How do female flycatchers avoid using sperm from the wrong species? What proteins are in the female reproductive tract fluid?
The female reproductive tracts of species with internal fertilization are not passive arenas in which fertilization occurs, but active participants in interactions between the male ejaculate and the female. These interactions can affect sperm behavior, morphology, and fertility in a selective manner, biasing fertilizations towards a specific male or, in the case of hybrid matings, a male of the same species.
Foto: Bjørn Aksel Bjerke
Collared and pied flycatchers are closely related species that sometimes mate in the wild, producing sterile hybrid offspring with a high cost to fitness. However, sperm from the collared flycatcher swim at a suppressed speed in fluid from the pied flycatcher female reproductive tract. This suggests that the fluid contains molecules that interact with sperm differently between the species. This project aims to explore the composition of female reproductive tract fluid in these two species to identify these interacting molecules.
Project (field and lab):
Depending on travel restrictions, the project will involve fieldwork in Öland, Sweden (late may – early June) collecting female reproductive tract fluid from collared and pied flycatchers that have mated to either the same species or the opposite. The labwork in this project will involve processing these samples and quantifying the protein content.
Arild Johnsen and Emma Whittington