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Characterisation of the rheotaxis and thigmotaxis responses of stallion sperm

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dc.contributor.advisor Fair, Seán Sugrue, Emer 2018-08-14T15:22:34Z 2018-08-14T15:22:34Z 2018
dc.description peer-reviewed en_US
dc.description.abstract To navigate their way towards the site of fertilisation in the oviducts, sperm orientate and swim against a flow of mucus (rheotaxis) and while doing so, are guided by the sensation of touch along the epithelial lining of the reproductive tract (thigmotaxis). The aim of this study was to characterise the rheotactic and thigmotactic response of stallion sperm within a microfluidic channel (800 μm wide, 20 μm deep and 58.5 mm in length). Stallion sperm rheotaxis was assessed within the microfluidic channel in response to (i) A range of flow velocities (ii) Varying media viscosity (iii) Sperm distribution across the microfluidic channel and (iv) Sperm hyperactivation and compared to human and ram sperm. Stallion sperm progressed furthest at a velocity range of 10-30 μm/s, with an optimum velocity of 20 μm/s, and a viscosity of 2.5 cP or greater reduced sperm rheotaxis (P<0.05). Stallion sperm that were hyperactivated were unable to exhibit rheotaxis within the microfluidic channel, whereas, both hyperactivated human and ram sperm did exhibit positive rheotaxis. Both hyperactivated and non-hyperactivated human and ram sperm reorietated and swam against the flow, and while non-hyperactivated stallion sperm reoriented and swam against the flow, hyperactivated stallion sperm did not and were swept downstream with the flow. The number of sperm swimming near the microfluidic channel walls was higher than in the centre (P<0.05). This is the first study to illustrate that stallion sperm are rheotactically responsive and increasing viscosity reduces this response. We also demonstrated that sperm are inclined to swim along a surface and uniquely, hyperactivated stallion sperm are non-progressive and do not exhibit a rheotactic response unlike other species. The swimming pattern of hyperactivated stallion sperm against a fluid flow is uncoordinated and non-progressive similar to the erratic pattern traditionally observed in a static environment. This study provides a novel insight into species differences in sperm rheotatic response. en_US
dc.language.iso eng en_US
dc.publisher University of Limerick en_US
dc.subject reproductive tract en_US
dc.subject in vitro fertilisation en_US
dc.subject stallion sperm en_US
dc.subject Irish sport horse en_US
dc.title Characterisation of the rheotaxis and thigmotaxis responses of stallion sperm en_US
dc.type info:eu-repo/semantics/masterThesis en_US
dc.type.supercollection all_ul_research en_US
dc.type.supercollection ul_published_reviewed en_US
dc.type.supercollection ul_theses_dissertations en_US
dc.rights.accessrights info:eu-repo/semantics/openAccess en_US

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