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Submitted to: Agricultural Biotechnology
Publication Type: Book / Chapter Publication Acceptance Date: 6/18/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Predetermining the sex of offspring has been of interest to mankind since virtually the beginning of time. Theories abound as to how one could predetermine sex. Many theories have their origins from the Greek philosophers. The keenest interest has always focused on in vitro manipulation of sperm prior to insemination instead of determining the sex of the embryo. This is of the most interest since sex determination is then based on the chromosome content of the fertilizing sperm. This chapter will deal primarily with the successful development of a method to preselect the gender of offspring of mammals which is based on the inherent difference in DNA content between the X- and Y-chromosome bearing spermatozoa. The pioneering experiments of Lush sought to separate X from Y sperm based on density centrifugation. These efforts still continue today though considerable research effort has been expended to develop other sexing methods. Generally speaking, most of these efforts fall under the heading of "physical separation" methods. None of the physical separation methods have been validated with offspring born that demonstrate a significantly skewed sex ratio. In recent years, nearly all such methods have been tested using DNA content for differentiating X from Y sperm by flow cytometry. No method has shown anything but a 50:50 sperm sex ratio. In no case has there been evidence to support the claims made for various "physical separation" procedures or other non-DNA based separation procedures. Only methods based on X and Y sperm DNA difference have demonstrated a skewing of the sex ratio in offspring of rabbits, swine and cattle respectively. |
