Fig. 1: A novel short transcript of ACE2 is expressed in airway epithelia.
a, Sashimi plot showing splice junction between exons (Ex) 9 and 10, and between exons 9a and 10, counted from RNA-seq reads from one nasal brushing sample. GENCODE v.33 gene build exons and new SCALLOP transcriptome build exons, showing new exon 9a in a new transcript encompassing exons 9a–19, assembled by SCALLOP tool. Letters ‘A’, ‘B’ and ‘C’ indicate locations of primers for RT–PCR (Fig. 1c). Nucleotide sequence of novel exon 9a, plus 5′ UTR, start codon and splice junction, are shown. b, Box and whisker plot showing expression levels of short and long ACE2 transcripts in primary NECs (reads mapped to exon 9a/10 or exon 9/10 per million mapped reads) (P = 0.0201, paired, two-way Student’s t-test; n = 6 donors). c, Agarose gel electrophoresis image of long-range, transcript-specific PCR products amplifying full short ACE2 transcript and exons 9–19 of long ACE2 transcript from nasal epithelial brushings and BCi-NS1.1 cells, using different pairs of primers (A and C or B and C), specific to regions of ACE2 shown in a. d, Sanger sequencing electropherogram traces showing sequence at exon/exon boundaries of long ACE2 transcript exons 9–10 and short ACE2 transcript exons 9a–10. Amino acid (aa) translation is shown below.
