Exploitable genetic variation can be changed under environmental and genetic stress. Consequences for livestock breeding - a review

Livestock breeding is exploitation of genetic variation in herdbook populat ions. Results of long term selection (domestication) experiments led to the assumption that some genes are normally silent and can be activated under generic and environmental stress. RUTHERFORD and LINDQUIST (Nature 336: 336 -342, 1998) provided the first evidence of a molecular mechanism which can activate silent genes. This article discusses this field of research with r espect to the livestock breeding.