>>14311106The earliest way of identifying genes was by noticing what happened when you broke them (usually in Drosophila). That's why a gene (and the protein it codes for) integral to eye development is called 'eyeless', because its the gene where, if you break it, you get a fly with no eyes.
Sevenless was named on the same principle. When you break it Drosophila fail to develop the seventh retinal cell. Son of Sevenless is called that just necessary because its downstream of Sevenless in the signaling pathway, and because it makes a nice parallel to Bride of Sevenless. This abbreviates to BOSS, because it's necessary for the development of a precursor of the R7 cell. Sev cannot perform its function unless BOSS is functional - so BOSS is the boss of the developmental pathway. Geneticists love wordplay and crap puns.
