The source of symmetry breaking in vertebrate oocytes is unknown. Animal-vegetal oocyte polarity is established by the Balbiani body (Bb), a conserved structure found in all animals examined that contains an aggregate of specific mRNAs, proteins, and organelles. The Bb specifies the oocyte vegetal pole, which is key to forming the embryonic body axes as well as the germline in most vertebrates....

Ovarian follicle development, which accompanies morphogenesis of the silkworm egg has three distinct phases: spheric, ellipsoidal and flattened-ellipsoid. Transitions between phases are rapid and form-stability (characterized by length/width ratio) is preserved from the beginning of the ellipsoidal phase. The geometric stability of the follicle-oocyte-ovariole system, the polarity of the egg an...

Cell migration is fundamental in both animal morphogenesis and disease. The migration of individual cells is relatively well-studied; however, in vivo, cells often remain joined by cell-cell junctions and migrate in cohesive groups. How such groups of cells coordinate their migration is poorly understood. The planar polarity pathway coordinates the polarity of non-migrating cells in epithelial ...

Group cell migration is a highly coordinated process that is involved in a number of physiological events such as morphogenesis, wound healing and tumor metastasis. Unlike single cells, collectively moving cells are physically attached to each other and retain some degree of apical-basal polarity during the migratory phase. Although much is known about direction sensing, how polarity is regulat...

Cell polarity in higher animals is controlled by evolutionarily conserved protein complexes, which localize to the cytocortex in a polarized manner. The PAR-3/PAR-6/atypical protein kinase C (aPKC) complex is the first to become asymmetrically localized, and it controls the localization of additional complexes functioning further downstream in the regulation of cell polarity. The first componen...

The follicle cell monolayer that encircles each developing Drosophila oocyte contributes actively to egg development and patterning, and also represents a model stem cell-derived epithelium. We have identified mutations in the receptor-like transmembrane tyrosine phosphatase Lar that disorganize follicle formation, block egg chamber elongation and disrupt Oskar localization, which is an indicat...

The attachment of the cytoskeleton to the plasma membrane is crucial in controlling the polarized transport of cell-fate-determining molecules. Attachment involves adaptor molecules, which have the capacity to bind to both the plasma membrane and elements of the cytoskeleton, such as microtubules and actin filaments. Using the Drosophila oocyte as a model system, we show that the type I phospha...

In Drosophila the posterior positioning of the oocyte within the germline cluster defines the initial asymmetry during oogenesis. From this early event, specification of both body axes is controlled through reciprocal signaling between germline and soma. Here it is shown that the mutation hold up (hup) affects oocyte positioning in the egg chamber, follicle cell fate and localization of differe...