Determination of the relative abundance of mRNAs in a polyribosome-associated pool

Polyribosomal fractions derived from P25 mice were the starting material for IPs of the FMRP protein and associated mRNA. Therefore we wanted to determine the relative abundance of all mRNAs in the starting pool for the IP as a denominator with which to compare the IPed material. [mRNA profiling]: We prepared polyribosomes on sucrose gradients in duplicate from 2 FVB WT mice, age P25, and purified RNA from polyribosomal fractions of each of the two gradients.以P25月龄小鼠来源的多聚核糖体组分（polyribosomal fractions）作为免疫沉淀（IP，Immunoprecipitation）脆性X智力低下蛋白（FMRP）及其结合mRNA的起始材料。因此，本研究拟确定该免疫沉淀实验起始样本池中所有mRNA的相对丰度，以此作为参照分母，用于与经免疫沉淀富集的样本进行比对。[mRNA表达谱分析（mRNA profiling）]：我们从2只P25月龄FVB品系野生型（WT，Wild Type）小鼠中，通过蔗糖密度梯度离心法制备了两份重复的多聚核糖体样本，并分别从两次梯度离心得到的多聚核糖体组分中提取纯化RNA。