The eggs of insects are unusual in that they often have bilateral symmetry when they are laid, indicating that both anterior-posterior (AP) and dorsal-ventral (DV) symmetries are broken during oogenesis. The molecular basis of this process is well understood in Drosophila melanogaster, in which symmetry breaking events for both axes depend on the asymmetric position of the oocyte nucleus and on...

The Drosophila oocyte develops within a cyst of 16 germline cells interconnected by ring canals. Polarized, microtubule-based transport of unknown determinants is required for oocyte formation, but whether polarity is established during or after cyst formation is not clear. We have analyzed how polarity develops in stem cells and dividing cysts by following the growth of the fusome, a vesiculat...

The Drosophila melanogaster body axes are defined by the precise localization and the restriction of molecular determinants in the oocyte. Polarization of the oocyte during oogenesis is vital for this process. The directed traffic of membranes and proteins is a crucial component of polarity establishment in various cell types and organisms. Here, we investigate the role of the small GTPase Rab6...

It has long been appreciated that the oocyte cortex plays a key role in regulating fertilization and establishing embryonic polarity. Recent studies have identified the anti-phosphatase EGG-3 as a cortical anchor for regulatory proteins required for launching embryogenesis in Caenhorhabditis elegans.

Obesity was shown to cause reproductive dysfunctions such as reduced conception, infertility and early pregnancy loss. However, the possible effects of obesity on oocyte quality are still not fully understood. In this study we investigated the effects of both diet and gene mutation induced obesity on impairments in mouse oocyte polarization, oxidative stress, and epigenetic modifications. Our r...

Mammalian oocyte meiotic maturation involves oocyte polarization and a unique asymmetric division, but until now, the underlying mechanisms have been poorly understood. Arp2/3 complex has been shown to regulate actin nucleation and is widely involved in a diverse range of processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Whether Arp2/3 complex participates ...

The anterior-posterior axis of Drosophila originates from two symmetry-breaking steps during early oogenesis. First, one of the two pro-oocytes within the cyst of 16 germline cells is selected to become the oocyte. This cell then comes to lie posterior to the other germline cells of the cyst, thereby defining the polarity of the axis. Here we show that the oocyte reaches the posterior of the cy...

The Drosophila oocyte, although often thought of as an undifferentiated cell, is in fact highly polarized, and the subcellular organization of the oocyte is critical for subsequent development of the embryo. Recent results show that cell-cell signaling between the germline and the somatic components of the egg chamber establish the dorsal-ventral and anterior-posterior axes of the egg and conse...

A novel protein required for RNA interference in Drosophila, Armitage, was identified in a screen for genes involved in embryonic axis formation. In armitage mutants, oocyte polarity and the regulation of oskar mRNA translation are impaired, suggesting that RNA silencing regulates the first steps of Drosophila development.