File:Mouse- Hand2 forelimb buds.jpg

Early deletion of Hand2 in mouse forelimb buds phenocopies the Shh loss-of-function skeletal phenotype.

(A) Whole mount in situ hybridization detects Hand2 transcripts in wild-type (Wt) and mouse embryos that lack the Hand2 gene in their forelimb bud mesenchyme (H2Δ/Δc) at E9.75 (28 somites). Hand2 transcripts are absent from forelimb buds of H2Δ/Δc mouse embryos.

(B) Skeletons of mouse forelimbs at E14.5, stained with alcian blue (cartilage) and alizarin red (bone). Prx1-Cre mediated inactivation of Hand2 (H2Δ/Δc) phenocopies the ShhΔ/Δ limb skeletal phenotype. Control: Prx1-Cretg/+.

(C) Shh and Ptc1 transcripts are absent from H2Δ/Δc limb buds at E10.25 (32 somites for Shh) and E10.0 (29 somites for Ptc1).

(D) Detection of apoptotic cells by LysoTracker Red (LysoT). Hand2 deficient limb buds are compared to control (Prx1-Cretg/+ and H2+/f) and ShhΔ/Δ limb buds at E10.0 (30 somites), E10.75 (37 somites), and E11.0. The white arrowhead points to the precocious initiation of cell death in H2Δ/Δc forelimb buds (compare white to open arrowheads; n = 2/4).

In all panels, limb buds are oriented with the anterior to the top and the posterior to the bottom.

Original File name: Journal.pgen.1000901.g001.png

Distinct roles of Hand2 in initiating polarity and posterior Shh expression during the onset of mouse limb bud development. Galli A, Robay D, Osterwalder M, Bao X, Bénazet JD, Tariq M, Paro R, Mackem S, Zeller R. PLoS Genet. 2010 Apr 8;6(4):e1000901. PMID: 20386744

Citation: Galli A, Robay D, Osterwalder M, Bao X, Bénazet J-D, et al. (2010) Distinct Roles of Hand2 in Initiating Polarity and Posterior Shh Expression during the Onset of Mouse Limb Bud Development. PLoS Genet 6(4): e1000901. doi:10.1371/journal.pgen.1000901

Editor: Clifford J. Tabin, Harvard Medical School, United States of America

Received: September 11, 2009; Accepted: March 9, 2010; Published: April 8, 2010

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