Balancing lifespan and reproduction: understanding the role of nuclear receptor E75


An extended lifespan is commonly observed to come at the cost of reproduction, which is thought to reflect physiological or genetic constraints. The genetic factors that drive the correlated evolution of these two traits have remained elusive, however. By combining experimental evolution with genome re-sequencing in the fruit fly (Drosophila melanogaster), we identified the nuclear receptor E75 as a candidate gene for regulating this trade-off, which was confirmed by further functional tests. Within E75, we have investigated an individual SNP allele of which two variants (“T” or “G”) are present in natural populations. By using CRISPR-Cas9, we constructed genetically identical lines that differ only in the identity of this SNP to be able to investigate the function of these alleles. Studies on these CRISPR lines have shown significant effects of the E75 SNP on both reproduction and egg quality, whereas the effect on lifespan appears to be context-dependent. The aim of your project would be to further elucidate how these SNP alleles function.


This project will give you the opportunity to learn all about the powerful Drosophila model system. We will study gene expression patterns of the different E75 CRISPR lines using RT-qPCR. This will be combined with phenotypic assays on various aspects of the physiology and morphology of reproduction.

Skills to be learned: Handling fruit flies; molecular techniques such as RNA extraction, RT-qPCR; microdissection; phenotypic assays on reproduction.

Supervision and information

Dr. Katja Hoedjes (Room H128, W&N building, Vrije Universiteit)