RNA-seq for WT and R6/2 (HD) mice with Translin-associated protein X (TRAX) knockdown

For the bilateral intrastriatal delivery of AAV expressing control or TRAX shRNA, mice were anesthetized with ketamine/xylazine HCl (87.56 and 7.5 ug/kg, respectively, via an intraperitoneal injection) and injected with the indicated AAV (2 µl per injection spot, 2.5*10^9 vector genome/µl) with a 10 ml syringe (Hamilton, Reno, NV, USA) at a rate of 0.5 ul/min. The AAV was injected at the desired position: AP+0.5, L±2, DV-2.5 and -3.5 mm relative to bregma and the dura surface. Then the mouse brains were removed from the mice directly for dissection of striatum. RNA was extracted by TRIzol reagent or miRNeasy mini kit (Qiagen). DNase digestion was performed by the DNA-free™ Kit (Life Technologies, Carlsbad, CA, USA) or the RNase-free DNase set (Qiagen) following the manufacturer’s instructions. The concentration and purity of RNA were measured at 260, 280 and 230 nm by a NanoDrop (Thermo Fisher Scientific, Waltham, MA, USA). RNA was qualified by a Bioanalyzer 2100 (Agilent Technology, Santa Clara, CA, USA) with an RNA 6000 LabChip kit (Agilent Technology). For mRNA, the RNA was prepared based on Illumina’s official protocol. Library construction was carried out by TruSeq Stranded Total RNA Library Prep Gold Kit (Illumina, San Diego, CA, USA) followed by AMPure XP beads (Beckman Coulter, Brea, CA, USA) size selection. Libraries were sequenced using sequencing-by-synthesis (SBS) technology (Illumina). Sequencing data and FASTQ reads were generated using an inhouse Welgene ’Biotech pipeline according to Illumina’s base calling program bcl2fastq v2.20.