P element-mediated duplications of genomic regions in Drosophila melanogaster

Abstract Drosophila were genetically transformed with a hobo transgene that contains a terminally truncated but otherwise complete P element fused to the promoter from the Drosophila hsp70 gene. Insertions of this H(hsp/CP) transgene on either of the major autosomes produced the P transposase in both the male and female germlines, but not in the soma. Heat-shock treatments significantly increased transposase activity in the female germline; in the male germline, these treatments had little effect. The transposase activity of two insertions of the H(hsp/CP) transgene was not significantly greater than their separate activities, and one insertion of this transgene reduced the transposase activity of P(ry+, Δ2-3)99B, a stable P transgene, in the germline as well as in the soma. These observations suggest that, through alternate splicing, the H(hsp/CP) transgene produces a repressor that feeds back negatively to regulate transposase expression or function in both the somatic and germline tissues. The H(hsp/CP) transgenes are able to induce gonadal dysgenesis when the transposase they encode has P-element targets to attack. However, this ability and the ability to induce P-element excisions are repressed by the P cytotype, a chromosomal/cytoplasmic state that regulates P elements in the germline.

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The Regulatory Properties of Autonomous Subtelomeric P Elements Are Sensitive to a Suppressor of variegation in Drosophila melanogaster

Genetics ◽

10.1093/genetics/143.4.1663 ◽

1996 ◽

Vol 143 (4) ◽

pp. 1663-1674 ◽

Cited By ~ 3

Author(s):

Stéphane Ronsseray ◽

Monique Lehmann ◽

Danielle Nouaud ◽

Dominique Anxolabéhère

Keyword(s):

Drosophila Melanogaster ◽

Genetic Recombination ◽

Natural Populations ◽

P Element ◽

Single Element ◽

Heterochromatin Protein 1 ◽

X Chromosomes ◽

P Elements ◽

Associated Sequences ◽

Regulatory Properties

Abstract Genetic recombination was used in Drosophila melanogaster to isolate P elements, inserted at the telomeres of X chromosomes (cytological site 1A) from natural populations, in a genetic background devoid of other P elements. We show that complete maternally inherited P repression in the germline (P cytotype) can be elicited by only two autonomous P elements at 1A and that a single element at this site has partial regulatory properties. The analysis of the surrounding chromosomal regions of the P elements at 1A shows that in all cases these elements are flanked by Telomeric Associated Sequences, tandemly repetitive noncoding sequences that have properties of heterochromatin. In addition, we show that the regulatory properties of P elements at 1A can be inhibited by some of the mutant alleles of the Su(var)205 gene and by a deficiency of this gene. However, the regulatory properties of reference P strains (Harwich and Texas 007) are not impaired by Su(var)205 mutations. Su(var)205 encodes Heterochromatin Protein 1 (HP1). These results suggest that the HP1 dosage effect on the P element properties is sitedependent and could involve the structure of the chromatin.

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hobo enhancer trapping mutagenesis in Drosophila reveals an insertion specificity different from P elements.

Genetics ◽

10.1093/genetics/135.4.1063 ◽

1993 ◽

Vol 135 (4) ◽

pp. 1063-1076 ◽

Cited By ~ 2

Author(s):

D Smith ◽

J Wohlgemuth ◽

B R Calvi ◽

I Franklin ◽

W M Gelbart

Keyword(s):

Drosophila Melanogaster ◽

Transposable Element ◽

Enhancer Trap ◽

P Element ◽

Present Evidence ◽

P Elements ◽

Element Insertion ◽

Enhancer Trapping ◽

Indispensable Tool

Abstract P element enhancer trapping has become an indispensable tool in the analysis of the Drosophila melanogaster genome. However, there is great variation in the mutability of loci by these elements such that some loci are relatively refractory to insertion. We have developed the hobo transposable element for use in enhancer trapping and we describe the results of a hobo enhancer trap screen. In addition, we present evidence that a hobo enhancer trap element has a pattern of insertion into the genome that is different from the distribution of P elements in the available database. Hence, hobo insertion may facilitate access to genes resistant to P element insertion.

