Sex selection in mammals: a review

New methods for sperm separation and embryo sexing provide the opportunity to select the gender of the offspring of domestic mammals. We review here procedures currently available for pre- and post-fertilization sex determination, including flow cytometric selection of X- and Y-chromosome bearing spermatozoa and the application of the polymerase chain reaction to biopsied embryos. Modern techniques are considered in the context of the development of the field and parallel innovations in human medicine are briefly considered.