Fig. 2

Seasonal changes in osteoclast activity in female goldfish scales. (A) Representative samples of goldfish scale expressing tartrate-resistant acid phosphatase (TRAP) (left panel) and the TRAP negative scale (right panel); white arrows indicate TRAP-stain-positive area. (B) Ratios of TRAP-positive scales in female goldfish (left graph) and the ratios of TRAP-negative scales in female goldfish (right panel) from January 2009 to August 2009 (each month n = 4-6; 200 scales were analyzed for each individual). Different letters indicate significant differences (P < 0.05). (C) Expression levels of genes involved in osteoclast activation were examined in female goldfish scales from December 2008 to August 2009 [for cathepsin K (cathK) and receptor activator of nuclear factor κβ ligand (rankl)] or June 2009 [for vacuolar- ATPase subunit d2 (V-ATPase)] (each month n = 8 for each gene examined). Different letters indicate significant differences (P < 0.05). Average expression levels in December (Dec) were set to 1. Abbreviations: Dec, December; Jan, January; Feb, February; Mar, March; Apr, April; Jun, June; Aug, August.