In vivo transfection of testicular germ cells and transgenesis by using the mitochondrially localized jellyfish fluorescent protein gene

We aimed to introduce foreign DNA into spermatogenic cells in the testis by injection of the DNA encoding jellyfish fluorescent proteins, green fluore scent protein (GFP) and yellow fluorescent protein (YFP) into the seminifer ous tubules and in vivo electroporation. We obtained fluorescent spermatozo a only when using the gene of the YFP protein fused to a mitochondrial loca lization signal peptide. Intracytoplasmic injection into oocytes of these s permatozoa gave fluorescent fetuses and pups, Almost all of the individuals produced from fluorescent spermatozoa were transgenic. We confirmed integr ation of the gene into chromosomes and its transmission into offspring. Thi s is the first report of gene transfer into germ cells and subsequent produ ction of transgenic offspring. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.