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| Remize, Marine; Planchon, Frederic; Loh, Ai Ning; Le Grand, Fabienne; Lambert, Christophe; Bideau, Antoine; Bidault, Adeline; Corvaisier, Rudolph; Volety, Aswani; Soudant, Philippe. |
| The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13CO2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum. The Dinophyte growth was monitored for 54 h using high-frequency sampling. A. minutum presented a growth in two phases. A lag phase was observed during the first 30 h of development and had been associated with the probable temporary encystment of Dinophyte cells. An exponential growth phase was then observed after t30. A. minutum rapidly incorporated 13C into 22:6n-3, which ended up being the most 13C-enriched... |
| Tipo: Text |
Palavras-chave: PUFA synthesis; 22:6n-3; DHA; PKS pathway; Dinophyte; Alexandrium minutum; Encystment. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00654/76562/77688.pdf |
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| Rolland, Steven; Mengue, Luce; Noël, Cyril; Crapart, Stéphanie; Mercier, Anne; Aucher, Willy; Héchard, Yann; Samba-louaka, Ascel. |
| Acanthamoeba castellanii is a ubiquitous free-living amoeba. Pathogenic strains are causative agents of Acanthamoeba keratitis and granulomatous amoebic encephalitis. In response to adverse conditions, A. castellanii differentiate into cysts, which are metabolically inactive and resistant cells. This process, also named encystment, involves biochemical and genetic modifications that remain largely unknown. This study characterizes the role of the ACA1_384820 Acanthamoeba gene during encystment. This gene encodes a putative N-acetyltransferase, belonging to the Gcn5-related N-acetyltransferase (GNAT) family. We showed that expression of the ACA1_384820 gene was down-regulated as early as two hours after induction of encystment in A. castellanii.... |
| Tipo: Text |
Palavras-chave: Acanthamoeba castellanii; Encystment; N-acetyltransferase; Lateral gene transfer; Freeliving amoebae. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00625/73693/73214.pdf |
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| Maeda, Hajime; Akematsu, Takahiko; Fukui, Risa; Matsuoka, Tatsuomi. |
| The resting cysts of Colpoda cucullus were resistant to not only drying, but high and low temperatures. The critical temperatures for the survival of wet cysts ranged from 40 oC (3-hr exposure) to 45 oC (10-min exposure), and those of the dried cysts ranged from 80 oC (3-hr exposure) to 100 oC (30-min exposure). Frozen (-30 oC, 3 hr) and remelted wet cysts also survived. Ca2+-induced resting cysts excysted when the external Ca2+ was removed. However, the excystment-inducing effect by Ca2+ removal was canceled by the addition of cations such as Na+, K+, and Mg2+ in the surrounding medium. When the mature cysts transformed in a diluted buffer without any other salts were temporally exposed to Ca2+ and subsequently resuspended in the buffer without Ca2+,... |
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Palavras-chave: Colpoda; Encystment; Excystment; Resistance to temperature; Ca2+; Porphyrins. |
| Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/146 |
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| Watoh, Tomoko; Sekida, Satoko; Yamamoto, Keisuke; Kida, Akemi; Matsuoka, Tatsuomi. |
| Morphological changes during resting cyst formation (encystment) of Colpoda cucullus were examined. At 1 hr after encystment induction, a number of vesicles containing the electron-dense and toluidine blue (TB) positive materials were fused with large vacuoles to excrete the contents, and the vacuoles opened to the extracellular space to excrete. In this stage, the rounded precystic cells were surrounded by the first-synthesized cyst wall layer (L1 layer), and the cilia were resorbed inside the L1 layer. Thereafter (1-2 hr), a secondary layer (L2 layer) was formed and subsequently a deeply TB stained substance was diffused into the space between the plasma membrane and L2 layer. At 3-6 hr, numerous endoplasmic reticula (ER) associated with ribosomes... |
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Palavras-chave: Colpoda; Encystment; Cyst wall; Toluidine blue. |
| Ano: 2005 |
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/148 |
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