(
A) Clustering of the rare POMC-expressing PNECs in a NEB. Fluorescence confocal micrographs (left) and schematics (right) of a NEB in adult PN68 wild type (CD-1) mouse lung immunostained for CGRP (green) and POMC (red). Two optical sections (separated by 65μm) of the same NEB are shown. Dotted circles, individual PNECs; dashed lines, basement membrane. In schematic at right, green fill circles are CGRP+, POMC- PNECs, yellow fill circles are CGRP+ POMC + double-positive PNECs, and gray fill circles are non-CGRP-expressing cells in cluster. Scale bar, 10μm. (
B) Integrated rarefaction (interpolation, solid line) and prediction (extrapolation to 500 PNECs, dashed extension) curve showing cumulative number of distinct peptidergic genes expressed by PNECs, as determined by bootstrapping with 200 re-samplings of the scRNA-seq profiles of 268 individual PNECs (176 flow-sorted and 92 captured by microfluidics). Grey shading, 95% confidence intervals. Rarefaction curve is based on detected expression but not magnitude of expression of each peptidergic gene in each profiled PNEC (
Figure 2).