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<< wοΦίι Among considerable technological breakthroughs in reproductive biology in the past were (1) induction of ovulation, (2) cryopreservation of gametes and embryos, (3) assisted fertilization, (4) in vitro culture of germ cells and fertilized eggs. (5) preimplantation genetic diagnosis and (6) development of contraceptives. One should realize that all pioneers met formidable technical difficulties and received little or no attention/encouragement from others when they started to work. I will tell you a few examples. Even though reproductive technology has advanced greatly during the last century, big room for improvement remains. Today, the number of couples who leave infertility clinics empty-handed still far exceeds that of the couples who are able to bring their babies home. At present, we cannot help people who have no germ cells. Will it be possible to transform somatic cells to germ cells? Will it be possible to change mitosis to meiosis without problems of genomic imprinting? Under normal conditions, the majority of male and female germ cells degenerate during their development. Will it be possible to rescue then from degeneration? Can we develop safer and simple methods for male and female contraception? Many babies are born prematurely with lasting problems. Will it be possible to construct an artificial womb same or even "better" than a natural womb? Assisted reproduction is confronted with the problem of possible transmission of "defective" genes to the next generation. Will it be possible to correct defective genes in gametes/zygotes? For example, will it be possible to add missing genes to defective Y-chromosome or will it be possible to replace a defective Y-chromosome with a normal one from another individual? Animals (and humans ) can be cloned using adult somatic cells. This asexual reproduction sounds efficient, but we must think of the reasons why Mother Nature did not choose this method of reproduction for most of the animal species. In the beginning of the last century scientists were asked what will be invented during the next 100 years. Some scientists imagined trips to the moon. The vehicle they conceived looked like a steam engine train, not a lunar rocket. Their dream came true, but not in the way they imagined. Perhaps, this forebodes the 21st century. What we imagine today may come true, but perhaps not in the way we predict. The most exciting things to ensue cannot be predicted. The only thing we can do is to dream of what no other person dares and work on it step by step. ϊ{YΘwlΘwοΦAnϋοορ, 39(3) 221-222, 2002 |
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