Study about alternatively spliced form expression of MIWC water channel in the process of development in rats.

去年，我们研究了水通道蛋白4 （AQP4）的选择性剪接形式（SF）与非剪接形式（NSF）在脑和肾脏发育过程中的表达比例变化。在SD雄性大鼠出生前14、7天和出生后0、3、7、14天，采用定量RT-PCR结合ELISA法研究两种表达形式的表达比例。结果AQP4在出生前SF和NSF的表达都非常微弱。然而，出生后，在NSF表达增强之前，可以明显检测到SF的表达。今年，我们通过原位杂交研究了两种形式的AQP4在个体发育时期的定位。AQP4的SF和NSF的cRNA探针用35S标记，应用于大鼠个体发育期的冷冻组织切片。在大鼠出生前，AQP4在发育中的肾和脑中检测到的SF信号比NSF信号更明显。这一证据被认为与RT-PCR ELISA分析中观察到的表达模式相一致。这些结果表明，AQP4基因的选择性剪接可能起到了一种“开关”的作用，使AQP4从无活性形式转变为活性形式，以适应环境。

In last year, we examined changes in expression ratio of alternatively spliced form (SF) of aquaporin 4 (AQP4) vs non-spliced form (NSF) in brain and kidney in the process of development. The expression ratio of both forms was studied by use of quantitative RT-PCR in combination with ELISA method at day 14 and 7 before birth, and day 0,3,7 and 14 after birth in SD male rats. In results, the expression of both SF and NSF of AQP4 were very faint before birth. However, after birth, the expression of SF was clearly detected before enhancement of NSF expression. In this year, we performed in situ hybridization to study the localization of both form of AQP4 in individual developmental period. cRNA probes for SF and NSF of AQP4 were labeled with 35S and applied to frozen tissue sections obtained from individual developing period of rats. The signals corresponding to SF of AQP4 were detected in developing kidney and brain more obviously than NSF signals in rats before birth. This evidence was thought to be conpatible with expression pattern observed in RT-PCR ELISA analysis.These results suggest that alternative splicing of AQP4 gene might play a role as a kind of "switching" to change of AQP4 from inactive form to active form to adjust circumstance.