The lipid constitution of the canine sperm plasma membrane is unknown, hindering the development of protective mechanisms during in vitro manipulation. The goals of this experiment are: to assess the lipid composition of the plasma membrane of motile and static sperm, to describe the plasma membrane composition during sperm maturation in the different segments of the epididymis (head, body and tail) and detect changes in plasma membrane after cryopreservation. This experiment also aim to evaluate the plasma membrane lipids involved in canine sperm freezability. In the first step of the present research, 10 male dogs will have their semen collected by digital massage. An aliquot of the semen will be centrifuged by density gradient in order to separate the motile and static sperm. The remainder of the ejaculate will be cryopreserved for later analysis. The same dog will be submitted to orchiectomy for sperm collection from the epididymal head, body and tail. Samples will be submitted to plasma membrane lipid extraction and subsequent analysis by mass spectrometry to determine the lipid composition of the plasma membrane. In the second step of the experiment, 20 dogs will have their semen cryopreserved and analyzed for motility and membrane integrity after thawing. Animals with better and worse freezability will be evaluated for lipid composition of the plasma membrane by mass spectrometry seeking for lipid factors related sperm freezability in dogs.
News published in Agência FAPESP Newsletter about the scholarship: