Heat-stress-induced programmed cell death in Heterosigma akashiwo (Raphidophyceae)
- 作者：Jennifer E. Dingman ; Janice E. Lawrence ; jlawrenc@unb.ca
- 关键词：Ac-DEVD-CHO ; acetyl Asp-Glu-Val-Asp aldehyde (caspase 3 inhibitor) ; Ac-DEVD-pNA ; acetyl Asp-Glu-Val-Asp p-nitroaniline (colorimetric caspase-3/7 substrate) ; Ac-VAD-FMK ; acetyl Val-Ala-Asp (OMe)-fluoromethylketone (caspase inhibitor) ; AC-YEVD-CMK ; acetyl T
- 刊名：Harmful Algae
- 出版年：2012
- 期刊代码：81_15689883
- 类别：env
- 出版时间：April, 2012
- 卷：16
- 期：Complete
- 页码：108-116
- 文件大小：562 K
摘要
Programmed cell death (PCD) was previously thought to only occur in metazoans. Recent studies have revealed PCD in yeast, prokaryotes, and some species of phytoplankton. However, the need for PCD assays with reliable controls currently limits the study of PCD in natural environments. We examined heat-stressed cultures of Heterosigma akashiwo (Y. Hada) Y. Hada ex Y. Hara and M. Chihara for DNA fragmentation (using the terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL) assay), externalization of phosphatidylserine residues (using Annexin-V) and caspase-like activity (using CaspACE and Caspase-Glo 8), which are all diagnostic of cells undergoing PCD but not necrosis. Additionally, we treated cultures with the broad-spectrum caspase inhibitor z-VAD-FMK to rescue cells otherwise destined for death. Our results demonstrate the range of inducible responses of H. akashiwo to heat-stress: recovery from 35 掳C heat-stress, PCD-induction due to 37 掳C and 40 掳C heat-stress, and necrotic death or cyst formation due to 50 掳C heat-stress. The identification of a reliable inducer and markers for PCD provides key tools for further studies into the physiology and ecology of this harmful bloom-former.