Trisha Wittkopp’s lab has just published a very interesting paper where they look at the effects of cis– and trans-regulatory mutations in yeast.  This paper gives a nice picture of the properties of mutations that are potentially available for selection.  Definitely worth reading.

Contrasting Properties of Gene-Specific Regulatory, Coding, and Copy Number Mutations in Saccharomyces cerevisiae: Frequency, Effects, and Dominance