title: Modulation of the oviductal environment by gametes.
abstract: The notion of a gamete recognition system that alerts females to the presence of gametes in their reproductive tract profoundly influences our understanding of the physiology of events leading to conception and the bearing of offspring. Here, we show that the female responds to gametes within her tract by modulating the environment in which pregnancy is initially established. We found distinct alterations in oviductal gene expression as a result of sperm and oocyte arrival in the oviduct, which led directly to distinct alterations to the composition of oviductal fluid in vivo. This suggests that either gamete activates a cell-type-specific signal transduction pathway within the oviduct. This gamete recognition system presents a mechanism for immediate and local control of the oviductal microenvironment in which sperm transport, sperm binding and release, capacitation, transport of oocytes, fertilization, and early cleavage-stage embryonic development occur. This may explain the mechanisms involved in postcopulatory sexual selection, where there is evidence suggesting that the female reproductive tract can bias spermatozoa from different males in the favour of the more biologically attractive male. In addition, the presence of a gamete recognition system explains the oviduct's ability to tolerate spermatozoa while remaining intolerant to pathogens.
authors.affiliation: Academic Unit of Reproductive and Developmental Medicine, University of Sheffield, Level 4, The Jessop Wing, Tree Root Walk, Sheffield S10 2SF, United Kingdom.
authors.forename: A Stephen
authors.initials: AS
authors.lastname: Georgiou
authors.forename: Ambrosius P L
authors.initials: AP
authors.lastname: Snijders
authors.forename: Edita
authors.initials: E
authors.lastname: Sostaric
authors.forename: Reza
authors.initials: R
authors.lastname: Aflatoonian
authors.forename: Jose L
authors.initials: JL
authors.lastname: Vazquez
authors.forename: Juan M
authors.initials: JM
authors.lastname: Vazquez
authors.forename: Jordi
authors.initials: J
authors.lastname: Roca
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Martinez
authors.forename: Phillip C
authors.initials: PC
authors.lastname: Wright
authors.forename: Alireza
authors.initials: A
authors.lastname: Fazeli
mesh_terms: D000818:Animals; D005187:Fallopian Tubes / Q000378:metabolism* / Q000601:surgery; D005260:Female; D005306:Fertilization; D007553:Isotope Labeling; D008297:Male; D009865:Oocytes / Q000502:physiology*; D011247:Pregnancy; D040081:Protein Array Analysis; D011506:Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D011897:Random Allocation; D013094:Spermatozoa / Q000502:physiology*; D013552:Swine / Q000378:metabolism / Q000601:surgery
chemical_list: D011506:Proteins