maelstrom is required for an early step in the establishment of Drosophila oocyte polarity: posterior localization of grk mRNA

Abstract

We describe a mutant, maelstrom, that disrupts a previously unobserved step in mRNA localization within the early oocyte, distinct from nurse-cell-to-oocyte RNA transport. Mutations in maelstrom disturb the localization of mRNAs for Gurken (a ligand for the Drosophila Egf receptor), Oskar and Bicoid at the posterior of the developing (stage 3–6) oocyte. maelstrom mutants display phenotypes detected in gurken loss-of-function mutants: posterior follicle cells with anterior cell fates, bicoid mRNA localization at both poles of the stage 8 oocyte and ventralization of the eggshell. These data are consistent with the suggestion that early posterior localization of gurken mRNA is essential for activation of the Egf receptor pathway in posterior follicle cells. Posterior localization of mRNA in stage 3–6 oocytes could therefore be one of the earliest known steps in the establishment of oocyte polarity. The maelstrom gene encodes a novel protein that has a punctate distribution in the cytoplasm of the nurse cells and the oocyte until the protein disappears in stage 7 of oogenesis.

Proteome Analysis Unravels Mechanism Underling the Embryogenesis of the Honeybee Drone and Its Divergence with the Worker (Apis mellifera lingustica)

“…Moreover, except for the role in the cytoskeleton organization, proteins in the cytoskeleton class also participate in the rudimentary establishment and tissue specification in Drosophila. For example, actin-interacting protein is involved in the differentiation of imaginal disc-derived wing hair, 74 protein maelstrom homologue takes part in the specification of oocyte anterior/posterior, 75 and Spec is related to the development of central nervous system and oocyte construction, 76 which is underscored by the strong expression of Mael and Spec at their genetic level (Figure 7, Figure S5).…”

An in vivo RNAi assay identifies major genetic and cellular requirements for primary piRNA biogenesis in Drosophila

“…First, studies on transposon biology have uncovered important concepts of the host control system and have also identified a number of essential genetic loci involved (Prud'homme et al , 1995; Aravin et al , 2001; Jensen et al , 2002; Desset et al , 2003; Ronsseray et al , 2003; Sarot et al , 2004; Pelisson et al , 2007). Second, sterility and egg patterning screens have uncovered more than a dozen factors that turned out to be piRNA pathway members (Schupbach and Wieschaus, 1991; Clegg et al , 1997; Lin and Spradling, 1997; Cook et al , 2004; Chen et al , 2007; Pane et al , 2007). And finally, research centred on small RNA pathways and bioinformatics analysis of piRNA populations has allowed combining the diverse genetic findings into a coherent model of transposon control in Drosophila (Aravin et al , 2003; Vagin et al , 2006; Brennecke et al , 2007; Gunawardane et al , 2007).…”

MAEL facilitates metabolic reprogramming and breast cancer progression by promoting the degradation of citrate synthase and fumarate hydratase via chaperone‐mediated autophagy

“…The Maelstrom (MAEL) gene was originally cloned in Drosophila in 1997, which is necessary for the establishment of oocyte polarity [13]. In male mice, MAEL plays main roles in meiosis and spermatogenesis [14,15].…”