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WHY X Y? Cloning is not just for females anymore. The same University of Hawaii researchers that cloned 50 healthy female mice a year ago (T. Wakayama et al., "Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei," Nature, 394:369-74, July 23, 1998) recently reported the first-ever cloning of an adult male mouse (T.W. Wakayama, R. Yanagimachi, "Cloning of male mice from adult tail-tip cells," Nature Genetics, 22:127-8, June 1999). Named "Fibro" after the fibro

Written byEugene Russo
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WHY X Y? Cloning is not just for females anymore. The same University of Hawaii researchers that cloned 50 healthy female mice a year ago (T. Wakayama et al., "Full-term development of mice from enucleated oocytes injected with cumulus cell nuclei," Nature, 394:369-74, July 23, 1998) recently reported the first-ever cloning of an adult male mouse (T.W. Wakayama, R. Yanagimachi, "Cloning of male mice from adult tail-tip cells," Nature Genetics, 22:127-8, June 1999). Named "Fibro" after the fibroblast cells from which he was cloned, the mouse was the first documented case of a male mammal cloned from adult cells, cells taken from the tip of a mouse's tail. Past successful clonings have used cells from the female reproductive system. Fibro was one of only three mice that reached full term out of 274 attempted clonings. The other two died soon after birth. Senior author of the study, Ryuzo Yanagimachi, a ...

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