Oocyte polarity requires a Bucky ball-dependent feedback amplification loop

• DOI: 10.1242/dev.090449
• Publication Date: 2014-02-04T12:25:39Z
• Authors: Amanda E. Heim; Odelya Hartung; Sophie Rothhämel; Elodie Ferreira; Andreas Jenny; Florence L. Marlow
• Keywords: Cell polarity; Polarity in embryogenesis

In vertebrates, the first asymmetries are established along animal-vegetal axis during oogenesis, but underlying molecular mechanisms poorly understood. Bucky ball (Buc) was identified in zebrafish as a novel vertebrate-specific regulator of oocyte polarity, acting through unknown interactions. Here we show that endogenous Buc protein localizes to Balbiani body, conserved, asymmetric structure oocytes requires for its formation. Asymmetric distribution precedes body formation, defining earliest marker polarity zebrafish. Through transgenic strategy, determined excess disrupts and results supernumerary bodies 3'UTR-dependent manner, roles buc introns regulating activity. Analyses mosaic ovaries indicate pattern determines number animal pole-specific micropylar cells associated with an egg via close-range signal or direct cell contact. We demonstrate interactions between mRNA two conserved RNA-binding proteins (RNAbps) localized body: RNA binding multiple splice isoforms 2 (Rbpms2) Deleted azoospermia-like (Dazl). interact Rbpms2; dazl mRNAs Dazl protein. Cumulatively, these studies polarization depends on tight regulation buc: establishes RNAbps, initiating feedback amplification mechanism which recruits RNAbps turn recruit other RNAs body.