Transgenesis in rats: Technical aspects and models

Abstract

The production of transgenic rats by DNA-microinjection into fertilized ova has now become an established procedure, although fewer than 20 lines have been described during the last 5 years. Overall, transgenic rats remain more difficult to produce than transgenic mice, but satisfactory yields have been obtained by several laboratories. A review of the methods used to generate transgenic rats shows considerable variation between different laboratories, particularly in choice of strain, superovulation protocols and the use of embryo culture before reimplantation. In some instances, the production of transgenic rats has provided data that are new and relevant, compared to data obtained in mice bearing the same transgene. Models have been developed for human diseases such as hypertension and autoimmunity, and applications have been found in the study of carcinogenesis and in pharmacological research. Transgenic rat technology also opens up interesting perspectives for transplantation research, in which microsurgery is an essential procedure. Intensive research is in progress in several laboratories to produce rat embryonic stem (ES) cell lines, but existing lines have not participated in germ line formation a prerequisite for their use in gene knock out experiments.

In vivo cell lineage analysis in cyproterone acetate-treated rat liver using genetic labeling of hepatocytes

“…LacZ transgenic rats were generated by microinjection of a DNA construct encoding the cytoplasmic form of E. coli ␤-galactosidase driven by the human immunodeficiency virus-long terminal repeat (HIV-LTR) promoter 20 into eggs from the SpragueDawley strain according to previously described protocols. 21,22 All animals received food and drinking water ad libitum throughout the experimental period.…”

Germline transgenesis in rodents by pronuclear microinjection of Sleeping Beauty transposons

“…For mice, pronuclear injection of transgenes often yields more than 20% founders among the live offspring 27,30 . In rats the reported efficiency of classical microinjection is much lower than in mice, possibly due to the significantly lower percentage of ova surviving the microinjection procedure 28,31,32 . Standard pronuclear injection of a transgene involves the introduction of a small number of identical copies of a linearized DNA molecule into a freshly fertilized oocyte.…”

“…Since 1981, the most routinely applied method in mice has been pronuclear DNA-injection 27 . This methodology has also been adapted to rats and is performed in a very similar way 28,29 . For mice, pronuclear injection of transgenes often yields more than 20% founders among the live offspring 27,30 .…”

Gene Therapy of Some Genetic Diseases by Transferring Normal Human Genomic DNA into Somatic Cells and Stem Cells from Patients

“…Microinjection technique has been used in transgenic animals for many years (Bishop & Smith, 1989;Chan & Yang, 2009;Charreau et al, 1996;Filipiak & Saunders, 2006;Ménoret et al, 2010;Tesson et al, 2005;Yang et al, 2008). Microinjection technique also has been used as a tool to clone animals-first, an unfertilized egg's nucleus is removed; then a nucleus of a somatic cell is microinjected into the denucleated egg; now the egg contains a whole copy of the diploid genomic DNA from the somatic cell and can be cultured in vitro to form a blastocyst; and the blastocyst is implanted into the womb of an animal; eventually a cloned animal is born (Campbell et al, 1996;Vajta & Gjerris, 2006;Willadsen, 1986;Wilmut et al, 1997).…”