The Nature of Genetic Disease

Many people label any problem that appears to be inherited a “genetic disease.” However, though there are legitimate genetic diseases, there are also a variety of problems that have an inherited component but are of a fundamentally different nature. Dealing effectively with any genetic problem requires an understanding of …

Eliminating Mutation: The Impossible Dream

Though it is not practical to eliminate all deleterious mutation, the incidence of affected individuals may be significantly reduced through a combination of intelligent breeding practice and the development of DNA tests. Why do we have mutations? Mutations are changes in an organism’s DNA that potentially affect the correct functioning of genes. They occur naturally …

Breeding Schemes

Breeders often talk about inbreeding and outcrossing as though they were the only possibilities — and generally with negative comments about the latter. There are other possibilities, and I have long been a proponent of assortative mating. It is not a theoretical concept that doesn’t work in practice; I …

POPULATION GENETICS AND BREEDING

Early genetics When Mendel’s work was rediscovered at the beginning of the twentieth century, the new field of Genetics went in several directions. The T. H. Morgan (1) school quickly got tired of crossing green to yellow peas and moved on to discovering white-eyed fruit flies, linkage and genetic maps. …

BASIC GENETIC CONCEPTS

Introduction Most of you are undoubtedly aware that color and certain diseases such as progressive retinal atrophy (PRA) are inherited — that is, passed down from one or both the parents. However, you may wonder how a trait that does not appear in the dam’s pedigree can suddenly turn up …