Transcript localisation: Human and mouse TBX2, TBX3, and TBX5 transcripts detected by riboprobes are found asymmetrically across the embryonic neural retina, with highest levels of transcripts within dorsal and peripheral retina. The dorsoventral gradient of TBX2 expression cannot be detected before the ganglion cell layer (GCL) forms and expression is found to be restricted to the inner neuroblastic retina and later to the GCL and inner nuclear layer.
TBX2 transcript is also detected in the optic and otic vesicles at 9.5 dpc, and in the naso-facial mesenchyme, and later in the developing limbs and other internal organ primordia (of lungs and genitalia).
Later at around 8 and 10 dpc, TBX2 is detected in allantois, inflow tract (IFT), outflow tract (OFT) and atrio-ventricular canal (AVC) of the developing mouse heart. Chick heart development is also consistent in terms of similar TBX2 expression patterns.
During mammary development, TBX2 expression is detected at 11.5 dpc in the mesodermal milk lines.