library_construction_protocol: For targeted transcriptome sequencing, RNA (15ng) isolated from  small  intestinal crypts was retro-transcribed to cDNA using SuperScript VILO cDNA Synthesis Kit  (11754-05; Invitrogen). Barcoded libraries were prepared using the Ion  AmpliSeq Transcriptome Mouse  Gene  Expression  Panel,  Chef-Ready  Kit  (A36412; Thermo  Scientific)  as  per  the  manufacturer's  protocol