PT  - JOURNAL ARTICLE
AU  - Riparbelli, Maria Giovanna
AU  - Callaini, Giuliano
TI  - The meiotic spindle of the <em>Drosophila</em> oocyte: the role of Centrosomin and the central aster
AID  - 10.1242/jcs.02413
DP  - 2005 Jul 01
TA  - Journal of Cell Science
PG  - 2827--2836
VI  - 118
IP  - 13
4099  - http://jcs.biologists.org/content/118/13/2827.short
4100  - http://jcs.biologists.org/content/118/13/2827.full
SO  - J. Cell Sci.2005 Jul 01; 118
AB  - We provide here the first evidence that a distinct midzone is present in the Drosophila melanogaster female meiosis I spindle. This region has the ability to bind the Pavarotti kinesin-like (PAV-KLP) and Abnormal spindle (Asp) proteins, indicating a correct organization of the central spindle microtubules. We also identified the core component centrosomal protein centrosomin (CNN) at an unexpected site within the anaphase I spindle, indicating a role for CNN during the biogenesis of the female meiotic apparatus. However, there are no apparent defects in the midzone organization of cnn oocytes, whereas defects occur later when the central aster forms. The primary mutant phenotype of cnn oocytes is the failure to form a developed central microtubule organizing center (MTOC), although twin meiosis II spindles usually do form. Thus the central MTOC may not be essential for the formation of the inner poles of twin meiosis II spindles, as generally proposed, but it might be involved in maintaining their proper spacing. We discuss the proposal that, in the presence of a central MTOC, a chromatin-driven mechanism of spindle assembly like that described during meiosis I may control the morphogenesis of the twin meiosis II spindles.