The Study of Human-Animal Interactions The CAIRC Scholarship Program Summary of the Past Researches
Summary of the Past Scholarship Research
From "Letter from CAIRC" July 2001
Research Theme: "A Trial of Prediction of Aptitude in Service Dogs — Personality-related Genes Used as Indicators"

By Yoko Niimi, Naoto Matsuura, Dr. Miho (Murayama) Inoue

The search for genes associated with personality made a stride forward in 1996 with a report of the discovery of a gene related to the tendency to seek novelty, and genes associated with buoyant and anxious personality traits have also been discovered. The gene initially discovered to be associated with novelty-seeking, or the "fad gene," is the dopamine receptor gene D4 (DRD4).

It has been reported that within DRD4 there is a repetitive sequence polymorphism, in which a greater number of repetitions of the allele coincides with stronger curiosity. Yoko Niimiís research group is working on the isolation of such personality-related genes in dogs. They are attempting to verify the potential association between specific genes in dogs and personality and behavior, and have already published a number of research papers.

In 1999, Ms. Niimi and her associates conducted a study of this section of canine DNA, and reported that they had confirmed the existence of the repeated sequence in the DRD4 gene, and identified four types of allele. In this research project, they have identified 5 more types of allele, confirming the existence of a total of 9. In addition, they conducted a genetic analysis focusing on these allelic genes of 14 breeds of dog, each of which have differing behavioral characteristics.

"Upon conducting a principal component analysis based on the frequency of these alleles, we were able to establish correlations between base scores for each of the 14 breeds and behavioral scoring for each breed based on a survey of canine veterinarians. Among 6 behavioral characteristics such as playfulness and obedience, it became evident that specific alleles were linked to obedience and aggression toward other dogs. In addition, a comparison of varieties of dog indigenous to Europe and Asia showed distinctions in the distribution of the frequencies of these alleles."

Currently, the training of a guide dog requires two years and involves an enormous cost, and ultimately only one in three of them are able to work as guide dogs. If genes associated with behavioral characteristics can be found, it may become possible to breed dogs appropriately as well as to selectively raise dogs more effectively.