150
added near the base of the advancing furrow. The new plasma membrane therefore
has a composition different from that of the original egg surface (Kalt 1971a, b;
Sanders and Singal 1975 ; Byers and Armstrong 1986 ; Aimar 1997 ). The main
source of the new basolateral membrane appears to be a pool of post-Golgi vesicles
produced during oogenesis which contributes membrane lipids, glycoproteins, and
extracellular matrix components to the growing surface (Kalt 1971a, b; Servetnick
et al. 1990 ). Roberts et al. ( 1992 ) provided direct evidence that Golgi-derived vesi-
cles generated during late oogenesis can fuse specifically with the new membrane.
4.4.2.2 Microtubule-Dependent Exocytosis of Basolateral Membrane
in the Cleavage Plane
The massive localized delivery of new basolateral membrane to the advancing
cleavage furrow is known to be microtubule dependent in both Xenopus and zebraf-
ish. A distinctive array of antiparallel microtubule bundles, referred to as a furrow
microtubule array, develops along the base of advancing furrows in both Xenopus
(Danilchik et al. 1998 ) and zebrafish (Jesuthasan 1998 ; Fig. 4.10). Their appearance
and general geometry distinguish furrow microtubule arrays from other
Fig. 4.10 FMA reorganization in Xenopus and zebrafish. (a–c) FMA in Xenopus: overview (a)
and magnified views at the base of the furrow (b) and in more vegetal regions of the advancing
furrow (c). (d–f) FMA in zebrafish furrows: early furrow shows a parallel arrangement of FMA
tubules, oriented perpendicular to the plane of the furrow (d), maturing furrow shows distally
accumulating FMA tubules in a tilted, V-shaped arrangement (e), and complete furrows show
FMA disassembly (f). Scale bar in (d) corresponds to 10 μm for panels (d–f). Panels (d)–(f) cour-
tesy of Celeste Eno
A. Hasley et al.