Journal: Human molecular genetics
Article Title: Transgenic mice expressing the myotilin T57I mutation unite the pathology associated with LGMD1A and MFM.
doi: 10.1093/hmg/ddl160
Figure Lengend Snippet: Figure 1. Transgene design and expression. (A) The human myotilin cDNA was cloned downstream of the skeletal muscle-specific HSA promoter and the VP1 splice donor and acceptor sites. The human myotilin cDNA includes the full-length coding region (gray box) and 50- and 30-UTRs (white boxes). A c-myc epitope tag (red line) was appended to the myotilin N-terminus. Both wild-type (TgWT) and T57I point mutant (TgT57I) myotilin transgenic mice were generated. (B) The transgene was genotyped by PCR using a forward HSA primer and a reverse myotilin 50-UTR primer. þ/Tg, transgene-positive heterozygote; þ/þ, control littermate. (C) Reverse transcription–PCR of total RNA from brain (B), heart (H), kidney (K), liver (L), spinal cord (SC) and skeletal muscle (SM) shows that the TgT57I transcript is observed only in skeletal muscle. (D) Western blot survey of several soluble fractions of muscle lysates from 3-month-old TgT57I mice. The myotilin C-term peptide antibody reacts to both murine and transgenic human myotilin peptides; the c-myc antibody is specific to the trans- gene products. Ab, abdomenal wall muscle; Bi, biceps; Di, diaphragm; Ed, extensor digitorum longus; Ga, gastrocnemius; Qu, quadriceps; So, soleus; Ti, tibialis. (E) Soluble fractions of quadriceps lysates from 3-month-old transgenic mice were analyzed by western blot to show relative expression levels. The c-myc anti- body shows that the TgWT product is expressed at 2.3-fold higher levels than the TgT57I product. The myotilin antibody shows that the TgWT levels are 7.7-fold higher than endogenous myotilin levels. TgT57I levels are 2.6-fold higher than endogenous levels, as determined by optical scanning densitometry on diluted samples. (F and G) A Cy3-conjugated c-myc antibody was used to specifically immunolocalize transgene products in soleus muscle cross-sections. TgWT (F) staining is stronger than TgT57I (G) staining. (H and I) Double-labeling of TgT57I quadriceps muscle transverse sections with a slow isoform-specific myosin antibody (H) and the c-myc antibody (I) shows that the transgene is expressed in both slow type I and fast type II fibers.
Article Snippet: Generation and characterization of myotilin transgenic mice The wild-type myotilin cDNA was isolated from a pTriplEx human skeletal muscle cDNA library (BD Clontech) and cloned into a modified pBluescript vector (Stratagene) containing an enhanced HSA promoter cassette and two SV40 polyadenylation signals.
Techniques: Expressing, Clone Assay, Mutagenesis, Transgenic Assay, Generated, Control, Reverse Transcription, Western Blot, Staining, Labeling
