FIGURE 1.

Haploid-specific expression of CALR3 and chaperone activity. A, CALR3 was detected only in the testis when various tissues were examined by Western blot analysis. B, testis lysates collected from mice of different ages were examined by Western blotting. CALR3 appeared as a faint signal at 3 weeks (wks) of age, whereas CLGN was detected at 2 weeks of age. It should be noted that ADAM1 is composed of two independent proteins, ADAM1A and ADAM1B (43). C, immunofluorescence staining of a testicular section with anti-CLGN (shown in red) and anti-CALR3 (shown in green) antibodies. Sequential sections were stained with hematoxylin and eosin (upper left panel). CALR3 was detected in elongating spermatids, whereas CLGN was detected in pachytene spermatocytes to elongating spermatids. D, co-localization of CLGN and CALR3 was observed in elongating spermatids. Green, CALR3; red, CLGN; blue, Hoechst 33258. Scale bars = 200 μm (C) and 4 μm (D).