More than one route to fertility

Male sexual traits are notoriously variable, which is puzzling, as traits essential for fitness are expected to exhibit low variation due to strong directional selection. Though many solutions have been proposed, we still lack satisfactory, general explanations. A good example in found in Drosophila melanogaster, in which there are over 250 seminal fluid compounds that have essential functions, but which also exhibit substantial diversity. It remains unclear why some seminal fluid proteins have multiple functions, some only one, and why there is so much apparent functional redundancy.

An exciting hypothesis is that this abundant variation is maintained because there are multiple ways in which males can achieve reproductive success. This challenge forms the focus of this PhD project, which the student will tackle in three major aims, testing whether males (i) exhibit distinct seminal fluid protein profiles, (ii) respond in a consistent manner to sexual competition, and (iii) have seminal fluid protein profiles that are associated with distinct sperm phenotypes.

The student will be immersed within an international, collaborative, tailored training environment designed to foster innovation and independence. The student will receive expert training in leading ‘omics analyses from colleagues at the Earlham Institute, and undertake two training visits with colleagues at Cornell University (USA).

This will equip the student with state-of-the-art skills in evolutionary genomics and bioinformatics, giving them a strong set of varied skills for future career development. The impacts are expected to be new explanations for the maintenance of semen diversity and new understanding of fertility mechanisms and how they might be improved.

References

Sirot, L. K., A. Wong, T. Chapman, and M. F. Wolfner. 2014. Sexual conflict and seminal fluid proteins: a dynamic landscape of sexual interactions.in W. R. Rice and S. Gavrilets, editors. Sexual Conflict. . CSHL Press

Hotzy, C., Fowler, E., Kiehl, B., Francis, R., Mason, J., Moxon, S., Rostant, W., Chapman, T. and Immler, S., 2022. Evolutionary history of sexual selection affects microRNA profiles in Drosophila sperm. Evolution, 76:310-319.

Chow, C. Y., M. F. Wolfner, and A. G. Clark. 2010. The Genetic Basis for Male × Female Interactions Underlying Variation in Reproductive Phenotypes of Drosophila. Genetics 186:1355-1365.

Perry, J. C., L. Sirot, and S. Wigby. 2013. The seminal symphony: how to compose an ejaculate. Trends in Ecology and Evolution 28:414-422.

Wigby, S., L. K. Sirot, J. R. Linklater, N. Buehner, F. C. F. Calboli, A. Bretman, M. F. Wolfner, and T. Chapman. 2009. Seminal fluid protein allocation and male reproductive success Current Biology 19:1-7.