...Veronique Duboc; Fatima A. Sulaiman; Eleanor Feneck; Anna Kucharska; Donald Bell; Muriel Holder-Espinasse; Malcolm P. O. Logan ABSTRACT We dissect genetically a gene regulatory network that involves the transcription factors Tbx4 , Pitx1 and Isl1 acting cooperatively to establish the hindlimb bud...

... genome occupancy and their putative target genes. Tbx4 and Hoxc10 interact directly with each other, have the ability to bind to a previously unrecognized T-box–Hox composite DNA motif and show synergistic activity when acting on reporter genes. Pitx1, the master regulator for hindlimb specification...

...Veronique Duboc; Malcolm P. O. Logan The forelimbs and hindlimbs of vertebrates are morphologically distinct. Pitx1, expressed in the hindlimb bud mesenchyme, is required for the formation of hindlimb characteristics and produces hindlimb-like morphologies when misexpressed in forelimbs. Pitx1...

... is essential for cell shape changes and morphogenesis in the developing vertebrate gut and that Shroom3 transcription in the gut requires the Pitx1 transcription factor. Moreover, we show that Pitx proteins directly activate Shroom3 transcription, and we identify Pitx-responsive regulatory elements...

...Alexandre Marcil; Émilie Dumontier; Michel Chamberland; Sally A. Camper; Jacques Drouin Two closely related homeobox transcription factors, Pitx1 and Pitx2, have been implicated in patterning of lateral plate mesoderm derivatives: Pitx1 for specification of hindlimb identity and Pitx2...

... factors, Pit1, Gata2, Egr1 and Sf1 , on a threshold level of PITX2. The related Pitx1 gene has a role in hormone gene transcription, and it is important late in ontogeny for the final expansion of the differentiated cell types. Pitx1 and Pitx2 have overlapping functions in the expansion of Rathke’s pouch...

... of limbs. The morphological differences between the forelimbs and hindlimbs, a feature shared by all jawed vertebrates, can be explained by coevolution between the T-box genes and asymmetrically distributed modifying factors, including Pitx1 . The ideas presented here have broader implications...