Developmental biotechnology for aquaculture, with special reference to surrogate production in teleost fishes

Abstract

The purpose of this review is to introduce surrogate production as a new technique for fish-seed production in aquaculture. Surrogate production in fish is a technique used to obtain the gametes of a certain genotype through the gonad of another genotype. It is achieved by inducing germ-line chimerism between different species during early development. Primordial germ cells (PGCs) are a key material of this technique to induce germ-line chimera. In several species, it has been reported that PGCs differentiated from the blastomeres inherited some maternally supplied mRNA located at the terminal regions of the early cleavage furrows. PGCs from donor species (or strains) are isolated and transplanted into host species to induce the germ-line chimera.Four methods for inducing germ-line chimera, namely, blastomere transplantation, blastoderm-graft transplantation, transplantation of PGC from the genital ridge and transplantation visualized PGC with GFP fluorescence, are described. Several problems preventing the successful induction of germ-line chimera in various fish species are mentioned. Surrogate production, however, has the possibility to allow efficient fish-seed production and effective breeding and transfer of biodiversity to an aquaculture strain.Conservation and efficient utilization of genetic resources will be achieved through surrogate production combined with the cryopreservation of PGCs.

Early embryonic development in pikeperch (Sander lucioperca) related to micromanipulation

“…Transplantation of germline stem cells (GSC) provides an increased supply of donorderived gametes for surrogate hosts. The fish-seed production is expected to become more efficient by the realization of surrogate production between two different species that have different biological characteristics (Yamaha et al 2007). For example, the life cycle of the fish might be shortened if a species that has shorter life cycle is used as the surrogate host and produces donor gametes.…”

Identification of a germ cell marker gene, the dead end homologue, in Chinese sturgeon Acipenser sinensis

“…Recent developments in biotechnology, including isolation and transplantation of germ cells from donor into a host species lacking germ cells, for surrogate reproduction, has opened the possibility of efficient and sustainable aquaculture and conservation of endangered species (Yamaha et al, 2007;Xu et al, 2010). Identification and isolation of germ cells are the basic and critical steps in this technology.…”

Isolation and cryopreservation of early stages of germ cells of tench (Tinca tinca)

“…Germ cell transplantation to induce chimerism in fish species is an expanding focus of research. This technique can enhance the production of gametes of species that are commercially valuable, endangered, or have complex reproduction, using a more readily available species or one easily adapted to artificial reproduction as a surrogate host (Okutsu et al 2006a;Yamaha et al 2007). Primordial germ cell transplantation was developed (Saito et al 2008(Saito et al , 2010 due to the advantage of their migration to genital ridge via chemotaxis.…”

“…The germ-line cells, primordial germ cells (PGCs), and their subsequent stages, spermatogonia/oogonia (SG/OG), have the potential to undergo proliferation (Brinster 2002), differentiate into functional gametes, and transmit genetic information to the next generation (Okutsu et al 2006b) making them suitable for xenogeneic transplantation (Yamaha et al 2007). The major difference between manipulation of PGCs and SG is the relatively simple method of isolation of a large number of SG from testes, compared to the successful isolation of only tens of PGCs (Saito et al 2008(Saito et al , 2010.…”