Why Do Corgi Mixes Always Look Like Corgis?

TL;DR

Corgis have short legs due to a mutant gene called a retrogene, which is dominant and causes dwarfism. This gene has been passed down through thousands of years of breeding.

Transcript

Thanks to Brilliant for supporting this episode of SciShow! Go to Brilliant.org/SciShow to learn more. [♩INTRO] You might have noticed that a lot of corgi mixes look exactly like… a corgi in a costume of a different dog breed. The Internet certainly has. Go pull up some pictures. We’ll wait. No matter what, though, something about these pups always... Read More

Key Insights

• 🤙 Corgis and other breeds with short legs have a specific mutant gene called a retrogene that causes dwarfism.
• 🧑‍🏭 The retrogene in corgis is derived from the FGF4 gene, which codes for a growth factor.
• 🥺 The retrogene alters the dog's development, leading to shorter limbs and stumpy legs.
• 🤵 Short-legged dog breeds have been selectively bred for thousands of years, indicating human preference for this trait.
• 🍻 The retrogene linked to dwarfism in corgis is also associated with similar genetic changes in humans.
• 🦿 The same retrogene responsible for short legs is also associated with spinal diseases in dogs.
• 🍰 Corgis and other short-legged breeds have both copies of the FGF4 retrogene, further contributing to their distinctive appearance.

Questions & Answers

Q: Why do corgis have such short legs compared to other dog breeds?

Corgis have short legs due to a dominant retrogene, a mutant gene that causes dwarfism. This gene has been selectively bred for over generations, resulting in the distinctive corgi appearance.

Q: Are there other dog breeds with similar short legs?

Yes, other breeds like dachshunds and basset hounds also have short legs. These breeds also carry the FGF4 retrogene, which affects limb growth and results in dwarfism.

Q: What is a retrogene and how does it form?

A retrogene is formed when mRNA, a molecule transcribed from DNA, is converted back into DNA and reinserted into the genome. These retrogene copies can sometimes produce proteins, resulting in genetic traits like dwarfism.

Q: Are there any disadvantages to the corgi's short legs?

Yes, the same retrogene that causes dwarfism and short legs in corgis is also linked to spinal diseases that can cause pain and neurological damage. Scientists are still studying the exact mechanism and effects of this link.

Summary & Key Takeaways

• Corgis and corgi mixes have stumpy legs that distinguish them from other dog breeds.

• Dwarfism in corgis is caused by a retrogene, a mutant gene that has been passed down through breeding.

• The retrogene is derived from a gene called FGF4, which codes for a growth factor and alters the dogs' development, leading to short legs.