RESUMO
Tiger puffer fish (Takifugu rubripes) has become the main fish species cultured in China since the last century because of its high economic value. Male and female tiger puffer fish need 2 and 3 years each to reach sexual maturity, which limits the development of breeding research for this species. In recent years, in vitro culture of fish spermatogonial stem cells (SSCs) have shown potential in aquaculture. In the present study, we established a spermatogenic stem cell line from T. rubripes (TrSSCs). TrSSCs were characterized by polygonal morphology, predominantly retained 44 chromosomes, and grew rapidly at 26 °C and in L-15. TrSSCs were still able to grow stably after more than one year of in vitro culture. TrSSCs showed positive alkaline phosphatase staining. TrSSCs expressed germ cell-associated genes, including dnd, ddx4, piwil, gfra1b, sox2, myca, nanog, ly75, and dazl, as determined by semiquantitative assays, and almost all cells were found to express the germ cell genes ddx4 and gfra1b in a fluorescence in situ hybridization assay. In vitro, induction experiments demonstrated the TrSSCs possessed the ability to differentiate into other types of cells. Our research has enriched the fish spermatogonial stem cell resource bank, which will provide an efficient research model for sex determination and sex control breeding in fish, establishing a foundation for subsequent breeding research.
RESUMO
Food wastes are rich in nutrients and can be used for producing useful chemicals through biotransformation. Some oleaginous microorganisms can use food wastes to produce lipids and high value-added metabolites such as polyunsaturated fatty acids, squalene, and carotenoids. This not only reduces the production cost, but also improves the economic value of the products, thus has large potential for commercial production. This review summarized the advances in food waste treatment, with a focus on the lipid production by oleaginous microorganisms using food wastes. Moreover, challenges and future directions were prospected with the aim to provide a useful reference for related researchers.
