کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2131069 1086620 2010 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Two-stage dependence for 1-methyladenine induced reinitiation of meiotic maturation in starfish oocytes
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی تحقیقات سرطان
پیش نمایش صفحه اول مقاله
Two-stage dependence for 1-methyladenine induced reinitiation of meiotic maturation in starfish oocytes
چکیده انگلیسی

The maturation hormone 1-methyladenine (1-MA) causes meiotic resumption of prophase arrested immature starfish oocytes. Continuous exposure to ≥ 0.5 µM 1-MA causes germinal vesicle breakdown (GVBD) in ∼ 20 min, but oocytes pretreated for > 30 min with a subthreshold dose of 1-MA undergo GVBD much faster (∼ 10 min) when they are exposed to 1 µM 1-MA. Furthermore, a very low subthreshold 1-MA suffices to start the maturation process: oocytes exposed to 0.005 µM 1-MA for up to 10 min followed by 1 µM 1-MA is equivalent to continuous exposure to 1 µM 1-MA. These dose and timing relationships indicate that there is a two-stage dependence on 1-MA. A possible explanation for this dependence is that there are two processes involved: an initial process that is triggered by a low dose of 1-MA, and a second process that cannot start until the first process is completed and is stimulated by a higher dose of 1-MA. These subthreshold 1-MA effects on GVBD timing are not directly coupled to changes in calcium physiology that also occur during maturation. Subthreshold 1-MA was found to cause a transient accumulation of Cdc2/cyclin B into the nucleus. The two-stage dependence indicates that there are unsuspected features in this well-studied pathway leading to GVBD. In the animal, this hormone dependence may help to synchronize maturation throughout all parts of the ovary.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Cell Research - Volume 316, Issue 16, 1 October 2010, Pages 2654–2663
نویسندگان
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