Fig. 2. Characterization of Tln1HSA-CREko mice. (A-E) Cross-sections of wild-type and Tln1HSA-CREko mutant muscle were stained with antibodies to talin 1 at P8 (A,B) and 6 months (C,D). Talin 1 expression was detected at the sarcolemma in wild-type (A,C) but not mutant mice (B,D). In the mutants, talin 1 expression remained in cells between skeletal muscle fibers (B,D, arrowheads) that were identified as blood vessels by staining with antibodies to VE-cadherin (E). (F) Western blots with extracts from P2 and P8 gastrocnemius and soleus muscle, respectively. Expression of talin 1 was markedly reduced in Tln1HSA-CREko mice. Residual protein levels were likely to be due to talin 1 expression in endothelial cells. Talin 2 expression was detected in muscle extracts, but no compensatory upregulation was evident. Membranes were probed for tubulin (-tub) as a loading control. (G) Analysis of Tln1 and Tln2 transcript levels in gastrocnemius muscle by quantitative real-time PCR. Data are plotted relative to Tln1 mRNA levels (n=3; mean ±s.e.; ^*P=0.004 at P5; P=0.002 at 6 months). (H) Growth curve of wild-type and Tln1HSA-CREko mice up to 60 weeks of age revealed no differences between the two genotypes. Scale bars: 25 µm in A-D; 50 µm in E.