Basic genetics

Genetics is an exciting topic and a topic that many find difficult. However, it is something that do - and should so - affect our breeding and selection of animals for breeding. Understanding genetics is essential for understanding how the heritability works in defects and diseases, how inheritability in coat color, mentality and exterior is done.

This text is in no way meant to be give any totally comprehends or one hundred percent covering of the it work, the text should simply be seen as an easy marker in the subject. A quick look in to the topic if you like.

The monk Gregor Johann Mandel (1822-1884) is one of the big names in genetics. Mandel was the one who discovered the laws of heredity, although he was unaware of genes and chromosomes. Mandel was between the years 1857-1868 Abbot and during this time he worked frequently in his monastery garden and experimented on first and foremore peas. The results that he got led to his discovery of the laws in inheritance. What Mandel had discovered was that if you crossed two individuals who were different in type, one would be visible and the second property is hidden. Unfortunately, it took many years after his discovering this that we fully comprehended it´s importance.

The basis of life as we know it is about a molecule called deoxyribonucleic acid, better known by the acronym DNA. Yet another molecule is important and that's ribonucleic acid, also known under its acronym RNA.

DNA is shaped like a corkscrew-shaped ladder. Each "rung" is a pair and there are four different types of such links. How these links appear on the DNA ladder is what determines what kind of information is available and form the “individual”. Think of it as a genetic morse-code where the links, and length is what determines what the meaning are and which the code is.
RNA is the molecule that detects the DNA and, after what the DNA says string connects the amino acids, which are proteins with different functions.
DNAis in our chromosomes, which in turn is in our cells. These chromosomes are always in a pair, one from the father and one from the mother. Humans have 46 chromosomes and 23 pair in each cell, while the dogs have 78 chromosomes and 39 pair. Each chromosome has a code, a gene for the location of a specific type of protein must be linked, this place is always the same on the chromosomes, and this place is called the locus (loci, when there are several).

A gene can be explained as being a description of a particular feature of the future of the animal, such as hair color, eye color, cheek size, etc.

There are often several genes that fit into the same locus and encode the protein at this location in a very particular way.

Each such gene is called an allele. These alleles are inherited one from the bitch and one from the dog and individual, they will always form a pair. At each locus there is this couple, two copies of the gene, one from the bitch and one from the dog. These alleles can look the same from both bitch and dog, or they may be different. How these two alleles will integrate and what the outcome will be in the future of the animal depends on many factors, of course, primarily depend on what the specific trait of these particular alleles affect.

Are two of the alleles of the same type in the individual then he is homozygous for this trait while the individual having two different alleles are heterozygous for this trait.

When a heterozygote is mated to another heterozygous or indeed a homozygote of the "hidden" gene, there is always the possibility that in the future offspring are showing a different type than the parent animal appears to have been carrying. It is what separates phenotype from genotype. The phenotype is the visible or measurable properties of the individual, gender, hair color, hair length, eye color, etc. This while, the genotype is the individual's genetic code that is not always visible to the naked eye. Same phenotype does not mean that animal have the same genotype.

The heterozygous black and tan and the homozygous red are two of the same phenotype, although not of the same genotype. There are also genes that are either dominant or recessive red as black and tan without codominanta.
A heterozygous individual displays when both properties. Although incompletely dominant genes are where the heterozygous individuals have incomplete features from the two alleles, a cross between alleles, if you like.

What one should always be aware of is that genes never can be mixed or deleted out. If an individual no longer have their ancestor's dominant genes they are not inherited in the individual and not shown until an individual who carries the dominant genes are mixed into the dog.
However, an individual does not exterior show his ancestor's recessive gene. And this “not showing” does not mean that these genes are not inherited by him. Types of exterior that not comes to light over many of generations can appear long after it has been seen in the ancestor.

In the first of the individual in which the “belived lost” gene are doubled, if there is one or ten generations in between have no real meaning.
When shown once more it is the strong probability that this particular allele is, in fact inherited between generations and, therefore a remaining gen in each generation.