Limits...
History of the discovery of a master locus producing piRNAs: the flamenco/COM locus in Drosophila melanogaster.

Goriaux C, Théron E, Brasset E, Vaury C - Front Genet (2014)

Bottom Line: The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998.As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals.Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire GReD, Faculté de Médecine, Clermont Université - Université d'Auvergne, Clermont-Ferrand France ; INSERM, U 1103, Clermont-Ferrand France ; CNRS, UMR 6293, Clermont-Ferrand France.

ABSTRACT
The discovery of transposable elements (TEs) in the 1950s by B. McClintock implied the existence of cellular regulatory systems controlling TE activity. The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998. As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals. Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets.

No MeSH data available.


The Rev line: (A) History of the unstable line, Rev, recovered after a PM mutagenesis performed on the wIR6 line. In Rev, recurrent mutations affecting the eye color are recovered giving rise to derived lines successively called RevI, RevII, RevIII, and RevIV. (B) FISH mapping of ZAM (red) and Idefix (yellow) in wIR6 (left) and Rev (right). (C) Molecular structure of different alleles of the white gene recovered in the Rev lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4120762&req=5

Figure 1: The Rev line: (A) History of the unstable line, Rev, recovered after a PM mutagenesis performed on the wIR6 line. In Rev, recurrent mutations affecting the eye color are recovered giving rise to derived lines successively called RevI, RevII, RevIII, and RevIV. (B) FISH mapping of ZAM (red) and Idefix (yellow) in wIR6 (left) and Rev (right). (C) Molecular structure of different alleles of the white gene recovered in the Rev lines.

Mentions: In 1997, an unstable line called Rev was recovered after a PM mutagenesis performed on the line bearing the wIR6 allele (Leblanc et al., 1997; Figure 1A). The wIR6 allele is due to the insertion of the non-LTR retrotransposon I-factor into the first intron of the white gene. It gives an orange eye phenotype to flies (Lajoinie et al., 1995). From the PM mutagenesis (Robertson et al., 1988), a fly with a wild-type red-eye phenotype was recovered and established as a line subsequently called Rev because of the eye phenotype reversion from orange to red. It was found that the white locus had suffered a 8.4 kb insertion 3 kb upstream from the white start site of transcription (TSS; Figure 1C). This insertion corresponded to a novel TE from the gypsy-family that was previously uncharacterized and that has been named ZAM (Leblanc et al., 1997). ZAM did not only insert upstream of white. In situ hybridization and Southern analyses performed on the Rev genome revealed the presence of some 20 copies of ZAM, whereas ZAM was not found on the chromosomal arms of the original parental line wIR6 (Figure 1B; Desset et al., 1999). From Rev, a series of mutations affecting eye coloration has been recovered, most of them affecting the white locus (Figure 1A). This second event of mutation resulted from the insertion of a novel gypsy-like transposable element designated Idefix that inserted 1.7 kb upstream of the TSS of the white gene. This second mutational event was recovered as a recurrent specific mutation in 11 independent individuals (Figures 1A,C; Desset et al., 1999). Genome analysis of Rev revealed that this line also suffered a recent and massive invasion of Idefix (Figure 1B).


History of the discovery of a master locus producing piRNAs: the flamenco/COM locus in Drosophila melanogaster.

Goriaux C, Théron E, Brasset E, Vaury C - Front Genet (2014)

The Rev line: (A) History of the unstable line, Rev, recovered after a PM mutagenesis performed on the wIR6 line. In Rev, recurrent mutations affecting the eye color are recovered giving rise to derived lines successively called RevI, RevII, RevIII, and RevIV. (B) FISH mapping of ZAM (red) and Idefix (yellow) in wIR6 (left) and Rev (right). (C) Molecular structure of different alleles of the white gene recovered in the Rev lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4120762&req=5

Figure 1: The Rev line: (A) History of the unstable line, Rev, recovered after a PM mutagenesis performed on the wIR6 line. In Rev, recurrent mutations affecting the eye color are recovered giving rise to derived lines successively called RevI, RevII, RevIII, and RevIV. (B) FISH mapping of ZAM (red) and Idefix (yellow) in wIR6 (left) and Rev (right). (C) Molecular structure of different alleles of the white gene recovered in the Rev lines.
Mentions: In 1997, an unstable line called Rev was recovered after a PM mutagenesis performed on the line bearing the wIR6 allele (Leblanc et al., 1997; Figure 1A). The wIR6 allele is due to the insertion of the non-LTR retrotransposon I-factor into the first intron of the white gene. It gives an orange eye phenotype to flies (Lajoinie et al., 1995). From the PM mutagenesis (Robertson et al., 1988), a fly with a wild-type red-eye phenotype was recovered and established as a line subsequently called Rev because of the eye phenotype reversion from orange to red. It was found that the white locus had suffered a 8.4 kb insertion 3 kb upstream from the white start site of transcription (TSS; Figure 1C). This insertion corresponded to a novel TE from the gypsy-family that was previously uncharacterized and that has been named ZAM (Leblanc et al., 1997). ZAM did not only insert upstream of white. In situ hybridization and Southern analyses performed on the Rev genome revealed the presence of some 20 copies of ZAM, whereas ZAM was not found on the chromosomal arms of the original parental line wIR6 (Figure 1B; Desset et al., 1999). From Rev, a series of mutations affecting eye coloration has been recovered, most of them affecting the white locus (Figure 1A). This second event of mutation resulted from the insertion of a novel gypsy-like transposable element designated Idefix that inserted 1.7 kb upstream of the TSS of the white gene. This second mutational event was recovered as a recurrent specific mutation in 11 independent individuals (Figures 1A,C; Desset et al., 1999). Genome analysis of Rev revealed that this line also suffered a recent and massive invasion of Idefix (Figure 1B).

Bottom Line: The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998.As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals.Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets.

View Article: PubMed Central - PubMed

Affiliation: Laboratoire GReD, Faculté de Médecine, Clermont Université - Université d'Auvergne, Clermont-Ferrand France ; INSERM, U 1103, Clermont-Ferrand France ; CNRS, UMR 6293, Clermont-Ferrand France.

ABSTRACT
The discovery of transposable elements (TEs) in the 1950s by B. McClintock implied the existence of cellular regulatory systems controlling TE activity. The discovery of flamenco (flam) an heterochromatic locus from Drosophila melanogaster and its ability to survey several TEs such as gypsy, ZAM, and Idefix contributed to peer deeply into the mechanisms of the genetic and epigenetic regulation of TEs. flam was the first cluster producing small RNAs to be discovered long before RNAi pathways were identified in 1998. As a result of the detailed genetic analyses performed by certain laboratories and of the sophisticated genetic tools they developed, this locus has played a major role in our understanding of piRNA mediated TE repression in animals. Here we review the first discovery of this locus and retrace decades of studies that led to our current understanding of the relationship between genomes and their TE targets.

No MeSH data available.