UMMS Affiliation

Department of Neurobiology; Tzumin Lee Lab; Graduate School of Biomedical Sciences, Neuroscience Program; Department of Medicine, Division of Hematology/Oncology

Publication Date


Document Type



Animals; Brain; Chromosome Mapping; Chromosomes; Clone Cells; Crosses, Genetic; DNA-Binding Proteins; Drosophila; Drosophila Proteins; Ecdysone; Female; Gene Expression; Genes, Homeobox; Genes, Insect; Genetic Complementation Test; Immunohistochemistry; Insect Proteins; Larva; Male; Metamorphosis, Biological; *Mutation; Neurons; Nucleoproteins; Organ Culture Techniques; Recombination, Genetic


Developmental Neuroscience


Polyhomeotic (Ph), which forms complexes with other Polycomb-group (PcG) proteins, is widely required for maintenance of cell identity by ensuring differential gene expression patterns in distinct types of cells. Genetic mosaic screens in adult fly brains allow for recovery of a mutation that simultaneously disrupts the tandemly duplicated Drosophila ph transcriptional units. Distinct clones of neurons normally acquire different characteristic projection patterns and can be differentially labeled using various subtype-specific drivers in mosaic brains. Such neuronal diversity is lost without Ph. In response to ecdysone, ph mutant neurons are transformed into cells with unidentifiable projection patterns and indistinguishable gene expression profiles during early metamorphosis. Some subtype-specific neuronal drivers become constitutively activated, while others are constantly suppressed. By contrast, loss of other PcG proteins, including Pc and E(z), causes different neuronal developmental defects; and, consistent with these phenomena, distinct Hox genes are differentially misexpressed in different PcG mutant clones. Taken together, Drosophila Ph is essential for governing neuronal diversity, especially during steroid hormone signaling.

Rights and Permissions

Publisher PDF posted as allowed by the publisher's author rights policy at

DOI of Published Version



Development. 2006 Apr;133(7):1231-40. Epub 2006 Feb 22. Link to article on publisher's site

Journal/Book/Conference Title

Development (Cambridge, England)


Co-author Suewei Lin is a student in the Neuroscience program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.

Related Resources

Link to Article in PubMed

PubMed ID




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