Figure 4.

The Formin genomic region 10.24 regulates expression of endogenous and exogenous transcription units inserted into the ld locus. (A) Formin transcript distribution in a wild-type embryo around gestational day 10.5 (hemisection). (B) LacZ recapitulates the Formin transcript distribution in the Fmn^Δ10 allele. (C) Limb bud mesenchymal LacZ is specifically lost in the Fmn^Δ10.24 allele. (D–F) Forelimb buds of the embryos shown in A–C. Black arrowheads indicate Fmn/LacZ distribution in the mesenchyme and open arrowhead indicates the loss of LacZ in the Fmn^Δ10.24 allele. (G–J) Limb bud mesenchyme-specific expression of the Hygro^R (G) and Neo^R (H–J) genes inserted into the ld locus. Genotypes are indicated as defined in the legend for Figure 2A.