A simple genetic architecture underlies morphological variation in dogs

Area of Science:

• Genomics
• Animal Genetics
• Evolutionary Biology

Background:

• Domestic dogs display unparalleled phenotypic diversity, exceeding other terrestrial mammals in body size variation.
• Understanding the genetic basis of this diversity is crucial for evolutionary and comparative biology.

Purpose of the Study:

• To create a high-density canine genetic variation map.
• To identify genomic regions associated with diverse phenotypic traits in dogs.
• To investigate the role of human-directed selection in shaping canine genetics.

Main Methods:

• Genotyping 915 dogs (80 breeds, 83 wild canids, 10 shelter dogs) across 60,968 single-nucleotide polymorphisms (SNPs).
• Integrating genomic data with external measurements (breed standards, individuals) and skeletal measurements (museum specimens).
• Association mapping to link genomic regions with 57 phenotypic traits, including body size, dimensions, and skeletal morphology.

Main Results:

• Identified 51 genomic regions associated with phenotypic variation across 57 traits.
• Found that a small number of quantitative trait loci (<=3) explain most phenotypic variation for many traits.
• Detected signatures of recent selection in numerous genomic regions, particularly those linked to breed-defining traits (e.g., body size, coat, ear shape).

Conclusions:

• Human-directed selection has significantly altered the genetic architecture of key traits in domestic dogs.
• The study demonstrates the effectiveness of multi-trait mapping in a genotyped canine population.
• Genomic insights into canine diversity provide a model for understanding trait evolution in other species.