ABSTRACT: The differentiation capability of induced pluripotent stem cells (iPSCs) towards certain cell types for disease modelling and drug screening assays might be influenced by their somatic cell of origin. Here, we have compared the neural induction of human iPSCs generated from either fetal neural stem cells (fNSCs), dermal fibroblasts or CD34+ hematopoietic stem cells. Neural progenitor cells (NSCs) and neurons could be generated at similar efficiencies from all iPSCs. Whole genome transcriptome analysis and an expression analysis of neural genes in iPSC-derived NSCs revealed a separation of neuroectoderm- from mesoderm-derived cells. Furthermore, we found genes, which were similarly expressed between fNSCs and neuroectoderm- but not mesoderm-derived NSCs. Notably, these neural signatures were retained after transplantation into the cortex of mice and paralleled with increased survival and integration of neuroectoderm-derived cells in vivo. These results indicated distinct origin- dependent neural cell identities in differentiated human iPSCs both in vitro and in vivo. RNA samples for microarray analysis were prepared using RNeasy columns (Qiagen, Germany) with on-column DNA digestion. 300 ng of total RNA per sample were used as the input in the linear amplification protocol (Ambion), which involved the synthesis of T7-linked double-stranded cDNAs and 12hrs of in vitro transcription incorporating biotin-labeled nucleotides. Purified and labeled cRNA was then hybridized for 18 hrs onto HumanHT-12 v4 expression BeadChips (Illumina, USA) following the manufacturer's instructions. After the recommended washing, the chips were stained with streptavidin-Cy3 (GE Healthcare) and scanned using the iScan reader (Illumina) and the accompanying software. The samples were exclusively hybridized as biological replicates. The RNA samples from in vivo transplanted and FACS sorted cells were amplified using the TargetAmp 2-Round Biotin-aRNA Amplification Kit 3.0 (Epicentre, USA) from 100 pg to 50 microg. 43 samples were analyzed Fib, Human fibroblast F134, 2 replicates CD34+, Human Cord Blood CD34+ Hematopoyetic Stem Cell (HSC), 1 replicate fNSC, Human fetal Neural Stem Cells (NSC), 1 replicate fNSC-1FiPSCa-NSC, Human one factor (POU5F1) fetal Neural Stem Cell (NSC) induced reprogrammed cell (iPSC) clone a, in vitro differentiated to NSC, 2 replicates fNSC-1FiPSCb-NSC, Human one factor (POU5F1) fetal Neural Stem Cell (NSC) induced reprogrammed cell (iPSC) clone b, in vitro differentiated to NSC, 2 replicates fNSC-2FiPSCa-NSC, Human two factors (POU5F1, KLF4) fetal Neural Stems Cell (NSC) induced reprogrammed cell (iPSC) clone a, in vitro differentiated to NSC, 2 replicates CD34-2FiPSCa-NSC, Human two factors (POU5F1, KLF4) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone a, in vitro differentiated to NSC, 2 replicates CD34-4FiPSCa-NSC, Human four factors (POU5F1, KLF4, SOX2, CMYC) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone a, in vitro differentiated to NSC, 2 replicates CD34-4FiPSCb-NSC, Human four factors (POU5F1, KLF4, SOX2, CMYC) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone b, in vitro differentiated to NSC, 2 replicates Fib-4FiPSCa-NSC, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone a, in vitro differentiated to NSC, 2 replicates Fib-4FiPSCb-NSC, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone b, in vitro differentiated to NSC, 2 replicates Fib-4FiPSCc-NSC, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone c, in vitro differentiated to NSC, 1 replicate H1-ESC-NSC, Human H1 embryonic stem cell (ESC), in vitro differentiated to NSC, 2 replicates HUES6-ESC-NSC, Human HUES6 embryonic stem cell (ESC), in vitro differentiated to NSC, 1 replicate fNSC-1FiPSCa, Human one factor (POU5F1) fetal Neural Stem Cell (NSC) induced reprogrammed cell (iPSC) clone a, 1 replicate fNSC-1FiPSCb, Human one factor (POU5F1) fetal Neural Stem Cell (NSC) induced reprogrammed cell (iPSC) clone b, 1 replicate fNSC-2FiPSCa, Human two factors (POU5F1, KLF4) fetal Neural Stems Cell (NSC) induced reprogrammed cell (iPSC) clone a, 1 replicate CD34-2FiPSCa, Human two factors (POU5F1, KLF4) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone a, 1 replicate CD34-4FiPSCa, Human four factors (POU5F1, KLF4, SOX2, CMYC) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone a, 1 replicate CD34-4FiPSCb, Human four factors (POU5F1, KLF4, SOX2, CMYC) cord blood CD34+ Hematopoyetic Stem Cell (HSC) induced reprogrammed cell (iPSC) clone b, 1 replicate Fib-4FiPSCa, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone a, 1 replicate Fib-4FiPSCb, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone b, 1 replicate H1-ESC, Human H1 embryonic stem cell (ESC), 3 replicates HUESC6-ESC, Human HUESC6 embryonic stem cell (ESC) , 2 replicates Fib-4FiPSCa-NSC-In Vivo, Human four factors (POU5F1, KLF4, SOX2, CMYC) fibroblast induced reprogrammed cell (iPSCs) clone a, in vivo differentiated to NSC, 2 replicates fNSC-1FiPSCa-NSC-In Vivo, Human one factor (POU5F1) fetal Neural Stem Cell (NSC) induced reprogrammed cell (iPSC) clone a, in vivo differentiated to NSC, 4 replicates