Nurse cells of the thymus were discovered in mice thirty years ago [ 2], but later they had also been isolated from humans, rats, pigs, fish, ewes, frogs and chickens [ 46].
Figure 1E shows that in normal mice, one year of CR led to a reduction in the HOMA score compared to AL controls (P<0.01), while CR did not alter the already improved HOMA score in GHRKO mice.
The investigators gave feed containing 12,500, 25,000, or 50,000 parts per million (1.25 %, 2.5 %, or 5%%) of milk thistle extract to groups of 50 male and female rats and mice for two years.
To examine whether Ing2 deficiency affects tumorigenesis and the aging processes, we observed Ing2+/+ (n = 22) and Ing2−/− (n = 28) mice for two years.
Macroscopic (PET scan) and histological examinations indicated an increase in the incidence of hepatic tumors in the iLID mice at two years of age (Fig. 3G).
While most of the native mice collected over two years were found in no-cat areas, 79% of all the house mice were collected in areas colonized by the cats.
Using the iLID model, we induced IGF-1 deficiency after the critical phase of growth and development and followed the mice up to two years of age.
Thus there are short and medium lived species (mice live around two years in the lab, while rabbits live some 20 years) that apparently do not display telomere-dependent RS and only display STASIS, while a long-lived species (humans) displays both.
Why does a mouse live only two years, while a man lives up to hundred years?
The median life span of a DBA/1 mouse is about two years (104 weeks).
