Dual roles of tear lipocalins as ‘chemical signalling’ and ‘toxic waste disposal’ systems of the house mouse
- Published
- Accepted
- Subject Areas
- Bioinformatics, Evolutionary Studies, Genetics, Zoology
- Keywords
- pheromone, immunity, lipocalins, toxic waste hypothesis, tears, sex dimorphism
- Copyright
- © 2017 Stopka et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2017. Dual roles of tear lipocalins as ‘chemical signalling’ and ‘toxic waste disposal’ systems of the house mouse. PeerJ Preprints 5:e2702v1 https://doi.org/10.7287/peerj.preprints.2702v1
Abstract
Mammalian tears are produced by lacrimal glands to protect eyes and to function in chemical communication and immunity. However, excess tears flow through nasolacrimal ductsto nasal tissues, and via the nasopharyngeal duct to the oral cavity where digestion starts. Tears contain soluble proteins that attack pathogens, as well as proteins from the lipocalin family that – with their capacity to transport volatile organic compounds (VOCs) in their eight-stranded beta barrel – are involved in sexual signalling and may also transport toxic VOCs towards digestion. Therefore, we generated the tear proteome of the wild-living house mouse (Mus musculus musculus) and detected a total of 719 proteins in tears with 20% being sexually dimorphic. Those proteins that showed the most elevated sexual dimorphisms are VOC transporters from the recently discovered odorant binding protein (OBP), and major urinary protein (MUP) families, thus demonstrating that tears have the potential to elicit sex-specific signals in combination with different lipocalins. Moreover, some tear lipocalins are non-dimorphic – with MUP20/Darcin, LCN11, and LCN13 being good examples – thus suggesting that they are involved in other biological processes besides sexual signalling.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Supplementary Dataset
Original data from LC-MS/MS (i.e. log2 transformed peak areas, and peptides) and from the RNAseq-based analysis (i.e. Count table).