The polarity factor Bucky ball associates with the centrosome and promotes microtubule rearrangements to establish the oocyte axis in zebrafish

Expression of Concern: The polarity factor Bucky ball associates with the centrosome and promotes microtubule rearrangements to establish the oocyte axis in zebrafish by Forbes et al. This Expression of Concern relates to the Advance Article 'The polarity factor Bucky ball associates with the centrosome and promotes microtubule rearrangements to establish the oocyte axis in zebrafish' (The corresponding author of this article, currently posted online as an Advance Article, contacted us regarding potential issues with some of the data contained in this manuscript. The authors are currently investigating the matter, in consultation with their Research Integrity Office. Development is publishing this Expression of Concern to alert readers to the situation while the investigation takes place, and it is not a statement as to the validity of the data. The article will remain posted on the Advance Articles page until the matter is resolved. This course of action follows the advice set out by COPE (Committee on Publication Ethics), of which Development is a member. Title: The polarity factor Bucky ball associates with the centrosome and promotes microtubule rearrangements to establish the oocyte axis in zebrafish. Summary Cell polarity is a conserved feature of eukaryotic cells that relies on establishment and maintenance of intracellular asymmetries. Primary oocytes of all animals examined contain an evolutionarily conserved structure known as the Balbiani body (Bb), one of the earliest known asymmetries in oocytes. Despite its conserved nature little is understood about the molecular and cellular events that polarize vertebrate oocytes. The vertebrate specific bucky ball (buc) is the only gene known to be required for Bb assembly. We have previously shown that Buc protein is an indicator of polarity at zygotene stage, before Bb formation. To determine when oocyte polarity is established we examined Buc and the cytoskeleton at earlier stages of meiosis and in mitotic oogonia, also known as cystocytes. Buc is present in midstage cystocytes and prior to zygotene stage Buc is recruited to the centrosome, independent of meiotic progression. Dynamic microtubules are enriched around the centrosome in pre-Bb oocytes, revealing that these cells are polarized. This early microtubule enrichment is normal when buc is disrupted, but at later stages functional Buc or Bb-associated activity is required for robust MT organization. Consistent with a role for Buc in generating these cytoskeletal asymmetries, we detected asymmetric perinuclear EB3 foci, which are indicative of polarized microtubules that form proximal to the centrosome in a …