ABSTRACT
INTRODUCTION Embryology provides an essential key to understanding the structure and function of the normal urinary tract and the origins of the congenital anomalies encountered in urological practice. The conventional study of embryology, supplemented by additional information from scanning electron microscopy and immunocytochemistry, has provided us with a detailed picture of the developmental anatomy of the embryo and fetus. Now, equipped with the powerful new research methods of molecular biology, notably polymerase chain reaction and fluorescent in situ hybridization, researchers can study the genetic mechanisms regulating this complex and tightly ordered anatomical sequence. As well as mapping and sequencing genes, research is under way to isolate the many gene products responsible for implementing the genetic ‘programme’ encoded on DNA at a cellular and molecular level. Moreover, the function of specific genes is being extensively documented by studying the consequences of experimentally induced null or ‘knockout’ gene deletions in experimental rodents. The successful culture of pluripotent embryonic stem cells,1 coupled with changes in the law permitting research into therapeutic cloning of early embryonic tissue, may ultimately pave the way to the use of a wide range of human cells for tissue reconstruction or regenerative repair. Advances in the new science of developmental biology will create new opportunities for the diagnosis, prevention and possible treatment of inherited disorders and genetically determined anomalies of the genitourinary system. However, these opportunities will also bring new
responsibilities and ethical dilemmas. Much of this chapter is devoted to a practical, clinically orientated account of developmental anatomy, but it would be incomplete without some consideration of genetics and the rapidly advancing field of developmental biology.
