کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2175829 | 1093854 | 2006 | 8 صفحه PDF | دانلود رایگان |
Fertilization in mammalian eggs is accompanied by oscillatory changes in intracellular Ca2+ concentration, which are critical for initiating and completing egg activation events and the developmental program. Ca2+/Camodulin-dependent protein kinase II (CaMKII) is a multifunctional enzyme that is postulated to be the downstream transducer of the Ca2+ signal in many cell types. We tested the hypothesis that CaMKII is the major integrator of Ca2+-induced egg activation events and embryo development by microinjecting a cRNA that encodes a constitutively active (Ca2+-independent) mutant form of CaMKII (CA-CaMKII) into mouse eggs. Expression of this cRNA, which does not increase intracellular Ca2+, induced a sustained rise in CaMKII activity and triggered egg activation events, including cell cycle resumption, and degradation and recruitment of maternal mRNAs; cortical granule exocytosis, however, did not occur normally. Furthermore, when mouse eggs were injected with sperm devoid of Ca2+-releasing activity and activated with either CA-CaMKII cRNA or by SrCl2, similar rates and incidence of development to the blastocyst stage were observed. These results strongly suggest that CaMKII is a major integrator of the Ca2+ changes that occur following fertilization.
Journal: Developmental Biology - Volume 296, Issue 2, 15 August 2006, Pages 388–395