The Fate Of The Male Germ Cell

THE FASCINATION The male germ cell is the only cell of the human organism that leaves the body when it has achieved its final, highly sophisticated structure and properties. The male germ cell is designed for one purpose only: to reach the female gametes and to fertilize them. The various stages in the development of the male germ cell are characterized by proliferative phases, by the recombination of the maternal and paternal chromosomes, and by the differentiation and development of a specialized transport vehicle, the spermato zoon. Furthermore, the establishment of a special pool of stem cells, the spermatogonia, guarantees the continuity of the sperm-generation process from puberty to old age. THE FATE OF THE MALE GERM CELL The destiny of any individual germ cell is determined by a program that we know only in fragments. On the one hand every human male is able to produce many billions of germ cells in his lifetime, yet the chance of any single sperm reaching and fertilizing the female germ cell is exceedingly rare. A fertility disturbance means that somewhere during the complicated playing out of the germ cell program mistakes are made, and the program fails. It is still a fact that more than 50% of men presenting with male factor infertility have to be diagnosed as idiopathic, largely because of our lack of knowledge and conse quent lack of appropriate diagnostic tools.

Infertility affects more than one in ten couples worldwide and is related to highly heterogeneous pathologies sometimes only discernible in the germ line. Its complex etiology often, but not always, includes genetic factors besides anatomical defects, immunological interference, and environmental aspects. Nearly 30% of infertility cases are probably caused only by genetic defects. Thereby experimental animal knockout models convincingly show that infertility can be caused by single or multiple gene defects. Translating those basic research findings into clinical studies is challenging, leaving genetic causes for the vast majority of infertility patients unexplained. Nevertheless, a large number of candidate genes have been revealed by sophisticated molecular methods. This book provides a comprehensive overview on the subject of infertility written by the leading authorities in this field. It covers topics including basic biological, cytological, and molecular studies, as well as common and uncommon syndromes. It is a must-read for human geneticists, endocrinologists, epidemiologists, zoologists, and counsellors in human genetics, infertility, and assisted reproduction.

THE FASCINATION The male germ cell is the only cell of the human organism that leaves the body when it has achieved its final, highly sophisticated structure and properties. The male germ cell is designed for one purpose only: to reach the female gametes and to fertilize them. The various stages in the development of the male germ cell are characterized by proliferative phases, by the recombination of the maternal and paternal chromosomes, and by the differentiation and development of a specialized transport vehicle, the spermato zoon. Furthermore, the establishment of a special pool of stem cells, the spermatogonia, guarantees the continuity of the sperm-generation process from puberty to old age. THE FATE OF THE MALE GERM CELL The destiny of any individual germ cell is determined by a program that we know only in fragments. On the one hand every human male is able to produce many billions of germ cells in his lifetime, yet the chance of any single sperm reaching and fertilizing the female germ cell is exceedingly rare. A fertility disturbance means that somewhere during the complicated playing out of the germ cell program mistakes are made, and the program fails. It is still a fact that more than 50% of men presenting with male factor infertility have to be diagnosed as idiopathic, largely because of our lack of knowledge and conse quent lack of appropriate diagnostic tools.

This book provides a comprehensive overview of endocrinology of the male reproductive system, explaining how it works and how, sometimes, it fails to work. World-class specialists present state of the art knowledge on all aspects, including anatomy, physiology, molecular biology, genetics, pathophysiology, clinical manifestations of testicular diseases, endocrine aspects of andrological and sexual diseases, and therapy. Extensive consideration is given to sexual development, testicular function, the clinical approach to disorders of male reproduction, male hypogonadism, sexual dysfunction, and male infertility. In addition, sociodemographic, psychological, and ethical aspects of male reproductive disorders are discussed. The book is intended as a major reference for endocrinologists, andrologists, and sexologists, as well as basic and clinical scientists. It is published as part of the SpringerReference program, which delivers access to living editions constantly updated through a dynamic peer-review publishing process.

The success of Assisted Reproductive Technology is critically dependent upon the use of well optimized protocols, based upon sound scientific reasoning, empirical observations and evidence of clinical efficacy. Recently, the treatment of infertility has experienced a revolution, with the routine adoption of increasingly specialized molecular biological techniques and advanced methods for the manipulation of gametes and embryos. This textbook – inspired by the postgraduate degree program at the University of Oxford – guides students through the multidisciplinary syllabus essential to ART laboratory practice, from basic culture techniques and micromanipulation to laboratory management and quality assurance, and from endocrinology to molecular biology and research methods. Written for all levels of IVF practitioners, reproductive biologists and technologists involved in human reproductive science, it can be used as a reference manual for all IVF labs and as a textbook by undergraduates, advanced students, scientists and professionals involved in gamete, embryo or stem cell biology.