The Middle East blind mole-rat or Palestine mole-rat (''Nannospalax ehrenbergi'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family

Spalacidae The Spalacidae, or spalacids, are a family of rodents in the large and complex superfamily Muroidea. They are native to eastern Asia, the Horn of Africa, the Middle East, and southeastern Europe. It includes the blind mole-rats, bamboo rats, mole ...

Taxonomy

It was formerly classified in the genus ''

Spalax ''Spalax'' is a genus of rodent in the family Spalacidae, subfamily ''Spalacinae'' (blind mole-rats). It is one of two extant genera in the subfamily Spalacinae, alongside ''Nannospalax''.' Species in this genus are found in eastern Europe a ...

'', but more recent phylogenetic evidence supports it and two other species belonging to the genus ''

Nannospalax ''Nannospalax'' is a genus of rodent in the family Spalacidae, found in eastern Europe and western Asia. It is one of two genera in the blind mole-rats (subfamily Spalacinae), alongside ''Spalax''. Members of this genus are also known as small-b ...

''. Of the three ''Nannospalax'' species, ''N. ehrenbergi'' is the only one to also belong to the

subgenus In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between t ...

''Nannospalax'' (unless the potential species within ''N. ehrenbergi'' are also considered their own species).

Possible cryptic species

Cytogenetic Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis an ...

studies have shown ''N. ehrenbergi'' in Israel may actually be a

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

containing several

cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

with

chromosome number Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

s 2n=52, 2n=54, 2n=58 and 2n=60. Close to the 'border line' of the niche of each subspecies there is mating between individuals from different subspecies/different 2n chromosome number. Birth of fertile offspring implies that

speciation Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within ...

of the subspecies has not been completed. In 2001, four new ''Nannospalax'' species (then classified within ''Spalax'')

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to geographical regions within

Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...

Palestine __NOTOC__ Palestine may refer to: * State of Palestine, a state in Western Asia * Palestine (region), a geographic region in Western Asia * Palestinian territories, territories occupied by Israel since 1967, namely the West Bank (including East ...

and the

Golan Heights The Golan Heights ( ar, هَضْبَةُ الْجَوْلَانِ, Haḍbatu l-Jawlān or ; he, רמת הגולן, ), or simply the Golan, is a region in the Levant spanning about . The region defined as the Golan Heights differs between di ...

were described based on chromosome divergence by a team of researchers led by Eviatar Nevo. These were: * The Mount Carmel blind mole-rat (''N. carmeli'') - endemic to

Mount Carmel Mount Carmel ( he, הַר הַכַּרְמֶל, Har haKarmel; ar, جبل الكرمل, Jabal al-Karmil), also known in Arabic as Mount Mar Elias ( ar, link=no, جبل مار إلياس, Jabal Mār Ilyās, lit=Mount Saint Elias/Elijah), is a c ...

in northern Israel, including the vicinity of

Afik Afik () is an Israeli settlement organized as a kibbutz in the Golan Heights. It was established in 1972 close to the abandoned Syrian village of Fiq following Israel's capture and occupation of the Golan Heights in the 1973 Yom Kippur War. I ...

, Kabri, and

Tzippori Tzippori () is a moshav in northern Israel, in the Lower Galilee. The moshav is within the jurisdiction of the Jezreel Valley Regional Council. The moshav is located at the site of the ancient settlement of Sepphoris, after which it was named. H ...

settlements. * The Upper Galilee Mountains blind mole rat (''N. galili'') - endemic to

Upper Galilee The Upper Galilee ( he, הגליל העליון, ''HaGalil Ha'Elyon''; ar, الجليل الأعلى, ''Al Jaleel Al A'alaa'') is a geographical-political term in use since the end of the Second Temple period. It originally referred to a mountai ...

in northern Israel, including the vicinity of

Kerem Ben Zimra Kerem Ben Zimra ( he, כֶּרֶם בֶּן זִמְרָה) is a moshav in northern Israel. Near Safed in the Upper Galilee, it falls under the jurisdiction of Merom HaGalil Regional Council. In it had a population of . History The moshav was fo ...

settlement. * The Golan Heights blind mole-rat (''N. golani'') - endemic to the Golan Heights, including the vicinity of

Mount Hermon Mount Hermon ( ar, جبل الشيخ or جبل حرمون / ALA-LC: ''Jabal al-Shaykh'' ("Mountain of the Sheikh") or ''Jabal Haramun''; he, הַר חֶרְמוֹן, ''Har Hermon'') is a mountain cluster constituting the southern end of the ...

Quneitra , ''Qunayṭrawi'' or ''Qunayṭirawi'' , population_density_metro_sq_mi = , population_urban = , population_density_urban_km2 = , population_density_urban_sq_mi = , population_blank1_title = , population_bla ...

and Eliad. * The Judean Mountains blind mole-rat (''N. judaei'') - endemic to the

Judaean Mountains The Judaean Mountains, or Judaean Hills ( he, הרי יהודה, translit=Harei Yehuda) or the Hebron Mountains ( ar, تلال الخليل, translit=Tilal al-Khalīl, links=, lit=Hebron Mountains), is a mountain range in Palestine and Israel wh ...

in central Israel and Palestine, including the vicinity of

Kibbutz A kibbutz ( he, קִבּוּץ / , lit. "gathering, clustering"; plural: kibbutzim / ) is an intentional community in Israel that was traditionally based on agriculture. The first kibbutz, established in 1909, was Degania. Today, farming h ...

