In the heart and muscle, transcripts containing exon Xa were expressed at slightly higher levels than transcripts lacking exon Xa.
However, in human fetal heart, the predominant transcripts employ a proximal AAUAAA, located 362 bp downstream of the stop codon (Fig. 2B).
In rabbit, the VLDLR transcript with the O-linked sugar region (type-1 VLDLR) is the major transcript in heart and muscle, whereas the transcript for VLDLR lacking the O-linked sugar region (type-2 VLDLR) is preferentially expressed in non-muscle tissues, including cerebrum, cerebellum, kidney, spleen, adrenal gland, testis, ovary and uterus [ 15].
In the muscle tissues, skeletal muscle, aorta and heart, the TRPC3 transcript dominated over all other members of the TRPC subfamily (Fig. 2A).
To examine the distribution of DNA methylation peaks in relation to the distance from their promoters, we calculated peak numbers at different distance ranges from transcription start sites and primary transcripts in hearts, livers, and spleens of the MRL/MpJ and C57BL/6J mouse (Fig. 6).
Indeed, mp single and mp arf7/nhp4 (nonphototropic hypocotyl4) double mutants show reduced or no expression of PLT1 and PLT2 transcripts from heart stage onward, which suggests that the activation of PLT transcription occurs downstream of the ARFs [ 11, 12].
Interestingly, the absolute abundance of MYH7 transcripts in heart was higher than MYH6 (Fig. 3A).
In human heart muscle several TRPC transcripts have been detected.
All differentially expressed transcripts in heart (DBI and SLC27A1) and testes (DBI and GOT2) were more abundant in humans.
Another interesting observation is that more than 30%% of the transcripts in heart and 28%% of the transcripts in skeletal muscle correspond to genes encoding mitochondrial proteins, which demonstrates the extreme specialization of both the heart and skeletal muscle to provide energy for the contraction.
