Comparison of germline mosaics of genes in the Polycomb group of Drosophila melanogaster

Genetics. 1995 May;140(1):231-43.


The genes of the Polycomb group (PcG) repress the genes of the bithorax and Antennapedia complexes, among others. To observe a null phenotype for a PcG gene, one must remove its maternal as well as zygotic contribution to the embryo. Five members of the PcG group are compared here: Enhancer of Polycomb [E(Pc)], Additional sex combs (Asx), Posterior sex combs (Psc), Suppressor of zeste 2 [Su (z) 2] and Polycomblike (Pcl). The yeast recombinase (FLP) system was used to induce mitotic recombination in the maternal germline. Mutant embryos were analyzed by staining with antibodies against six target genes of the PcG. The loss of the maternal component leads to enhanced homeotic phenotypes and to unique patterns of misexpression. E(Pc) and Su(z) 2 mutations had only subtle effects on the target genes, even when the maternal contributions were removed. Asx and Pcl mutants show derepression of the targets only in specific cell types. Psc shows unusual effects on two of the targets, Ultrabithorax and abdominal-A. These results show that the PcG genes do not act only in a common complex or pathway; they must have some independent functions.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antennapedia Homeodomain Protein
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology
  • Drosophila Proteins*
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics*
  • Embryo, Nonmammalian / ultrastructure
  • Enhancer Elements, Genetic*
  • Gene Expression Regulation*
  • Genes, Insect*
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / physiology
  • Insect Hormones / genetics
  • Insect Hormones / physiology
  • Models, Genetic
  • Mosaicism / genetics*
  • Nuclear Proteins*
  • Nucleoproteins / genetics
  • Nucleoproteins / physiology
  • Organ Specificity
  • Polycomb Repressive Complex 1
  • Proteins / genetics*
  • Proteins / physiology
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology
  • Transcription Factors*


  • Antennapedia Homeodomain Protein
  • Antp protein, Drosophila
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Homeodomain Proteins
  • Insect Hormones
  • Nuclear Proteins
  • Nucleoproteins
  • Pc protein, Drosophila
  • Pcl protein, Drosophila
  • Proteins
  • Repressor Proteins
  • Scr protein, Drosophila
  • Transcription Factors
  • Ubx protein, Drosophila
  • ph-d protein, Drosophila
  • abd-A protein, Drosophila
  • Psc protein, Drosophila
  • Polycomb Repressive Complex 1