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Presenting Author(s) Malcolm Logan
Abstract Title Signals controlling limb initiation and limb position.
Full author List Malcolm Logan, Carolina Minguillon, Charalambos Rallis, Jo Del Buono
Text of abstract

We are interested in identifying the signals that control processes from limb bud initiation to final morphogenesis of the individual elements of the limb.

Using mouse, chick and zebrafish embryos we are exploiting gene misexpression and gene deletion approaches to study the function of two members of the T-box family of transcription factors, Tbx5 and Tbx4, and a paired-type homeodomain factor, Pitx1 in limb initiation and specification of limb-type identity. Using conditional gene deletion in mouse embryos, we have shown previously that following deletion of Tbx5 in the limbs, the forelimb fails to form. We are now using this genetic background to test the properties of transgene-expressed genes to rescue the forelimb defect.

Previously, we have demonstrated that misexpression of Pitx1 in the chick wing is capable of partially transforming forelimb to hindlimb identity. We have extended these studies by producing transgenic lines in the mouse in which transgene-derived, Pitx1 can dramatically alter normal forelimb morphology when ectopically expressed. We are using recently developed Optical Projection Tomography (OPT) methods to produced 3-D images of limbs from wild-type and mutant pups. We are using these 3-D imaging methods to study the effect of ectopic Pitx1 on limb morphogenesis and to produce models of normal limb morphology.
Which session is your work most relevant to: Limb initiation