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Genetic and Molecular Characterization of sting, a Gene Involved in Crystal Formation and Meiotic Drive in the Male Germ Line of Drosophila melanogaster

Genetics ◽

10.1093/genetics/151.2.749 ◽

1999 ◽

Vol 151 (2) ◽

pp. 749-760 ◽

Cited By ~ 2

Author(s):

Armin Schmidt ◽

Gioacchino Palumbo ◽

Maria P Bozzetti ◽

Patrizia Tritto ◽

Sergio Pimpinelli ◽

...

Keyword(s):

Amino Acids ◽

Drosophila Melanogaster ◽

Null Allele ◽

Germ Line ◽

Meiotic Drive ◽

P Element ◽

Crystal Formation ◽

Male Sterile ◽

Male Sterile Mutation

Abstract The sting mutation, caused by a P element inserted into polytene region 32D, was isolated by a screen for male sterile insertions in Drosophila melanogaster. This sterility is correlated with the presence of crystals in spermatocytes and spermatids that are structurally indistinguishable from those produced in males carrying a deficiency of the Y-linked crystal (cry) locus. In addition, their morphology is needle-like in Ste+ flies and star-shaped in Ste flies, once again as observed in cry– males. The sti mutation leads to meiotic drive of the sex chromosomes, and the strength of the phenomenon is correlated with the copy number of the repetitive Ste locus. The same correlation is also true for the penetrance of the male sterile mutation. A presumptive sti null allele results in male sterility and lethal maternal effect. The gene was cloned and shown to code for a putative protein that is 866 amino acids long. A C-terminal domain of 82 amino acids is identified that is well conserved in proteins from different organisms. The gene is expressed only in the germline of both sexes. The interaction of sting with the Ste locus can also be demonstrated at the molecular level. While an unprocessed 8-kb Ste primary transcript is expressed in wild-type males, in X/Y homozygous sti males, as in X/Y cry– males, a 0.7-kb mRNA is produced.

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Identification of Chromosome Inheritance Modifiers in Drosophila melanogaster

Genetics ◽

10.1093/genetics/157.4.1623 ◽

2001 ◽

Vol 157 (4) ◽

pp. 1623-1637 ◽

Cited By ~ 7

Author(s):

Kenneth W Dobie ◽

Cameron D Kennedy ◽

Vivienne M Velasco ◽

Tory L McGrath ◽

Juliani Weko ◽

...

Keyword(s):

Drosophila Melanogaster ◽

Biological Activity ◽

Cancer Progression ◽

Birth Defects ◽

Mitotic Chromosome ◽

P Element ◽

Inverse Pcr ◽

Gtpase Activating Protein ◽

New Genes ◽

Genomic Analyses

Abstract Faithful chromosome inheritance is a fundamental biological activity and errors contribute to birth defects and cancer progression. We have performed a P-element screen in Drosophila melanogaster with the aim of identifying novel candidate genes involved in inheritance. We used a “sensitized” minichromosome substrate (J21A) to screen ∼3,000 new P-element lines for dominant effects on chromosome inheritance and recovered 78 Sensitized chromosome inheritance modifiers (Scim). Of these, 69 decreased minichromosome inheritance while 9 increased minichromosome inheritance. Fourteen mutations are lethal or semilethal when homozygous and all exhibit dramatic mitotic defects. Inverse PCR combined with genomic analyses identified P insertions within or close to genes with previously described inheritance functions, including wings apart-like (wapl), centrosomin (cnn), and pavarotti (pav). Further, lethal insertions in replication factor complex 4 (rfc4) and GTPase-activating protein 1 (Gap1) exhibit specific mitotic chromosome defects, discovering previously unknown roles for these proteins in chromosome inheritance. The majority of the lines represent mutations in previously uncharacterized loci, many of which have human homologs, and we anticipate that this collection will provide a rich source of mutations in new genes required for chromosome inheritance in metazoans.

