تحميل كتاب The Genetics and Biology of Sex Determination-J. Wiley PDF احمد المالكي

نبذة عن كتاب The Genetics and Biology of Sex Determination-J. Wiley :

كتاب The Genetics and Biology of Sex Determination-J. Wiley PDF احمد المالكي : 2002م - 1443هـ نبذه عن الكتاب: The Ciba/Novartis Foundation meetings are amazing. I remember the ¢rst one I attended, back in 1958. Last week I was in the University of California in Berkeley, talking to Professor Howard Bern, the distinguished comparative biologist. He said, ‘Do you know how my scienti¢c career began? It was when, as a young graduate student, I was invited to a Ciba Foundation meeting in 1952, on germ cells’ (Ciba Foundation 1953). I hope that in another 40 years’ time, some of you will be saying something similar about this meeting. It is the discussions that we have at these meetings that are so exciting. I would like to set the scene. I should probably start with a word of explanation. The ¢rst question that many of you will be asking is, why are there so many Australians in the room? You might think that it is because Peter Koopman proposed the meeting, but that isn’t the reason. Sex ‘down under’ is done rather di¡erently, so we have much to learn from Gondwanaland about the evolution of sex. We are going to hear a great deal at this meeting about the evolution of sex determination, which is currently a very exciting topic. But let me remind all of you how we de¢ne sex. If you produce many small highly motile gametes, you are male. If you produce fewer, large, sessile gametes, you are female. Although we are going to be discussing sex determination, almost all of the papers will be dealing not with the type of gametes that are ultimately produced, but with the morphology of the gonadal soma. I think we need to remember that the somatic sex of the gonad is a secondary issue; it is germ cell sex that ultimately determines maleness or femaleness. Although we know much about the genetic control of gonadal somatic di¡erentiation, we are largely ignorant of the genetic control of the germ cells. .