The ability of sperm selection techniques to remove single- or double-strand DNA damage.

A wide variety of techniques for the preparation of sperm are currently available, of which the most commonly employed are density-gradient centrifugation (DGC) and swim-up (SUP). To date, these methods appear to be effective in selecting functional sperm for assisted reproduction techniques (ART), but they may have negative effects on sperm DNA. In this study, the ability of these semen processing techniques to eliminate spermatozoa containing single- and double-strand DNA damage was assessed by the two-tailed comet assay and the sperm chromatin dispersion test in 157 semen samples from patients seeking assisted reproduction treatment.

A highly conserved pericentromeric domain in human and gorilla chromosomes.

Significant similarity between human and gorilla genomes has been found in all chromosome arms, but not in centromeres, using whole-comparative genomic hybridization (W-CGH). In human chromosomes, centromeric regions, generally containing highly repetitive DNAs, are characterized by the presence of specific human DNA sequences and an absence of homology with gorilla DNA sequences. The only exception is the pericentromeric area of human chromosome 9, which, in addition to a large block of human DNA, also contains a region of homology with gorilla DNA sequences; the localization of these sequences coincides with that of human satellite III.

DNA fragmentation in frozen sperm of Equus asinus: Zamorano-Leonés, a breed at risk of extinction.

The dynamics of sperm DNA fragmentation (sDF) and sperm viability were analyzed in frozen-thawed sperm samples of Equus asinus (Zamorano-Leonés), a breed at risk of extinction. Sperm DNA fragmentation was assessed using an adaptation of the sperm chromatin dispersion test developed for stallions in five different frozen samples. Sperm were thawed and incubated at different temperatures (37 degrees C, 25 degrees C, and 4 degrees C) and sDF was assessed at different times and compared.