Editing Cell growth (section)

===Other experimental systems for the study of cell size regulation===
One common means to produce very large cells is by cell fusion to form [[syncytium|syncytia]]. For example, very long (several inches) [[skeletal muscle]] cells are formed by fusion of thousands of [[myocyte]]s. Genetic studies of the fruit fly ''[[Drosophila melanogaster|Drosophila]]'' have revealed several genes that are required for the formation of multinucleated muscle cells by fusion of [[myoblast]]s.<ref>{{cite journal
|vauthors=Menon SD, Osman Z, Chenchill K, Chia W | title = A positive feedback loop between Dumbfounded and Rolling pebbles leads to myotube enlargement in Drosophila
| journal = J. Cell Biol.
| volume = 169
| issue = 6
| pages = 909–20
|date=June 2005
| pmid = 15955848
| pmc = 2171639
| doi = 10.1083/jcb.200501126
}}</ref> Some of the key proteins are important for [[cell adhesion]] between myocytes and some are involved in adhesion-dependent cell-to-cell [[signal transduction]] that allows for a cascade of cell fusion events.

Increases in the size of [[plant cell]]s are complicated by the fact that almost all plant cells are inside of a solid [[cell wall]]. Under the influence of certain plant hormones the cell wall can be remodeled, allowing for increases in cell size that are important for the growth of some plant tissues.

Most unicellular organisms are microscopic in size, but there are some giant [[bacterium|bacteria]] and [[protozoa]] that are visible to the naked eye. (See [https://web.archive.org/web/20040328112742/http://wikibooks.org/wiki/Biology_Cell_biology_Introduction_Cell_size Table of cell sizes]—Dense populations of a giant sulfur bacterium in Namibian shelf sediments<ref>{{cite journal |vauthors=Schulz HN, Brinkhoff T, Ferdelman TG, Mariné MH, Teske A, Jorgensen BB |s2cid=32571118 |title=Dense populations of a giant sulfur bacterium in Namibian shelf sediments |journal=Science |volume=284 |issue=5413 |pages=493–5 |date=April 1999 |pmid=10205058 |doi= 10.1126/science.284.5413.493|bibcode = 1999Sci...284..493S }}</ref>—[https://web.archive.org/web/20040427144107/http://www.bms.ed.ac.uk/research/others/smaciver/chaos.htm Large protists of the genus ''Chaos'', closely related to the genus ''Amoeba''].)

In the rod-shaped bacteria ''E. coli'', ''Caulobacter crescentus'' and ''B. subtilis'' cell size is controlled by a simple mechanisms in which cell division occurs after a constant volume has been added since the previous division.<ref>{{Cite journal
 | title = Cell-size control and homeostasis in bacteria
 | journal = [[Current Biology]]
 | volume = 25
 | issue = 3
 | pages = 385–391
 |date=February 2015
 | doi = 10.1016/j.cub.2014.12.009
 | pmid = 25544609
| pmc = 4323405
 | last1 = Taheri-Araghi
 | first1 = S
 | last2 = Bradde
 | first2 = S
 | last3 = Sauls
 | first3 = J. T.
 | last4 = Hill
 | first4 = N. S.
 | last5 = Levin
 | first5 = P. A.
 | last6 = Paulsson
 | first6 = J
 | last7 = Vergassola
 | first7 = M
 | last8 = Jun
 | first8 = S
 | bibcode = 2015CBio...25..385T
 }}</ref><ref>{{Cite journal
 | title = A constant size extension drives bacterial cell size homeostasis
 | journal = [[Cell (journal)|Cell]]
 | volume = 159
 | issue = 6
 | pages = 1433–1446
 |date=December 2014
 | doi = 10.1016/j.cell.2014.11.022
 | pmid = 25480302
| pmc = 4258233
 | last1 = Campos
 | first1 = M
 | last2 = Surovtsev
 | first2 = I. V.
 | last3 = Kato
 | first3 = S
 | last4 = Paintdakhi
 | first4 = A
 | last5 = Beltran
 | first5 = B
 | last6 = Ebmeier
 | first6 = S. E.
 | last7 = Jacobs-Wagner
 | first7 = C
 }}</ref> By always growing by the same amount, cells born smaller or larger than average naturally converge to an average size equivalent to the amount added during each generation.