Fig. 1
From: The Role of a Single Formin Isoform in the Limb and Renal Phenotypes of Limb Deformity
Disruption of isoform IV of the ld gene
(A) Murine ld locus. The alternative splicing of isoforms I–IV are shown (after Jackson-Grusby et al. 1992). Not all 24 exons are shown, only those important for distinguishing the four isoforms. (B) Targeting strategy. Top: genomic organization of the wild-type ld gene (129 strain) around the 5′ -terminal exon (black box) of isoform IV. Middle: replacement-type targeting construct for isoform IV. A FGK-neo gene (arrow, indicating direction of transcription) was inserted into this exon at a unique BamHI site of isoform IV, in the opposite orientation relative to transcription, and introduced stop codons in all three reading frames of isoform IV. Bottom: structure of the mutant locus (ldGKO allele) after homologous recombination with the targeting construct. The location of the flanking (probe 1) and internal (probe 2) probes used for Southern analysis are indicated by bars under the wild type allele. Restriction enzyme sites: B, BamHI; Bg, BgIII; H, HindIII; N, NotI; R, EcoRI; X, XbaI; Xh, XhoI.