Two New Genetic Variants Discovered in Pura Raza Española Horses for Blue Eyes

Does your horse have blue eyes? Do you think it might carry the genetic variant for blue eyes? You can learn more about the genetics that go into blue eyes (and how to test for it!) here:

Pura Raza Española horses are world renowned for their Spanish beauty. But, have you ever seen one with a white mask, tall stockings, and captivating blue eyes?

Step into the world of Yeguada Sierra de la Espada, owned by the Gil Torrano family, and prepare to be impressed by a herd of horses like no other. These magnificent creatures boast a rare and captivating beauty with their flashy white patterns which are exceptionally uncommon among PRE horses. It’s a sight that takes your breath away and makes you wonder what makes them so uniquely stunning.

Alberto Gil Torrano shared a background story about this unique herd of horses:

“In the sun-kissed region of Murcia, Spain, lies the charming village of Sierra de la Espada, home to an extraordinary man whose passion for horses has created an enduring legacy. Meet Juan José Gil, the founder of Yeguada Sierra de la Espada, a place where dedication and love for equines have converged, giving rise to a dream come true.

Established in the year 1986, Yeguada Sierra de la Espada has stood as a sanctuary for an exclusive breed of horses – the Pure Spanish Breed (PRE). These magnificent creatures, with their unique and captivating coat patterns, have charmed the hearts of admirers worldwide. The stud farm prides itself on its distinction as the sole breeder of Spanish horses boasting masks, four white stockings, and mesmerizing blue eyes – a truly rare gem in the equine industry, celebrating the elegance of the Andalusian horse.

At the heart of Yeguada Sierra de la Espada’s success stands a mare like no other – Zahara GT. This exceptional equine has been the cornerstone of the stud farm’s breeding program, playing a vital role in the discovery of the new SW9 giltor gene, thanks to the collaborative efforts with Etalon. Beyond the pursuit of excellence in breeding, Yeguada Sierra de la Espada holds a profound mission: to promote and honor the nobility of Spanish horses.

The allure of their specimens’ beauty and grace seeks to inspire a deep appreciation for the magic that only these horses can offer. With almost four decades of dedication, Yeguada Sierra de la Espada continues to spread its wings, carrying the torch of compassion for these majestic creatures. From the founder’s visionary pursuit to the collective efforts of the farm’s team, the story echoes the sentiment that horses are truly special beings deserving of utmost love and protection.”

Discoveries are a team effort; they take place when horse owners ask questions, and Alberto Gil Torrano was confident there was something unique in the genetics of his herd. The mystery deepened when initial genetic analysis revealed that these horses didn’t carry any previously known white mutations. Something extraordinary was unfolding, and the team at Etalon Equine Genetics knew they had to delve deeper into the story.

The Etalon research team, led by Aiden McFadden, began on a scientific journey to uncover the secrets behind these remarkable coat patterns. First, they implemented advanced sequencing technologies to explore each horse’s genetic code. A particular focus was specifically placed on the MITF and PAX3 regions which have been linked, in prior Etalon studies, to the “Splashed White” phenotype.

Through a meticulous comparison of the sequencing data with established genetic markers and reference genomes, the research team identified not one, but two previously undiscovered mutations: Splashed White 9 (SW9) in the MITF region and Splashed White 10 (SW10) in the PAX3 region. The study has now been published in the Journal of Equine Veterinary Science.

“After finding the first mutation, what would become SW9, I was surprised to see it didn’t explain all of the white markings. Finding a second novel mutation in the same family is like getting two birds with one stone!” said McFadden.

To understand the functional impact of these mutations, the researchers utilized computational modeling tools which predict the impact of each mutation on a living animal. These assessments shed light on how the mutations influence the migration and pigmentation of melanocytes, the cells responsible for determining coat coloration in horses.

In addition to the genetic analysis, the horses were visually evaluated and their markings, or “phenotypes”, scored using established systems from previous genetic studies. This phenotypic assessment allows the researchers to establish a correlation between the presence of the newly identified mutations and the observed splashed white presence (or phenotype) in each horse.

Based on their findings, the research team proposed naming designation for the identified variants that followed both the standard science while paying homage to the horses in which they were discovered. The new mutations have been labeled, Splashed White 9/Giltor (SW9) for the MITF variant and Splashed White 10/Giltor (SW10) for the PAX3 mutation: a standing tribute to the Gil Torrano herd and adhering to established naming conventions in the field.

The discovery of these novel variants has far-reaching implications for our understanding of the genetic basis of splashed white phenotypes in horses. With this newfound knowledge, targeted breeding programs can be developed to preserve and manage these distinctive traits.

Etalon has now released testing for Splashed White 9/Giltor and Splashed White 10/Giltor. Tests for each variant are available for $79, or as a bundle for $149! Breeders can utilize Etalon’s equine genetic testing to identify horses carrying these specific variants and selectively breed them to perpetuate the splashed white coat patterns.

Do you think your horse might carry the SW9/Giltor or SW10/Giltor variant? Order your DNA testing to find out!