TY - JOUR
T1 - Maelstrom coordinates microtubule organization during Drosophila oogenesis through interaction with components of the MTOC
AU - Sato, Kaoru
AU - Nishida, Kazumichi M.
AU - Shibuya, Aoi
AU - Siomi, Mikiko C.
AU - Siomi, Haruhiko
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2011/11/15
Y1 - 2011/11/15
N2 - The establishment of body axes in multicellular organisms requires accurate control of microtubule polarization. Mutations in Drosophila PIWI-interacting RNA (piRNA) pathway genes often disrupt the axes of the oocyte. This results from the activation of the DNA damage checkpoint factor Checkpoint kinase 2 (Chk2) due to transposon derepression. A piRNA pathway gene, maelstrom (mael), is critical for the establishment of oocyte polarity in the developing egg chamber during Drosophila oogenesis. We show that Mael forms complexes with microtubuleorganizing center (MTOC) components, including Centrosomin, Mini spindles, and γTubulin. We also show that Mael colocalizes with aTubulin and γTubulin to centrosomes in dividing cyst cells and follicle cells. MTOC components mislocalize in mael mutant germarium and egg chambers, leading to centrosome migration defects. During oogenesis, the loss of mael affects oocyte determination and induces egg chamber fusion. Finally, we show that the axis specification defects in mael mutants are not suppressed by a mutation in mnk, which encodes a Chk2 homolog. These findings suggest a model in which Mael serves as a platform that nucleates other MTOC components to form a functional MTOC in early oocyte development, which is independent of Chk2 activation and DNA damage signaling.
AB - The establishment of body axes in multicellular organisms requires accurate control of microtubule polarization. Mutations in Drosophila PIWI-interacting RNA (piRNA) pathway genes often disrupt the axes of the oocyte. This results from the activation of the DNA damage checkpoint factor Checkpoint kinase 2 (Chk2) due to transposon derepression. A piRNA pathway gene, maelstrom (mael), is critical for the establishment of oocyte polarity in the developing egg chamber during Drosophila oogenesis. We show that Mael forms complexes with microtubuleorganizing center (MTOC) components, including Centrosomin, Mini spindles, and γTubulin. We also show that Mael colocalizes with aTubulin and γTubulin to centrosomes in dividing cyst cells and follicle cells. MTOC components mislocalize in mael mutant germarium and egg chambers, leading to centrosome migration defects. During oogenesis, the loss of mael affects oocyte determination and induces egg chamber fusion. Finally, we show that the axis specification defects in mael mutants are not suppressed by a mutation in mnk, which encodes a Chk2 homolog. These findings suggest a model in which Mael serves as a platform that nucleates other MTOC components to form a functional MTOC in early oocyte development, which is independent of Chk2 activation and DNA damage signaling.
KW - Axis specification
KW - Centrosome
KW - Drosophila oogenesis
KW - Maelstrom
KW - Microtubule
KW - Pirna
UR - http://www.scopus.com/inward/record.url?scp=81255188693&partnerID=8YFLogxK
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U2 - 10.1101/gad.174110.111
DO - 10.1101/gad.174110.111
M3 - Article
C2 - 22085963
AN - SCOPUS:81255188693
VL - 25
SP - 2361
EP - 2373
JO - Genes and Development
JF - Genes and Development
SN - 0890-9369
IS - 22
ER -