Drosophila larvae have 8 obvious abdominal segments, and rudiments of the 9th and 10th abdominal segments have been described, based on ENGRAILED expression patterns in early embryos. The bithorax complex has a series of regulatory domains, one for each parasegment, from PS5 (~3rd thoracic segment) through the posterior abdominal segments. The domains were first described by E. B. Lewis, based on mapping of mutations affecting different segments. These domains have been confirmed by enhancer trap expression patterns, by parasegment-specific discontinuities in H3K27 methylation patterns, and by the coincidence of most domain borders with binding sites for CTCF. We have used CRISPR-mediated gene conversion to introduce a Gal4 reporter into putative parasegmental domains towards the distal end of the bithorax complex. We see distinctive expression patterns, especially in the CNS, corresponding to domains for PS12-16 (~7th through 11th abdominal segments). We are currently working to isolate nuclei from each of these parasegments, in order to confirm these domains with H3K27me3 maps.