Study On Genetic Variation Of Obedience Behavior Of Police Dogs Based On Genome-Wide Data

Police dogs are very special kind of dogs,which are the result of conscious breeding and training of human beings and constantly strengthening their behavioral characteristics.Police dogs participate in all aspects of human life,such as rescue,hunting,patrolling,vigilance,arrest and so on.It is an indispensable helper for police all over the world.Obedience is one of the most basic police traits of dogs.The obedience of police dogs to trainers is a prerequisite for the training and using of police dogs.However,the current breeding of police dogs is mainly carried out through the observation of post-representative types,which has a certain degree of subjectivity and inefficiency.So studying the obedience behavior of police dogs in whole genome level is of great significance to the breeding of police dogs.As a kind of behavioral traits,obedience behavior is always complex,which is not only controlled by polygenes,but also easily affected by environmental factors.Even if the character of obedience behavior is more complex,it is still associated with genetic genes.Therefore,it is feasible to study the molecular mechanism of obedience behavior traits by genome-wide association analysis.However,there are few genetic mechanism studies on obedience behavior at present.Lisa Lit et al evaluated the frequency of DAT-VNTR allele and considered that it is related to the score of obedience^[1].In this study,20 Belgian Malinois（BM）and 20 Chinese kunming dogs（KMD）were selected and a total of 40 police dogs were selected to analyze their Obedience behavior phenotype data and genome sequencing data.First of all,through PCA and population structure analysis,it is found that Belgian Malinois and Chinese kunming dogs are independent groups,and there is a phenomenon of population stratification,but the genetic relationship between the two populations is very close and there is a phenomenon of mixing.These results suggest that Belgian Malinois and Chinese kunming dogs have different but closer genetic background.Then the correlation signals related to traits were detected by genome-wide association study and genetic difference analysis,and 295 candidate sites with overlapping results were found.Some of the genes in which these sites are located are known to be associated with behavioral characteristics or mental illness,and may be genes that affect obedience behavior.The sites which are very significant in the results of genome-wide association study,and their P value is 5.54E-119,and they are also used as candidate sites.Further study on the above 55 candidate sites found that the allele frequencies of some sites changed with the change of obedience.For example,the allele frequency of Chr16:54087058 increased with the increase of obedience,and the T gene allele frequency of Chr23:10664020 decreased with the increase of obedience.Based on the above conclusions,we designed a genotyping experiment for part of candidate sites（Li Xue,not publish）.After adding more police dogs（a total of 143individuals）,it was found that the gene allele frequencies of Chr16:54087058and Chr23:10664020 showed the same trend in the population with high obedience and those with low obedience.This suggests that the expression of these genes is likely to play an important role in obedience behavior.The sites are located in ENSCAFG00000025123 gene（Chr16:54087058）and ULK4 gene（Chr23:10664020）respectively.ENSCAFG00000025123 gene is a lnc RNA gene,which has not been specifically reported.And many literatures have reported that ULK4 gene is associated with schizophrenia in human.To sum up,through genome-wide association analysis and genetic difference analysis,we screened out the association sites of police dog obedience behavior traits and carried out genotyping experiments to verify it.And we found a series of genes related to police dog obedience behavior.Part of these genes are known to be associated with mental illness.This not only provides a new perspective for us to explore the genetic mechanism of police dog obedience behavior,better understand the evolution of police dog behavior,but also provides a theoretical basis for future police dog genetics and breeding.