SSC Niche and SSC In Zebrafish Figure 3. SSC niche in zebrafish testes. Whole-mount of vasa::egfp testes analyzed under fluorescence (A,B) and CLSM (C–E). A,B. Most of the brightest and small spots (type A undifferentiated spermatogonia) (arrowheads) are adjacent the triangle/lozenge dark areas (interstitium). Scale bars = 0.1 mm and 0.5 mm, respectively. C–E. Vasa is highly expressed in type A undifferentiated spermatogonia, and is gradually decreased during the spermatogenesis. Aund*/Aund (arrowheads), type B spermatogonia (SGB), primary spermatocytes (SCI), secondary spermatocytes (SCII), spermatids (ST), spermatids and spermatozoa (ST/SZ). Note that most of Aund*/Aund (arrowheads) are situated near the interstitium (D, dark areas; E, delimited by PLoS ONE | www.plosone.org 6 September 2010 | Volume 5 | Issue 9 | e12808