Extension of cell life-span and telomere length in animals cloned from senescent somatic cells

Science. 2000 Apr 28;288(5466):665-9. doi: 10.1126/science.288.5466.665.


The potential of cloning depends in part on whether the procedure can reverse cellular aging and restore somatic cells to a phenotypically youthful state. Here, we report the birth of six healthy cloned calves derived from populations of senescent donor somatic cells. Nuclear transfer extended the replicative life-span of senescent cells (zero to four population doublings remaining) to greater than 90 population doublings. Early population doubling level complementary DNA-1 (EPC-1, an age-dependent gene) expression in cells from the cloned animals was 3.5- to 5-fold higher than that in cells from age-matched (5 to 10 months old) controls. Southern blot and flow cytometric analyses indicated that the telomeres were also extended beyond those of newborn (<2 weeks old) and age-matched control animals. The ability to regenerate animals and cells may have important implications for medicine and the study of mammalian aging.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Southern
  • Cattle / genetics*
  • Cell Division
  • Cells, Cultured
  • Cellular Senescence*
  • Clone Cells
  • Cloning, Organism*
  • DNA, Complementary
  • Embryo Transfer
  • Eye Proteins*
  • Female
  • Fibroblasts
  • Flow Cytometry
  • In Situ Hybridization, Fluorescence
  • Longevity
  • Matched-Pair Analysis
  • Nerve Growth Factors*
  • Nuclear Transfer Techniques*
  • Proteins / genetics
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Serpins / genetics
  • Telomere / ultrastructure*


  • DNA, Complementary
  • Eye Proteins
  • Nerve Growth Factors
  • Proteins
  • RNA, Messenger
  • Serpins
  • pigment epithelium-derived factor