A role of polycomb group genes in the regulation of gap gene expression in Drosophila

Pelegri, Francisco; Lehmann, Robert

doi:10.1016/0168-9525(90)90006-r

Cited by 45 publications

(57 citation statements)

References 28 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…gene, hb (Pelegri and Lehmann, 1994). In this study, we also found that some pho mutant embryos showed an expansion in the expression territory of Kr and kni to a more anterior domain (Supplementary Figs.…”

Section: Discussionsupporting

confidence: 74%

The Pleiohomeotic Functions as a Negative Regulator of Drosophila even-skipped Gene during Embryogenesis

Kim

Shim

Jeon

et al. 2011

Molecules and Cells

View full text Add to dashboard Cite

Section: Discussionsupporting

confidence: 74%

The Pleiohomeotic Functions as a Negative Regulator of Drosophila even-skipped Gene during Embryogenesis

Kim

Shim

Jeon

et al. 2011

Molecules and Cells

View full text Add to dashboard Cite

“…In the case of PRE/TREs, the information required to turn gene activity off or on after each new cell division is carried on the PRE/TRE, and copied to both new daughter cells at replication and mitosis. The epigenetic nature of PRE/TRE states has been confirmed by several studies that have demonstrated that transgenic PRE/TREs, with their own or foreign promoters, can maintain gene expression states through many cell divisions in the absence of the initial activating or repressing factors (Cavalli and Paro, 1998;Maurange and Paro, 2002;Pelegri and Lehmann, 1994;Poux et al, 1996;Rank et al, 2002).These studies have shown that PRE/TRE elements have dual potential for the epigenetic maintenance of both activated and silenced states. PRE/TREs also have the potential to switch between these states if experimentally induced to do so by a change in transcriptional status at the promoter (Cavalli and Paro, 1998;Cavalli and Paro, 1999) or by genetic removal of PcG or TrxG proteins (Beuchle et al, 2001;Klymenko and Muller, 2004).…”

mentioning

confidence: 54%

Section: Introductionmentioning

confidence: 77%

Polycomb/Trithorax response elements and epigenetic memory of cell identity

2007

View full text Add to dashboard Cite

DEVELOPMENT 223Polycomb/Trithorax group response elements (PRE/TREs) are fascinating chromosomal pieces. Just a few hundred base pairs long, these elements can remember and maintain the active or silent transcriptional state of their associated genes for many cell generations, long after the initial determining activators and repressors have disappeared. Recently, substantial progress has been made towards understanding the nuts and bolts of PRE/TRE function at the molecular level and in experimentally mapping PRE/TRE sites across whole genomes. Here we examine the insights, controversies and new questions that have been generated by this recent flood of data. IntroductionDuring the 1990s, studies of the regulation of homeotic genes in the Drosophila Bithorax complex (BX-C) uncovered very different behaviour for two classes of cis-regulatory DNA element: initiator elements and maintenance elements (or Polycomb/Trithorax group response elements, PRE/TREs) (Busturia et al., 1989;Chan et al., 1994;Chiang et al., 1995;Simon et al., 1993;Simon et al., 1990) (reviewed by Maeda and Karch, 2006). One can think of these two types of elements as 'shift workers' that use very different strategies to regulate the expression patterns of the same genes at different stages of embryonic development. In the first three hours of development, the initiator elements are in control: the output of each homeotic gene depends on the local concentrations of segmentation gene products (these are activators and repressors that are present in different concentrations at different positions of the embryo). However, a few hours after these homeotic gene patterns have been established, the segmentation gene products decay, and thus the positional information they provide is lost. The transcriptional history of each gene is subsequently maintained throughout the rest of development, and into adulthood, by the ubiquitously expressed Polycomb group (PcG) and Trithorax group proteins (TrxG), which work antagonistically via the PRE/TRE elements to maintain active (TrxG) or silenced (PcG) transcriptional states (Moehrle and Paro, 1994). Although the effects of mutations in the PcG and TrxG genes are seen only after the segmentation gene products decay, the PcG and TrxG proteins themselves appear to associate with PRE/TREs much earlier, so that PRE/TREs are 'preloaded' with PcG and TrxG proteins, ready to maintain the transcriptional states that are set by the transiently acting segmentation gene products (Orlando et al., 1998).The maintenance of transcriptional memory at PRE/TREs is 'epigenetic'. This term has suffered much overuse and abuse in recent years, but we use here the classical definition given by Ptashne and Gann (Ptashne and Gann, 2002) (p100): "a change in the state of expression of a gene that does not involve a mutation, but that is nevertheless inherited (after cell division) in the absence of the signal (or event) that initiated that change". In the case of PRE/TREs, the information required to turn gene activity off or on after ea...

show abstract

“…The role of PcG proteins has been best characterized in silencing of Hox genes, although PcG silencing also occurs at many non-Hox loci (Bello et al, 1998;Chen and Rasmuson-Lestander, 2009;Dura and Ingham, 1988;Netter et al, 1998;Pelegri and Lehmann, 1994;Schuettengruber et al, 2007). PRC2 silences genes by effecting histone modifications, particularly trimethylation of histone H3 at lysine 27 (Czermin et al, 2002) (for a review, see Schuettengruber et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

The enhancer of trithorax and polycomb gene Caf1/p55 is essential for cell survival and patterning in Drosophila development

et al. 2011

View full text Add to dashboard Cite

SUMMARYIn vitro data suggest that the human RbAp46 and RbAp48 genes encode proteins involved in multiple chromatin remodeling complexes and are likely to play important roles in development and tumor suppression. However, to date, our understanding of the role of RbAp46/RbAp48 and its homologs in metazoan development and disease has been hampered by a lack of insect and mammalian mutant models, as well as redundancy due to multiple orthologs in most organisms studied. Here, we report the first mutations in the single Drosophila RbAp46/RbAp48 homolog Caf1, identified as strong suppressors of a senseless overexpression phenotype. Reduced levels of Caf1 expression result in flies with phenotypes reminiscent of Hox gene misregulation. Additionally, analysis of Caf1 mutant tissue suggests that Caf1 plays important roles in cell survival and segment identity, and loss of Caf1 is associated with a reduction in the Polycomb Repressive Complex 2 (PRC2)-specific histone methylation mark H3K27me3. Taken together, our results suggest suppression of senseless overexpression by mutations in Caf1 is mediated by participation of Caf1 in PRC2-mediated silencing. More importantly, our mutant phenotypes confirm that Caf1-mediated silencing is vital to Drosophila development. These studies underscore the importance of Caf1 and its mammalian homologs in development and disease.

show abstract

A role of polycomb group genes in the regulation of gap gene expression in Drosophila

Cited by 45 publications

References 28 publications

The Pleiohomeotic Functions as a Negative Regulator of Drosophila even-skipped Gene during Embryogenesis

The Pleiohomeotic Functions as a Negative Regulator of Drosophila even-skipped Gene during Embryogenesis

Polycomb/Trithorax response elements and epigenetic memory of cell identity

The enhancer of trithorax and polycomb gene Caf1/p55 is essential for cell survival and patterning in Drosophila development

Contact Info

Product

Resources

About