Transient Response of Brain Heat Shock Proteins 70 and 90 to Acute Osmotic Stress in Tilapia (Oreochromis mossambicus)

摘要

Meng-Wen Yang, Wei-Tung Huang, May-Jywan Tsai, Ing-Fong Jiang, and Ching-Feng Weng (2009) Transient response of brain heat shock proteins 70 and 90 to acute osmotic stress in tilapia (Oreochromis mossambicus). Zoological Studies 48(6): 723-736. Previous studies demonstrated that gills play a major role in osmoregulation during salinity changes. However, the regulatory mechanism in the tilapia brain under osmolarity challenge remains unexplored. Tilapia Oreochromis mossambicus were transferred directly from fresh water (FW) to 25 ppt seawater (SW) for 1, 2, 4, 8, and 24 h; or to 35 ppt SW for 1, 2, and 4 h, to determine whether heat shock protein (HSP)70 and HSP90 in the brain respond to acute hyperosmotic stress. After transfer to 25 ppt SW, HSP70 and HSP90 messenger (m) RNA remained at higher levels compared to the FW group. HSP70 and HSP90 protein levels in the anterior and middle brain regions at I h after SW transfer were higher than those of the FW group, and they had increased in the whole brain at 1 h and were sustained to 4 h following transfer. After transfer to 35 ppt SW, HSP70 mRNA had decreased at I h and increased at 4 h compared to values in FW; however, a lower HSP90 mRNA level was observed at 4 h. For the whole brain, protein levels of HSP70 and HSP90 after transfer to 35 ppt SW increased compared to those in FW except at 2 h after transfer. The results suggest that HSP70 and HSP90 may be involved in regulating the tilapia brain when faced with acute osmotic stress and may subsequently facilitate adaptation to a SW environment. http://zoolstud.sinica.edu.tw/Journals/48.6/723.pdf