title: Effect of ejaculate, bull, and a double swim-up sperm processing method on sperm sex ratio.
abstract: Offspring gender preselection has applications of considerable economic, health and ecological interest. In this study we analysed modifications of the percentages of spermatozoa bearing Y and X chromosomes when semen samples are submitted to a double swim-up technique as a possible method for producing embryos of known sex with in vitro fertilisation protocols. As an initial experiment to provide accurate evaluation of the method we determined the possible incidence of natural deviations in the primary sex ratio between bulls or ejaculates, analysing the percentage of Y-chromosome DNA bearing spermatozoa (%Y-CDBS) with a polymerase chain reaction (PCR) amplification of X- and Y-specific fragments. Ejaculates were tested by direct semiquantitative PCR sexing and by sexing blastocysts produced in vitro with these spermatozoa. Bulls and ejaculates did not have any effect on the %Y-CDBS or on the sex ratio of embryos produced in vitro using these ejaculates. However, our double swim-up sperm preparation method produced differences in %Y-CDBS in some of the sperm fractions, suggesting that there are intrinsic differences in capacitation of X- and Y-bearing spermatozoa that might be used to produce embryos of the desired sex with in vitro fertilisation.
authors.affiliation: Departamento de Reproducción Animal y Conservación de Recursos Zoogenéticos, INIA, Ctra de la Coruña Km 5.9, Madrid 28040, Spain.
authors.forename: Ninoska
authors.initials: N
authors.lastname: Madrid-Bury
authors.forename: Raúl
authors.initials: R
authors.lastname: Fernández
authors.forename: Adela
authors.initials: A
authors.lastname: Jiménez
authors.forename: Sonia
authors.initials: S
authors.lastname: Pérez-Garnelo
authors.forename: Pedro Nuno
authors.initials: PN
authors.lastname: Moreira
authors.forename: Belén
authors.initials: B
authors.lastname: Pintado
authors.forename: Julio
authors.initials: J
authors.lastname: de la Fuente
authors.forename: Alfonso
authors.initials: A
authors.lastname: Gutiérrez-Adán
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002417:Cattle; D002469:Cell Separation / Q000379:methods*; D004247:DNA; D004542:Ejaculation; D005260:Female; D005307:Fertilization in Vitro; D006493:Heparin / Q000494:pharmacology; D008297:Male; D016133:Polymerase Chain Reaction; D012732:Sex Determination Analysis / Q000379:methods; D012743:Sex Preselection / Q000379:methods*; D012744:Sex Ratio; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000166:cytology / Q000502:physiology*; D014960:X Chromosome; D014998:Y Chromosome
chemical_list: D006493:Heparin; D004247:DNA