The molecular biology of development [antikvár]

PREFACE The time has come for direct attack upon the centrai problem of biology, the problem of how it is that a single celi, the fertilized egg, gives rise to an adult creature made of many différent kinds of cells. This process, which we know as develop-ment, has been described and thought about by biologists for as long as there has been a science of biology. Its nature has remained a mystery because we have not heretofore understood enough about the nature of life itself. Today we do. We know that ali cells contain the directions for all cell life, written in the DNA of their chromosomes, and that these directions include spécification of how to make the many kinds of enzyme molecules by means of which the cell converts available substances into metabolites suitable for the making of more cells. This is the picture of life given to us by molecular biology and it is general, it applies to all cells of all creatures. It is a description of the manner in which all cells are similar. But higher creatures, such as people and pea plants, possess différent kinds of cells. The time has come for us to find out what molecular biology can tell us about why différent cells in the same body are différent from one another, and how such différences arise. To this new study of development biologists and molecular biologists alike can and must contribute. This book is addressed to the biologist who wishes to acquaint himself with those portions of molecular biology which are pertinent to the study of development. It is addressed, too, to the molecular biologist who wishes to acquaint himself with some of the ways in which the insights of modem biology are being applied to develop-mental matters. This is a small book and it cannot therefore include ali of the facts pertinent to both developmental and molecular biology. It is the author's hope, however, that it can serve as a guide to a new land, a guide to the new world of the molecular biology of development. This book has been written at Oxford during my tenure of the Eastman Visiting Professorship. My gratitude is due to ali those who made my stay in Oxford such a pleasant and productive one; Professor Geoffrey Blackman for the hospitality