Spalax

Life-forms

Superregnum: Eukaryota
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Cladus: Craniata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Cladus: Synapsida
Cladus: Eupelycosauria
Cladus: Sphenacodontia
Cladus: Sphenacodontoidea
Ordo: Therapsida
Cladus: Theriodontia
Subordo: Cynodontia
Cladus: Mammaliaformes
Classis: Mammalia
Subclassis: Trechnotheria
Infraclassis: Zatheria
Supercohort: Theria
Cohort: Eutheria
Cohort: Placentalia
Cladus: Boreoeutheria
Superordo: Euarchontoglires
Ordo: Rodentia
Subordo: Myomorpha
Superfamilia: Muroidea

Familia: Spalacidae
Subfamilia: Spalacinae
Genus: Spalax
Species (8 + 1†): †S. antiquus – S. arenarius – S. denizliensis – S. giganteus – S. graecus – S. istricus – S. microphthalmus – S. uralensis – S. zemni
Name

Spalax Güldenstädt, 1770: 410

Type species: Spalax microphthalmus Güldenstädt, 1770, by monotypy.

References
Additional references

Raicu, P., Bratosin, S. & Hamar, M. 1968. Study on karyotype of Spalax leucodon Nordm. and S. microphtalmus Guld. Caryologia 21: 127–135. [not seen]
Raicu, P.; Duma D. 1969. Cytogenetical study in Spalax leucodon Nordm. in Moldavia (Rumania). Genetical research 13(1): 99–104. DOI: 10.1017/S0016672300002779
Erten, H. 2018. Spalax denizliensis sp. nov. (Spalacidae, Rodentia) from an Early Pleistocene-aged locality in the Denizli Basin (southwestern Turkey). Turkish Journal of Zoology 42(1): 62-67. Full article (PDF). Reference page.

Links

Spalax in Mammal Species of the World.
Wilson, Don E. & Reeder, DeeAnn M. (Editors) 2005. Mammal Species of the World – A Taxonomic and Geographic Reference. Third edition. ISBN 0-8018-8221-4.

Vernacular names
čeština: Slepec
English: Blind Mole-rats
українська: Сліпак

The genus Spalax contains the blind, fossorial, or subterranean mole rats, which are one of several types of rodents that are called "mole rats".[1] The hystricognath mole-rats of the family Bathyergidae are completely unrelated, but some other forms are also in the family Spalacidae. Zokors (subfamily Myospalacinae), root rats, and bamboo rats (subfamily Rhizomyinae) are spalacids sometimes referred to as mole rats. Blind mole rats are in the family Spalacidae, but are unique enough to be given a separate subfamily, Spalacinae. Alternate opinions on taxonomy consider the blind mole-rats to be the only members of the family Spalacidae and rank other spalacid subfamilies as full families. Other authors group all members of the superfamily Muroidea into a single family, Muridae. The Spalacinae contains two genera and eight species. Some authorities treat all species as belonging to a single genus, Spalax.

Spalax mole rats are truly blind.[2] Their very small eyes are completely covered by a layer of skin. Unlike many other fossorial rodents, Spalax mole rats do not have enlarged front claws and do not appear to use their forearms as a primary digging tool. Digging is almost exclusively conducted using their powerful front teeth, which are separated from the rest of the mouth by a flap of skin. When a Spalax mole rat closes its mouth, its incisors are still on the outside. Blind mole rats may have evolved from spalacids that used their front limbs to dig, because their olecranon processes are large relative to the rest of their arms. The olecranon process is a part of the ulna bone where muscles attach, and digging animals tend to have enlarged olecranon processes to provide a large surface for their large and powerful muscles to attach.

Because they are completely blind, blind mole rats have been important laboratory animals in tests on how eyes and eye proteins function. Although Spalax has only atrophied subcutaneous eyes and it is sightless, its circadian rhythm is kept. A few publications (Avivi et al.) have proved that the circadian genes that control the biological clock are expressed in a similar manner as in sighted, above-ground mammals.

