Minos as a Genetic and Genomic Tool in Drosophila melanogaster

Abstract

Much of the information about the function of D. melanogaster genes has come from P-element mutagenesis. The major drawback of the P element, however, is its strong bias for insertion into some genes (hotspots) and against insertion into others (coldspots). Within genes, 59-UTRs are preferential targets. For the successful completion of the Drosophila Genome Disruption Project, the use of transposon vectors other than P will be necessary. We examined here the suitability of the Minos element from Drosophila hydei as a tool for Drosophila genomics. Previous work has shown that Minos, a member of the Tc1/mariner family of transposable elements, is active in diverse organisms and cultured cells; it produces stable integrants in the germ line of several insect species, in the mouse, and in human cells. We generated and analyzed 96 Minos integrations into the Drosophila genome and devised an efficient ''jumpstarting'' scheme for production of single insertions. The ratio of insertions into genes vs. intergenic DNA is consistent with a random distribution. Within genes, there is a statistically significant preference for insertion into introns rather than into exons. About 30% of all insertions were in introns and 55% of insertions were into or next to genes that have so far not been hit by the P element. The insertion sites exhibit, in contrast to other transposons, little sequence requirement beyond the TA dinucleotide insertion target. We further demonstrate that induced remobilization of Minos insertions can delete nearby sequences. Our results suggest that Minos is a useful tool complementing the P element for insertional mutagenesis and genomic analysis in Drosophila. O NE of the main goals of modern genetics is to link the many thousands of genes identified through the sequencing of whole genomes of model organisms to gene function. The most powerful technique for this purpose so far has been transgenesis with mobile elements. This technique is a means to disrupt, overexpress, or misexpress single genes to identify expression patterns and also to characterize genetic pathways and their interactions. One of the main advantages of insertional mutagenesis over the classical method of chemical mutagenesis is the ease with which the targeted gene can be identified, since it carries an inserted tag.The P element was the first mobile element that enabled germ-line transformation of an insect species (Rubin and Spradling 1982). Since then, thousands of single P-element insertions causing lethality, semilethality, sterility, semisterility, and visible phenotypes have been created and analyzed in Drosophila (Cooley et al.

The Drosophila DAXX-Like Protein (DLP) Cooperates with ASF1 for H3.3 Deposition and Heterochromatin Formation

“…To analyze the function of Drosophila DLP in vivo, we generated mutant alleles of dlp by the imprecise excision of the Minos element present in the Mi(ET1)Daxx MB03646 line (24,25). The Minos element was inserted in the middle of dlp (Fig.…”

Editing Transgenic DNA Components by Inducible Gene Replacement in Drosophila melanogaster

“…In comparison, the HACK method at best requires only a single F 1 cross to yield a swap (e.g., 100% efficiency). In addition, the crossing schemes required for P-element swapping are more complicated, and since it requires the replacement of one P element for another, it cannot be applied to transgenic components generated using other transposons, such as piggyBac (Handler et al 1998) or Minos (Metaxakis et al 2005). Furthermore, since piggyBac and Minos elements excise precisely during transposition, transgenes generated by these elements are not amendable to similar transposase-mediated replacement strategies.…”

In vivo detection of lamellocytes in Drosophila melanogaster

“…The 3xP3 promoter also shows an expression pattern similar to that of the eyeless driver, which appears in the eye discus, brain, gut and anal plate (Fig. 1A, arrowheads) showing up as a background fluorescence appearing in all stocks carrying the MiET1 element [16]. The insertion blocks the expression of the Atilla protein encoded by the atilla gene, but does not affect the expression of other, independent lamellocyte-specific markers [10], as L2 and L6 (Fig.…”