Dataset Information

Mutations in Su(var)205 and Su(var)3-7 suppress P-element-dependent silencing in Drosophila melanogaster.

ABSTRACT: In Drosophila melanogaster, the w(+) transgene in P[lacW]ci(Dplac) is uniformly expressed throughout the adult eye. However, when other P elements are present, this w(+) transgene is randomly silenced and this produces a variegated eye phenotype. This P-element-dependent silencing (PDS) is limited to w(+) transgenes inserted in a specific region on chromosome 4. In a screen for genetic modifiers of PDS, we isolated mutations in Su(var)205, Su(var)3-7, and two unidentified genes that suppress this variegated phenotype. Therefore, only a few of the genes encoding heterochromatic modifiers act dose dependently in PDS. In addition, we recovered two spontaneous mutations of P[lacW]ci(Dplac) that variegate in the absence of P elements. These P[lacW]i(Dplac) derivatives have a gypsy element inserted proximally to the P[lacW]ci(Dplac) insert. The same mutations that suppress PDS also suppress w(+) silencing from these P[lacW]ci(Dplac) derivative alleles. This indicates that both cis-acting changes in sequence and trans-acting P elements cause a similar change in chromatin structure that silences w(+) expression in P[lacW]ci(Dplac). Together, these results confirm that PDS occurs at P[lacW]ci(Dplac) because of the chromatin structure at this chromosomal position. Studying w(+) variegation from P[lacW]ci(Dplac) provides a model for the interactions that can enhance heterochromatic silencing at single P-element inserts.

SUBMITTER: Bushey D

PROVIDER: S-EPMC1448784 | biostudies-literature | 2004 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mutations in Su(var)205 and Su(var)3-7 suppress P-element-dependent silencing in Drosophila melanogaster.

Bushey Daniel D Locke John J

Genetics 20041101 3

In Drosophila melanogaster, the w(+) transgene in P[lacW]ci(Dplac) is uniformly expressed throughout the adult eye. However, when other P elements are present, this w(+) transgene is randomly silenced and this produces a variegated eye phenotype. This P-element-dependent silencing (PDS) is limited to w(+) transgenes inserted in a specific region on chromosome 4. In a screen for genetic modifiers of PDS, we isolated mutations in Su(var)205, Su(var)3-7, and two unidentified genes that suppress thi ...[more]

PMID: 15579693

Similar Datasets

Project description:Fly strains were obtained from the Bloomington Stock Center. The chromosomes containing the gene deletion mod(mdg4)L3101 {y[1] w[1118]; P{w[+mC]=lacW}mod(mdg4)[L3101]/TM3, Ser[1]}, HP1 {In(1)w[m4h]; Su(var)205[5]/In(2L)Cy,In(2R)Cy, Cy[1]}, mod(mdg4)G16853 {w[1118]; P{w[+mC]=EP}mod(mdg4)[G16853]/TM6C, Sb[1]}, and Jil-1Scim {y[1]; P{y[+mDint2] w[BR.E.BR]=SUPor-P}JIL-1[Scim] ry[506]} were introgressed into the genetic background y[1]; bw[1]; e[4]; ci[1] ey[R] to generate the strains Mod(mdg4)/+, Su(var)205/+ and JIL-1/+. All females used in the introgression were collected within 7 hours after eclosion. For gene expression analyses, flies were grown in incubators at 25°C, 65% of relative humidity, and constant light. Newly emerged male adults flies harboring the mutations and the Y chromosomes Yohio and Ycongo(Mod(mdg4)/+;Yohio and Mod(mdg4)/+;Ycongo, Su(var)205/+;Yohio and Su(var)205/+;Ycongo, and JIL-1/+;Yohio and JIL-1/+;Ycongo) were collected and aged for 2 days at the same rearing condition before they were flash-frozen in liquid nitrogen. Four replicas of each sample were collected and stored at -80°C. Total RNA was extracted from whole flies using TRIzol (Life Technologies). The synthesis of cDNA and its labeling with fluorescent dyes (Cy3 and Cy5) as well as hybridization reactions were carried out using 3DNA protocols and reagents (Genisphere). The genetic interaction of the Y chromosome and the mutation was studied by the following contrasts: 1) male flies Mod(mdg4)/+;Yohio versus male flies Mod(mdg4)/+;Ycongo; 2) male flies Su(var)205/+;Yohio versus male flies Su(var)205/+;Ycongo; 3) male flies JIL-1/+;Yohio versus male flies JIL-1/+;Ycongo). As reference we used the same genetic background without the mutations [+/+;Ycongo (background 2) and +/+;Yohio (background 2)]. Slides were scanned using Axon 400B scanner (Axon Instruments) and GenePix Pro 6.0 software. Foreground fluorescence of dye intensities was normalized by the Loess method in Bioconductor / Limma.

Dataset Information

Mutations in Su(var)205 and Su(var)3-7 suppress P-element-dependent silencing in Drosophila melanogaster.

Publications

Mutations in Su(var)205 and Su(var)3-7 suppress P-element-dependent silencing in Drosophila melanogaster.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure