Naked mole-rat: Difference between revisions
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{{Automatic Taxobox |
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Ryan price you fat downie |
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| name = Naked mole rat |
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| status = LC |
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| status_system = iucn3.1 |
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| status_ref =<ref name=iucn>{{IUCN2008|assessors=Maree, S. & Faulkes, C.|year=2008|id=9987|title=Heterocephalus glaber|downloaded=5 January 2009}}</ref> |
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| trend = stable |
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| fossil_range = Early [[Pliocene]] - Recent |
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| image = Nacktmull.jpg |
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| image_width = 200px |
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| taxon = Heterocephalus glaber |
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| display parents = 3 |
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| parent_authority = Rüppell, 1842 |
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| grandparent_authority = Landry, 1957 |
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| range_map=Heterocephalus glaber dis.png |
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| range_map_caption=Distribution of the Naked Mole Rat |
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| binomial = '''''Heterocephalus glaber''''' |
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| binomial_authority = [[Eduard Rüppell|Rüppell]], 1842 |
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}} |
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The '''naked [[Blesmol|mole rat]]''' (''Heterocephalus glaber'') also known as the '''sand puppy''' or '''desert mole rat''', is a burrowing [[rodent]] native to parts of [[East Africa]] and the only [[species]] currently classified in the [[genus]] '''''Heterocephalus'''''. It was once thought to be one of only two [[eusociality|eusocial]] [[mammal]]s (the other being the [[Damaraland Mole Rat|Damaraland mole rat]]) but this classification is controversial owing to disputed definitions of 'eusociality' as well as the existence of other mammals that satisfy the original definition of Wilson (1971).<ref name="O'Riain and Faulkes, (2008)">O'Riain, M.J. and Faulkes, C. G., (2008). African mole rats: eusociality, relatedness and ecological constraints. In J. Korb and J. Heinze (eds.), Ecology of Social Evolution, 207-223. http://www.springerlink.com/content/q11245457q771m3t/</ref> It has a highly unusual set of physical traits that enables it to thrive in an otherwise harsh, underground environment, including a lack of pain sensation in its skin and a very low [[metabolism]]. |
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==Physical description== |
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Typical individuals are {{convert|8|to|10|cm|in|0|abbr=on}} long and weigh {{convert|30|to|35|g|oz}}. Queens are larger and may weigh well over {{convert|50|g|oz}}, the largest reaching {{convert|80|g|oz}}. They are well-adapted to their underground existence. Their eyes are quite small, and their visual acuity is poor. Their legs are thin and short; however, they are highly adept at moving underground and can move backward as fast as they can move forward. Their large, protruding teeth are used to dig, and their lips are sealed just behind the teeth to prevent soil from filling their mouths while digging. They have little hair (hence the common name) and wrinkled pink or yellowish skin. |
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==Physiology== |
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The naked mole rat is well adapted for the limited availability of [[oxygen]] within the tunnels that are its habitat: its [[lung]]s are very small and its blood has a very strong affinity for oxygen, increasing the efficiency of oxygen uptake. It has a very low respiration and metabolic rate for an animal of its size, about 2/3 that of a mouse of the same size, thus using oxygen minimally. In long periods of hunger, such as a drought, its metabolic rate can be reduced by up to 25 percent. |
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[[File:Naked Mole Rats-cropped.jpg|thumb|left|Captive naked mole rats huddling together]] |
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The naked mole rat does not regulate its body temperature in typical mammalian fashion, ''[[homeostasis]]''. They are thermoconformers rather than thermoregulators in that, unlike other mammals, body temperature tracks ambient temperatures. The relationship between oxygen consumption and ambient temperature, however, switches from a typical [[poikilotherm]]ic pattern to a [[homeotherm]]ic mode at 28°C.<ref name="Daly et al., (1997)">Daly, T.J.M., Williams, L.A. and Buffenstein, R., (1997). Catecholaminergic innervation of interscapular brown adipose tissue in the naked mole-rat (Heterocephalus glaber). Journal of Anatomy, 190: 321-326. doi: 10.1046/j.1469-7580.1997.19030321.x</ref> At lower temperatures, they use behavioural thermoregulation, as when cold, naked mole rats huddle together or bask in the shallow, more sun-warmed parts of their burrow systems. Conversely, when they get too hot, they retreat to the deeper, cooler parts of their tunnel system. |
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The skin of naked mole rats lacks a key [[neurotransmitter]] called [[substance P]] that is responsible in [[mammal]]s for sending [[pain]] signals to the [[central nervous system]]. When naked mole rats are exposed to acid or [[capsaicin]], they feel no pain. When they are injected with substance P, however, the pain signaling works as it does in other mammals, but only with capsaicin and not with the acids. This is proposed to be an adaptation to the animal living in high levels of [[carbon dioxide]] due to poorly ventilated living spaces, which would cause acid to build up in their body tissues.<ref>{{cite journal |last=Park |first=Thomas J. |coauthors=et ''al.'' |year=2008 |pmc=2214810|title=Selective Inflammatory Pain Insensitivity in the African Naked Mole-Rat (''Heterocephalus glaber'') |journal=[[PLoS Biology]] |volume=6 |issue=1 |pages=e13 |doi=10.1371/journal.pbio.0060013 |pmid=18232734}}</ref> |
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Naked mole rats' substance P deficiency has also been tied to their lack of the histamine-induced itching and scratching behavior typical to rodents.<ref>{{cite journal|title=Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P.|url=http://www.molecularpain.com/content/6/1/29|doi=10.1186/1744-8069-6-29|pmc=2886013|pmid=20497578|year=2010|last1=St John Smith|first1=E|last2=Blass|first2=GR|last3=Lewin|first3=GR|last4=Park|first4=TJ|volume=6|issue=1|pages=29|journal=Molecular pain}}</ref> |
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==Ecology and behavior== |
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===Distribution and habitat=== |
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The naked mole rat is native to the drier parts of the tropical grasslands of East Africa, predominantly southern [[Ethiopia]], [[Kenya]], and [[Somalia]]. |
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Clusters averaging 75 to 80 individuals live together in complex systems of burrows in arid African deserts. The tunnel systems built by naked mole rats can stretch up to two or three miles in cumulative length.<ref name=selfish_gene>{{cite book|last=Dawkins|first=Richard|year=1976|title=The Selfish Gene|publisher=Oxford University Press|isbn=0-19-286092-5}}</ref> |
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=== Roles === |
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The naked mole rat is one of the two species of mammals that exhibit [[eusociality]]. This eusocial structure is similar to that found in [[ant]]s, [[termite]]s, and some [[bee]]s and [[wasp]]s. Only one female (the queen) and one to three males reproduce, while the rest of the members of the colony function as workers. The queen and breeding males are able to breed at one year of age. Workers are sterile, with the smaller focusing on gathering food and maintaining the nest, while larger workers are more reactive in case of attack. |
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The [[Damaraland mole rat]] (''Cryptomys damarensis'') is the only other eusocial mammal currently known. |
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==== Queen and gestation ==== |
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The relationships between the queen and the breeding males may last for many years; other females are temporally sterile. Queens live from 13 to 18 years, and are extremely hostile to other females behaving like queens, or producing hormones for becoming queens. When the queen dies, another female takes her place, sometimes after a violent struggle with her competitors. Once established, the new queen stretches the space between the [[vertebrae]] in her backbone to become longer and ready to bear pups.<ref>[http://www.sandiegozoo.org/animalbytes/t-naked_mole-rat.html San Diego’s Animals. Mammals: Naked Mole-rat]</ref> |
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Gestation is about 70 days. A litter typically ranges from three to twelve pups, but may be as large as 28. The average litter size is 11.<ref>[http://www.news.cornell.edu/releases/Aug99/rat_mamm.hrs.html ''Counting mole-rat mammaries and hungry pups, biologists explain why naked rodents break the rules''], Roger Segelken, Cornell News, August 9, 1999</ref> In the wild, naked mole-rats usually breed once a year, if the litter survives. In captivity, they breed all year long and can produce a litter every 80 days.<ref name=ross>{{cite book |author=Ross Piper |title=Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals |publisher=Greenwood Press |location=Westport, Conn |year=2007 |isbn=0-313-33922-8 }}</ref> The young are born blind and weigh about {{convert|2|g|oz}}. The queen nurses them for the first month; after which the other members of the colony feed them [[feces]] until they are old enough to eat solid food. |
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==== Workers ==== |
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Smaller workers focus on acquiring food and maintaining tunnels, while the larger workers are more reactive in case of attacks.<ref>{{cite web|url=http://news.bbc.co.uk/2/hi/science_and_environment/10088502.stm|title=Meet the 'sabre-toothed sausage'|author=Rebecca Morelle|publisher=BBC News|date=2010, May 5}}</ref> As in certain bee species, the workers are divided along a continuum of different worker-caste behaviors instead of discrete groups.<ref name=selfish_gene/> Some function primarily as tunnellers, expanding the large network of tunnels within the burrow system, and some primarily as [[soldier]]s, protecting the group from outside [[predation|predators]]. Workers are sterile when there is no new reproductive role to fill. |
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==== Colonies ==== |
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Colonies range in size from 20 to 300 individuals, with an average of 75.<ref>[http://nationalzoo.si.edu/Publications/ZooGoer/2002/3/nakedmolerats.cfm ''The Naked Truth About Mole-Rats''], Jill Locantore, Smithsonian Zoogoer, May/June 2002</ref> |
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===Diet=== |
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[[File:Naked Mole Rat Eating.jpg|thumb|A captive naked mole rat eating]] |
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Naked mole rats feed primarily on very large [[tuber]]s (weighing as much as 1000 times the body weight of a typical mole rat) that they find deep underground through their mining operations, but also eat their own feces ([[coprophagia]]).<ref name=selfish_gene/> A single tuber can provide a colony with a long-term source of food—lasting for months, or even years,<ref name=selfish_gene/> as they eat the inside but leave the outside, allowing the tuber to regenerate. [[Symbiosis|Symbiotic]] [[bacteria]] in their intestines ferment the fibres, allowing previously indigestible cellulose to be turned into volatile fatty acids. |
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==Longevity== |
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The naked mole rat is also of interest because it is extraordinarily long-lived for a rodent of its size (up to 28 years) and holds the record for the longest living rodent.<ref>{{cite journal |author=Buffenstein R, Jarvis JU |title=The naked mole rat—a new record for the oldest living rodent |journal=Sci Aging Knowledge Environ |volume=2002 |issue=21 |pages=pe7 |year=2002 |month=May |pmid=14602989 |doi=10.1126/sageke.2002.21.pe7 |url=http://sageke.sciencemag.org/cgi/pmidlookup?view=long&pmid=14602989}}</ref> The reason for their longevity is debated, but is thought to be related to their ability to substantially reduce their metabolism during hard times, and so prevent oxidative damage. This has been referred to as "living their life in pulses."<ref>{{cite web|url=http://www.sciencedaily.com/releases/2007/10/071015225336.htm |title=Ugly Duckling Mole Rats Might Hold Key To Longevity |publisher=Sciencedaily.com |date=2007-10-16 |accessdate=2009-03-11}}</ref> Because of their extraordinary longevity, an international effort was put into place to sequence the genome of the naked mole rat.<ref>{{cite web|url=http://genomics.senescence.info/sequencing/heterocephalus.html |title=Proposal to Sequence an Organism of Unique Interest for Research on Aging: Heterocephalus glaber, the Naked Mole-Rat |publisher=Genomics.senescence.info |date= |accessdate=2009-04-30}}</ref> A draft genome was made available in 2011.<ref>{{cite web |url=http://mr.genomics.org.cn |title=Naked Mole-Rat Database |author= |date= |work= |publisher=Naked Mole-Rat Database 2011 |accessdate=5 July 2011}}</ref><ref>{{cite web |url=http://naked-mole-rat.org/ |title=Naked Mole-Rat Genome Resource |author= |date= |work= |publisher=Naked Mole-Rat Genome Resource 2011 |accessdate=5 July 2011}}</ref><ref>{{cite journal |author=Kim |title=Genome sequencing reveals insights into physiology and longevity of the naked mole rat |journal=Nature |volume=2011 |issue=21 |pages=223–7 |year=2011 |month=Oct |pmid=21993625 |doi=10.1038/nature10533 |url=http://www.nature.com/nature/journal/vaop/ncurrent/full/nature10533.html |display-authors=1 |last2=Fang |first2=Xiaodong |last3=Fushan |first3=Alexey A. |last4=Huang |first4=Zhiyong |last5=Lobanov |first5=Alexei V. |last6=Han |first6=Lijuan |last7=Marino |first7=Stefano M. |last8=Sun |first8=Xiaoqing |last9=Turanov |first9=Anton A.}}</ref> |
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==Resistance to cancer== |
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Naked mole rats appear to have a high resistance to cancer; cancer has never been observed in them. A potential mechanism that averts cancer is an "over-crowding" gene, [[p16 (gene)|p16]], which prevents cell division once a group of cells reaches a certain size. Most mammals, including naked mole rats, have a gene called [[p27 (gene)|p27]] which does a similar task, but prevents cellular reproduction at a much later point than p16 does. The combination of p16 and p27 in naked mole rats cells is a double barrier to cell proliferation.<ref>{{cite web|url=http://sciencenow.sciencemag.org/cgi/content/full/2009/1026/2 |title=Naked Mole Rat Wins the War on Cancer: Jocelyn Kaiser |publisher=AAAS |date= 26 October 2009|accessdate=27 October 2009}}</ref> Hypersensitivity to [[contact inhibition]] may be the reason for the cancer resistance of the naked mole rat.<ref>{{cite journal | doi=10.1073/pnas.0905252106 | author=Seluanov A, Hine C, Azpurua J, Feigenson M, Bozzella M, Mao Z, Catania KC, Gorbunova V | title=Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat | journal=Proc Natl Acad Sci U S A | volume=106 | issue=46 | year=2009 | pages=19352–7 | url = http://www.pnas.org/content/106/46/19352.long | pmid=19858485 | pmc=2780760 }}</ref> |
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==Conservation status== |
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Naked mole rats are not threatened. They are widespread and numerous in the drier regions of [[East Africa]]. |
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==References== |
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{{Reflist}} |
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==External links== |
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{{commons|Heterocephalus glaber|Naked Mole Rat}} |
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{{wikispecies|Heterocephalus glaber|Naked Mole Rat}} |
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* {{cite web |
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| url = http://animaldiversity.ummz.umich.edu/site/accounts/information/Heterocephalus_glaber.html |
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| title = ''Heterocephalus glaber'', naked mole rat |
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| publisher = Animal Diversity Web |
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| first = Deborah | last = Ciszek |
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| year = 1999 | accessdate = January 2010 |
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}} |
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* {{cite web |
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| url = http://www.brookfieldzoo.org/pagegen/htm/fix/fg/fg_body.asp?sAnimal=Naked+mole-rat |
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| title = Heterocephalus glaber: Cooperation is Key |
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| publisher = Brookfield Zoo |
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| accessdate = January 2010 |
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}} |
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* {{cite web |
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| url = http://www.brookfieldzoo.org/pgpages/pagegen.26.aspx |
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| title = Naked Mole Rat Queen |
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| publisher = Chicago Zoological Society |
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| accessdate = January 2010 |
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}} (For [[Microsoft Internet Explorer|MSIE]] only?)<!--- layout look like crap on FF --> |
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* {{cite web |
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| url = http://www.cas.vanderbilt.edu/bioimages/animals/mammalia/naked-mole-rat.htm |
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| title = Naked mole rat (''Heterocephalus glaber'') images |
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| publisher = Bioimages at [[Vanderbilt University]] |
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| year = 2003 | first = Steve | last = Baskauf |
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| accessdate = January 2010 |
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}} |
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* {{cite web |
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| url = http://www.livescience.com/humanbiology/061009_aging_rats.html |
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| title = Naked Mole-rats Hold Clues to Human Aging |
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| date = October 2006 | accessdate = January 2010 |
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| first = Jeanna | last = Bryner | publisher = LiveScience |
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}} |
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* {{cite journal |
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| url = http://www.springerlink.com/content/nnxdge13894eqk1a/ |
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| title = Tool use by naked mole-rats |
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| journal = Animal Cognition | pages = 71–74 |
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| first1 = Gabriela | last1 = Shuster1 | first2 = P. W. | last2 = Sherman |
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| publisher = Springer Berlin / Heidelberg |
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| issue = 1 | volume = 1 | year = 1998 |
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| doi = 10.1007/s100710050009 |
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}} |
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* {{cite web |
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| url = http://www.livescience.com/animals/080128-mole-rat-pain.html |
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| title = Strange Creature Immune to Pain |
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| first = Charles Q. | last = Choi |
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| publisher = LiveScience |
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| date = January 2008 | accessdate = January 2010 |
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}} |
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* {{cite web |
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| url = http://nationalzoo.si.edu/Animals/SmallMammals/default.cfm?cam=NMR |
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| title = Small Mammals (with a naked mole-rat webcam) |
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| publisher = Smithsonian National Zoological Park |
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| accessdate = January 2010 |
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}} |
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{{Bathyergidae nav}} |
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[[Category:Bathyergidae]] |
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[[Category:Coprophagous animals]] |
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[[Category:Mammals of Africa]] |
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[[Category:Sequenced genomes]] |
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{{Link GA|de}} |
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[[bn:নেকেড মোল ইঁদুর]] |
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[[br:Razh-goz noazh]] |
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[[ca:Farumfer]] |
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[[cs:Rypoš lysý]] |
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[[de:Nacktmull]] |
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[[nv:Tʼáá łichíʼígo náʼagéédí]] |
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[[es:Heterocephalus glaber]] |
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[[eo:Heterocefalo]] |
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[[eu:Heterocephalus glaber]] |
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[[fr:Rat-taupe nu]] |
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[[ga:Caochfhrancach]] |
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[[it:Heterocephalus glaber]] |
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[[lb:Plakeg Maulefsrat]] |
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[[hu:Csupasz turkáló]] |
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[[nl:Naakte molrat]] |
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[[ja:ハダカデバネズミ]] |
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[[no:Nakenrotte]] |
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[[pl:Golec]] |
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[[pt:Rato-toupeira-pelado]] |
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[[ru:Голый землекоп]] |
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[[simple:Naked Mole Rat]] |
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[[sr:Heterocephalus glaber]] |
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[[fi:Kaljurotta]] |
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[[sv:Kalråtta]] |
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[[uk:Землекоп голий]] |
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[[vi:Chuột chũi Đông Phi]] |
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[[zh:裸鼹鼠]] |
Revision as of 09:22, 23 March 2012
Naked mole rat Temporal range: Early Pliocene - Recent
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![]() | |
Scientific classification ![]() | |
Missing taxonomy template (fix): | Heterocephalus glaber |
Binomial name | |
Heterocephalus glaber Rüppell, 1842
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![]() | |
Distribution of the Naked Mole Rat |
The naked mole rat (Heterocephalus glaber) also known as the sand puppy or desert mole rat, is a burrowing rodent native to parts of East Africa and the only species currently classified in the genus Heterocephalus. It was once thought to be one of only two eusocial mammals (the other being the Damaraland mole rat) but this classification is controversial owing to disputed definitions of 'eusociality' as well as the existence of other mammals that satisfy the original definition of Wilson (1971).[2] It has a highly unusual set of physical traits that enables it to thrive in an otherwise harsh, underground environment, including a lack of pain sensation in its skin and a very low metabolism.
Physical description
Typical individuals are 8 to 10 cm (3 to 4 in) long and weigh 30 to 35 grams (1.1 to 1.2 oz). Queens are larger and may weigh well over 50 grams (1.8 oz), the largest reaching 80 grams (2.8 oz). They are well-adapted to their underground existence. Their eyes are quite small, and their visual acuity is poor. Their legs are thin and short; however, they are highly adept at moving underground and can move backward as fast as they can move forward. Their large, protruding teeth are used to dig, and their lips are sealed just behind the teeth to prevent soil from filling their mouths while digging. They have little hair (hence the common name) and wrinkled pink or yellowish skin.
Physiology
The naked mole rat is well adapted for the limited availability of oxygen within the tunnels that are its habitat: its lungs are very small and its blood has a very strong affinity for oxygen, increasing the efficiency of oxygen uptake. It has a very low respiration and metabolic rate for an animal of its size, about 2/3 that of a mouse of the same size, thus using oxygen minimally. In long periods of hunger, such as a drought, its metabolic rate can be reduced by up to 25 percent.
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/1f/Naked_Mole_Rats-cropped.jpg/220px-Naked_Mole_Rats-cropped.jpg)
The naked mole rat does not regulate its body temperature in typical mammalian fashion, homeostasis. They are thermoconformers rather than thermoregulators in that, unlike other mammals, body temperature tracks ambient temperatures. The relationship between oxygen consumption and ambient temperature, however, switches from a typical poikilothermic pattern to a homeothermic mode at 28°C.[3] At lower temperatures, they use behavioural thermoregulation, as when cold, naked mole rats huddle together or bask in the shallow, more sun-warmed parts of their burrow systems. Conversely, when they get too hot, they retreat to the deeper, cooler parts of their tunnel system.
The skin of naked mole rats lacks a key neurotransmitter called substance P that is responsible in mammals for sending pain signals to the central nervous system. When naked mole rats are exposed to acid or capsaicin, they feel no pain. When they are injected with substance P, however, the pain signaling works as it does in other mammals, but only with capsaicin and not with the acids. This is proposed to be an adaptation to the animal living in high levels of carbon dioxide due to poorly ventilated living spaces, which would cause acid to build up in their body tissues.[4]
Naked mole rats' substance P deficiency has also been tied to their lack of the histamine-induced itching and scratching behavior typical to rodents.[5]
Ecology and behavior
Distribution and habitat
The naked mole rat is native to the drier parts of the tropical grasslands of East Africa, predominantly southern Ethiopia, Kenya, and Somalia.
Clusters averaging 75 to 80 individuals live together in complex systems of burrows in arid African deserts. The tunnel systems built by naked mole rats can stretch up to two or three miles in cumulative length.[6]
Roles
The naked mole rat is one of the two species of mammals that exhibit eusociality. This eusocial structure is similar to that found in ants, termites, and some bees and wasps. Only one female (the queen) and one to three males reproduce, while the rest of the members of the colony function as workers. The queen and breeding males are able to breed at one year of age. Workers are sterile, with the smaller focusing on gathering food and maintaining the nest, while larger workers are more reactive in case of attack.
The Damaraland mole rat (Cryptomys damarensis) is the only other eusocial mammal currently known.
Queen and gestation
The relationships between the queen and the breeding males may last for many years; other females are temporally sterile. Queens live from 13 to 18 years, and are extremely hostile to other females behaving like queens, or producing hormones for becoming queens. When the queen dies, another female takes her place, sometimes after a violent struggle with her competitors. Once established, the new queen stretches the space between the vertebrae in her backbone to become longer and ready to bear pups.[7]
Gestation is about 70 days. A litter typically ranges from three to twelve pups, but may be as large as 28. The average litter size is 11.[8] In the wild, naked mole-rats usually breed once a year, if the litter survives. In captivity, they breed all year long and can produce a litter every 80 days.[9] The young are born blind and weigh about 2 grams (0.071 oz). The queen nurses them for the first month; after which the other members of the colony feed them feces until they are old enough to eat solid food.
Workers
Smaller workers focus on acquiring food and maintaining tunnels, while the larger workers are more reactive in case of attacks.[10] As in certain bee species, the workers are divided along a continuum of different worker-caste behaviors instead of discrete groups.[6] Some function primarily as tunnellers, expanding the large network of tunnels within the burrow system, and some primarily as soldiers, protecting the group from outside predators. Workers are sterile when there is no new reproductive role to fill.
Colonies
Colonies range in size from 20 to 300 individuals, with an average of 75.[11]
Diet
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/cf/Naked_Mole_Rat_Eating.jpg/220px-Naked_Mole_Rat_Eating.jpg)
Naked mole rats feed primarily on very large tubers (weighing as much as 1000 times the body weight of a typical mole rat) that they find deep underground through their mining operations, but also eat their own feces (coprophagia).[6] A single tuber can provide a colony with a long-term source of food—lasting for months, or even years,[6] as they eat the inside but leave the outside, allowing the tuber to regenerate. Symbiotic bacteria in their intestines ferment the fibres, allowing previously indigestible cellulose to be turned into volatile fatty acids.
Longevity
The naked mole rat is also of interest because it is extraordinarily long-lived for a rodent of its size (up to 28 years) and holds the record for the longest living rodent.[12] The reason for their longevity is debated, but is thought to be related to their ability to substantially reduce their metabolism during hard times, and so prevent oxidative damage. This has been referred to as "living their life in pulses."[13] Because of their extraordinary longevity, an international effort was put into place to sequence the genome of the naked mole rat.[14] A draft genome was made available in 2011.[15][16][17]
Resistance to cancer
Naked mole rats appear to have a high resistance to cancer; cancer has never been observed in them. A potential mechanism that averts cancer is an "over-crowding" gene, p16, which prevents cell division once a group of cells reaches a certain size. Most mammals, including naked mole rats, have a gene called p27 which does a similar task, but prevents cellular reproduction at a much later point than p16 does. The combination of p16 and p27 in naked mole rats cells is a double barrier to cell proliferation.[18] Hypersensitivity to contact inhibition may be the reason for the cancer resistance of the naked mole rat.[19]
Conservation status
Naked mole rats are not threatened. They are widespread and numerous in the drier regions of East Africa.
References
- ^ Template:IUCN2008
- ^ O'Riain, M.J. and Faulkes, C. G., (2008). African mole rats: eusociality, relatedness and ecological constraints. In J. Korb and J. Heinze (eds.), Ecology of Social Evolution, 207-223. http://www.springerlink.com/content/q11245457q771m3t/
- ^ Daly, T.J.M., Williams, L.A. and Buffenstein, R., (1997). Catecholaminergic innervation of interscapular brown adipose tissue in the naked mole-rat (Heterocephalus glaber). Journal of Anatomy, 190: 321-326. doi: 10.1046/j.1469-7580.1997.19030321.x
- ^ Park, Thomas J. (2008). "Selective Inflammatory Pain Insensitivity in the African Naked Mole-Rat (Heterocephalus glaber)". PLoS Biology. 6 (1): e13. doi:10.1371/journal.pbio.0060013. PMC 2214810. PMID 18232734.
