RT-PCR analysis
Total RNA was isolated from each tissue using Trizol. A 1 μg of total RNA was reverse transcribed using SuperscriptII (Invitrogen). RT-PCR primers, which span introns, for detection of mr-s cDNA were 5'-TGTCCAGCCCAGCCAACCCAAGGAGACGACA-3' and 5'-TGTGGTCTCCTCATCAGTGAAGA-3'. Product size was 292 bp (positions 965–1256 of Genbank Accession Number #AY458844). Primer pairs for mouse G3PDH were 5'-ACCACAGTCCATGCCATCAC-3' and 5'-TCCACCACCCTGTTGCTGTA- 3' which amplified a 452-bp product (positions 587–1038 of Genbank Accession Number #BC85275).