The study’s results would scientifically explain why different dogs have different personalities.
How different dog breeds have distinct behavioral and personality traits – and how these characteristics are dependent on their genomes (by definition, the genome is the set of genes of a cell or an organism) – has until now been unknown. This study, funded by the National Human Genome Research Institute (NHGRI) and published in the journal Cell, involved citizen science projects ( project activities related to scientific research involving ordinary citizens and non-scientists) that used DNA samples and surveys collected from dog owners from all over the world. Researchers have found that genomic differences between dog breeds are related to the development of their nervous systems.
The study, led by Emily Dutrow, a researcher in Ostrander’s group, first mapped the diversification of dog lineages over time. They used genomic data of more than 4,000 domestic, semi-fertile and feral dogs collected from various available datasets. These datasets included whole genome sequencing results and subsets of variations in a genome. The researchers also used behavioral data from a survey conducted by the University of Pennsylvania School of Veterinary Medicine in Philadelphia of more than 46,000 dogs, which assessed characteristics such as trainability , energy and fearfulness of strangers.
“We have identified 10 major canine lineages and behavioral traits related to these lineages. By looking at the most select breeds, we can see how each dog breed lineage is unique in its genomic variation and behavior.”
said Elaine Ostrander, chief of the Cancer Genetics and Comparative Genomics Branch within NHGRI’s Intramural Research Program and author of the study. “One of the most surprising findings is that many of the genomic changes that define major dog lineages are also found in modern wolves. This indicates that humans participated, through breed selection, in producing gene variations among the wild ancestors of dogs to create unique types of dogs suited to perform specific tasks,” said Dr. Dutrow. For thousands of years, selective breeding has resulted in dog breeds that are specialized for a variety of tasks, including hunting, herding and guarding. For example, herding dogs (such as border collies)they instinctively know how to herd cattle with minimal training.
The challenge was to analyze the huge collections of data. Using tools used in studies that, for example, look at how stem cells develop into different specialized cells, the researchers reconstructed how canine lineages developed. “To study the genomic basis of breeds, researchers usually compare different breeds with different behaviors. But the difficulty is finding meaningful results among the variations in dog behavior,” said Dr. Ostrander. “Instead of looking at a snapshot in time, our study mapped how dog breed lineages diversified over hundreds of years and explains how the different breeds we see today are the result of human selection.”
- Domestic dog lineages reveal genetic drivers of behavioral diversification (cell.com)
