FlyBase is saddened to report that Bruce Baker, our colleague and friend whose work uncovered molecular mechanisms of Drosophila sex determination and dosage compensation, died unexpectedly on July 1, 2018. He was 72.

Bruce did his graduate work with Larry Sandler and a postdoc with Jim Crow before moving to faculty positions at UNC, UCSD and Stanford. In 2008, he moved to the Janelia Research Campus of the HHMI, from which he retired in 2016.

His creative use of genetics and molecular biology demonstrated that sex is determined by an assessment of the number of X chromosomes (relative to autosomes) to initiate an RNA splicing cascade that controls all aspects of somatic sexual dimorphism, from external morphologies to sex-specific mating behaviors. In a seminal paper, he described the phenotypes associated with mutants in each of the major loci affecting sex determination, providing the groundwork that he and others used to elegantly dissect the sex determination pathway. Throughout his career he embraced emerging technologies to answer questions about how sexual morphology and behavior are controlled at the molecular and cellular level.

For all of us who still love and do science, we remember his high scientific standards, love of hands-on teaching at the bench, and unparalleled enthusiasm for discovery.

For a more complete rendering of his career, contributions and personal relationships please see http://genestogenomes.org/in-memoriam-bruce-baker