Genetic background of aggressive behaviour in dogs

Sylwia Uchman,Wilhelm Grzesiak,Leonard Gugała,Anna Frost,Witold Stanisław Proskura,Justyna Wawrzyniak,Andrzej Dybus

doi:10.2754/avb201382040441

Sylwia Uchman, Wilhelm Grzesiak + Show 5 more

Open Access

https://doi.org/10.2754/avb201382040441

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Abstract

The background of aggression is very complicated and the basis of its occurrence has not been well explained yet. It is thought that tendency to aggressiveness is an effect of both environmental and genetic factors. Aggression is a very undesirable behavioural trait in dogs living with humans. The aim of this study was to determine the relationship between two polymorphisms: DRD4 intron II VNTR and C/T substitution in exon I HTR2B genes and aggressive behaviour in dogs. The VNTR polymorphism in the DRD4 gene was detected by agarose gel electrophoresis following PCR amplification, whereas C/T substitution in the HTR2B gene was analysed using amplification created restriction site-polymerase chain reaction (ACRS-PCR). A total of 121 dogs of several breeds were analyzed. All animals were classified based on a veterinary interview and observation in two groups: aggressive (n = 21) and non-aggressive (n = 100). Significant differences in DRD4 genotype frequencies between aggressive and non-aggressive dogs were observed (P < 0.05). The study provides a clear evidence of an association of VNTR polymorphism within intron II of the DRD4 gene with the occurrence of aggressive behaviour in dogs. Moreover, the findings give good justification for further research aimed at evaluation of the possibility of using this genetic marker in Marker-assisted Selection.

Highlights

Within domestic dog species, over 400 pure breeds established by selective breeding for various purposes can be recognized
The aim of this study was to establish whether there is a relationship between aggressive behaviour in dogs and two polymorphisms: DRD4 gene intron II VNTR identified by Nara et al (2005) and C/T substitution in HTR2B gene exon I identified by Våge and Lingaas (2008)
The present study attempted to determine the relationship between two polymorphisms: DRD4 intron II VNTR and C/T substitution in exon I HTR2B genes and aggressive behavior in dogs

Summary

Introduction

Over 400 pure breeds established by selective breeding for various purposes can be recognized. The tendency to aggressiveness seems to be a resultant of both environmental and genetics-related factors (Picciotto and Wickman 1998; Houpt 2007; Barsky 2010) Different substance groups such as hormones, enzymes and neurotransmitters are involved in the modulation of aggressive behavior (Nelson and Chiavegatto 2001). Dopamine and its receptor antagonists e.g. haloperidol were used in Address for correspondence: Witold Stanisław Proskura Laboratory of Molecular Cytogenetics West Pomeranian University of Technology Doktora Judyma 10, 71-466 Szczecin, Poland the treatment of aggressive behaviour in psychotic patients (Fitzgerald 1999). It is understandable because dopamine plays a crucial role in many related activities including aggression (Summers and Winberg 2006). The aim of this study was to establish whether there is a relationship between aggressive behaviour in dogs and two polymorphisms: DRD4 gene intron II VNTR identified by Nara et al (2005) and C/T substitution in HTR2B gene exon I identified by Våge and Lingaas (2008)

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