Fig. 3. Immunohistochemical analysis of Fxr1p expression in adult zebrafish tissues. Cryostat sections from adult zebrafish were immunoincubated using Affi5 antibodies. Significant Fxr1p expression was present in the brain (A), the testis (B) and in skeletal muscle tissue (C). Note the nuclear labelling in Purkinje cells of the cerebellum (A). All immature spermatogenic cells of the testis showed Fxr1p expression (B). A transversal section of skeletal muscle shows that Fxr1p expression is mainly present at the sarcolemma and at the myoseptum (C). A higher magnification of the myoseptum is shown in (D). P, Purkinje cells; I, immature spermatogenic cells; S, sarcolemma; M, myoseptum. Scale bars, 3.5 µm (A); 30 µm (B); 80 µm (C); 320 µm (D).