Activation of the Complementary sex determiner (Csd) protein by amino acid polymorphism

• Applicant: Professor Dr. Martin Beye
• Subject Area: Evolutionary Cell and Developmental Biology (Zoology)
• Term: from 2009 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 108461341

In the proposed project we seek to understand the molecular mechanism of complementary sex determination. Some initial sex determination signals have been identified in few model systems, however, we have thus far very little understanding how these initial signals molecularly establish sexual determined states in the first place. In the honeybee Csd-proteins that are derived from two alleles (heterozygosity) activate female differentiation through the sexual splicing of the fem gene. Csd-proteins that are expressed from a single allele or same alleles result in male differentiation. We still lack an understanding of the processes through which few amino acid differences can control ON and OFF activity states. This is a fascinating, basic regulatory principle that is shared among the multiple specificities. Our work has so far identified binding domains that are required to recognize the allele specificity. In the proposed project we will test the role of essential binding domains and amino acids in activating the switch into the female-determining state. This work will also add to our understanding of the molecular path which was taken during the evolutionary rise of this new primary signal. Finally, we will characterize other genetic factors essential for complementary sex determination.

• DFG Programme: Research Grants