title: The battle of the sexes starts in the oviduct: modulation of oviductal transcriptome by X and Y-bearing spermatozoa.
abstract: BACKGROUND
  Sex allocation of offspring in mammals is usually considered as a matter of chance, being dependent on whether an X- or a Y-chromosome-bearing spermatozoon reaches the oocyte first. Here we investigated the alternative possibility, namely that the oviducts can recognise X- and Y- spermatozoa, and may thus be able to bias the offspring sex ratio.
  
  
  RESULTS
  By introducing X- or Y-sperm populations into the two separate oviducts of single female pigs using bilateral laparoscopic insemination we found that the spermatozoa did indeed elicit sex-specific transcriptomic responses. Microarray analysis revealed that 501 were consistently altered (P-value < 0.05) in the oviduct in the presence of Y-chromosome-bearing spermatozoa compared to the presence of X-chromosome-bearing spermatozoa. From these 501 transcripts, 271 transcripts (54.1%) were down-regulated and 230 transcripts (45.9%) were up-regulated when the Y- chromosome-bearing spermatozoa was present in the oviduct. Our data showed that local immune responses specific to each sperm type were elicited within the oviduct. In addition, either type of spermatozoa elicits sex-specific signal transduction signalling by oviductal cells.
  
  
  CONCLUSIONS
  Our data suggest that the oviduct functions as a biological sensor that screens the spermatozoon, and then responds by modifying the oviductal environment. We hypothesize that there might exist a gender biasing mechanism controlled by the female.
authors.forename: Carmen
authors.initials: C
authors.lastname: Almiñana
authors.forename: Ignacio
authors.initials: I
authors.lastname: Caballero
authors.forename: Paul Roy
authors.initials: PR
authors.lastname: Heath
authors.forename: Saeedeh
authors.initials: S
authors.lastname: Maleki-Dizaji
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Parrilla
authors.forename: Cristina
authors.initials: C
authors.lastname: Cuello
authors.forename: Maria Antonia
authors.initials: MA
authors.lastname: Gil
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Vazquez
authors.forename: Juan Maria
authors.initials: JM
authors.lastname: Vazquez
authors.forename: Jordi
authors.initials: J
authors.lastname: Roca
authors.forename: Emilio Arsenio
authors.initials: EA
authors.lastname: Martinez
authors.forename: William Vincent
authors.initials: WV
authors.lastname: Holt
authors.affiliation: Academic Unit of Reproductive and Developmental Medicine, Department of Human metabolism, The University of Sheffield, Level 4, The Jessop Wing, Tree Root Walk, Sheffield S10 2SF, UK. A.Fazeli@Sheffield.AC.UK.
authors.forename: Alireza
authors.initials: A
authors.lastname: Fazeli
mesh_terms: D000818:Animals; D005260:Female; D008297:Male; D010057:Oviducts / Q000502:physiology*; D019849:Sex Determination Processes; D013094:Spermatozoa / Q000378:metabolism*; D013552:Swine; D059467:Transcriptome; D014960:X Chromosome; D014998:Y Chromosome