Establishment of anterior-posterior and dorsal-ventral polarity within the Drosophila egg chamber requires signaling between the germline and the somatic cells of the ovary. The gene gurken (grk) encodes a TGFalpha-like protein that is localized within the developing oocyte and is thought to locally activate torpedo/Egfr (top/Egfr), the Drosophila homolog of the EGF receptor, which is expressed...

The mature mammalian oocyte is highly polarized because asymmetrical spindle migration to the oocyte cortex ensures extrusion of small polar bodies in the two meiotic divisions, essential for generation of the large egg. Actin filaments, myosin motors, and formin-2, but not microtubules, are required for spindle migration. Here, we show that Cdc42, a key regulator of cytoskeleton and cell polar...

The Drosophila oocyte develops within a polarized cyst of 16 interconnected germ cells (reviewed in King, 1970; Spradling, 1993). Cysts form by a process of incomplete cell division in region 1 of the germarium, a tripartite structure at the anterior of each ovariole (reviewed in de Cuevas et al., 1997; see Fig. 1A-C). Although they appear equivalent initially, one of the 16 cells (cystocytes) ...

PAR-1 kinases are required for polarity in diverse cell types, such as epithelial cells, where they localize laterally. PAR-1 activity is believed to be transduced by binding of 14-3-3 proteins to its phosphorylated substrates, but the relevant targets are unknown. We show that PAR-1 phosphorylates Bazooka/PAR-3 on two conserved serines to generate 14-3-3 binding sites. This inhibits formation ...

in this study the effect of input parameters of the edm process (pulse on-time, duty cycle and tool polarity), on the material removal rate (mrr), tool wear ratio (twr) and maximum surface roughness (rmax) in the machining aisi h13 tool steel has been studied. this study shows that increasing the duty cycle in the two conditions of tool polarity, material removal rate and the maximum surface ro...