Many of the spermatocytes in cyst cell-sSpi/EGFR-testes were single (Figure 3D, arrow), or in clusters of only two (Figure 3D′, arrow), four (Figure 3D′′, arrows), or eight cells instead of the normal 16, 32, or 64-cell clusters and expressed spermatocyte-specific molecular markers, such as a spermatocyte arrest-Green Fluorescent Protein (sa-GFP, compare Figures 3F–F′′ to Figure 3E, arrows point to GFP in the germline nucleoli) [59]. Here, EGFR is linked to cyst.