@article {683, title = {Combinatorial action of Grainyhead, Extradenticle and Notch in regulating Hox mediated apoptosis in Drosophila larval CNS.}, journal = {PLoS Genet}, volume = {13}, year = {2017}, month = {2017 Oct}, pages = {e1007043}, abstract = {

Hox mediated neuroblast apoptosis is a prevalent way to pattern larval central nervous system (CNS) by different Hox genes, but the mechanism of this apoptosis is not understood. Our studies with Abdominal-A (Abd-A) mediated larval neuroblast (pNB) apoptosis suggests that AbdA, its cofactor Extradenticle (Exd), a helix-loop-helix transcription factor Grainyhead (Grh), and Notch signaling transcriptionally contribute to expression of RHG family of apoptotic genes. We find that Grh, AbdA, and Exd function together at multiple motifs on the apoptotic enhancer. In vivo mutagenesis of these motifs suggest that they are important for the maintenance of the activity of the enhancer rather than its initiation. We also find that Exd function is independent of its known partner homothorax in this apoptosis. We extend some of our findings to Deformed expressing region of sub-esophageal ganglia where pNBs undergo a similar Hox dependent apoptosis. We propose a mechanism where common players like Exd-Grh-Notch work with different Hox genes through region specific enhancers to pattern respective segments of larval central nervous system.

}, keywords = {Amino Acid Sequence, Animals, Apoptosis, Central Nervous System, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Enhancer Elements, Genetic, Female, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Larva, Male, Nuclear Proteins, Receptors, Notch, Transcription Factors}, issn = {1553-7404}, doi = {10.1371/journal.pgen.1007043}, author = {Khandelwal, Risha and Sipani, Rashmi and Govinda Rajan, Sriivatsan and Kumar, Raviranjan and Joshi, Rohit} } @article {684, title = {Role of Homothorax in region specific regulation of Deformed in embryonic neuroblasts.}, journal = {Mech Dev}, volume = {138 Pt 2}, year = {2015}, month = {2015 Nov}, pages = {190-7}, abstract = {

The expression and regulation of Hox genes in developing central nervous system (CNS) lack important details like specific cell types where Hox genes are expressed and the transcriptional regulatory players involved in these cells. In this study we have investigated the expression and regulation of Drosophila Hox gene Deformed (Dfd) in specific cell types of embryonic CNS. Using Dfd neural autoregulatory enhancer we find that Dfd autoregulates itself in cells of mandibular neuromere. We have also investigated the role of a Hox cofactor Homothorax (Hth) for its role in regulating Dfd expression in CNS. We find that Hth exhibits a region specific role in controlling the expression of Dfd, but has no direct role in mandibular Dfd neural autoregulatory circuit. Our results also suggest that homeodomain of Hth is not required for regulating Dfd expression in embryonic CNS.

}, keywords = {Animals, Central Nervous System, Drosophila, Drosophila Proteins, Enhancer Elements, Genetic, Gene Expression Regulation, Developmental, Genes, Homeobox, Homeodomain Proteins, Neural Stem Cells, Organogenesis}, issn = {1872-6356}, doi = {10.1016/j.mod.2015.09.003}, author = {Kumar, Raviranjan and Chotaliya, Maheshvari and Vuppala, Sruthakeerthi and Auradkar, Ankush and Palasamudrum, Kalyani and Joshi, Rohit} }