The promise of genetics

I graduated from veterinary school in 1957, and I cannot recall hearing anything about DNA during my education. It may have been mentioned, but if it was, its importance escaped me. After practicing for 6 years, I decided to extend my education by attending the University of Northern Colorado to earn a master’s degree in zoology. There I learned the fascinating story of DNA and realized the marvelous implications of the genetic code. Suddenly, genetics came alive for me. I went on to teach genetics, along with several other courses in the biological sciences, at the college level As usually happens to a new teacher, I learned a great deal more about my subject as I taught it. Within a few years, I had an opportunity to work toward a PhD at Oregon State University in the field of animal genetics. I was fascinated with chromosomes, and my thesis involved a study of radiation damage to chromosomes. My major professor was Dr. Ralph Bogart who had written a text on livestock genetics. I learned a great deal from him about traditional genetics, which included qualitative inheritance, quantitative inheritance, breeding systems, and selection. But even then, in the late 1960s, the new knowledge of genes and how they worked was beginning to change emphasis of traditional genetics. Seeing my enthusiasm for the “new” genetics, Dr. Bogart suggested that we collaborate in the writing of a book on the genetics of the horse. He asked me to outline the proposed book, and I took the opportunity to weave as much of the “new” genetics into it as practical without neglecting the traditional genetic ideas. At that time, “new” genetics involved such things as biochemical polymorphism, the mode of gene action, protein structures, and chromosome abnormalities. Our preface in 1971 read, “It is our opinion that horse breeders will want to have a better comprehension of genetics in general. With this in mind, we have included some material that may appear to horsemen today to have little or no practical application. However, one must realize that many facts in use today in the field of livestock production may have appeared to have no practical value 10 to 40 years ago when the facts were first established.” The book was self-published, and I later revised it for publication by Lea and Febiger as Genetics and Horsebreeding. A part of my 1982 preface to this book read, “During this past decade, the horseman’s interest and general knowledge in equine genetics has boomed. Ten years ago reference material was scarce—mainly confined to old pamphlets and a few scientific articles. Today, dozens of horse magazines publish articles concerning sophisticated genetic concepts—often reprinted from a scientific journal.” The September issue of JEVS reprinted an article by Dr. James D. Murray from the Department of Population Health and Reproduction, University of California, Davis, titled Horse Genomics and Reproduction. This excellent article described why genetics has been thrust to the forefront of veterinary science and horse breeding in particular. A summary of Dr. Murray’s article is as follows: “The rapid and continual development of new methodology has greatly expanded opportunities to undertake genetic studies across a wide range of species. Construction of genetic maps for an animal like the horse, with its long gestational period, late maturity, and the production of single young is now not only possible but also rapidly advancing. Several different types of genetic maps, albeit at low resolution, are now available for the horse. The principal mapping strategies being used are linkage, somatic cell hybrid (SCH) and radiation hybrid (RH panels), and in situ hybridization (physical mapping). Construction of gene sequence by overlapping clones from DNA libraries will likely occur for selected genes of particular interest in horses, but has not yet been applied to horse gene mapping. To capitalize on the wealth of genomic information being developed for humans and the mouse, a comparative gene map using the strategies listed above is also well underway for the horse. Expression sequence tags (ESTs) are just now beginning to be developed in the horse, but should result in the production of microarrays for assessing global gene expression patterns within the near future. For researchers in all fields of horse biology, genome analysis is rapidly becoming a reality and its application will assist the development of a better understanding of the horse.” Copyright 2002, Elsevier Science (USA). All rights reserved. 0737-0806/02/2210-0015$35.00/0 doi:10.1053/jevs.2002.37338