Differential expression of 10 genes in the hypothalamus of two generations of rats selected for a reaction to humans

Abstract

Individual behavioral differences are due to an interaction of the genotype and the environment. Phenotypic manifestation of aggressive behavior depends on the coordinated expression of gene ensembles. Nonetheless, the identif ication of these genes and of combinations of their mutual inf luence on expression remains a diff icult task. Using animal models of aggressive behavior (gray rats that were selected for a reaction to humans; tame and aggressive rat strains), we evaluated the expression of 10 genes potentially associated with aggressiveness according to the literature: Cacna1b,

Domestication Explains Two-Thirds of Differential-Gene-Expression Variance between Domestic and Wild Animals; The Remaining One-Third Reflects Intraspecific and Interspecific Variation

“…Following our previous article [ 36 ] on a factor analysis of qPCR-identified DEGs within in the hypothalamus of tame versus aggressive rats [ 34 ], in this work, we processed Table 6 by principal component analysis ( Figure 1 : STEP 2), the results of which are presented in Figure 3 . In this figure, one can see that the first (main) principal component PC1 ( X -axis) is proportional to arithmetic means of the log2 values measured by independent experiments on domestic animals compared with their wild congeners.…”

“…As depicted by a Venn diagram in Figure 1 (STEP 1), next, we managed to compile 54 pairs of homologous DEGs (listed in Table 6), where each pair contains one DEG taken from Table 4 (i.e., columns i to iv of Table 6) as well as its homologous DEG chosen from the 2347 DEGs characterized in Table 2 as detailed in columns v to xi of Table 6. Following our previous article [36] on a factor analysis of qPCR-identified DEGs within in the hypothalamus of tame versus aggressive rats [34], in this work, we processed Table 6 by principal component analysis (Figure 1: STEP 2), the results of which are presented in Figure 3. In this figure, one can see that the first (main) principal component PC1 (X-axis) is proportional to arithmetic means of the log2 values measured by independent experiments on domestic animals compared with their wild congeners.…”

“…Additionally, by quantitative polymerase chain reaction (qPCR), we have identified seven hypothalamic DEGs of tame versus aggressive rats [ 34 ] as the above-mentioned laboratory model of animal domestication [ 19 , 20 ]. Finally, applying the factor analysis [ 35 ] to these seven rat DEGs, we for the first time observed that artificial selection for behavior, adaptation to laboratory living conditions, and intraspecific variety equally well explain the differential-gene-expression variance of tame versus aggressive rats [ 36 ]. That is why the present work generalizes our above-mentioned qPCR-based findings at the whole-genome scale.…”