title: Cloned cows with short telomeres deliver healthy offspring with normal-length telomeres.
abstract: Dolly, the first mammal cloned from a somatic cell, had shorter telomeres than age-matched controls and died at an early age because of disease. To investigate longevity and lifetime performance in cloned animals, we produced cloned cows with short telomeres using oviductal epithelial cells as donor cells. At 5 years of age, despite the presence of short telomeres, all cloned cows delivered multiple healthy offspring following artificial insemination with conventionally processed spermatozoa from noncloned bulls, and their milk production was comparable to that of donor cows. Moreover, this study revealed that the offspring had normal-length telomeres in their leukocytes and major organs. Thus, cloned animals have normal functional germ lines, and therefore germ line function can completely restore telomere lengths in clone gametes by telomerase activity, resulting in healthy offspring with normal-length telomeres.
authors.affiliation: Laboratory of Reproduction and Development, National Institute of Agrobiological Sciences, Ibaraki 305-0901, Japan. nmiya@affrc.go.jp
authors.forename: Norikazu
authors.initials: N
authors.lastname: Miyashita
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Kubo
authors.forename: Miharu
authors.initials: M
authors.lastname: Yonai
authors.forename: Kanako
authors.initials: K
authors.lastname: Kaneyama
authors.forename: Norio
authors.initials: N
authors.lastname: Saito
authors.forename: Ken
authors.initials: K
authors.lastname: Sawai
authors.forename: Akira
authors.initials: A
authors.lastname: Minamihashi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suzuki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kojima
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagai
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000235:genetics*; D002417:Cattle / Q000235:genetics* / Q000502:physiology; D002478:Cells, Cultured; D019976:Cloning, Organism / Q000662:veterinary; D036861:Delivery, Obstetric / Q000662:veterinary; D004624:Embryo Transfer / Q000662:veterinary; D005260:Female; D006262:Health; D053652:Nuclear Transfer Techniques / Q000662:veterinary; D011247:Pregnancy; D011270:Pregnancy, Animal; D059505:Telomere Homeostasis / Q000235:genetics / Q000502:physiology*; D059506:Telomere Shortening / Q000235:genetics / Q000502:physiology*