Genetic Control of the Behavior of ISIAH Rats in the Open Field Test

Genetic control of behavior in ISIAH rats with inherited stress-induced arterial hypertension in an open field test was investigated. Genome scanning (QTL analysis) was carried out in a group of male F 2 hybrids (ISIAH × WAG) at the age of 6 months using 149 microsatellite polymorphic markers. The following traits were studied: latent period of the onset of movement, locomotor activity (LA) in the first minute of the first open field test, LA on the periphery of the open field area, vertical activity (rearing) and grooming on the periphery of the open field area, defecation. The polygenic control of all studied traits has been determined. Various effects of ISIAH rat alleles in the found QTLs are shown: in some loci, the presence of ISIAH rat alleles leads to an increase in the trait value; in others, it leads to its decrease; and for a number of loci, the effects on the phenotype are shown in a heterozygous state. Among the found loci, 11 were described for the first time: three of them (on chromosomes 5, 11, and 18) are associated with the trait of locomotor activity in the first minute of the first open field test; one locus (on chromosome 14) is associated with locomotor activity at the periphery of the open field; one locus (on chromosome 17) is associated with grooming at the periphery of the open field; two loci (on chromosomes 17 and 18) are associated with rearing at the periphery of the open field; and four loci (on chromosomes 11, 12, 14, and 19) are associated with the level of defecation. Common loci associated with both behavior and previously studied traits that can influence behavior have been identified. On chromosome 5, a common locus associated with two behavioral traits and with a basal plasma corticosterone concentration has been described. On chromosome 8, a common locus associated with locomotor activity at the periphery of the open field area and with the concentration of dopamine in the brain stem was found. On chromosome 18, a common locus for four traits of behavior and the level of norepinephrine in the hypothalamus was identified. The results obtained contribute to the functional annotation of the rat genome.