Fig. 12. Quantification of calpain B, M and T mRNAs in tissues from intermolt land crabs using real-time PCR. Transcript levels, expressed as log copy number, were determined in nine tissues. Elongation factor 2 (EF2) mRNA (GenBank accession #AY552550) served as an internal standard to normalize the PCR reactions. P-values between means for each calpain within each tissue are given at the top of each graph (see Table 3 for primers and Materials and methods for statistical analysis). There were three general patterns of expression. In skeletal muscle (A,B), CalpM and CalpB were expressed at similar levels, which were at least an order of magnitude higher than CalpT expression. In heart, gill, thoracic ganglion, digestive gland and testis (C–G), CalpB was expressed at higher levels than CalpM and CalpT. In ovary and integument (H,I), CalpM was expressed at higher levels than CalpB, which was expressed at higher levels than CalpT.