color sidedness in cattle

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knabe

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http://www.nature.com/nmiddleeast/2012/120417/full/nmiddleeast.2012.56.html

A colour pattern in domesticated cattle is caused by a mutational mechanism in which gene fragments are shuttled from one chromosome to another, according to research published in
Nature
Colour sidedness is determined by two genetic variants located respectively on chromosome 29 for Belgian blue and 6 for brown Swiss cows, according DNA sequencing of the genes involved revealed how the variation is generated.
One of the variants is in the LUZP2 gene on chromosome 29. The gene is interrupted by a large fragment of DNA containing the KIT gene, which is excised from chromosome 6.
The other variant is derived from the first one by excision of a fragment DNA containing chromosome 6 and 29 sequences, including a segment of the LUZP2 gene, which is shuttled back to chromosome 6.
The researchers confirmed these findings by analysing DNA from seven other breeds of cattle breeds and domesticated yaks, and found the same variants in all of them, suggesting that the two genes identified probably account for colour sidedness in most, if not all, cattle.
The unusual coat colour pattern is thought to result from dysregulation of the KIT gene, which is known to be critical for the survival and migration of melanocyte cells, which produce the pigment melanin, during embryonic development.
It's still unclear whether the novel serial translocation process identified in the study is unique to cattle. In humans, the mechanism may contribute to the mutations that make cells cancerous, and the researchers have identified a large number of sites in the human genome where this may have occurred.


also this.

http://www.nature.com/nmiddleeast/2014/140113/full/nmiddleeast.2014.13.html
might be time to see if it's in cattle.  the middle east human populations are the most defect dense in the world.  ripe for dna studies.
 

knabe

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Hollister, CA
https://med.stanford.edu/news/all-news/2014/06/subtle-change-in-dna-protein-levels-determines-blond-or-brunett.html


The researchers found that the blond hair commonly seen in Northern Europeans is caused by a single change in the DNA that regulates the expression of a gene that encodes a protein called KITLG, also known as stem cell factor. This change affects how much KITLG is expressed in the hair follicles without changing how it’s expressed in the rest of the body.


The study shows that even small, tissue-specific changes in the expression of genes can have noticeable morphological effects. It also emphasizes how difficult it can be to clearly connect specific DNA changes with particular clinical or phenotypic outcomes. In this case, the change is subtle: A single nucleotide called an adenine is replaced by another called a guanine on human chromosome 12. The change occurs over 350,000 nucleotides away from the KITLG gene and only alters the amount of gene expression about 20 percent — a relatively tiny blip on a biological scale more often assessed in terms of gene expression being 100 percent “on” or “off.”
 
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