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Zhang Z, Liu J, Meriano J, Ru C, Xie S, Luo J, Sun Y. Human sperm rheotaxis: a passive physical process. Sci Rep 2016; 6:23553. [PMID: 27005727 PMCID: PMC4804285 DOI: 10.1038/srep23553] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/02/2016] [Indexed: 12/14/2022] Open
Abstract
A long-standing question in natural reproduction is how mammalian sperm navigate inside female reproductive tract and finally reach the egg cell, or oocyte. Recently, fluid flow was proposed as a long–range guidance cue for sperm navigation. Coitus induces fluid flow from oviduct to uterus, and sperm align themselves against the flow direction and swim upstream, a phenomenon termed rheotaxis. Whether sperm rheotaxis is a passive process dominated by fluid mechanics, or sperm actively sense and adapt to fluid flow remains controversial. Here we report the first quantitative study of sperm flagellar motion during human sperm rheotaxis and provide direct evidence indicating that sperm rheotaxis is a passive process. Experimental results show that there is no significant difference in flagellar beating amplitude and asymmetry between rheotaxis-turning sperm and those sperm swimming freely in the absence of fluid flow. Additionally, fluorescence image tracking shows no Ca2+ influx during sperm rheotaxis turning, further suggesting there is no active signal transduction during human sperm rheotaxis.
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Affiliation(s)
- Zhuoran Zhang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Jun Liu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Jim Meriano
- LifeQuest Centre for Reproductive Medicine, Toronto, ON, Canada
| | - Changhai Ru
- Jiangsu Provincial Key Laboratory of Advanced Robotics &Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, China
| | - Shaorong Xie
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Department of Mechatronic Engineering, Shanghai University, China
| | - Jun Luo
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Department of Mechatronic Engineering, Shanghai University, China
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada.,Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON, Canada
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Basic research: Just keep swimming - sperm exhibit a 2D slither motion. Nat Rev Urol 2015; 13:2. [PMID: 26620613 DOI: 10.1038/nrurol.2015.291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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