Abstract 2119 Deletion of Hox Gene Cluster Regulatory Sequences in Drosophila

Hox genes encode vital transcription factor proteins that regulate a wide variety of target genes during animal development, influencing vital processes such as skeletal formation, organogenesis, segmentation, and limb formation.In nearly all species Hox genes are organized into clusters in which their spatial arrangement within the cluster correlates with the relative expression region within the organism.This phenomenon has been referred to as colinearity.Mutation or misregulation of these genes frequently results in body plan abnormalities, such as the transformation of one regional identity into another.Previous studies have investigated both the regulatory network of Hox gene-dependent targets and the regulation of the Hox genes themselves.For instance, regulatory sequences within the bithorax Hox cluster (BX-C) of Drosophila melanogaster control the transcription of Hox genes Ultrabithorax (Ubx), Abdominal-A (Abd-A), and Abdominal-B (Abd-B).The current study aims to investigate the potential regulatory role of three long non-coding RNAs (lncRNAs)-CR44945, CR45750, and TS16-that are located between Ubx and Abd-A and near the known bxd Hox regulatory sequences.Given the important role of lncRNAs in regulating target genes in other systems, we chose to use CRISPR/Cas9-mediated germline deletion to investigate roles they may play in regulation of Hox gene expression.We generated sgRNA targeting constructs to delete each of these three sequences.Following targeting injections, we screened for deletion mutants by PCR.We will characterize the deletion mutants by examining the resulting wing, haltere, and abdomen phenotype.Observed changes in phenotype may suggest which BX-C cluster Hox genes have altered expression, and we will measure Ubx, Abd-A, and Abd-B expression by qPCR to confirm any expression changes.These results will deepen our understanding of the regulation of targets by these lncRNAs and will also identify additional players in Hox gene regulation.