An integrative genetical genomics study in Arabidopsis reports that six QTL hot spots have system-wide effects on a wide range of molecular and phenotypic traits, providing empirical evidence for phenotypic buffering.

The phenomenon of genetic buffering was initially described by Waddington in 1942 (ref. 1). One of the key examples of genetic buffering is that of Hsp90, a molecular chaperone that secures the proper functioning of many different developmental signaling pathways in Drosophila and Arabidopsis. In the presence of Hsp90, much of the genetic variation remains hidden, but upon impairment of Hsp90 function, novel and discrete phenotypic variants appear2. This evolutionarily conserved buffering system may allow organisms to accumulate mutations without negative impacts on fitness, and increase their chances for evolutionary adaptation in conditions when the genetic variation is expressed3.