AnAge entry for Heterocephalus glaber

Classification (HAGRID: 02483)

Taxonomy
Kingdom: Animalia
    Phylum: Chordata
        Class: Mammalia (Taxon entry)
            Order: Rodentia
                Family: Bathyergidae
                    Genus: Heterocephalus
Species
Heterocephalus glaber
Common name
Naked mole-rat
Synonyms
Heterocephalus ansorgei, Heterocephalus dunni, Heterocephalus phillipsi, Heterocephalus progrediens, Heterocephalus scortecci, Heterocephalus stygius

Lifespan, ageing, and relevant traits

Maximum longevity
31 years (captivity)
Source
Rochelle Buffenstein, pers. comm.
Sample size
Large
Data quality
High
Observations

These bizarre underground animals from the Horn of Africa live in cooperative colonies, a protected and thermally buffered environment. Their body temperature is relatively low and they appear to be cold-intolerant. They are one of the longest-lived rodents and are extremely resistant to cancer [0689], though cases of cancer have been reported [1248]. The INK4 locus of naked mole rats encodes a functional p15/p16 hybrid isoform (in addition to the other products) which is expressed in response to a number of cancer related stresses. In cultured cells this hybrid product has a stronger ability to induce cell-cycle arrest than either p15 or p16 and may contribute to the increased cancer resistance of this species [1176].

Record longevity belongs to one specimen caught in the wild in 1980 that lived over 30 years in captivity until it died in 2010, making it at least 31 years of age when it died (Rochelle Buffenstein, pers. comm.). In the wild, breeders have been known to live up to 17 years but non-breeders do not commonly live more than 2 or 3 years (Stan Braude, pers. comm.).

Unlike other mammals, naked mole-rats appear to maintain good health for most of their lifespan and do not exhibit the typical age-associated increase in mortality [0756]. Older animals can be less active but few age-related changes have been described [0981]. Naked mole-rats maintain cardiac function with age and show no evidence of cardiac hypertrophy or arterial stiffening [1177]. Nonterminal pathologies like sarcopenia and kyphosis have been observed in old animals [0925]. In addition to their cancer resistance naked mole-rats appear to have natural protection against amyloid beta plaque formation, a process implicated in Alzheimer's disease (AD). In one study, the brains of the longest lived naked mole-rats contained similar levels of amyloid beta to mouse models of AD yet showed no evidence of extracellular plaque formation [1178]. Even young naked mole-rats have high levels of soluble amyloid beta in their brains, linked to lower levels of UPS-mediated amyloid beta degradation [1179]. Another study found that levels of phosphorylated tau protein, also implicated in AD, were higher in naked mole-rats than mouse models. Despite this, the phosphorylated tau protein maintained normal axonal localisation [1180]. This suggests naked mole-rats also have a resistance to neurodegenerative disease.

Life history traits (averages)

Female sexual maturity
228 days
Male sexual maturity
Gestation
70 days
Weaning
36 days
Litter size
7 (viviparous)
Litters per year
3.5
Inter-litter interval
81 days
Weight at birth
2 g
Weight at weaning
11 g
Adult weight
35 g
Postnatal growth rate
0.0046 days-1 (from Gompertz function)
Maximum longevity residual
368%

Metabolism

Typical body temperature
305ºK or 32.1ºC or 89.8ºF
Basal metabolic rate
0.1280 W
Body mass
35.3 g
Metabolic rate per body mass
0.003626 W/g

References

External Resources

Integrated Taxonomic Information System
ITIS 584677
Animal Diversity Web
ADW account
Encyclopaedia of Life
Search EOL
NCBI Taxonomy
Taxonomy ID 10181
Entrez
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Ageing Literature
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Internet
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