When Richard Goldschmidt' coined the term "intersexuality" in 1915, he intended it to apply to normally dioecious species which exhibit some kind of mixture between male and female characters. However, as knowledge of the bewildering variability present in the sexual orga nization of members of the animal kingdom has increased, the original meaning of the word has changed. Today many authors define inter sexuality as "the presence of both male and female characteristics, or of intermediate sexual characteristics, in a single individual".2 This more extensive and widely accepted concept justifies the title of our book •. Among all the anatomical and physiological features of living organisms the reproductive system has a unique importance for the perpetuation of the species. Conversely, reproductive processes are of little or no account for the viability of the individual. Therefore, within the framework of general biology reproduction has all too often been looked at solely from the point of view of genetics. Lively discussions about genotypic versus phenotypic sex determination long dominated the sci entific literature on sexuality in animals; this one-sided emphasis has tended to obscure many important facets of an organism's ability to reproduce. Recent developments in current biological research have brought the classic problem of sex differentiation into focus again, and the rapid progress being made in comparative endocrinology has added a new di mension to the study of reproductive biology.

How do males become male and females become female? And what are the consequences if the decision is not incisive? Drawing upon interests in animal genetics and molecular biology, the author endeavours to answer these difficult yet fascinating questions. Originally published in 1995, this book describes the genetic determination of sex and examines how sexual organs are differentiated. Using examples of intersexuality, chimaeras and asymmetries, the book describes the underlying molecular basis of sex determination and sexual differentiation, and focuses on the critical role of the rate of embryonic development in these vital processes. Male precocity is a recurrent theme, as is the involvement of Sertoli cells and their secretion of anti-Müllerian hormone. An invaluable book for reproductive physiologists, geneticists and developmental biologists whose interests may extend from animal science through veterinary medicine to human clinical medicine.

The Pineal Gland of Vertebrates Including Man

Following an opening chapter by the late Susumu Ohno on paralogues of sex-determining genes, the five best-studied genes essential for early mammalian gonadal development are portrayed in detail: SF-1 and WT1 and their roles in early events in gonadal development, SRY and SOX9 in testis determination, and the anti-testis gene DAX-1. Subsequent chapters look at the roles of these genes in sex determination in marsupial mammals, birds, reptiles, amphibians and fish, and review the different sex-determining mechanisms, genetic and environmental, that operate in these different vertebrate classes. Two insights emerge: one, that the same basic set of genes appears to operate during early gonadal development in all vertebrates, despite the differences in mechanisms; the other, that sex determination in vertebrates results from a complex network of regulatory interactions and not from a simple hierarchical cascade of gene actions.

The cloning of the SRY gene and the attainment of XX mice transgenic for the Sry gene opened a new era in research on sex determination. This book surveys current knowledge of sex chromosomes and sex determination in all vertebrate classes, relying on the restriction of genetic recombination in sex chromosomes as the unifying concept of this subject. The book's interdisciplinary approach integrates contributions from the fields of cytogenetics, molecular biology, developmental biology, and evolutionary genetics. A detailed treatment of the meiotic behavior of sex chromosomes is featured, and the entire text is supplemented by numerous schemes, drawings, and electron micrographs. The book will be valuable to general cytogeneticists, vertebrate zoologists, and veterinarian and medical practitioners interested in the foundations of sex determination and the current knowledge of sex chromosomes. It will also interest students in advanced undergraduate and graduate courses in these areas.

First published in 1995, the book describes personal experiences of those who cross-dress and sex change, how they organise themselves socially - in both `outsider' and `respectable' communities. The contributors consider the dominant medical framework through which gender blending is so often seen and look at the treatment afforded gender blending in literature, the press and the recently emerged telephone sex lines. The book concludes with a discussion of the lively debates that have taken place concerning the politics of transgenderism in recent years, and examines its prominence in recent contributions to contemporary cultural theory and queer theory.

The purpose of the first four volumes of the Handbook of Genetics is to bring together collections of relatively short, authoritative essays or an notated compilations of data on topics of significance to geneticists. Many of the essays will deal with various aspects of the biology of certain species or species groups selected because they are favorite subjects for genetic investigation in nature or the laboratory. Often there will be an encyclo pedic amount of information available on such species, with new papers appearing daily. Most of these will be written for specialists in a jargon that is bewildering to a novice, and sometimes even to a veteran geneticist working with evolutionarily distant organisms. For such readers what is needed is a written introduction to the morphology, life cycle, reproductive behavior, and culture methods for the species in question. What are its particular advantages (and disadvantages) for genetic study, and what have we learned from it? Where are the classic papers, the key bibli ographies, and how does one get stocks of wild type or mutant strains? Lists giving the symbolism and descriptions for selected mutants that have been retained and are thus available for future studies are provided whenever possible. Genetic and cytological maps, mitotic karyotypes, and haploid DNA values are also included when available. Volume 4 deals with certain vertebrate species that have been studied in considerable detail from the standpoint of genetics or molecular cytogenetics. Such data are available for only a relatively few vertebrates.