Marcella Spinaci

Assessment of Some Morphofunctional Characteristics of Flow-Cytometrically Sorted and Stained Boar Spermatozoa

The possibility to predetermine the sex of offspring is one of the most ambitious targets of reproductive biotechnology. Besides the scientific implication in human medicine (sex-linked hereditary diseases), gender preselection of farm animals would have the most evident impact. For specific breeding purposes it may be convenient to have either males or females. Herd productivity can be increased by the selection of animals with the sex that fits the best with performance. Sex preselection could furthermore be successfully applied to the preservation of endangered species. The possibility to determine sex is primarily based on: (1) the use of PCR in blastomers taken from preimplantation embryos, characterized by technical and ethical problems, and (2) the separation of chromosome-X bearing spermatozoa from chromosome-Y bearing spermatozoa by cytofluorimetry on the basis of their different relative DNA content (Johnson and Pinkel, 1986; Johnson and Welch, 1999). The use of sexed spermatozoa represents in theory a simple procedure (Seidel and Garner, 2002); however, the real possibility of separating enough X-bearing spermatozoa from Y-bearing spermatozoa for routine artificial insemination in sow under field conditions is far from being a reality (Johnson, 2002; Rath et al., 2003). During the sexing procedure sperm cells undergo chemical, physical and electrical stresses that can induce sperm damage. The objective of this study was to determine the effect of the staining procedure, with or without flow cytometry, on boar sperm membrane integrity, mitochondrial activity and blastocyst development in vitro. The evaluation of these parameters was also performed on stained and sorted semen after 24 h of storage at 17◦C.