State of the art and perspectives of application of sorted sperm cells in farm animals.

摘要

The most efficient way to shift the sex ratio of offspring is to select spermatozoa according to the sex chromosomes. The difference in their DNA content can be determined by flow cytometry to produce populations of either sex at high accuracy. As the method is based on single cell identification, the output of cells is limited, although major improvements were made by high-speed flow cytometry and improved cell orientation using UV laser. This review discusses the current practice in farm animal species. For bovine AI, sex sorted frozen spermatozoa are already available on a commercial basis, whereas in other species, especially in pigs, the high demand of spermatozoa can hardly be satisfied. However, in combination with other biotechniques like IVF, ICSI, GIFT and special insemination protocols, litters of acceptable size are produced under laboratory condition. As in horses and sheep, current research is focused on pigs regarding long time storage of the sex sorted spermatozoa in liquid nitrogen.