Difference? A single gene

2007/04/12 Rementeria Argote, Nagore - Elhuyar Zientziaren Komunikazioa

• Eboluzioa
• Genetika
• Zoologia

The dogs of the image are a tiny Chihuahua and a great Irish hunting dog. Although it seems a lie, both are adult dogs of the same species, but they have an important difference: size.

Therefore, both breed dogs are very suitable to study the genetic base of the size of dogs. In this they have worked at the Human Genome Research Institute of the United States and, sequenced by the genes of several dogs, have discovered that the one that separates large and small dogs is a single gene.

What's more, it seems that the key to the smallness of many canine breeds is in a single nucleotide of the IGF1 gene. This genetic variety of the smallest dogs dates back to remote times (centuries), so when growing the canine races it seems that man chose small specimens.

Photo: Tyrone Spady, NHGRI.