Thyrocyte-specific expression of Cre recombinase in transgenic mice

Abstract A transgenic mouse line that expresses Cre recombinase under control of the human thyroid peroxidase (TPO) gene promoter was established. The activity and specificity of the TPO‐driven Cre recombinase were examined by using Northern blotting and by crossing with the ROSA26 reporter transgenic mouse line. In the latter mice, Cre‐mediated recombination occurred only in the thyrocytes, and recombination commenced around embryonic day 14.5, at the time during thyroid organogenesis when TPO expression begins. This study demonstrates that the TPO ‐Cre transgenic mouse is a powerful tool to specifically delete loxP‐inserted (floxed) genes in thyrocytes and will be of great value in the study of thyrocyte‐specific genes during development and/or in adult thyroids. genesis 39:212–216, 2004. © 2004 Wiley‐Liss, Inc.