Genetic tests vary on what they are able to identify, and therefore how they can be used in managing genetic disease. Some tests measure the phenotype, or what can be seen in the animal. This may not directly relate to the genotype, or the genes regulating the defect. Genetic tests vary on what they are able to identify »»
Genetic tests vary on what they are able to identify
Mating based on phenotype
Mating based on phenotype is called assortative mating. Mating like to like is positive assortative mating. Mating like to unlike (i.e., bringing a new trait in or correcting a fault) is negative assortative mating.
The process of maintaining healthy lines with genetic diversity
Most breeds have closed gene pools, meaning that breeding individuals must have confirmed pedigrees of ancestry from the existing breed. No new genes can be introduced into the breed, and genes can be lost to the gene pool by selective breeding (or not breeding) of individuals. The problem with limited genetic diversity in purebred populations stems from the effects of deleterious genes. The process of maintaining healthy lines with genetic diversity »»
Understanding basic genetic concepts
Any trait or disorder that has a hereditary component is called genetic. Congenital disorders are those present at birth. Some congenital disorders are hereditary, and others are not. Those occurring spontaneously may be caused by environmental exposures to infections, or compounds such as drugs or toxins. Genetic disorders will sometimes only be evident much later in life, even though the genetic coding for the disorder is present at birth.
Polygenic disorders are those caused by more than one pair of genes.
With complex inheritance disorders, also known as polygenic disorders, a number of liability genes must combine to cross a threshold and produce an affected individual. Most polygenic disorders have no tests for carriers, but they do have phenotypic tests that can identify affected individuals. Polygenic disorders are those caused by more than one pair of genes. »»
Pronghorns, commonly called Antelope in the american west, are true American natives, found nowhere else in the world. They have roamed the plains and deserts of North America for at least the last million years in substantially the same form. Pronghorn (Antelopes) »»