Fig. 4. egl, mio double mutants arrest prior to pachytene. mio is required at an early stage of meiosis. (A-C) Germaria double labeled with C(3)G (red) and Orb (green). Magnified C(3)G staining is shown in upper right panel. (A) mio mutant: two pro-oocytes have thick thread-like C(3)G pattern, indicating that, like wild type, the mio pro-oocytes progress to pachytene. (B) egl null mutant (egl¹): all 16 cells form the less extended SC that is representative of late zygotene or early pachytene. (C) mio², egl¹ double mutants: all 16 cells show the dot pattern of C(3)G that is normally observed in early zygotene.