Thermal stress and fertility - how susceptible is the ejaculate?

• Applicant: Dr. Claudia Fricke
• Subject Area: Evolution, Anthropology ; Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 449160969

A number of diverse factors threatens biodiversity with rising temperatures being one that is currently prominently debated. Ectothermic animals will be directly harmed by heat stress, as the surrounding temperature regime determines their bodily functions. Particularly male reproductive success is at risk as temperature stress is expected to be detrimental to the ejaculate. Seminal fluid proteins besides sperm are part of the ejaculate, are transferred at mating to the female and are vital to male reproductive success. In this research program, I want to investigate the susceptibility of male ejaculatory proteins and the tissue producing them, to heat stress and assess measures in place to protect it from heat damage using the fruit fly Drosophila melanogaster. In addition, the phenotypic consequences for male-female mating interactions of potential heat damage to the ejaculate will be measured. Lastly, I want to test whether females upon receiving and storing an ejaculate, can protect sperm function against heat stress. With this comprehensive research program, covering the entire lifespan of an ejaculate from production by the male to transfer and storage inside the female, we can pinpoint the stage at which heat damage to the ejaculate is most severe. Further, we learn what mechanisms are in place to protect the ejaculate and maintain its ability for fertilisation and reproduction. The results from this research program will provide general insights into the ecology of a fundamental biological process and inform us of potential threats to species persistence.

• DFG Programme: Research Grants