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The DLA-results of all dogs are shown and updated in a table on our homepage (click here). Each column visualises the haplotype, and one can see that most of the dogs have at least one “X” in column 1, which is the haplotype Kooi1.
On that page the name of each dog is a link to KoiraNet where the pedigrees can be found. The coding of haplotypes is international and thus similar to all breeds. For example the most common haplotype for Finnish population Kooi1 equals (00901, 00101, 008011).
More information:
A significant issue on breeding kooikerhondjes is how to maintain healthy breed with the narrow genetic pool the breed has. Breeding is also known to further narrow the genetic diversity of dogs, and that might predispose kooikerhondjes to several diseases. An important gene cluster, called “major histocompatibility complex (MHC) at the canine chromosome 12, has been found in the dog’s genome. MHC complex is the home for genes that are responsible for the recognition of the individual’s own tissues and separating the foreign material. The ability is related to the genetic diversity of the individual’s MHC complex. It is very important that this area maintains as diverse as possible within a single dog breed to ensure the health and vitality of the breed. The narrowing down the genetic variance on the MHC complex alters the individual, and the whole breed in general to increased susceptibility to autoimmune diseases (e.g. diabetes, atophy, hypothyroiditis, a number of inflammatory disorders).
It could be assumed that autoimmune disorders on kooikerhondje are associated with homozygosity on the haplotypes located at the MHC-area, since many canine autoimmune disorders have already been found to have a connection to that. The MHC-area includes two clusters of genestrings called the DLA, that are always inherited as a whole string, not as separate genes. The individual inherits the clusters from the parentdogs, one DLA cluster (genestring) from the sire, and one DLA cluster (genestring) from the dame. If the inherited DLA clusters are identical, the individual will have homozygote haplotypes whereas if they are different, the indivual will have heterozygote haplotypes. At the wild animal poplulations heterozygosity is preferred, and that should be the aim for breeding a healthy dogbreed as well. Some examples of inheritance is shown on Table below.
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Sire
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Dame
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Offspring
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Combination 1
homotzygote x homotzygote
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Kooi1/Kooi1
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Kooi1/Kooi1
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All puppies homotzygotes Kooi1/Kooi1
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Combination 2
homotzygote x heterotzygote
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Kooi1/Kooi1
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Kooi1/Kooi2
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Statistically
50 % of puppies homotzygote Kooi1/Kooi1
50 % of puppies heterotzygote Kooi1/Kooi2
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Combination 3
homotzygote x heterotzygote
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Kooi3/Kooi3
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Kooi1/Kooi2
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Statistically
50 % of puppies heterotzygote Kooi1/Kooi3
50 % of puppies heterotzygote Kooi2/Kooi3
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Combination 4
heterotzygote x heterotzygote
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Kooi1/Kooi2
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Kooi1/Kooi3
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Statistically
25 % of puppies homotzygote Kooi1/Kooi1
25 % of puppies heterotzygote Kooi1/Kooi2
25 % of puppies heterotzygote Kooi1/Kooi3
25 % of puppies heterotzygote Kooi2/Kooi3
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Combination 5
heterotzygote x heterotzygote
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Kooi1/Kooi3
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Kooi2/Kooi4
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Statistically
25 % of puppies heterotzygote Kooi1/Kooi2
25 % of puppies heterotzygote Kooi1/Kooi4
25 % of puppies heterotzygote Kooi2/Kooi3
25 % of puppies heterotzygote Kooi3/Kooi4
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The Finnish Kooikerhondje Association started a research on kooikerhondje MHC complex (DLA-typing) during 2011. The decision was to support the members of the club with the dogs living in Finland by paying approximately the half of the costs of an individual dog. The owner of the dog will pay the other half. The financial support from the club requires the owner to publish the results, and enables the club to announce the results on the homepage. By the beginning of December 2011 there has been 154 kooikerhondje blood samples donated to the Hannes Lohi research group’s blood bank (donation of blood is free of charge for the owner). Thus far 24 kooikerhondjes have been examined for the MHC-complex from the blood samples, and the amount of different haplotypes found is 8.
| Haplotype |
DRB1 |
DQA1 |
DQB1 |
| Kooi1 |
00901 |
00101 |
008011 |
| Kooi2 |
01501 |
00601 |
01101 |
| Kooi3 |
02001 |
00401 |
01303 |
| Kooi4 |
02301 |
00301 |
00501 |
| Kooi5 |
01101 |
00201 |
01303 |
| Kooi6 |
01501 |
00601 |
02301 |
| Kooi7 |
00101 |
00101 |
00201 |
| Kooi8 |
01503 |
00601 |
02304 |
The amount of haplotypes is actually quite normal for a dog breed. Unfortunately the two or three most common haplotypes cover the majority of the population at the moment, and the remaining 5 haplotypes are minority. Yet the sample is still small and growing, however, the predominance of the most common haplotype is likely to remain in the Finnish population.
We’d suggest that all the breeding committees would have a look on that table and discuss the ideology of maintaining the diversity of the breed. In the coming years, we are planning to continue the research in Finland to have a DLA-profile of the breed. It would also be highly beneficial for the kooikerhondje breed to have the DLA-profile from other countries too, since the frequency of the alleles in the MHC-genes may vary from population to another. The Finnish Kooikerhondje Association challenges the other countries’ kooikerhondje breed clubs to join in the research, and possibly support their members to buy the research for their dogs. In Finland the organization that does the research is called Genoscoper (internet address: http://www.genoscoper.com/in_english2/ ), and the price of individual dog’s analysis is approximately 137e.
If we are able to maintain heterozygosity of the MHC region as vast as possible in the breeding lines of kooikerhondje, we should be able to reduce the risk for autoimmune or other diseases associated with the area. Also, it is preferable not to increase the homozygosity in the MHC-area, since that is a risk for autoimmune disorders. Naturally for breedingwise, there are several issues to consider, other than MHC-diversity, but this is very important issue that should not be overlooked.
Liitetiedostot:| Tiedosto | Kuvaus | Tiedosto koko | Viimeksi muokattu |
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 DLA-tutkimus | Kooikerhondjien DLA-tutkimus | 1105 Kb | Nov-30-2012 5:22pm |
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