Telomeres and Human Reproduction

Telomere dynamics differ between the female and male germ lines: oocytes have short telomeres, and their erosion recapitulates the reproductive aging phenotype, and telomere length in sperm increases with age.

Keri Horan Kalmbach, M.S., Danielle Mota Fontes Antunes, M.S., Roberta Caetano Dracxler, M.D., Taylor Warner Knier, B.A., Michelle Louise Seth-Smith, B.S., Fang Wang, Ph.D., Lin Liu, Ph.D., David Lawrence Keefe, M.D.

Volume 99, Issue 1, Pages 23-29, January 2013


Telomeres mediate biological aging in organisms as diverse as plants, yeast, mammals. We propose a Telomere Theory of Reproductive Aging that posits telomere shortening in the female germ line as the primary driver of reproductive aging in women. Experimental shortening of telomeres in mice, which normally do not exhibit appreciable oocyte aging, and which have exceptionally long telomeres, recapitulates the aging phenotype of human oocytes. Telomere shortening in mice reduces synapsis and chiasmata, increases embryo fragmentation, cell cycle arrest, apoptosis, spindle dysmorphologies and chromosome abnormalities. Telomeres are shorter in the oocytes from women undergoing IVF that go on to produce fragmented, aneuploid embryos and which fail to implant. In contrast, the testes are replete with spermatogonia that can rejuvenate telomere reserves throughout the life of the man by expressing telomerase. Differences in telomere dynamics across the lifespans of men and women may have evolved because of the difference in the inherent risks of aging on reproduction between men and women. Additionally, growing evidence links altered telomere biology to endometriosis and gynecological cancers, thus future studies should examine the role of telomeres in pathologies of the reproductive tract.

  • Cristian Muresanu

    I have a question for Dr. Keri Horan Kalmbach. If telomerase enzyme is created inside human sperm cells, and we already know that other cells in our body (including glial cells), do not express this enzyme, EVEN THE GENE FOR THAT IS PRESENT, please elaborate a hypothesis, if possible, on how to deliver that enzyme from the human sperm cells into the other cells of our body, thus telomeres lenght could be reset. Please e-mail me at and I thank you very much. I had performed a practical application, not yet properly explained as theory, by which, using the male reproductive system in a certain manner, might be possible to make the human sperm cells as kind of donor cells in the benefit of the other cells (so they can donate their parts, like mitochondria, telomerase enzyme, achrozomes and other useful molecules), if my approach is correct. Please write me back. I wish to offer you more ideas on e-mail.

  • fdominguez

    BeautifulBeautiful and clear review of the role of telomerases
    in human reproduction. Specially choking is the contrary effect of telomerase
    expression in the male and female gamete, does other publications support this hypothesis?

    Francisco Dominguez
    Fundacion IVI
    Valencia, Spain

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