title: Individual female differences in chemoattractant production change the scale of sea urchin gamete interactions.
abstract: Sperm selection by females is an important process influencing fertilization and, particularly in broadcast-spawning organisms, often occurs before sperm reach the egg. Waterborne sperm chemoattractants are one mechanism by which eggs selectively influence conspecific sperm behavior, but it remains an open question whether the eggs from different females produce different amounts of sperm chemoattractant, and how that might influence sperm behavior. Here, we quantify the differences in attractant production between females of the sea urchin species Lytechinus pictus and use computational models and microfluidic sperm chemotaxis assays to determine how differences in chemoattractant production between females affects their ability to attract sperm. Our study demonstrates that there is significant individual female variation in egg chemoattractant production, and that this variation changes the scope and strength of sperm attraction. These results provide evidence for the importance of individual female variability in differential sperm attraction and fertilization success.
authors.affiliation: University of Washington, Department of Biology, Seattle, WA 98195, USA.
authors.forename: Yasmeen H
authors.initials: YH
authors.lastname: Hussain
authors.affiliation: University of Washington, Department of Chemistry, Seattle, WA 98195, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Sadilek
authors.affiliation: University of Washington, Department of Biology, Seattle, WA 98195, USA.
authors.forename: Shukri
authors.initials: S
authors.lastname: Salad
authors.affiliation: University of California Los Angeles, Department of Ecology and Evolutionary Biology, Los Angeles, CA 90095, USA.
authors.forename: Richard K
authors.initials: RK
authors.lastname: Zimmer
authors.affiliation: University of Washington, Department of Biology, Seattle, WA 98195, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Riffell
mesh_terms: D000818:Animals; D002630:Chemotactic Factors / Q000096:biosynthesis*; D002633:Chemotaxis / Q000502:physiology*; D002851:Chromatography, High Pressure Liquid; D003198:Computer Simulation; D005260:Female; D005306:Fertilization / Q000502:physiology*; D047331:Lytechinus / Q000502:physiology*; D008297:Male; D013058:Mass Spectrometry; D044085:Microfluidics; D010063:Ovum / Q000166:cytology / Q000378:metabolism*; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology*
chemical_list: D002630:Chemotactic Factors