Lahav Lahav ( he, לַהַב, ''lit. blade'') is a kibbutz in southern Israel. Located around 20 km north of Beersheba and covering 33,000 dunams, it falls under the jurisdiction of Bnei Shimon Regional Council. In it had a population of . Hist ...

. Although the

ITIS The Integrated Taxonomic Information System (ITIS) is an American partnership of federal agencies designed to provide consistent and reliable information on the taxonomy of biological species. ITIS was originally formed in 1996 as an interagenc ...

and

Mammal Species of the World ''Mammal Species of the World: A Taxonomic and Geographic Reference'' is a standard reference work in mammalogy giving descriptions and bibliographic data for the known species of mammals. It is now in its third edition, published in late 2005, ...

still recognize these species, the

American Society of Mammalogists The American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammals, and professions studying them. There are over 4,500 members of this society, and they are primarily professional scientists ...

and the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

presently group these within ''N. ehrenbergi'' due to taxonomic uncertainty, such as lack of convincing genetic support for speciation, and the type locality of ''ehrenbergi'' itself likely falling within the range of one of these species.

Description

The Middle East blind mole-rat weighs . It has light gray fur and four sharp teeth, two large teeth in the upper jaw and two smaller teeth in the lower jaw. It has a life span of up to 20 years and is notable for its adaptability to severe lack of oxygen. In Israel, the blind mole-rat is a major agricultural pest. It digs long tunnels up to 80 centimeters deep and stores onions and tubers in underground chambers.Better_check_that_mole:_Has_an_Israeli_biologist_found_the_key_to_curing_cancer?_Haaretz
.html" ;"title="Haaretz">Better check that mole: Has an Israeli biologist found the key to curing cancer? Haaretz
">Haaretz">Better check that mole: Has an Israeli biologist found the key to curing cancer? Haaretz
/ref> The exceptional ecological adaptation strategies of the blind mole-rats can be seen in their different tongue morphologies, as evidenced by their tongue papillae. The tongue papillae differ between individuals in a species to adapt to different environmental regions with variant soil characteristics and food types.

Distribution and habitat

''N. ehrenbergi'' is found in Egypt, Iraq, Turkey and the Levant (

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

Jordan Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...

and

Lebanon Lebanon ( , ar, لُبْنَان, translit=lubnān, ), officially the Republic of Lebanon () or the Lebanese Republic, is a country in Western Asia. It is located between Syria to the north and east and Israel to the south, while Cyprus li ...

). The natural

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

of the mole is Mediterranean-type shrubbish vegetation, and it is threatened by

habitat loss Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

Use in research

According to Israeli researchers at

Haifa University The University of Haifa ( he, אוניברסיטת חיפה Arabic: جامعة حيفا) is a university located on Mount Carmel in Haifa, Israel. Founded in 1963, the University of Haifa received full academic accreditation in 1972, becoming Is ...

, the Middle East blind mole-rat is an important lab animal for researching cancer due to its apparent resistance to the disease. In a 2013 study, data on ''N. ehrenbergi'' resistance to cancer was documented: -No spontaneous tumors have ever been noticed in blind mole rat, based on observing thousands of individuals along half a century. -Inducing cancer with chemical carcinogens that lead to 100% of the expected tumors in mice and rats after 2–6 months, respectively, indicate an extraordinary cancer resistance of Spalax: Only 2 out of 12 animals, and old ones (>10 years old; Spalax can live ~>20 years; 5 times longer than its evolutionary relative, the rat) developed the expected tumor with one of the carcinogens and only after 18 and 30 months. - ''Nannospalax'' cells (

fibroblast A fibroblast is a type of cell (biology), biological cell that synthesizes the extracellular matrix and collagen, produces the structural framework (Stroma (tissue), stroma) for animal Tissue (biology), tissues, and plays a critical role in wound ...

s), and only ''Nannospalax'' cells, when grown in co-culture with cancer cells from different species, including a wide range of human cancer cells, kill the cancer cells. This is also true when "feeding" the cancer cells with the medium that ''Nannospalax'' cells grew in. Identification of the secreted substance/s by ''Nannospalax'' fibroblasts and the component on cancer cells' membrane they interact with, that lead to the cancer cells' death, can open a possibility for finding a general cure to cancer. Cancer resistance has also been noted in the two former species (''N. judaei'' and ''N. golani'') presently merged with this species. ''N. galili'' had its genome sequenced in 2014. Studies on the growth of

s ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

'' of ''N. judaei'' and ''N. golani'' showed that the process of

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

replaces the role of the systematic

apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...

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 A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or red ...

protein

p53 p53, also known as Tumor protein P53, cellular tumor antigen p53 (UniProt name), or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins (originally thought to be, and often s ...

, also used in humans, to prevent cells from undergoing apoptosis. 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 The type-I interferons (IFN) are cytokines which play essential roles in inflammation, immunoregulation, tumor cells recognition, and T-cell responses. In the human genome, a cluster of thirteen functional IFN genes is located at the 9p21.3 cyto ...

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

References