World's First Sex-Selected Filly Sets Pace for Industry

Equine Practice
January 1999

     Call Me Madam is the first horse in the world to have her sex selected prior to conception via a cutting-edge cell-sorting technology developed by XY Inc., a Fort Collins, Colorado, biotech company that expects to commercialize the technique in the coming years. The birth of Call Me Madam on August 6, 1998, is a first in the horse industry and a major breakthrough in one of the world's most promising biotech industries-sperm sorting, which separates sperm that carry the X chromosome and produce females from sperm that carry the Y chromosome and produce males. XY, which holds exclusive global rights to the sperm-sorting technology in non-human mammals, was formed as a joint venture of the Colorado State University Research Foundation and Cytomation, Inc., of Fort Collins, Colorado. Founded in May 1996, XY's original mission was to provide semen-sexing services to the US cattle industry. In January 1997, XY's mission expanded also to include horses, pigs, and endangered species, specifically, and all non-human mammals, potentially.
     Call Me Madam, born on a ranch outside Fort Collins, was carried by a mare named Feisty, impregnated via oviductal insemination, using sorted semen that was introduced by flank incision. XY's chief executive officer, Dr. Mervyn Jacobson, said "to produce a beautiful, live foal whose sex was predetermined 11 months earlier is a first on many fronts-scientific, economic, an ecologic."
     "A horse's gestation cycle is typically almost a year long. That's a long and expensive wait for a foal that's the wrong sex. If breeders can select a foal's sex, they can plan and build their business based on what clients are interested in buying, breeding, or raising for show," said Jacobson.
     Currently, the success of in vitro embryo production in horses lags far behind other domestic animals such as cows or pigs because of the horse's complex reproductive biology and the incredibly high number of sperm-500 million-needed to impregnate a mare.
     The breakthrough science of horse sperm sorting via flow cytometry was developed by XY scientists in conjunction with three other respected research teams at Colorado State University, the US Department of Agriculture, and Cytomation.
     USDA researchers developed and patented the technology that allows sperm to be sorted by flow cytometry. Cytomation built the computerized device-MoFlo-to speed the sorting process. Colorado State researchers discovered how to make female animals pregnant with unusually low doses of sperm. XY scientists perform sperm sorting, a living engineering process, that allows XY to dictate the sex of horses, cows, and other animals before artificial insemination occurs.
     Jacobson said, "This is truly historic. For 5,000 years people throughout the world have yearned to determine the sex of their animal herds. In relation to the horse, it took the joint collaboration of four research teams to make this dream come true."