(Ebook) The Sperm Cell - Production, Maturation, Fertilization, Regeneration by Christopher J. De Jonge, Christopher L. R. Barratt (eds.) ISBN 9781108139144, 1108139140

(Ebook) The Sperm Cell - Production, Maturation, Fertilization, Regeneration by Christopher J. De Jonge, Christopher L. R. Barratt (eds.) ISBN 9781108139144, 1108139140

Eggs are made for sperm. Sperm are made for eggs.All other (body) cells are made to support, directly orindirectly, the development of eggs and sperm and thesurvival of their united product: the zygote – the nextgeneration. he prime function of spermatozoa is todeliver the male genome safely into eggs. Any errorsduring sperm formation, maturation and union witheggs will result in serious problems in themale’s fertilityand in the wellbeing of the ofspring.his book covers our current knowledge of (1) theformation of spermatozoa, (2) the preparation of spermatozoafor fertilization, (3) the union of spermatozoawith eggs, (4) the awakening of ‘sleeping’ eggs by spermatozoaleading to embryo development, (5) genomicand nongenomic (e.g. environmental) factors afectingthe development and fertility of spermatozoa, and(6) the challenges of overcoming male (sperm) fertilityproblems. Information compiled in each chaptershould be considered a stepping stone to betterunderstanding and better control of male fertility andinfertility.The very first chapter of this book mentions thepossible production of ‘artificial human spermatozoa’from pluripotent stem cells such as human iPSCs.Obviously, it is not appropriate to use live animals orget assistance from live animal cells to achieve thisgoal. To eliminate or minimize the stress and risksthese cells would face during their transformation intohaploid cells, we must learnmuchmore about what isreally happening in the natural environment of spermatogeniccells, within the testes.he last chapter considersthe value of the mouse as a model for the studyof mammalian fertility and infertility. Is the mouse aperfect animal model to use for the study of fertilityand infertility of all mammals, including humans?Although the mouse is certainly one of the most heavilyused model animals for studying mammalian fertilityand reproduction, we must remember that eachanimal uses species-speciic tactics to produce its ofspring.What is found in one species must be extrapolatedto other species with caution.Today, it is theoretically possible to reproduce anymammals without males. In fact, hundreds of cowshave already been produced by somatic cell nucleartransfer. Clearly, males are not essential for animaland human reproduction. Why are there males?At the beginning of life on Earth, there were nomales. Females reproduced by themselves. During thecourse of evolution, a bisexual mode of reproductionemerged, and it has been maintained in most animals,including humans. Compared with animals propagatingunisexually (females only), animals using a bisexualmode of reproduction seemto be less vulnerable toextinction in the face of constantly changing, competitiveenvironments. Technically, human cloning (nonsexualreproduction) is possible today. In other words,humans can reproduce without males. Is this what wedesire? A few years ater the birth of Dolly (a clonedsheep) andmany clonedmice, I gave talks to groups ofpeople about animal and human cloning. At the end ofmy talk I asked the audience if they wanted to live ina world without men. With no exception, women didnot want to live in the worldwithoutmen. ‘It would beboring. We cannot use men?hat would be horrible.’Men are needed by women, and we will stay that way.When I started research as an undergraduate student,I thought everything written in books andresearch papers was a fact. I now know that what iswritten is authors’ interpretations or just a part ofthe whole story. Many things written in books andreported in original papers will be modiied and evendiscarded during the next 40–50 years. Science progressesthat way.The comprehensive collection of topics that composethis new edition of he Sperm Cell provide readerswith a map and compass to chart a course forfuture investigations. It is the readers’ task ater readingthese highly topical research areas to determine whatsubjects are let unclear and compelling, what nextcourses might be important to follow and what burgeoningquestions are yet to be studied.Ryuzo Yanagimachi, PhDProfessor Emeritus, Department of Anatomy,Biochemistry and Physiology, Institute of BiogenesisResearch, John A. Burns School of Medicine, Universityof Hawaii, Honolulu, Hawaii