The selection of the most motile spermatozoa is now a must in assisted fertilization. In this way sperm samples are "cleaned" of all slow, diseased, damaged spermatozoa. This increases the chances that IVF will have a happy outcome. However, scientists are still uncertain as to what factors influence sperm quality.
A team of biologists from the Technical University of Dresden has analyzed different types of bovine spermatozoa. He assessed its metabolism, motility and tail length, looking for connections. The data revealed a connection between the rate of metabolism and the movements of the flagellum. The faster the cell's metabolism, the better it moves in the flow. However, the correlation is not so immediate.
Veronika Magdanz explained the actual weight of the results. It is not simply a matter of looking for the sperm that metabolizes the most. Selected cells also have lower energy stores, as they consume more and faster. Certain metabolic pathways can therefore have negative consequences on the health of cells, damaging their integrity. For example, one of these pathways produces dangerous free radicals that accelerate the deterioration of spermatozoa.
The results of the study explain why select sperm based on how fast they move. It will be possible to apply them both to humans and to farm animals, albeit with a few more insights.