| description |
Combinatorial transcription codes generate the myriad of cell types during development, and thus likely provide crucial insights into directed differentiation of stem cells to a specific cell type. The LIM-complex composed of Isl1 and Lhx3 directs the specification of spinal motor neurons (MNs) in embryos. Here, we report that Isl1-Lhx3, a LIMcomplex-mimicking fusion, induces a signature of MN transcriptome and concomitantly suppresses interneuron differentiation programs, thereby serving as a potent and specific inducer of MNs in stem cells. We show that an equimolar ratio of Isl1 and Lhx3 and the LIM-domain of Lhx3 are crucial for generating MNs without upregulating interneuron genes. These led us to design Isl1-Lhx3, which maintains the desirable 1:1 ratio of Isl1 and Lhx3 and the LIM-domain of Lhx3. Isl1-Lhx3 drives MN differentiation with high specificity and efficiency in the spinal cord and embryonic stem cells, bypassing the need for sonic hedgehog. RNA-seq analysis revealed that Isl1-Lhx3 induces the expression of a battery of MN genes that control various functional aspects of MNs, while suppressing key interneuron genes. Our studies uncover a highly efficient method for directed MN generation and MN gene networks. Our results also demonstrate a general strategy of utilizing embryonic transcription complexes for producing specific cell types from stem cells.Overall design: Examine the RNA expression profiles of inducible motor neurons-embryonic stem cells (iMN-ESCs) with or without Dox treatment, with biological duplicates. |