Validation and Morphofunctional Characterization of Genes Involved in Spermatogonial Differentiation and Sexual Maturation in Zebrafish (Danio rerio)

Abstract

The applicant is a young outstanding scientist who has published 45 articles (1569 citations, H-index = 15), supervised 5 PhD thesis, coordinated successful project grants (over 500,000 EURO), and became quite early an Associate Professor. His studies were pioneer in developing spermatogonial stem cell (SSC) transplantation in zebrafish, and showing the role of crucial growth factors, Igf3, Amh and Gnih, on fish SSC regulation. The overarching goal of this research is to investigate new paracrine factors and indentify long non-coding RNAs (lncRNAs) that regulate SSC activity, and develop biotechnological strategies to delay puberty in fish. Early sexual maturation of males is still one the major problems limiting the further development of aquaculture in the world. Sexual precocity is an undesirable trait in fish which is correlated with negative aspects such as reduced growth and lower feed conversion. In males, the onset of puberty is generally associated with a switch in SSC activity, from self-renewal to differentiation towards meiosis. Therefore, understanding the mechanisms controlling the switch in SSC activity is the basis for developing approaches to control precocious puberty in males. Focusing on new growth factors and lncRNAs, functional studies that combine in vivo approaches and gain-of-function ex vivo models will be employed. Functional studies will be evaluated with a combination of histomorphometric, biochemical and molecular approaches. In this project, lambari (Astyanax altiparanae), a Neotropical model and promising species for Brazilian aquaculture, and zebrafish will be used as experimental models. Based on the knowledge acquired on the new gonadal factors, we propose to employ somatic gene transfer to delay the start of puberty in fish. The applicant is considered fully capable to coordinate the current project, and certainly will generate important knowledge to improve aquaculture.