawa endometrial cells include the envelopment of chromosomes with material containing endogenous biotin in the latter stages of cytokinesis doi:10.7287/peerj.preprints.772v1

Fleming H. 2016a. Mitonucleons formed during Differentiation of Ishikawa Endometrial Epithelial Cells are involved in Vacuole Formation that Elevates Monolayer Cells into Domes. Differentiation of Ishikawa Domes, Part 1, doi:10.7287/peerj.preprints.1728v1

Fleming H. 2016b. Pyknotic chromatin in mitonucleons elevating in syncytia undergo karyorhhexis and karyolysis before coalescing into an irregular chromatin mass: Differentiation of Ishikawa Domes, Part 2, doi:10.7287/peerj.preprints.1729v1

Fleming H. 2016c. Chromatin mass from previously aggregated, pyknotic, and fragmented monolayer nuclei is a source for dome cell nuclei generated by amitosis: Differentiation of Ishikawa Domes, Part 3, doi:10.7287/peerj.preprints.1730v1

Güttinger, S; Laurell, E; Kutay, U (2009), "Orchestrating nuclear envelope disassembly and reassembly during mitosis", Nat Rev Mol Cell Biol 10 (3): 178–191, doi:10.1038/nrm2641, PMID 19234477

Isakova GK, Shilova IE. 2000. Reproduction by "budding" of the trophoblast cells in the mink implanting blastocysts. Dokl Biol Sci. 371:214-6.

Schoenfelder KP, Fox DT 2015 The expanding implications of polyploidy. J Cell Biol. 25;209(4):485-91. doi:10.1083/jcb.201502016.

Thilly WG, Gostjeva EV, Koledova VV, Zukerberg LR, Chung D, Fomina JN, Darroudi F, Stollar BD. 2014. Metakaryotic stem cell nuclei use pangenomic dsRNA/DNA intermediates in genome replication and segregation. Organogenesis. 10(1):44-52. doi:10.4161/org.27684. Epub 2014 Jan 13.

Walen KH. 2004. Spontaneous cell transformation: karyoplasts derived from multinucleated cells produce new cell growth in senescent human epithelial cell cultures. In Vitro Cell Dev Biol Anim. 40(5-6):150-8.

Zybina EV, Zybina TG, Bogdanova MS, Stein GI 2005 Cell Biol Int. 29 (12): 1066-1070

source: https://en.wikipedia.org/wiki/Amitosis

Leave a Reply