Genomic structure of the 5 ' end of the porcine ryanodine receptor 3 gene (RYR3)

Ryanodine receptor 3 is a calcium channel located in the membrane of the en doplasmic reticulum. We isolated eight overlapping PAC clones from the porc ine ryanodine receptor 3 gene (RYR3) and determined the DNA sequences of th e first and second exon together with 5.8 kb of 5' flanking region and 10.3 kb of intron sequences. By comparing the porcine genomic sequence to the h uman RYR3 cDNA sequence the porcine transcription start site could be mappe d to a GC-rich region. Physical mapping of the isolated PAC clones revealed that the complete porcine RYR3 gene spans more than 200 kb of genomic DNA.