Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Jun;182(2):541-54.
doi: 10.1534/genetics.109.102186. Epub 2009 Apr 10.

Genetic architecture of tameness in a rat model of animal domestication

Affiliations

Genetic architecture of tameness in a rat model of animal domestication

Frank W Albert et al. Genetics. 2009 Jun.

Abstract

A common feature of domestic animals is tameness-i.e., they tolerate and are unafraid of human presence and handling. To gain insight into the genetic basis of tameness and aggression, we studied an intercross between two lines of rats (Rattus norvegicus) selected over >60 generations for increased tameness and increased aggression against humans, respectively. We measured 45 traits, including tameness and aggression, anxiety-related traits, organ weights, and levels of serum components in >700 rats from an intercross population. Using 201 genetic markers, we identified two significant quantitative trait loci (QTL) for tameness. These loci overlap with QTL for adrenal gland weight and for anxiety-related traits and are part of a five-locus epistatic network influencing tameness. An additional QTL influences the occurrence of white coat spots, but shows no significant effect on tameness. The loci described here are important starting points for finding the genes that cause tameness in these rats and potentially in domestic animals in general.

PubMed Disclaimer

Figures

F<sc>igure</sc> 1.—
Figure 1.—
Behavior in the glove test. (A) The glove test measures the level of tameness or aggression toward an approaching hand. (B) PCA scores derived from glove test behaviors of tame F0 (blue), aggressive F0 (red), F1 (purple), and F2 (black) animals. Circles, females; squares, males.
F<sc>igure</sc> 2.—
Figure 2.—
Correlations between phenotypes. Positive correlation coefficients are shown in red and negative ones in blue. Red boxes mark correlations within the same test or group of traits.
F<sc>igure</sc> 3.—
Figure 3.—
QTL for tameness and aggression. (A) Evidence for linkage to tameness across the genome. High F-values indicate the presence of a QTL. The dashed horizontal line represents the genomewide significance threshold. Solid horizontal bars are 2-LOD drop confidence intervals for QTL position. Chromosome boundaries are indicated by upward tick marks on the x-axis. (B) Several traits map to the two QTL for tameness. Only significant QTL are shown. Black and red upward tick marks are microsatellite and SNP marker positions, respectively.
F<sc>igure</sc> 4.—
Figure 4.—
White coat spotting and tameness. (A) Tameness level of F2 animals with (n = 190) and without (n = 393) white ventral coat spots. (B) A QTL for spotting (black line) does not show linkage to tameness (red line). The vertical dashed line indicates the location of the Kit gene. Black and red upward tick marks are microsatellite and SNP positions, respectively.
F<sc>igure</sc> 5.—
Figure 5.—
An epistatic network for tameness. (A) Overview of QTL (circles) and epistatic interactions (lines). Only QTL in pairs with significant epistatic interactions are shown. Bold (nonbold) solid circles: the QTL was significant (suggestive) in the scan for single loci. Dashed circles: the QTL was significant only as part of an epistatic pair. Numbers in circles indicate QTL chromosome and position (centimorgans). (B–F) Phenotypes for two-locus genotypes. Circles indicate the mean phenotype for the respective two-locus genotypes; error bars show the standard error of the mean. The strength of the QTL effect at the first locus in the pair is indicated by the slope of the line connecting the homozygous genotypes [both alleles from the tame line (TT) vs. both alleles from the aggressive line (AA)]. An effect at the second locus in the pair is indicated by nonoverlapping allele effects at a given genotype of the first locus.

Similar articles

Cited by

References

    1. Albert, F. W., O. Shchepina, C. Winter, H. Römpler, D. Teupser et al., 2008. Phenotypic differences in behavior, physiology and neurochemistry between rats selected for tameness and for defensive aggression towards humans. Horm. Behav. 53 413–421. - PubMed
    1. Alvarez-Castro, J. M., and O. Carlborg, 2007. A unified model for functional and statistical epistasis and its application in quantitative trait loci analysis. Genetics 176 1151–1167. - PMC - PubMed
    1. Bailey, J. S., L. Grabowski-Boase, B. M. Steffy, T. Wiltshire, G. A. Churchill et al., 2008. Identification of quantitative trait loci for locomotor activation and anxiety using closely related inbred strains. Genes Brain Behav. 7 761–769. - PMC - PubMed
    1. Bates, D., 2007. lme4: Linear Mixed-Effects Models Using S4 Classes. R package version 0.99875–9. http://cran.r-project.org/web/packages/lme4/index.html.
    1. Belyaev, D. K., and P. M. Borodin, 1982. The influence of stress on variation and its role in evolution. Biol. Zent. Bl. 100 705–714.

Publication types

Substances

  NODES
Project 1
twitter 2