EP is the easiest and most economical method for gene transfer. Another advantage is that it can be used for any type of tissue or cell. Recently, due to its efficient infection into numerous cell types, including nonproliferating tissue cells, adenovirus-mediated in vivo transfer has been regarded as the most attractive tool for treating a disease using gene therapy. Blanchard and Boe-kelheide have carried out adenovirus-mediated gene transfer to adult rat testes. They showed that expression of the SV40-lacZ transgene used in their study was detected only in Sertoli cells and Leydig cells but not in germ cells, indicating that adenovirus-mediated gene transfer to the testes has a strict cell-type preference and cannot deliver a transgene into all types of spermatogenic germ cells. flovent inhaler
In contrast, it has been reported that gene transfer by EP showed no preference for the target cell type. Muramatsu et al. examined in vivo gene transfer by EP after DNA injection into the interstitial space of mouse testes. Transgene expression was detected in various types of testicular cells, both in the interstitium and seminiferous tubules. In our study using DNA injection into seminiferous tubules, significant expression of a transgene was restricted in germ cells and Sertoli cells within the tubules, but not in other somatic cells outside the tubules such as Leydig cells and peritubular cells (Fig. 1D). In short, transgenes retained in seminiferous tubules seem to be delivered equally to both germ and somatic cells residing within the tubules, and this has a positive effect on the efficiency of detecting a gene expressed in differentiating spermatogenic germ cells.