Identifikasi Single Nucleotide Polymorphism pada Gen Mono Amine Oxidase A sebagai Penanda Genetik untuk Sifat Agresif pada Domba

Abstract

In population, there is aggressive sheep in a small number which requires special management such as specific animal housing and routine management. The purpose of this study was to identify the variation of marker of SNP (single nucleotide polymorphism) DNA as genetic marker for aggressive trait in several sheep breed. Identification of point mutation in exon 8 of MAO-A gene associated with aggressive behavior in sheep may further be used to become DNA marker for aggressive trait in sheep. Five sheep breeds were used, i.e.: Barbados Black belly Cross (BC), Composite Garut (KG), Local Garut (LG), Composite Sumatra (KS) and St. Cross Croix (SC). Length of ten behavior trait performances, blood serotonin concentrations and DNA sequence of exon 8 of MAO-A gene from the aggressive and nonaggressive sheep were observed. PROC GLM of SAS Ver. 9.0 program was used to analyze behavior variable and blood serotonin concentrations. DNA polymorphism in exon 8 of MAO-A gene was analyzed using the MEGA software Ver. 4.0. Results show that the percentage of the aggressive rams of each breed was less than 10 percent; except for the KS sheep was higher (23%). Based on length of behavior, aggressive sheep group was not significantly different to non aggressive sheep group, except duration of care giving and drinking behavior. It was known that concentration of blood serotonin in aggressive and non aggressive rams was not significantly different. The aggressive trait in sheep has a mechanism of a different cause from that occurs in mice and humans. In this study, aggressive behavior in sheep was not associated with a mutation in exon 8 of MAO-A gene.