Resistance to cancer

Studies on the growth of fibroblasts in vitro of Spalax judaei and Spalax golani showed that the process of necrosis replaces the role of the systematic apoptosis normally used in most organisms. Generally low-oxygen conditions, such as those common in blind mole rats’ burrows, usually cause cells to undergo apoptosis. One study showed that in adaptation to a higher tendency of cell death, blind mole rats evolved a mutation in the tumor suppressor protein p53, also used in humans, to prevent cells from undergoing apoptosis.[3] Human cancer patients have similar mutations, and blind mole rats were thought to be more susceptible to cancer because their cells cannot undergo apoptosis. However, after a specific amount of time (within 3 days according to one study), the cells in blind mole rats release interferon-beta (which the immune system normally uses to counter viruses) in response to over-proliferation of cells caused by the suppression of apoptosis. In this case, the interferon-beta triggers cells to undergo necrosis, and this mechanism also kills cancer cells in blind mole rats. Because of tumor suppression mechanisms such as this, blind mole rats and other spalacids are resistant to cancer.[4][5][6]

The involvement of interferon in the so-called concerted cell death of Spalax cells via necrosis was highly criticized.[4] Serious questions have been raised on the inconsistent methodology used that led to this speculation.
Classification

Subfamily Spalacinae

Genus Spalax – Blind mole rats
Spalax antiquus[7]
Sandy mole rat, Spalax arenarius
Mount Carmel blind mole rat, Spalax carmeli
Middle East blind mole rat, Spalax ehrenbergi
Upper Galilee Mountains blind mole rat, Spalax galili
Giant mole rat, Spalax giganteus
Golan Heights blind mole rat, Spalax golani
Balkan mole rat, Spalax graecus
Spalax istricus[7]
Judean Mountains blind mole rat, Spalax judaei
Lesser mole rat, Spalax leucodon
Greater mole rat, Spalax microphthalmus
Munzur mole rat, Spalax munzuri
Nehring's blind mole rat, Spalax nehringi
Kazakhstan blind mole rat, Spalax uralensis
Podolsk mole rat, Spalax zemni

References

Macdonald, D., ed. (2006). The Encyclopedia of Mammals. Oxford: Oxford University Books. p. 203. ISBN 978-0-87196-871-5.
Lamarck, Jean-Baptiste (1809). Philosophie zoologique ou exposition des considérations relatives à l'histoire naturelle des animaux. Dentu.
Avivi, A; Ashur-Fabian, O; Joel, A; Trakhtenbrot, L; Adamsky, K; Goldstein, I; Amariglio, N; Rechavi, G; Nevo, E (16 October 2006). "P53 in blind subterranean mole rats – loss-of-function versus gain-of-function activities on newly cloned Spalax target genes". Oncogene. 26 (17): 2507–2512. doi:10.1038/sj.onc.1210045. PMID 17043642.
Saey, Tina Hesman (5 November 2012). "Cancer cells self-destruct in blind mole rats". Science News. Retrieved 27 November 2012.
Gorbunova, V.; Hine, C.; Tian, X.; Ablaeva, J.; Gudkov, A. V.; Nevo, E.; Seluanov, A. (2012). "Cancer resistance in the blind mole rat is mediated by concerted necrotic cell death mechanism". Proceedings of the National Academy of Sciences. 109 (47): 19392–6. Bibcode:2012PNAS..10919392G. doi:10.1073/pnas.1217211109. PMC 3511137. PMID 23129611. Retrieved 27 November 2012
Shams, Imad; Manov, Irena; Malik, Assaf; Band, Mark; Avivi, Aaron (2014). Fighting Cancer Underground: Hypoxia Tolerant Spalax Hides the Key for Treatment. The Plant & Animal Genome XXII Conference.

Old views and new insights: taxonomic revision of the Bukovina blind mole rat, Spalax graecus (Rodentia: Spalacinae) (PDF). 2013. doi:10.1111/zoj.12081.

8 ^ Irena Manov, Mark Hirsh, Theodore C Iancu, Assaf Malik, Nick Sotnichenko, Mark Band, Aaron Avivi and Imad Shams† (2013) Pronounced cancer resistance in a subterranean rodent, the blind mole-rat, Spalax: in vivo and in vitro evidence. BMC Biology [1]