A multiplier peroxiporin signal transduction pathway powers piscine spermatozoa
The primary task of a spermatozoon is to deliver its nuclear payload to the egg to form the next-generation zygote. With polyandry repeatedly evolving in the animal kingdom, however, sperm competition has become widespread, with the highest known intensities occurring in fish. Yet, the molecular con...
| Published in: | Proceedings of the National Academy of Sciences |
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| Main Authors: | , , , , , , , |
| Other Authors: | , |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
National Academy of Sciences (U.S.)
2021
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10261/259944 https://doi.org/10.1073/pnas.2019346118 https://doi.org/10.13039/501100003329 https://doi.org/10.13039/501100005416 |
| Summary: | The primary task of a spermatozoon is to deliver its nuclear payload to the egg to form the next-generation zygote. With polyandry repeatedly evolving in the animal kingdom, however, sperm competition has become widespread, with the highest known intensities occurring in fish. Yet, the molecular controls regulating spermatozoon swimming performance in these organisms are largely unknown. Here, we show that the kinematic properties of postactivated piscine spermatozoa are regulated through a conserved trafficking mechanism whereby a peroxiporin ortholog of mammalian aquaporin-8 (Aqp8bb) is inserted into the inner mitochondrial membrane to facilitate HO efflux in order to maintain ATP production. In teleosts from more ancestral lineages, such as the zebrafish (Danio rerio) and the Atlantic salmon (Salmo salar), in which spermatozoa are activated in freshwater, an intracellular Ca-signaling directly regulates this mechanism through monophosphorylation of the Aqp8bb N terminus. In contrast, in more recently evolved marine teleosts, such the gilthead seabream (Sparus aurata), in which spermatozoa activation occurs in seawater, a cross-talk between Ca- and oxidative stress-activated pathways generate a multiplier regulation of channel trafficking via dual N-terminal phosphorylation. These findings reveal that teleost spermatozoa evolved increasingly sophisticated detoxification pathways to maintain swimming performance under a high osmotic stress, and provide insight into molecular traits that are advantageous for postcopulatory sexual selection. This work was supported by Spanish Ministry of Economy, Industry and Competitiveness (MINECO) Grant AGL2016-76802-R (to J.C.) and Norwegian Research Council Grants 254872/E40 and 294768/E40 (to R.N.F.). F.C. and A.F. were supported, respectively, by a “Ramon y Cajal” contract (RYC-2015-17103) and a predoctoral grant (BES-2014-068745) from Spanish MINECO. |
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