| Popis: |
The transplant experiments described in this work may help to shorten the generation interval for long maturing endangered fish species and their more effective reproduction. Further, it is possible to preserve the separated spermatogonia and oogonia using a cryopreservation in liquid nitrogen. We conserve both paternal and maternal DNA and the gene pool of endangered fish species will not be depleted of maternal part. It's because we can freeze only sperm in the preservation of mature gametes. Fish eggs and embryos would not survive freezing. The described methods will be applied in the future to more effective rescue of critically endangered sturgeons by the transplantation of their germ cells into a Sterlet (Acipenser ruthenus). These methods can be suitable for application on other species of endangered fish in case of finding an appropriate recipient. As an example of our fish species is a European eel (Anguilla Anguilla). The Siberian sturgeon (Acipenser baeri) and the Sterlet (Acipenser ruthenus) were used as model organisms. For Siberian sturgeon the enzymatic dissociation technique, sorting of germ cells using Percoll gradient concentration and transplantation of sturgeon spermatogonia and oogonia were used. The results showed that the use of 0.3% of trypsin in PBS is optimal for dissociation of spermatogonia and oogonia, because this medium was dissociating the highest number of cells without reducing their viability. The separation of the early stages of germ cells has been successfully achieved by segregation in 10 to 30% of Percoll gradient with the help of centrifugation. After transplantation it was proved in spermatogonia as well in oogonia that they colonized the genital ridges of the host. The recipient became a chimera of a germ line, which can produce donor gametes throughout his life. |
