Genetic Mosaics And Cell Differentiation

The relationship of cell lineage and differentiation is one of the most intriguing problems in developmental biology. In most higher organisms, the analysis of the cell lineage has to rely on indirect methods. Only in the most suitable systems, like the nematodes, can the pattern of cell division be determined by direct observation under the microscope. In cases where this is not possible, the fate of the cells has to be examined by using cell markers. Most suitable for this purpose are genetic markers, provided that they do not interfere with the developmental pathway to be studied. However, suitable genetic markers and techniques for generating genetic mosaics are available in a few organisms only. Therefore, this volume is largely concerned with Drosophila and the mouse, which have been studied most extensively. In 1929 STURTEVANT introduced the analysis of gynandromorphs into devel opmental genetics. However, this important contribution remained largely unnoticed until the late sixties, when the potential of this technique for deter mining embryonic fate maps and the number of primordial cells was exploited, and the methodology extended to the mapping of mutational foci. Mitotic recombination was demostrated by STER:-

Women can be described as genetic mosaics because they have two distinctly different types of cells throughout their bodies. Unlike males, who have one X chromosome (inherited from their mother), females have two X chromosomes in every cell (one from each parent). The fathers copy works in some cells, while the mothers copy works in others. These two X chromosomes often function differently, especially if one carries a defective gene. Much has been written about the Y chromosome and its role in inducing maleness. This will be the first book about the X chromosome as a key to female development and the role of X-related factors in the etiology of sex differences in human disease. Barbara Migeon, from the renowned McKusick-Nathan Institute at Johns Hopkins, is a major figure in clinical genetics and is eminently qualified to write this book, and she writes clearly and effectively. She describes both the underlying molecular mechanisms and the remarkable genetic consequences of X inactivation and its role in determining the biological concepts characteristic of women. Females are Mosaics will be valuable to geneticists, biologists, and all health professionals interested in women's health.

Over the past few decades numerous scientists have called for a unification of the fields of embryo development, genetics, and evolution. Each field has glaring holes in its ability to explain the fundamental phenomena of life. In this book, the author shows how the phenomenon of cell differentiation, considered in its temporal and spatial aspects during embryogenesis, provides a starting point for a unified theory of multicellular organisms (plants, fungi and animals), including their evolution and genetics. This unification is based on the recent discovery of differentiation waves by the author and his colleagues, described in the appendices, and illustrated by a flip movie prepared by a medical artist. To help the reader through the many fields covered, a glossary is included.This book will be of great value to the researcher and practicing doctors/scientists alike. The research students will receive an in-depth tutorial on the topics covered. The seasoned researcher will appreciate the applications and the gold mine of other possibilities for novel research topics.

The presence of green and yellow ornamental plants around us, dark spots on our skin, people with brown and blue mosaic irises, and white-spotted dogs and horses are all well-known phenomena of life, and are recognisable genetic mosaics. Although such genetics mosaics live with us (and, in fact, we are all a genetic mosaics), little is known about the genetic bases of their origin. This book provides a general overview of the mechanisms that lead to the formation of different types of mosaics, listing an ample collection of examples to illustrate the impact of the genetic mosaics on our life. The book will appeal to the reader interested in understanding the relationship between genetic events and mosaicism, especially undergraduate and graduate students and medical doctors, as well as experts engaged in horticulture and animal breeding.