PT  - JOURNAL ARTICLE
AU  - Rebecca H. Herbst
AU  - Dana Bar-Zvi
AU  - Sharon Reikhav
AU  - Ilya Soifer
AU  - Michal Breker
AU  - Ghil Jona
AU  - Eyal Shimoni
AU  - Maya Schuldiner
AU  - Avraham Levy
AU  - Naama Barkai
TI  - Large-scale rewiring in a yeast hybrid
AID  - 10.1101/100263
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 100263
4099  - http://biorxiv.org/content/early/2017/01/13/100263.short
4100  - http://biorxiv.org/content/early/2017/01/13/100263.full
AB  - The merging of genomes in inter-specific hybrids can result in novel phenotypes, including increased growth rate and biomass yield, a phenomenon known as heterosis. We describe a budding yeast hybrid that grows faster than its parents under different environments. Phenotypically, the hybrid progresses more rapidly through cell cycle checkpoints, relieves the repression of respiration in fast growing conditions, does not slow down its growth when presented with ethanol stress, and shows increasing signs of DNA damage. A systematic genetic screen identified hundreds of alleles affecting hybrid growth whose identity vastly differed between the hybrid and its parent and between growth conditions. This large-scale rewiring of allele effects suggests that despite showing clear heterosis, the hybrid is perturbed in multiple regulatory processes. We discuss the possibility that incompatibilities contribute to hybrid vigor by perturbing safeguard mechanisms that limit growth in the parental background.