Temperature Dependent Sex Determination In Vertebrates

Edited by the world's foremost authorities on the subject, with essays by leading scholars in the field, this work shows how the sex of reptiles and many fish is determined not by the chromosomes they inherit but by the temperature at which incubation takes place.

Reptiles have been a topic for scientific study for many decades and remain widely studied around the world. In particular, their reproductive patterns and strategies have been extensively studied, proving useful in analysis of life-history strategies. A pivotal aspect of reptilian reproduction is incubation of eggs. Oviparity is found in all turtles, crocodilians and the tuatara and is prevalent in many lizards and snakes. Many aspects of the eggs, embryos and incubation conditions have been the subject of numerous scientific reports. This volume is dedicated to systematic analysis of reptilian incubation. The concept for the book is to look at reptilian eggs, development and incubation conditions in a functional way with particular emphasis on the natural incubation environment and, rather than concentrating on Family accounts, (e.g. incubation in crocodilians) the chapters review the topics in all reptile types allowing for the first time a systematic comparison of incubation between crocodilians, turtles and squamates. In addition to reviewing current information, the authors briefly look towards the future and outline areas where further research is needed.

Awarded Bookauthority's "Best Aquaculture Books of all Time" A comprehensive resource that covers all the aspects of sex control in aquaculture written by internationally-acclaimed scientists Comprehensive in scope, Sex Control in Aquaculture first explains the concepts and rationale for sex control in aquaculture, which serves different purposes. The most important are: to produce monosex stocks to rear only the fastest-growing sex in some species, to prevent precocious or uncontrolled reproduction in other species and to aid in broodstock management. The application of sex ratio manipulation for population control and invasive species management is also included. Next, this book provides detailed and updated information on the underlying genetic, epigenetic, endocrine and environmental mechanisms responsible for the establishment of the sexes, and explains chromosome set manipulation techniques, hybridization and the latest gene knockout approaches. Furthermore, the book offers detailed protocols and key summarizing information on how sex control is practiced worldwide in 35 major aquaculture species or groups, including fish and crustaceans, and puts the focus on its application in the aquaculture industry. With contributions from an international panel of leading scientists, Sex Control in Aquaculture will appeal to a large audience: aquaculture/fisheries professionals and students, scientists or biologists working with basic aspects of fish/shrimp biology, growth and reproductive endocrinology, genetics, molecular biology, evolutionary biology, and R&D managers and administrators. This text explores sex control technologies and monosex production of commercially-farmed fish and crustacean species that are highly in demand for aquaculture, to improve feed utilization efficiency, reduce energy consumption for reproduction and eliminate a series of problems caused by mixed sex rearing. Thus, this book: Contains contributions from an international panel of leading scientists and professionals in the field Provides comprehensive coverage of both established and new technologies to control sex ratios that are becoming more necessary to increase productivity in aquaculture Includes detailed coverage of the most effective sex control techniques used in the world's most important commercially-farmed species Sex Control in Aquaculture is the comprehensive resource for understanding the biological rationale, scientific principles and real-world practices in this exciting and expanding field.

Sex Determination, Volume 134, the latest release in the Current Topics in Developmental Biology series, contains current reviews in the field of vertebrate sex determination. It covers molecular pathways of sex determination in genetic and environmental species and encompasses both sex determination of somatic lineages and commitment of germ cells to male or female fate. Chapters in this new release cover, amongst other topics, Mapping the Sox9 Enhancer Elements, Epigenetic Regulation of Sex Determination, Evolution and Management of Sex Chromosomes, Regulation of Germ Cell Sex Identity in Medaka, Control of Sex Determination in Zebrafish, Sexually Dimorphic Germ Cell Identity in Mammals, and more. Contains reviews written by leading experts in each field Includes informative figures that illustrate principle points that are useful for teaching Written in a style that is clear and simple

Reptiles are a fascinating group for the study of sexual development because they exhibit a wide range of sex-determining mechanisms, from strict genetic sex determination (GSD) to strict thermal sex determination (TSD) and intermediate systems of GSD that are to various degrees overridden by environmental effects . This thematic issue presents the latest data on different aspects of sex determination in reptiles. Following an evolutionary perspective on why reptiles might be predisposed to evolve TSD, the papers in this issue explore in detail the different genetic and molecular mechanisms of sex determination and differentiation. They consider recent findings such as the discovery of new genes differentially expressed at male and female sex-determining temperatures, a new model of the role of aromatase, and the contribution of heat-shock proteins to TSD in the American alligator. Further studies examine the role played by sex allocation, the advantage of viviparity, and the effects of anthropogenic climate change on the sex ratio in TSD reptile populations. Providing a valuable overview for both students and researchers, this publication is essential reading for developmental and reproductive biologists, herpetologists, comparative endocrinologists, evolutionary biologists and geneticists.

Natural selection operates among individual organisms which differ in their genetic constitution. The degree of hereditary variability within a species is greatly enhanced by cross-fertilization. Indeed, the mechanism of sexual reproduction occurred very early in evolution, for it is seen today even in bacteria. In Escherichia coli, fertilization occurs by passage of the single chromosome from the male into the female bacterium (LEDERBERG, 1959). In multicellular organisms, the separation of germ from soma, and the production of haploid gametes became mandatory. The gametes were of two types. One, extremely mobile, was designed to seek out and penetrate the other, which loaded with nutrients, received the mobile gamete and intiated the development of a new individual. The foundation for true bisexuality was thus laid. In the primitive state of bisexuality, whether an individual is to be a sperm-producing male or an egg-producing female appears to be decided rather haphazardly. In the worm, Banelia viridis, the minute males are parasites in the female. Larvae that become attached to the proboscis of an adult female become males, while unattached larvae sink to the bottom and become females (BALTZER, 1935). The more sophisticated state of bisexuality was initiated by setting aside a particular pair of chromosomes for specialization and making either the male or the female a heterogametic sex. Sex chromosomes as we know them were thus born.

In this era of accelerated discovery and prolific output, Molecular Genetics of Sex Determination keeps readers abreast of this fields fast-moving biology. Its chapters were completed by experts in eacharea only months before publication. The text is organized into two parts. First, it reviews the basic biology of sex determination and summarizes ground-breaking work in mouse, marsupial, and Drosophila systems. Second, it covers current human genetics, clinical studies, and the syndromes of abnormal sex differentiation. With chapters by preeminent reproductive biologists, this is a capital work. Ohno's law is described by Ohno; the Lyon hypothesis, by Lyon; Sinclair tells how he cloned the testis-determining gene; and so on. Molecular Genetics of Sex Determination is authoritative, comprehensive, and current. It is prime reading for geneticists, developmental biologists, graduate students in these and related fields, clinical researchers, physicians, and medical students. Reviews the genetics of sex determination in 19 up-to-date chapters Features research on sex chromosomes and sex-determining genes Includes abnormalities of sex determination and clinical genetics Written by scientists who pioneered work in this field