Review. Fish as biofactories: indicible genetic systems and gene targeting

Abstract

The production of recombinant human proteins for pharmaceutical products in transgenic animals is progressingslowly. Compared to mammals, fish offer easier genetic manipulation since they produce hundreds of eggs per femaleand because of the independent development of fish embryos. Traditional methods in the past have employedfertilized egg injections with transgene constructions containing non-specific promoters and random genome integration.In fish, these methods have resulted in mosaicism and extrachromosomal expression. Inducible systems tocontrol the temporal and tissue specific expression and gene targeting methodologies to increase efficiency and controlof the locus of insertion of the transgene are, therefore, desirable. All these techniques incorporate stem cell manipulation,classification, selection and/or nuclear transplant of cell lines or stem cells. Some of these systemsinitially developed for mammalian cells are now available to be tested in fish. A large part of this field still remainsunexplored.

Transfection improvements of fish cell lines by using deacylated polyethylenimine of selected molecular weights

“…The efficiency of transfection was later improved by the use of commercially available liposomes such as Lipofectamine Ò , Fugene 6 Ò , TransIT LT1 Ò , and others, but their chemical composition is not available (unrevealed because of commercial reasons) [18,22,23]. In contrast, reports of high efficiencies of transfection of the rainbow trout gonad (RTG2) cell line are not abundant despite it being the best known trout cell line obtained to date [5,6,24].…”