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suggested) (help)CS1 maint: unflagged free DOI (link) - ^ St John Smith, E; Blass, GR; Lewin, GR; Park, TJ (2010). "Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P." Molecular pain. 6 (1): 29. doi:10.1186/1744-8069-6-29. PMC 2886013. PMID 20497578.
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: CS1 maint: unflagged free DOI (link) - ^ a b c d Dawkins, Richard (1976). The Selfish Gene. Oxford University Press. ISBN 0-19-286092-5.
- ^ San Diego’s Animals. Mammals: Naked Mole-rat
- ^ Counting mole-rat mammaries and hungry pups, biologists explain why naked rodents break the rules, Roger Segelken, Cornell News, August 9, 1999
- ^ Ross Piper (2007). Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals. Westport, Conn: Greenwood Press. ISBN 0-313-33922-8.
- ^ Rebecca Morelle (2010, May 5). "Meet the 'sabre-toothed sausage'". BBC News.
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(help) - ^ The Naked Truth About Mole-Rats, Jill Locantore, Smithsonian Zoogoer, May/June 2002
- ^ Buffenstein R, Jarvis JU (2002). "The naked mole rat—a new record for the oldest living rodent". Sci Aging Knowledge Environ. 2002 (21): pe7. doi:10.1126/sageke.2002.21.pe7. PMID 14602989.
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ignored (help) - ^ "Ugly Duckling Mole Rats Might Hold Key To Longevity". Sciencedaily.com. 2007-10-16. Retrieved 2009-03-11.
- ^ "Proposal to Sequence an Organism of Unique Interest for Research on Aging: Heterocephalus glaber, the Naked Mole-Rat". Genomics.senescence.info. Retrieved 2009-04-30.
- ^ "Naked Mole-Rat Database". Naked Mole-Rat Database 2011. Retrieved 5 July 2011.
- ^ "Naked Mole-Rat Genome Resource". Naked Mole-Rat Genome Resource 2011. Retrieved 5 July 2011.
- ^ Kim; et al. (2011). "Genome sequencing reveals insights into physiology and longevity of the naked mole rat". Nature. 2011 (21): 223–7. doi:10.1038/nature10533. PMID 21993625.
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ignored (help) - ^ "Naked Mole Rat Wins the War on Cancer: Jocelyn Kaiser". AAAS. 26 October 2009. Retrieved 27 October 2009.
- ^ Seluanov A, Hine C, Azpurua J, Feigenson M, Bozzella M, Mao Z, Catania KC, Gorbunova V (2009). "Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat". Proc Natl Acad Sci U S A. 106 (46): 19352–7. doi:10.1073/pnas.0905252106. PMC 2780760. PMID 19858485.
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External links
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- Ciszek, Deborah (1999). "Heterocephalus glaber, naked mole rat". Animal Diversity Web. Retrieved January 2010.
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(help) - "Heterocephalus glaber: Cooperation is Key". Brookfield Zoo. Retrieved January 2010.
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(help) - "Naked Mole Rat Queen". Chicago Zoological Society. Retrieved January 2010.
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(help) (For MSIE only?) - Baskauf, Steve (2003). "Naked mole rat (Heterocephalus glaber) images". Bioimages at Vanderbilt University. Retrieved January 2010.
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(help) - Bryner, Jeanna (October 2006). "Naked Mole-rats Hold Clues to Human Aging". LiveScience. Retrieved January 2010.
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(help) - Shuster1, Gabriela; Sherman, P. W. (1998). "Tool use by naked mole-rats". Animal Cognition. 1 (1). Springer Berlin / Heidelberg: 71–74. doi:10.1007/s100710050009.
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: CS1 maint: numeric names: authors list (link) - Choi, Charles Q. (January 2008). "Strange Creature Immune to Pain". LiveScience. Retrieved January 2010.
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(help) - "Small Mammals (with a naked mole-rat webcam)". Smithsonian National Zoological Park. Retrieved January 2010.
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(help)