As mentioned earlier, each NB produce many neurons toward the center of the medulla.
Neurons of the same lineage intersect the concentric zones.
Therefore, different types of medulla neurons may be produced in a lineage independent manner.
To demonstrate this possibility, clones containing single NB were labeled with GFP as shown here.
And we counted number of neurons that express concentric genes.
The results suggest many NBs have similar potential to produce a series of medulla neurons.
This result suggests birth order dependent mechanisms may regulate concentric gene expression.
For example, green cells are produced at first, magenta cells next, blue cells and so on.