Chimerism in native fish species as a tool for surrogate propagation in aquaculture

Abstract

Chimerism is a phenomenon in which the cells from a donor individual may coexist in other individuals. The transplantation of primordial germ cells (PGC) from a donor individual to a host give rise to a germline chimera. The resultant individuals from such transplantation may produce heterologous gametes, that is, host organisms of germ cells producing gametes from the donor species. This fact is interesting for aquaculture because species presenting easy reproductive management may be used to produce gametes from other species. Although such technology is feasible and may increase the aquacultural production, initially it is necessary to clear several aspects regarding to basic biology before achieve the production of germline chimeras. Therefore, we aim with this study to produce germline chimeras for surrogate production in aquaculture, using annual spawners as donor species and intertidal spawners as hosts, and then producing offspring over the year. This study has two distinct stages. During the first stage (basic), protocols of micromanipulation and blastomere transplantation will be obtained, including egg dechorionation, a detailed description of early developmental stages and traceability of primordial germ cells. During this stage we will also develop techniques for sterilization of host species by triploidization. The second stage related to the production of germline chimeras, will consist on the transplantation of cells from donor species to sterile triploid host, followed by confirmation of germline transmission by means of histological observations, flow cytometry and progeny test. We will also develop protocols for cryopreservation of PGC by vitrification, that will be used to obtain germline chimeras. From the technologies developed in this project, we expect to generate an alternative procedure to improve fingerling availability for fish farming. (AU)