Sex-specific responses to sexual familiarity, and the role of olfaction in Drosophila

• Studies of mating preferences have largely neglected the potential effects ofindividuals encountering their previous mates (‘directly sexually familiar’),or new mates that share similarities to previous mates, e.g. from the samefamily and/or environment (‘phenotypically sexually familiar’). Here, weshow that male and female Drosophila melanogaster respond to the direct andphenotypic sexual familiarity of potential mates in fundamentally differentways. We exposed a single focal male or female to two potential partners. Inthe first experiment, one potential partner was novel (not previously encountered)and one was directly familiar (their previous mate); in the secondexperiment, one potential partner was novel (unrelated, and from a differentenvironment from the previous mate) and one was phenotypically familiar(from the same family and rearing environment as the previous mate). Wefound that males preferentially courted novel females over directly or phenotypicallyfamiliar females. By contrast, females displayed aweak preference fordirectly and phenotypically familiar males over novel males. Sex-specificresponses to the familiarity of potential mates were significantly weaker orabsent in Orco1 mutants, which lack a co-receptor essential for olfaction, indicatinga role for olfactory cues in mate choice over novelty. Collectively, ourresults show that direct and phenotypic sexual familiarity is detected througholfactory cues and play an important role in sex-specific sexual behaviour.

Ämnesord

Natural Sciences  (hsv)

Naturvetenskap  (hsv)

Nyckelord

Coolidge effect

individual recognition

genetic relatedness

Orco

Drosophila melanogaster