Phenotypic differences in behavior, physiology and neurochemistry between rats selected for tameness and for defensive aggression towards humans.
To better understand the biology of tameness, i.e. tolerance of human presence and handling, we analyzed two lines of wild-derived rats (Rattus norvegicus) artificially selected for tameness and defensive aggression towards humans. In response to a gloved human hand, tame rats tolerated handling, whereas aggressive rats attacked. Cross-fostering showed that these behavioral differences are not caused by postnatal maternal effects. Tame rats were more active and explorative and exhibited fewer anxiety-related behaviors. They also had smaller adrenal glands, larger spleens and lower levels of serum corticosterone. Blood glucose levels were lower in tame rats, whereas the concentrations of nine amino acids were higher. In the brain, tame rats had lower serotonin and higher taurine levels than aggressive rats. Our findings reinforce the notion that tameness is correlated with differences in stress response and will facilitate future efforts to uncover the genetic basis for animal tameness.
Albert
Frank W
FW
Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. falbert@eva.mpg.de
Shchepina
Olesya
O
Winter
Christine
C
Römpler
Holger
H
Teupser
Daniel
D
Palme
Rupert
R
Ceglarek
Uta
U
Kratzsch
Jürgen
J
Sohr
Reinhard
R
Trut
Lyudmila N
LN
Thiery
Joachim
J
Morgenstern
Rudolf
R
Plyusnina
Irina Z
IZ
Schöneberg
Torsten
T
Pääbo
Svante
S
D000223:Adaptation, Psychological / Q000502:physiology; D000311:Adrenal Glands / Q000033:anatomy & histology; D000374:Aggression / Q000502:physiology*; D000596:Amino Acids / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D001007:Anxiety / Q000097:blood* / Q000235:genetics / Q000523:psychology; D001522:Behavior, Animal / Q000502:physiology*; D001786:Blood Glucose / Q000235:genetics / Q000502:physiology; D001921:Brain / Q000378:metabolism; D005106:Exploratory Behavior / Q000502:physiology; D005260:Female; D006234:Handling, Psychological; D008297:Male; D009929:Organ Size; D010641:Phenotype; D051381:Rats; D011919:Rats, Inbred Strains; D012641:Selection, Genetic; D012737:Sex Factors; D012931:Social Environment; D013045:Species Specificity; D013154:Spleen / Q000033:anatomy & histology; D013315:Stress, Psychological / Q000097:blood* / Q000523:psychology
D000596:Amino Acids; D001786:Blood Glucose