Julia Cramer

Taste represents an interface between environment and individual, and the receptor repertoire underlying taste perception impacts an organism’s diet and, consequently, its niche. Despite the ecological importance of taste, interestingly, birds lack the common sweet taste receptor (T1R2/T1R3) - and in species preferring sweet food it is still largely unknown how they discern sugars. The distribution of frugivores and nectarivores across the phylogenetic tree enables comparative studies of how mechanisms of sweet taste perception differ between close- and distantly-related species of fruit- and nectarfeeding birds. Are there changes in receptor structure and function similar to those recently found in hummingbirds?

I will investigate the extent of convergent evolution and explore how the underlying genetic changes map on the phylogenetic tree. I will focus on the phylogenetic clade of Coraciimorphae that encompasses fruit- and nectarfeeding- as well as insectivorous specialists, as well as other species which are mixed diet generalists. I will address the molecular basis of such diverse preferences and examine how the response properties of the T1R taste receptors differ between those species by taking an integrated approach, combining and validating molecular findings with behavioral testing.