Similar dynamics of repression at the transcript and protein level were observed for ITGA6/integrin α6 (CD49f), a cell surface marker for basal and luminal progenitors (supplementary material Fig. S2C,D).
Many of the DiI-labelled cells expressed glutamate decarboxylase (GAD) 67 and to a lesser extent γ-aminobutyric acid (GABA), indicating that they include interneuron progenitors (supplementary material Fig. S5).
The majority of the COS sequences in our dataset were derived from diploid progenitors (see Materials and Methods).
Meis1 was 1.8-fold downregulated after Sp1 knockdown in Flk1+ and progenitor cells (supplementary material Table S1), raising the possibility of a combined negative effect on hematopoietic development.
In contrast, elevated Wnt gene expression did not correlate with that of β-Catenin mRNA, Wnt receptors or markers of stem and progenitor cells (supplementary material Fig. S2).
Most notably, similar to embryonic NSCs from Tsc1c/− /Emx1- Cre+ mice, RGC-targeted Tsc1 mutant embryonic NSCs comprised the same frequency of GalC-IR oligodendrocytes as control cultures, with only a slight increase in the numbers of NG2pos/GalCneg-IR progenitor cells (supplementary material Fig. S3F).
We isolated Flk1+ cells containing hemangioblasts, plated those cells into blast culture and purified two successive stages of hemogenic endothelium development before and after the EHT as well as floating progenitor cells (supplementary material Fig. S3A) using cell sorting as outlined in Fig. 2B.
Because the ATCC948 strain is highly divergent from all published P. fluorescens genomes, we used a de novo assembly of the MA-line sequence to determine the genotype of the progenitor strain (see Materials and Methods).
RNA in situ hybridization analysis demonstrated that, along with loss of nkx2.5 expression, there is a decrease in expression of spi1 and the more posterior domains of fli1 and tal1 in the ALPM, marking myeloid and presumed endocardial progenitors, respectively (supplementary material Fig. S1).
This work has important implications for understanding the mechanisms underlying intestinal maturation and demonstrates that immature intestinal progenitors, including fetal-like material derived from human pluripotent stem cells, have the potential to be used in colonic regenerative medicine.
Throughout optic cup invagination transgene activity was present at low levels in NR progenitors and more prominently in RPE progenitors (Fig. 1; supplementary material Movie 2).
