Fig. 3.

A longer Axin1 transcript isoform containing partial cL1 is exclusively expressed in the penetrant Axin^cL1 mice. a A representative Northern blot showing that the wild type transcript (~ 3.8 kb) was detected in Axin^cL1 mice, both penetrant and silent, as well as wild type mice, whereas a longer transcript (~ 5 kb) was present only in penetrant Axin^cL1 mice (middle panel). Red triangles indicate the relative positions of the probes used in the upper panel, and the total RNA inputs are shown in the lower panel. b RT-PCR detection of the longer transcript isoform unique to penetrant Axin^cL1 mice. A pair of primers encompassing exons 5 and 8 (arrows in the upper panel) was used for PCR detection of WT (925 bp) and cL1-containing (~ 2.1 kb) transcripts (lower panel). c qPCR quantification of the longer transcript isoform unique to penetrant Axin^cL1 and homozygous Axin1^cL1/cL1 mice. Data are presented as means ± SEM, n = 3. d Schematic illustration of the alternative splicing event leading to the production of a longer transcript isoform unique to penetrant Axin^cL1 mice (upper panel), as supported by the Sanger sequencing results (lower panel)