Transcriptome analysis of E15.5 wild-type (Tbr2-f/+) andTbr2-Isl1/+ retinae

Isl1 encodes a member of the LIM/homeodomain family of transcription factors. During retinal development. Isl1 plays a critical role in RGC fate specification. Tbr2 is essential for the formation and maintaining the survival of ipRGCs. In this study, we tested whether ectopically expressing Isl1 in Tbr2-expressing cells affects the developmental program of Tbr2-expressing retinal neurons, including ipRGCs and a subset of wide-field displaced amacrine cells. We generated a Tbr2-Isl1 knock-in allele using gene targeting technique, and then used RNA-seq approach to compare transcriptome profiles between E15.5 wild-type (Tbr2-flox/+) and Tbr2-Isl1/+ retinas to uncover how Isl1 affects Tbr2-regulated genes. Retinal mRNA profiles of E15.5 wild-type (Tbr2fx) and Isl1 knockin (T2Isl1) retinas were generated by deep sequencing, in triplicate, using Illumina.

Isl1编码LIM同源结构域（LIM/homeodomain）家族转录因子的一员。在视网膜发育进程中，Isl1在视网膜神经节细胞（Retinal Ganglion Cell, RGC）的命运决定过程中发挥关键调控作用。Tbr2对于固有感光视网膜神经节细胞（ipRGCs）的形成及其存活维持不可或缺。本研究旨在探究：在表达Tbr2的细胞中异位表达Isl1，是否会影响该类视网膜神经元（包括ipRGCs与一类宽视野移位无长突细胞亚群）的发育程序。我们通过基因靶向技术构建了Tbr2-Isl1敲入等位基因，随后采用RNA测序（RNA-seq）技术，对E15.5天野生型（Tbr2-flox/+）与Tbr2-Isl1/+小鼠视网膜的转录组图谱开展对比分析，以揭示Isl1对Tbr2调控基因的影响机制。本研究依托Illumina测序平台，对E15.5天野生型（Tbr2fx）与Isl1敲入（T2Isl1）小鼠的视网膜mRNA进行了深度测序，每组设置3次生物学重复。