Comparative Genomics in Eukaryotes

This chapter outlines the development and current status of comparative eukaryotic genomics, from the earliest studies of basic chromosome structure to the sequencing of entire genomes. In the process, a review is provided for the structure, organization, and composition of the primary eukaryotic genomes that have been sequenced thus far. Although the word "genome," meaning the total hereditary material of an organism, was coined in 1920, the general concept of genome arose before 4th century, when Aristotle implicated blood as the heredity substance. The notions of "blood relations" and characteristics being "in one's blood" persist; it is now known that the blood of mammals actually contains very little genetic material because their erythrocytes contain neither nuclei nor mitochondria. Although its roots can be traced back to the earliest chromosomal work, comparative genomics involving complete genome sequencing is a science still in its infancy. Fast-growing and full of potential, its maturation is expected to influence an increasingly broad array of biological disciplines. Already, widespread implications can be envisioned for evolutionary biology, medicine, and agriculture; in some cases, these have already become reality. The large-scale comparison, and perhaps even manipulation, of genomes is a complex undertaking involving numerous empirical, analytical, and ethical issues. Both important challenges and exciting discoveries lie ahead for genome biology.