Stringent rosiglitazone-dependent gene switch in muscle cells without effect on myogenic differentiation.

We have developed a gene switch based on the human transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma) and its activation by rosiglitazone. However, ectopic expression of PPARgamma has been demonstrated to convert myogenic cells into adipocyte-like cells and, more generally, may interfere with the physiology of the target tissue. Consequently we modified the DNA-binding specificity of PPARgamma, resulting in a transcription factor that we named PPAR*.

TSPY-LTA transgenic mice develop endocrine tumors of the pituitary and adrenal gland.

In an attempt to determine the susceptibility of spermatogonia to malignant transformation transgenic mice were generated harboring a 1.3 kb 5'-flanking region of the germ cell specific expressed human testis specific protein, Y-encoded gene fused with the simian virus 40 large T antigen (TAg). Unexpectedly, TAg expression in transgenic mice was also detected in somatic tissues.