FIGURE 1.

Global down-regulation of transcripts encoding costamere proteins in perinatal Mef2A-deficient hearts. A, qRT-PCR analysis of 55 costamere transcripts in perinatal day 5 wild type and Mef2A knock-out hearts. cDNA generated from total RNA was pooled from five mice of each genotype and subjected to qRT-PCR. Twelve costamere transcripts were significantly reduced by 30% or more in Mef2A knock-out hearts: ANK2 (ankyrin 2), DMD (dystrophin), DYSB (dysbindin), FHL2 (four-and-a-half LIM domain 2), LAMB2 (laminin β2), OBSCN (obscurin), PDLIM1 (PDZ LIM domain 1), PDLIM5 (PDZ LIM domain 5), SGCA (sarcoglycan α), SGCB (sarcoglycan β), SGCG (sarcoglycan γ), and TCAP (titin-cap/telethonin). GAPDH was used as an internal control. B, costamere transcript analysis of cDNA from adult Mef2D knock-out hearts (n = 3) shows that only two of the twelve costamere target genes are significantly down-regulated. *, p ≤ 0.05; #, p ≤ 0.008 versus wild type mice.