Gene regulation in Drosophila melanogaster

Analysis of gene silencing in Drosophila melanogaster.

Drosophila Polycomb Group (PcG) complexes are responsible for the maintenance of the repressed state of specific genes, e.g. the homeotic genes. The genes in the Antennapedia and Bithorax complexes are activated in the early embryo by products of segmentation genes. Transient, localised activators and repressors determine the segmental domains of expression of each homeotic gene.

The specific expression patterns must, however, be remembered for the rest of development and this is where PcG proteins comes in. These complexes bind to regulatory regions, called Polycomb Response Elements (PREs) and thereby maintain a silenced state, while other protein complexes containing the Trithorax protein (TRX) mediate persistence of the active state. Which state the gene will be in, depends on the activity of the promoter at the blastoderm stage. There are two PcG complexes described; PRC1, consisting of Polycomb, Polyhomeotic, Pleiohomeotic and GAGA factors, and the E(z)/Esc (Enhancer of zeste/extra sex combs) complex, which also contains p55 and Rpd3 subunits.We have isolated a gene encoding another PcG protein, Suppressor-of-zeste-12 (Su(z)12) which is a subunit in the E(Z)/Esc complex. Mutants in the Su(z)12 gene exhibit very strong homeotic transformations and SU(Z)12 function is required throughout development to maintain the repressed state of the homeotic genes.The Su(z)12 protein is highly conserved in vertebrates and is related to at least three Arabidopsis proteins. Our current research concerns the role of Su(z)12 in the silencing complex and the function of the various conserved protein domains.

Regulation of toy; a Pax-6 gene in Drosophila melanogaster

There are two Pax-6 genes in Drosophila. They encode transcription factors that are important for the correct development of e.g. head structures of flies, a function that is conserved also in humans. One of the Pax-6 genes, toy (twin-of-eyeless), is expressed during early embryonic development and its product initiates the transcription of the second Pax-6 gene, eyeless (ey), by binding to a specific enhancer element in the first ey intron. Complete loss of Toy results in headless flies that die during the pupal stage (see Figure). Loss of ey cause eyeless flies, while weaker alleles give a small eye phenotype.Mutations in the mammalian homologs, the mouse Small eyes gene and the human Aniridia gene, also affect eye development. Homozygous mutant mice lack eye formation and heterozygous mutations of the human Pax-6 gene cause various forms of congenital eye abnormalities referred to as aniridia and Peters' anomaly. We are currently investigating the transcriptional regulation of the Drosophila toy gene by use of the GAL4/UAS system.

Publications

Author

Title

Year sorteringsordning

Fulltext

Jacobsson, Linn
Kronhamn, Jesper
Rasmuson-Lestander, Åsa

The Drosophila Pax6 paralogs have different functions in head development but can partially substitute for each other
Molecular Genetics and Genomics, 282(3): 217-231

2009

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Chen, Sa
Rasmuson-Lestander, Åsa

Regulation of the Drosophila engrailed gene by Polycomb repressor complex 2
Mechanisms of Development

2009

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Chen, Sa
Birve, Anna
Rasmuson-Lestander, Åsa

In vivo analysis of Drosophila SU(Z)12 function
Molecular Genetics and Genomics, 279(2): 159-170

2007

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Ryder, Edward
Ashburner, Michael
Bautista-Llacer, Rosa; et al.

The DrosDel deletion collection: A Drosophila genomewide chromosomal deficiency resource
Genetics, 177(1): 615-629

2007

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Zhou, Guang-Qian
Zhang, Youyi
Ferguson, David J P; et al.

The Drosophila ortholog of the endolysosomal membrane protein, endolyn, regulates cell proliferation.
J Cell Biochem, 99(5): 1380-96

2006

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Zeng, Qing-Yin
Westermark, Sven-Olof
Rasmuson-Lestander, Åsa; et al.

Detection and quantification of Cladosporium in aerosols by real-time PCR.
Journal of Environmental Monitoring, 8(1): 153-160

2006

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Zeng, Qing-Yin
Westermark, Sven-Olof
Rasmuson-Lestander, Åsa; et al.

Detection and quantification of Wallemia sebi in aerosols by real-time PCR, conventional PCR, and cultivation.
Applied and Environmental Microbiology, 70(12): 7295-7302

2004

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Ryder, Edward
Blows, Fiona
Ashburner, Michael; et al.

The DrosDel collection: a set of P-element insertions for generating custom chromosomal aberrations in Drosophila melanogaster.
Genetics, 167(2): 797-813

2004

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Zeng, Qing-Yin
Rasmuson-Lestander, Åsa
Wang, Xiao-Ru

Extensive set of mitochondrial LSU rDNA-based oligonucleotide probes for the detection of common airborne fungi.
FEMS Microbiology Letters, 237(1): 79-87

2004

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Tie, Feng
Prasad-Sinha, Jayashree
Birve, Anna; et al.

A 1-megadalton ESC/E(Z) complex from Drosophila that contains polycomblike and RPD3.
Mol Cell Biol, 23(9): 3352-62

2003

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Page Editor: Åsa Rasmuson-Lestander
2011-11-02

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