Washington, Aug 28 (ANI): Using data from Portuguese water dogs - the breed of President Barack Obama's dog Bo - researchers at the University of Utah have found a gene that gives some members of this dog breed curly hair and others long, wavy hair.
The researchers showed that variations in only three genes account for the seven major types of coat seen in purebred dogs.
The findings also point the way toward understanding complex human diseases caused by multiple genes.
"We were part of a team that found three genes that control 90 percent of the seven coat types that characterize different breeds of purebred dogs," said K. Gordon Lark, one of 20 co-authors of the study.
"We helped identify the gene that controls curly or wavy coats," added study co-author Kevin Chase.
The study showed that combinations of various forms of only three genes - named RSPO2, FGF5 and KRT71 - account for seven major coat types in purebred dogs.
The researchers analysed over 1,000 dogs from 80 domestic breeds, and found that RSPO2 is the gene associated with whether or not a dog has a moustache and large eyebrows (known together as "furnishings").
They also found that FGF5 is linked to whether a dog's fur is long or short and KRT71 determines if the hair is curly or wavy.
All purebred dogs have the three genes, but the presence or absence of mutant, variant forms of those genes - rather than the ancestral forms inherited from wolves - determines coat types.
They pointed out that curly haired dogs with furnishings - such as the bichon frise breed and some Portuguese water dogs, including President Obama's dog Bo - have the variant form of all three genes.
Portuguese water dogs come in both curly haired and wavy haired varieties, depending on what form of the KRT71 gene they have.
Chase said that wavy haired Portuguese water dogs fit in the new study's long hair with furnishings category.
He noted that the KRT71 gene really controls the extent of curl, not curl versus no curl.
The researchers assisted the NIH research by sharing data on Portuguese water dogs, which they have studied for years.
"Our contribution to this paper is data collected on the Portuguese water dog that indicated that keratin genes controlled the amount of curliness. Our data plus other data from the Ostrander group narrowed this down to KRT71," said Lark.
KRT71 carries the code that produces keratin 71, a structural protein in hair.
However, Lark said that the other two genes involved in determining dog coat types are more interesting in the sense that they produce proteins that regulate a variety of processes in living organisms, not just the kind of coat a dog has.
That makes them relevant to diseases of dogs and humans.
"Dogs share many diseases and other traits with humans. That's why they were used for many decades so extensively for pharmaceutical and medical-physiological-biochemical testing. Not surprisingly they share much of their genome [genetic blueprint] with humans also," said Lark.
The study has been published in the journal Science. (ANI)