Formation of the first cleavage furrow in the telolecithal egg of Loligo was studied with the electron microscope. Before the actual furrow forms, a dense filamentous band develops below the plasma membrane from membrane-bounded dense bodies which appear to be Golgi-derived. The egg surface is thrown into a number of longitudinal folds which parallel the furrow and eventually become incorporate...

In fertilized eggs of Xenopus laevis a marked flattening of the pigmented animal hemisphere has been observed. The flattening begins 15-20 minutes before the appearance of the cleavage furrow. As the furrow develops, the pigmented surface relaxes and rounds up. The initial appearance of the furrow is thus shown to be a combination of furrow deepening and rounding up of adjacent pigmented surfac...

A large increase in surface area must accompany formation of the amphibian embryo first cleavage furrow. The additional membrane for this areal expansion has been thought to be provided entirely from cytoplasmic stores during furrowing. We have radioiodinated surface proteins of fertilized, precleavage Xenopus laevis embryos and followed their redistribution during first cleavage by autoradiogr...

Two to 10 /ig/ml cytochalasin B (CB) caused retraction of the first cleavage furrow in Triturus eggs, a spreading of the unpigmented surface from the furrow region and a flattening of the whole egg. CB appears to act against the contractility of the microfilamentous band at mid-cleavage so as to relax the furrow and also to weaken unpigmented surface to allow the egg to flatten. Uncleaved eggs ...

To complete the cell cycle, the cleavage furrow draws the plasma membrane toward the cell center, pinching the cytoplasm into two lobes that are subsequently separated into two cells. The position of the cleavage furrow is induced by the mitotic spindle during early anaphase. Although the mechanism of cleavage furrow positioning is not understood at a molecular level, recent results suggest tha...

UNLABELLED Ventral furrow formation in Drosophila is an outstanding model system to study the mechanisms involved in large-scale tissue rearrangements. Ventral cells accumulate myosin at their apical sides and, while being tightly coupled to each other via apical adherens junctions, execute actomyosin contractions that lead to reduction of their apical cell surface. Thereby, a band of constrict...

A ®eld experiment was conducted during the dry season of 1993/1994 at the Irrigation Research Farm, Institute for Agricultural Research, Samaru, Nigeria to evaluate water management options on the performance of tomato. The trial involved three furrow irrigation methods (conventional furrow, conventional furrow with cutback, and alternate furrow), two mulch treatments (without mulch and straw m...

Two of 10 mug/ml cytochalasin B (CB) caused retraction of the first cleavage furrow in Triturus eggs, a spreading of the unpigmented surface from the furrow region and a flattening of the whole egg. CB appears to act against the contractility of the microfilamentous band at mid-cleavage so as to relax the furrow and also to weaken unpigmented surface to allow the egg to flatten. Uncleaved eggs ...

A field study was initiated to evaluate a 3and 5-day furrow-irrigation schedule in a rice-production system. Averaged across furrow-irrigation schedules, ‘XL723’ height was greater than ‘Cybonnet’ in July and August of the growing season; however, panicle number was greater for Cybonnet than XL723. Yield components (spikelets, total kernels, and total filled kernels/panicle) and rough-rice yiel...

Phosphoinositides play important roles in regulating the cytoskeleton and vesicle trafficking, potentially important processes at the cleavage furrow. However, it remains unclear which, if any, of the phosphoinositides play a role during cytokinesis. A systematic analysis to determine if any of the phosphoinositides might be present or of functional importance at the cleavage furrow has not bee...