A single shot to generate a transgenic abalone by direct testis injection

摘要

A powerful system for in vivo study of gene regulation, expression and function has been provided by transgenic animals which make it possible to generate many varieties with special genetic traits encoded by specific genes and to produce many mutants with particular defective gene. The delivery of foreign DNA molecules into gametes or embryos of aquatic animals has been studied for more than 20 years (Gong and Hew 1995, Sin 1997), including commercially important species of finfish and shellfish. In finfishes, microinjection is the most common method for transferring the foreign DNA into oocyte nuclei (Ozato et al. 1986, Tsai et al 1995b), cytoplasm of developing embryos (Chourrout et al 1986, Dunham et al 1987) and fertilized eggs (Fletcher et al. 1988, Dunham et al 1992, Lu et al 1992). Rather than microinjection, electroporation is a simple, convenient and more efficient method of implanting exogenous DNA fragments into fertilized eggs (Inoue et al. 1990, Powers et al 1992; Tsai and Tseng 1994). In shellfishes, genes have been transferred by electroporation of red abalone (Haliotis rufescens) embryos (Powers et al. 1995), retroviral infection for dwarf surf clams (Mulina lateralis) (Lu et al. 1996), particle bombardment for Pacific oyster (Crassostrea gigas) (Cadoret et al. 1997a), and microinjection, electroporation or chemical-mediated trans-fection of embryos for Eastern oyster (C. virginica) (Cadoret et al. 1997b, Buchanan et al. 2001). But, there was no documentation of transgene integration or inheritance. Furthermore, those methods are insufficient for quickly treating the tremendously large number of eggs spawned by cultured species of shellfishes for transferring genes to fertilized eggs.