Human Sperm Markers of Cryodamage Resistance

Sperm freezing has been employed for decades for male fertility preservation in cases of foreseeable or unexpected loss of fertility to guarantee future paternity, and also as a complement of assisted reproduction techniques. Sperm quality after thawing is highly variable, even among consecutive samples from the same individual, with mean survival rates around 40%. To date, the molecular basis of the adequate resistance or intolerance to freezing/thawing protocols is unknown, and its knowledge can lead to improvement in the selection of the samples to be frozen and also in the adequate supplement of cryopreservation media. Microarray analysis provides a powerful tool to address the molecular explanation beyond this behaviour, yielding results about comparative messenger ribonucleic acid (mRNA)expression under the two different biological conditions: optimal and suboptimal survival. Then, the aim of the investigators' study is to determine the genomic profile of sperm samples depending on their survival resistance to cryopreservation, to determine genes involved in cryodamage sensitivity.