Editing Mammal (section)

===Species lifespan===
{{See also|Life expectancy|Maximum life span}}
Among mammals, species maximum lifespan varies significantly (for example the [[shrew]] has a lifespan of two years, whereas the oldest [[bowhead whale]] is recorded to be 211 years).<ref name="pmid19896964">{{cite journal | vauthors = Lorenzini A, Johnson FB, Oliver A, Tresini M, Smith JS, Hdeib M, Sell C, Cristofalo VJ, Stamato TD | display-authors = 6 | title = Significant correlation of species longevity with DNA double strand break recognition but not with telomere length | journal = Mechanisms of Ageing and Development | volume = 130 | issue = 11–12 | pages = 784–792 | year = 2009 | pmid = 19896964 | pmc = 2799038 | doi = 10.1016/j.mad.2009.10.004 }}</ref> Although the underlying basis for these lifespan differences is still uncertain, numerous studies indicate that the ability to [[DNA repair|repair DNA damage]] is an important determinant of mammalian lifespan. In a 1974 study by Hart and Setlow,<ref name="pmid4526202">{{cite journal | vauthors = Hart RW, Setlow RB | title = Correlation between deoxyribonucleic acid excision-repair and life-span in a number of mammalian species | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 71 | issue = 6 | pages = 2169–2173 | date = June 1974 | pmid = 4526202 | pmc = 388412 | doi = 10.1073/pnas.71.6.2169 | bibcode = 1974PNAS...71.2169H | doi-access = free }}</ref> it was found that DNA excision repair capability increased systematically with species lifespan among seven mammalian species. Species lifespan was observed to be robustly correlated with the capacity to recognise DNA double-strand breaks as well as the level of the DNA repair protein [[Ku80]].<ref name="pmid19896964"/> In a study of the cells from sixteen mammalian species, genes employed in DNA repair were found to be [[Downregulation and upregulation|up-regulated]] in the longer-lived species.<ref name="pmid27874830">{{cite journal | vauthors = Ma S, Upneja A, Galecki A, Tsai YM, Burant CF, Raskind S, Zhang Q, Zhang ZD, Seluanov A, Gorbunova V, Clish CB, Miller RA, Gladyshev VN | display-authors = 6 | title = Cell culture-based profiling across mammals reveals DNA repair and metabolism as determinants of species longevity | journal = eLife | volume = 5 | date = November 2016 | pmid = 27874830 | pmc = 5148604 | doi = 10.7554/eLife.19130 | doi-access = free }}</ref> The cellular level of the DNA repair enzyme [[poly ADP ribose polymerase]] was found to correlate with species lifespan in a study of 13 mammalian species.<ref name="pmid1465394">{{cite journal | vauthors = Grube K, Bürkle A | title = Poly(ADP-ribose) polymerase activity in mononuclear leukocytes of 13 mammalian species correlates with species-specific life span | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 89 | issue = 24 | pages = 11759–11763 | date = December 1992 | pmid = 1465394 | pmc = 50636 | doi = 10.1073/pnas.89.24.11759 | bibcode = 1992PNAS...8911759G | doi-access = free }}</ref> Three additional studies of a variety of mammalian species also reported a correlation between species lifespan and DNA repair capability.<ref name="pmid7266079">{{cite journal | vauthors = Francis AA, Lee WH, Regan JD | title = The relationship of DNA excision repair of ultraviolet-induced lesions to the maximum life span of mammals | journal = Mechanisms of Ageing and Development | volume = 16 | issue = 2 | pages = 181–189 | date = June 1981 | pmid = 7266079 | doi = 10.1016/0047-6374(81)90094-4 | s2cid = 19830165 }}</ref><ref name="pmid7060140">{{cite journal | vauthors = Treton JA, Courtois Y | title = Correlation between DNA excision repair and mammalian lifespan in lens epithelial cells | journal = Cell Biology International Reports | volume = 6 | issue = 3 | pages = 253–260 | date = March 1982 | pmid = 7060140 | doi = 10.1016/0309-1651(82)90077-7 | doi-broken-date = 4 April 2025 }}</ref><ref name="pmid3974310">{{cite journal | vauthors = Maslansky CJ, Williams GM | title = Ultraviolet light-induced DNA repair synthesis in hepatocytes from species of differing longevities | journal = Mechanisms of Ageing and Development | volume = 29 | issue = 2 | pages = 191–203 | date = February 1985 | pmid = 3974310 | doi = 10.1016/0047-6374(85)90018-1 | s2cid = 23988416 }}</ref>