Genom may play a role that female mammals live longer

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Hi everybody,

in new study scientists create a mouse with a genom from

two female mice and no father. This mice were leaner

an lived longer than normal mice with the gnome from a father

and a mother. This means the female genome plays a role why female

mammals life longer than male.

Hum. Reprod. Advance Access published online on December 1, 2009

Human Reproduction, doi:10.1093/humrep/dep400

http://humrep.oxfordjournals.org/cgi/content/abstract/dep400v1

Longevity in mice without a father

Manabu Kawahara1 and Tomohiro Kono2,3

1 Laboratory of Animal Resource Development, Faculty of Agriculture, Saga

University, 1 Honjo-machi, Saga 840-8502, Japan 2

Department of BioScience, Tokyo University of Agriculture, Setagaya-ku, Tokyo

156-8502, Japan

3 Correspondence address. Tel/Fax: +81-3-5477-2543; E-mail: tomohiro@...

BACKGROUND: Females live longer than males in many mammalian species, including

humans. It has been observed that women are at an advantage over men with regard

to the lifespan; however, the reason for this sex difference in longevity is

unclear. Bi-maternal mice (BM), which are produced in a `sperm-free' manner,

could provide an opportunity to analyse the longevity of animals lacking

paternal genomes.

METHODS AND RESULTS: We studied the longevity of BM, which were generated using

two sets of female genomes—one derived from fully grown oocytes from normal

adults and the other from non-growing oocytes from newborn pups. These newborn

pups were also genetically manipulated in two regions—the imprinting centres of

Igf2-H19 and Dlk1-Gtl2—on chromosomes 7 and 12. We determined lifespan of the

control (n = 13) and BM (n = 13). Our results revealed that the bi-maternal

genotype clearly shifted the entire survival curve to the right, suggesting a

delay in the expression of all causes of mortality. BM survived 186 days longer

than controls. Furthermore, the body weight was significantly lower in the BM as

compared with the controls at 20 months after birth (P < 0.05), and leukocyte

composition analysis at 8 weeks revealed that the eosinophil

count was significantly increased in the BM as compared with the controls (P <

0.05, n = 6).

CONCLUSIONS: These findings demonstrate that the maternal genome may play a role

in ontogenetic longevity. Our results further suggested sex differences in

longevity, originating at the genome level, implying that the sperm genome has a

detrimental effect on longevity in mammals.