In Drosophila, this appears as discrete vesicles located throughout the cytoplasm. Cell surface localization is observed with anti-Comm antibodies in the absence of detergent.
Expression begins during the cellular blastoderm stage in a pattern of six stripes.
By stage 6, these stripes narrow, and an interstripe of comm expression is observed resulting in a pattern of 14 stripes. This striped epidermal expression is maintained throughout germ band elongation, suggesting that the comm promoter is sensitive to regulation by segmentation genes. These longitudinal stripes extend throughout the segmented region of the embryo. Initially the dorsal limit of this stripe is irregular, but subsequently this boundary is sharpened. COMM transcript is visible in a subset of neuroblasts and some early ganglion mother cells .