کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2056899 | 1075849 | 2010 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The beating pattern of the flagellum of Euglena gracilis under altered gravity during parabolic flights
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
علوم کشاورزی و بیولوژیک
علوم زراعت و اصلاح نباتات
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The unicellular freshwater flagellate Euglena gracilis shows negative gravitactic behavior. Previous experiments have revealed that the orientation is most likely an active physiological process in which the beating pattern of the flagellum is controlled by gravity and mediated by a change in the calcium concentration inside the cell. In a signal transduction chain, the calcium signal activates a calmodulin, which in turn raises the concentration of cAMP. This alters the beating pattern of the flagellum; reorientation is therefore not a passive process driven by buoyancy. In a recent parabolic flight experiment (ESA 45th parabolic flight campaign), we observed the beating of the flagellum with a high-resolution light microscope. Transition from hyper g to μg as well as from μg to hyper g caused a change of the beating pattern of the flagellum, which confirmed the physiological nature of the process. In μg cells stopped moving the flagellum or tried to reorient, while in hyper g, the cells realigned consecutively. The reaction times for the flagellar responses in previous experiments are confirmed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Plant Physiology - Volume 167, Issue 1, 1 January 2010, Pages 41-46
Journal: Journal of Plant Physiology - Volume 167, Issue 1, 1 January 2010, Pages 41-46
نویسندگان
S.M. Strauch, P. Richter, M. Schuster, D.-P. Häder,