RRC ID 33169
著者 Kaneuchi T, Sartain CV, Takeo S, Horner VL, Buehner NA, Aigaki T, Wolfner MF.
タイトル Calcium waves occur as Drosophila oocytes activate.
ジャーナル Proc Natl Acad Sci U S A
Abstract Egg activation is the process by which a mature oocyte becomes capable of supporting embryo development. In vertebrates and echinoderms, activation is induced by fertilization. Molecules introduced into the egg by the sperm trigger progressive release of intracellular calcium stores in the oocyte. Calcium wave(s) spread through the oocyte and induce completion of meiosis, new macromolecular synthesis, and modification of the vitelline envelope to prevent polyspermy. However, arthropod eggs activate without fertilization: in the insects examined, eggs activate as they move through the female's reproductive tract. Here, we show that a calcium wave is, nevertheless, characteristic of egg activation in Drosophila. This calcium rise requires influx of calcium from the external environment and is induced as the egg is ovulated. Pressure on the oocyte (or swelling by the oocyte) can induce a calcium rise through the action of mechanosensitive ion channels. Visualization of calcium fluxes in activating eggs in oviducts shows a wave of increased calcium initiating at one or both oocyte poles and spreading across the oocyte. In vitro, waves also spread inward from oocyte pole(s). Wave propagation requires the IP3 system. Thus, although a fertilizing sperm is not necessary for egg activation in Drosophila, the characteristic of increased cytosolic calcium levels spreading through the egg is conserved. Because many downstream signaling effectors are conserved in Drosophila, this system offers the unique perspective of egg activation events due solely to maternal components.
巻・号 112(3)
ページ 791-6
公開日 2015-1-20
DOI 10.1073/pnas.1420589112
PII 1420589112
PMID 25564670
PMC PMC4311822
MeSH Animals Calcium / metabolism* Drosophila / cytology Drosophila / metabolism* Inositol 1,4,5-Trisphosphate / metabolism Ion Transport Oocytes / metabolism*
IF 9.412
引用数 47
WOS 分野 DEVELOPMENTAL BIOLOGY
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