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Trans-acting Factors Required for Inclusion of Regulated Exons in the Ultrabithorax mRNAs of Drosophila melanogaster

Genetics ◽

10.1093/genetics/151.4.1517 ◽

1999 ◽

Vol 151 (4) ◽

pp. 1517-1529 ◽

Cited By ~ 2

Author(s):

James M Burnette ◽

Allyson R Hatton ◽

A Javier Lopez

Keyword(s):

Drosophila Melanogaster ◽

Alternative Splicing ◽

P Element ◽

Splicing Factors ◽

Loss Of Function ◽

Large Collection ◽

Splicing Pattern ◽

Alternatively Spliced ◽

Hypomorphic Alleles

Abstract Alternatively spliced Ultrabithorax mRNAs differ by the presence of internal exons mI and mII. Two approaches were used to identify trans-acting factors required for inclusion of these cassette exons. First, mutations in a set of genes implicated in the control of other alternative splicing decisions were tested for dominant effects on the Ubx alternative splicing pattern. To identify additional genes involved in regulation of Ubx splicing, a large collection of deficiencies was tested first for dominant enhancement of the haploinsufficient Ubx haltere phenotype and second for effects on the splicing pattern. Inclusion of the cassette exons in Ubx mRNAs was reduced strongly in heterozygotes for hypomorphic alleles of hrp48, which encodes a member of the hnRNP A/B family and is implicated in control of P-element splicing. Significant reductions of mI and mII inclusion were also observed in heterozygotes for loss-of-function alleles of virilizer, fl(2)d, and crooked neck. The products of virilizer and fl(2)d are also required for Sxl autoregulation at the level of splicing; crooked neck encodes a protein with structural similarities to yeast-splicing factors Prp39p and Prp42p. Deletion of at least five other loci caused significant reductions in the inclusion of mI and/or mII. Possible roles of identified factors are discussed in the context of the resplicing strategy for generation of alternative Ubx mRNAs.

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A novel repressor of P element transposition in Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672397003066 ◽

1998 ◽

Vol 71 (1) ◽

pp. 21-30 ◽

Cited By ~ 4

Author(s):

RICHARD M. BADGE ◽

JOHN F. Y. BROOKFIELD

Keyword(s):

Drosophila Melanogaster ◽

Inbred Line ◽

Gonadal Dysgenesis ◽

Full Length ◽

P Element ◽

Temperature Dependent ◽

P Elements

We have discovered, in an inbred line (Loua) of Drosophila melanogaster from Zaïre, a third chromosome showing unusual P element repression. Repression of P element transposition by this chromosome, named Loua3, is dominant zygotic and has three unusual properties. Firstly, its repression of the gonadal dysgenesis caused by a strong P haplotype is strongly temperature-dependent, being most evident at higher rearing temperatures. Secondly, subdivision of Loua3 by recombination abolishes repression: the effect is apparently a function of the intact chromosome. Finally, Loua3 also diminishes somatic lethality when chromosomes carrying many ‘ammunition’ elements (Birmingham2) are exposed to the constitutive transposase source Δ2-3(99B). The chromosome has 17 P elements, none full-length, located in at least 12 dispersed positions.

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The P-element-induced silencing effect of KP transposons is dose dependent in Drosophila melanogaster

Genome ◽

10.1139/g11-023 ◽

2011 ◽

Vol 54 (9) ◽

pp. 752-762 ◽

Cited By ~ 7

Author(s):

Alireza Sameny ◽

John Locke

Keyword(s):

Drosophila Melanogaster ◽

Critical Role ◽

Mutagenic Effect ◽

P Element ◽

Dependent Manner ◽

Concentration Dependent Manner ◽

P Elements ◽

Single Well ◽

Dose Dependent

Transposable elements are found in the genomes of all eukaryotes and play a critical role in altering gene expression and genome organization. In Drosophila melanogaster, transposable P elements are responsible for the phenomenon of hybrid dysgenesis. KP elements, a deletion-derivative of the complete P element, can suppress this mutagenic effect. KP elements can also silence the expression of certain other P-element-mediated transgenes in a process called P-element-dependent silencing (PDS), which is thought to involve the recruitment of heterochromatin proteins. To explore the mechanism of this silencing, we have mobilized KP elements to create a series of strains that contain single, well-defined KP insertions that show PDS. To understand the quantitative role of KP elements in PDS, these single inserts were combined in a series of crosses to obtain genotypes with zero, one, or two KP elements, from which we could examine the effect of KP gene dose. The extent of PDS in these genotypes was shown to be dose dependent in a logarithmic rather than linear fashion. A logarithmic dose dependency is consistent with the KP products interacting with heterochromatic proteins in a concentration-dependent manner such that two molecules are needed to induce gene silencing.

