The induction of germ-line chimerism is an expanding focus of fisheries research. This technique is having a potential to enhance the production of gametes of species that are commercially valuable, endangered, species with problematic reproduction, using a more common or easily available species or species adapted to artificial reproduction as a surrogate host. The main goal of this technology is to establish a small-bodied surrogate broodstock producing functional donor gametes based on germ cell transplantation. Extent preliminary experiments, including documentation of donor/host embryonic and larval development, characterization of germ cells enriched by documentation of their migratory activities, sterilization of the host, isolation and cryopreservation of donor germ cells, are key factors for launching this biotechnology. All these crucial points were the main objective of the present work. The whole thesis provided the focus on two different fish species. First, our commercially valuable fish, the tench, where we would like to apply our current knowledge to create a germ-line chimera within cyprinids by transplantation of tench germ cells to smaller and faster-reproducing fish species as white cloud mountain minnow. Secondly we focused on the endangered species (listed in IUCN Red List) of large body size with long reproductive cycle, the sturgeons. In this case, we have chosen sterlet as a host, providing an advantage of shorter generation interval and smaller body size, to produce gametes of donor, a critically endangered species of large body size with long reproductive cycle, such as beluga. This innovative technology could result in collection of sperm and eggs in shorter time from small-bodied host. In tench we firstly focused on embryonic and larval development documentation together with description of origin and migration pathways of primordial germ cells (PGCs). PGCs represent a powerful tool for creation a germ-line chimera within fish species because they transmit genetic information to the next generation (Linhartova et al., 2014a). Secondly, we reported a practical technique for isolation and cryopreservation of early stages of germ cells (GC), including spermatogonia (SG) and spermatocytes (Linhartova et al., 2014b). In case of sturgeons, Saito et al. (2014) firstly described the origin and migration patterns of sturgeon PGCs deposited at the vegetal pole of the egg similar to that in anurans. Secondly, Psenicka et al. (2015) reported isolation and cryopreservation of female and male GC, SG from testes and OG and pre-vitellogenic oocytes from ovary, of 2-4-year old Siberian sturgeon. Moreover the isolated GC were transplanted into host (sterlet) and process of transplantation resulted in successful colonization of sterlet genital ridge. The potential host for germ-cell tranplantation, sterlet, was sterilized by knock-down of germ cell specific gene, the dead end gene, by the morpholino antisense oligonucleotide (MO) agent (dnd-MO). These results reported the first known and functional method of sturgeon sterilization (Linhartova et al., manuscript). We provided important information on morphology and ultrastructure of beluga spermatozoa structure by scanning and transmission electron microscopy to increase knowledge of evolutionary and taxonomic relationships among sturgeons (Linhartova et al., 2013). Finally, this thesis presents several studies with differing focus of research but with one target goal to induce germ-line chimerism in fish. All these results are prerequisite of future application and development of surrogate production in these species.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:200449 |
| Date | January 2015 |
| Creators | LINHARTOVÁ, Zuzana |
| Source Sets | Czech ETDs |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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