title: Prestin is an anion transporter dispensable for mechanical feedback amplification in Drosophila hearing.
abstract: In mammals, the membrane-based protein Prestin confers unique electromotile properties to cochlear outer hair cells, which contribute to the cochlear amplifier. Like mammals, the ears of insects, such as those of Drosophila melanogaster, mechanically amplify sound stimuli and have also been reported to express Prestin homologs. To determine whether the D. melanogaster Prestin homolog (dpres) is required for auditory amplification, we generated and analyzed dpres mutant flies. We found that dpres is robustly expressed in the fly's antennal ear. However, dpres mutant flies show normal auditory nerve responses, and intact non-linear amplification. Thus we conclude that, in D. melanogaster, auditory amplification is independent of Prestin. This finding resonates with prior phylogenetic analyses, which suggest that the derived motor function of mammalian Prestin replaced, or amended, an ancestral transport function. Indeed, we show that dpres encodes a functional anion transporter. Interestingly, the acquired new motor function in the phylogenetic lineage leading to birds and mammals coincides with loss of the mechanotransducer channel NompC (=TRPN1), which has been shown to be required for auditory amplification in flies. The advent of Prestin (or loss of NompC, respectively) may thus mark an evolutionary transition from a transducer-based to a Prestin-based mechanism of auditory amplification.
authors.affiliation: The Ear Institute, University College London, 332 Gray's Inn Road, London, WC1X 8EE, UK.
authors.forename: Ryan G
authors.initials: RG
authors.lastname: Kavlie
authors.forename: Janice L
authors.initials: JL
authors.lastname: Fritz
authors.forename: Florian
authors.initials: F
authors.lastname: Nies
authors.forename: Martin C
authors.initials: MC
authors.lastname: Göpfert
authors.forename: Dominik
authors.initials: D
authors.lastname: Oliver
authors.forename: Joerg T
authors.initials: JT
authors.lastname: Albert
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Eberl
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D030801:Animals, Genetically Modified; D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000838:Anions / Q000378:metabolism; D057506:Arthropod Antennae / Q000502:physiology; D016466:CHO Cells; D003412:Cricetulus; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000502:physiology*; D005072:Evoked Potentials, Auditory; D006309:Hearing / Q000502:physiology*; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D018613:Microscopy, Confocal; D018408:Patch-Clamp Techniques; D016133:Polymerase Chain Reaction; D011984:Sensory Receptor Cells / Q000502:physiology*; D014162:Transfection; D014828:Vocalization, Animal
chemical_list: D027321:Anion Transport Proteins; D000838:Anions; D029721:Drosophila Proteins; C000600831:prestin protein, Drosophila