Total RNA extractions were performed using the Roche High pure RNA isolation kit. Superscript III reverse transcription reagents (Invitrogen) and random hexamers were used to prepare cDNAs. For qPCR quantification, 5 μl of SYBR Green I Master mix (Roche), ROX reference dye, 1 μl of IDT PrimeTime Primer set for corresponding assays, and 1 μl of cDNA were mixed for PCR amplification and detected by QuantStudio 5 real-time PCR systems instrument. For quantitative analysis, Hoxa9, Hoxb4, Hoxb13, Gata2, Gata6, Pou5f1, and Ccna2 expression was normalized to Actb expression. Primers were ordered from Primetime IDT. For RNA-seq, the first strand was synthesized using reverse transcription via Superscript III and random hexamers. The second strand was synthesized with deoxyuridine triphosphate to generate strand asymmetry using DNA polymerase I (NEB, M0209L) and the Escherichia coli ligase (Enzymatics, L6090L). RNA-seq libraries were constructed using the protocol described in (1 (link)), quantified by Qubit double-stranded DNA HS Assay Kit quality, and checked by High Sensitivity D1000 ScreenTape. Libraries were then sequenced as 50-bp single-end reads on a NovaSeq 6000 platform.