西亚试剂：divergence of a newly evolved polyubiquitin

Rapid functional divergence of a newly evolved polyubiquitin gene in Drosophila and its role in the trade-off between male fecundity and lifespan

Zubing Zhan, Yun Ding, Ruopin Zhao, Yue Zhang, Haijing Yu, Qi Zhou, Shuang Yang, Hui Xiang and Wen Wang

The cost of reproduction is a pivotal trade-off with various biological processes during the evolution of organisms. However, the genes and molecular mechanisms underlying the evolution of balancing reproductive capacity and its cost are still largely unknown. Here, we present a comprehensive study on the evolution, expression and biological functions of a newly evolved pair of X-linked polyubiquitin tandemly duplicated genes, CG32744 and CG11700, of which the duplication event occurred in Drosophila melanogaster lineage after the split from D. simulans clade. We found that CG32744 retains conserved polyubiquitin-coding sequences across Drosophila species and is ubiquitously expressed, while CG11700 has accumulated numerous amino acid changes and shows a male-specific expression pattern. Null mutants of CG11700 have a higher male fecundity but shorter lifespan while its overexpression decreases male fecundity. In contrast, the null mutants of the peptide-conserved CG32744 do not exhibit such. These results suggest that CG11700 might have experienced neofunctionalization and evolved important functions in the trade-off between male fecundity and lifespan, and that CG32744 likely has retained the ancestral function.