library_construction_protocol: Islets were gently dissociated into a single cell suspension in 500 μl Accutase (Innovative Cell Technologies) for up to 10 minutes at 37°C. Cells were then washed with PBS, passed through a 70 μm strainer and resuspended in a final volume of 200 μl. Cell viability and number of cells were determined using Trypan Blue Stain and a Countess Automated Cell Counter (ThermoFisher). 8,000 cells per sample were loaded onto the 10X Genomics Chromium Controller according to the 10X Genomics protocol. cDNA was prepared according to the 10X reverse transcriptase protocol as per manufacturer's instructions, and samples were stored at -80°C for concurrent library preparation and sequencing. Libraries were prepared according to the manufacturer's protocol for 10X Genomics Chromium Next GEM Single Cell V(D)J Reagent Kits v1.1. Libraries were pooled in equimolar concentration and sequenced to a targeted depth of 25,000 reads per cell with the Illumina NovaSeq SP 100 cycle kit with run parameters (read 1 28, index read i7 8, index read i5 0, read 2 60).