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Cytoplasmic dynein (ddlc1) mutations cause morphogenetic defects and apoptotic cell death in Drosophila melanogaster.

Molecular and Cellular Biology ◽

10.1128/mcb.16.5.1966 ◽

1996 ◽

Vol 16 (5) ◽

pp. 1966-1977 ◽

Cited By ~ 104

Author(s):

T Dick ◽

K Ray ◽

H K Salz ◽

W Chia

Keyword(s):

Drosophila Melanogaster ◽

Light Chain ◽

Blot Analysis ◽

Cytoplasmic Dynein ◽

P Element ◽

Female Sterility ◽

Dynein Light Chain ◽

Loss Of Function ◽

Light Chain Gene

We report the molecular and genetic characterization of the cytoplasmic dynein light-chain gene, ddlc1, from Drosophila melanogaster. ddlc1 encodes the first cytoplasmic dynein light chain identified, and its genetic analysis represents the first in vivo characterization of cytoplasmic dynein function in higher eucaryotes. The ddlc1 gene maps to 4E1-2 and encodes an 89-amino-acid polypeptide with a high similarity to the axonemal 8-kDa outer-arm dynein light chain from Chlamydomonas flagella. Developmental Northern (RNA) blot analysis and ovary and embryo RNA in situ hybridizations indicate that the ddlc1 gene is expressed ubiquitously. Anti-DDLC1 antibody analyses show that the DDLC1 protein is localized in the cytoplasm. P-element-induced partial-loss-of-function mutations cause pleiotropic morphogenetic defects in bristle and wing development, as well as in oogenesis, and hence result in female sterility. The morphological abnormalities found in the ovaries are always associated with a loss of cellular shape and structure, as visualized by a disorganization of the actin cytoskeleton. Total-loss-of-function mutations cause lethality. A large proportion of mutant animals degenerate during embryogenesis, and the dying cells show morphological changes characteristic of apoptosis, namely, cell and nuclear condensation and fragmentation, as well as DNA degradation. Cloning of the human homolog of the ddlc1 gene, hdlc1, demonstrates that the dynein light-chain 1 is highly conserved in flies and humans. Northern blot analysis and epitope tagging show that the hdlc1 gene is ubiquitously expressed and that the human dynein light chain 1 is localized in the cytoplasm. hdlc1 maps to 14q24.

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Generation and early differentiation of glial cells in the first optic ganglion of Drosophila melanogaster

Development ◽

10.1242/dev.115.4.903 ◽

1992 ◽

Vol 115 (4) ◽

pp. 903-911 ◽

Cited By ~ 6

Author(s):

M.L. Winberg ◽

S.E. Perez ◽

H. Steller

Keyword(s):

Drosophila Melanogaster ◽

Glial Cells ◽

Enhancer Trap ◽

P Element ◽

Cell Divisions ◽

Genetic Mosaic ◽

First Optic Ganglion ◽

Optic Ganglion ◽

Glial Lineage ◽

Enhancer Trap Lines

We have examined the generation and development of glial cells in the first optic ganglion, the lamina, of Drosophila melanogaster. Previous work has shown that the growth of retinal axons into the developing optic lobes induces the terminal cell divisions that generate the lamina monopolar neurons. We investigated whether photoreceptor ingrowth also influences the development of lamina glial cells, using P element enhancer trap lines, genetic mosaics and birthdating analysis. Enhancer trap lines that mark the differentiating lamina glial cells were found to require retinal innervation for expression. In mutants with only a few photoreceptors, only the few glial cells near ingrowing axons expressed the marker. Genetic mosaic analysis indicates that the lamina neurons and glial cells are readily separable, suggesting that these are derived from distinct lineages. Additionally, BrdU pulse-chase experiments showed that the cell divisions that produce lamina glia, unlike those producing lamina neurons, are not spatially or temporally correlated with the retinal axon ingrowth. Finally, in mutants lacking photoreceptors, cell divisions in the glial lineage appeared normal. We conclude that the lamina glial cells derive from a lineage that is distinct from that of the L-neurons, that glia are generated independently of photoreceptor input, and that completion of the terminal glial differentiation program depends, directly or indirectly, on an inductive signal from photoreceptor axons.

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