Fig. 6. ryr1b and ryr1a are expressed by fast and slow muscle, respectively. (A) Reverse transcriptase (RT)-PCR shows that both ryr1b and ryr1a are expressed at 1, 2 and 3 dpf, and in adults. RT-PCR with mRNA from deep muscles indicates that ryr1b but not ryr1a is expressed by adult fast muscles. (B-I) In situ hybridization with ryr1b (B-E) and ryr1a (F-I) probes. Wholemounts show that both genes are expressed by muscle at 24 (B,F) and 48 (D,H) hpf. Cross-sections show that ryr1b is expressed by deep, fast muscles (C,E), whereas ryr1a is expressed by superficial, slow muscles but not by fast muscles (G,I).