Moving up the hierarchy: A hypothesis on the evolution of a genetic sex determination pathway

✍ Scribed by Adam S. Wilkins

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 744 KB
• Volume: 17
• Category: Article
• ISSN: 0265-9247
• DOI: 10.1002/bies.950170113

✦ Synopsis

A hypothesis on the evolutionary origin of the genetic pathway of sex determination in the nematode Caenorhabditis elegans is presented here. It is suggested that the pathway arose in steps, driven by frequency-dependent selection for the minority sex at each step, and involving the sequential acquisition of dominant negative, neomorphic genetic switches, each one reversing the action of the previous one. A central implication is that the genetic pathway evolved in reverse orderfrom the final step in the hierarchy up to the first. The possible applicability of the model to the other wellcharacterized sex determination pathway, that of Drosophila melanogaster, and to sex determination in mammals, is discussed, along with some potential implications for pathway evolution in general. Finally, the specific molecular and population genetic questions that the model raises are Accepted