Genetics of hairlessness

!!!!!!HOT NEWS!!!!!!
There is now available DNA test for hairlessness

Hairless dog Hrhr - will survive

Heterozygous Hairless Crested carries the dominant gene for hairlessness (Hr) and the gene for a normal coat (hr). A lethal gene (Hr) is dominant over the recessive (hr). Thus the Heterozygous Hairless is referred to as (Hrhr). 
Pic.© Katarzyna Zienkiewicz

Hrhr

Hairless dog HrHr - dies

Homozygous Hairless Crested witch carries a double dose of the hairless gene (HrHr) will not survive.

Pic.© Katarzyna Zienkiewicz

HrHr

Powder Puff

The Powder Puff doesn't carry the hairless (Hr)gene, only the gene for coat (hr), thus the Powder Puff is referred to as (hrhr). This combination is not lethal.

Pic.© Katarzyna Zienkiewicz

hrhr

Crossings:

Crossing - Hairless Hrhr x Hairless Hrhr

Pic.© Katarzyna Zienkiewicz

 The mating of two Hairless (HrHr) x (HrHr) would result in the following average combinations:

1 (HrHr) (25%) - Homozygous Hairless - Death, letal genes;
2 (Hrhr)  (50%) - Heterozygous Hairlesses - Will survive;
1 (hrhr)   (25%) - Homozygous Powder Puff - Will survive.
But this mating could produce all Hairlesses (Hrhr) or all Powder Puffs (hrhr) or any combination.

 

Crossing - Hairless Hrhr x Powder Puff hrhr

Pic.© Katarzyna Zienkiewicz

Mating a Hairless (Hrhr) to a Powder Puff (hrhr) would net the following avarage results:

2 (Hrhr)  (50%) - Heterozygous Hairlesses - Will survive;
2 (hrhr)   (50%) - Homozygous Powder Puffs - Will survive.
But this mating could produce all Hairlesses (Hrhr) or all Powder Puffs (hrhr) or any combination.

 

Crossing Powder Puff hrhr x Powder Puff hrhr

Pic.© Katarzyna Zienkiewicz

A Combination of  Powder Puff (hrhr) to a Powder Puff (hrhr) will have a result of:

4 (hrhr)   (100%) - Homozygous Powder Puffs - Will survive.

Sum up:

x hairless (Hrhr) powder puff (hrhr)
hairless (Hrhr) 1 hairless (HrHr) - dies

2 hairlesses (Hrhr)

1 powder puff (hrhr)

2 hairlesses (Hrhr)

2 powder puffs (hrhr)

powder puff (hrhr)  

2 hairlesses (Hrhr)

2 powder puffs (hrhr)

 

4 powder puffs (hrhr)

Current research of expression of hairlessness

A team of European scientists, led by Tosso Leeb of the University of Berne in Switzerland, had been searching for years for the genetic roots of the Chinese crested’s hairlessness and its abnormal dentition.

Recent research has finally revealed that the hairless mutation results from the insertion of seven letters of genetic code, named FOXI3, into a gene on chromosome 17. This error turns a coated dog into a hairless. Analysis of DNA samples from 140 hairless dogs (Xolos, Peruvian Inca Orchids and Chinese Cresteds) and 87 coated dogs confirmed that every coated dog in the study lacked the mutation, and every hairless dog possessed one copy. Researchers were unable to find a single instance of a matched pair of genes containing this seven letter DNA duplication.

Genetic test for hairlessness is now available... Due to this test they can now find out wether a dog is a puff or a hairless, no more doubting !
But they want to take it further, they want to find out wich genes are responsible to bring the amount of hair in our dogs. Why for example that if we breed two true hairless, we still get hairy hairless in the litter.

"In the course of our research we are also looking for genetic factors influencing the amount of residual hair on hairless dogs. There are so-called true hairless dogs with very little or no hair and also hairless dogs with a substantial amount of residual body hair (sometimes termed "semi-coated). If you own a hairless dog and are willing to contribute to our research, please contact us."

For that Theresa-Bernadette Mausberg at the University in Bern needs more bloodsamples. This is her contact address:

Theresa-Bernadette Mausberg
Vetsuisse Fakultät Universität Bern
Institut für Genetik
Bremgartenstr. 109a
3001 Bern

theresa.mausberg@itz.unibe.ch

http://www.genetics.unibe.ch/content/e2353/e2814/index_eng.html

There is now available DNA test for hairlessness.


Furnished Coat & genetic test

A mutation responsible for 'furnishings' or 'satin' coat in dogs has recently been identified in the RSPO2 gene. Furnishings refer to the variation of longer facial hair seen in all wire haired breeds as well as some others. This finding was the result of an extensive collaborative effort by researchers from a number of universities and the National Human Genome Research Institute (NIH). The work was published by Cadieu et al. in the journal, Science (www.sciencexpress.org/27August 2009/Page2/10.1126/science.1177808), and the test offered here is based on that work. The mutation is a dominant one, so in breeds where the coat can vary, it is possible for a furnished dog to carry the 'unfurnished' trait (called satin by some).
http://www.vetgen.com/canine-furnished-coat.html
example of chinese crested with genetic status ff - unfurnished ('satin' coat) example of chinese crested with genetic status FF - furnished ('furnishing' coat)

Inbreeding calculator & theory

http://www.czerwonytrop.com/inb/index.php?full=ok&lng=en


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