scholarly journals Repression of P element-mediated hybrid dysgenesis in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 124 (3) ◽  
pp. 663-676 ◽  
Author(s):  
M J Simmons ◽  
J D Raymond ◽  
K E Rasmusson ◽  
L M Miller ◽  
C F McLarnon ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effect ◽  
Gonadal Dysgenesis ◽  
De Novo ◽  
Inbred Lines ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
P Elements ◽  
Hybrid Offspring ◽  
Element Movement

Abstract Inbred lines derived from a strain called Sexi were analyzed for their abilities to repress P element-mediated gonadal dysgenesis. One line had high repression ability, four had intermediate ability and two had very low ability. The four intermediate lines also exhibited considerable within-line variation for this trait; furthermore, in at least two cases, this variation could not be attributed to recurring P element movement. Repression of gonadal dysgenesis in the hybrid offspring of all seven lines was due primarily to a maternal effect; there was no evidence for repression arising de novo in the hybrids themselves. In one of the lines, repression ability was inherited maternally, indicating the involvement of cytoplasmic factors. In three other lines, repression ability appeared to be determined by partially dominant or additive chromosomal factors; however, there was also evidence for a maternal effect that reduced the expression of these factors in at least two of the lines. In another line, repression ability seemed to be due to recessive chromosomal factors. All seven lines possessed numerous copies of a particular P element, called KP, which has been hypothesized to produce a polypeptide repressor of gonadal dysgenesis. This hypothesis, however, does not explain why the inbred Sexi lines varied so much in their repression abilities. It is suggested that some of this variation may be due to differences in the chromosomal position of the KP elements, or that other nonautonomous P elements are involved in the repression of hybrid dysgenesis in these lines.

scholarly journals Genetic and molecular analysis of repression in the P–M system of hybrid dysgenesis in Drosophila melanogaster

1991 ◽  
Vol 57 (3) ◽  
pp. 213-226 ◽  
Author(s):  
Ellen M. Heath ◽  
Michael J. Simmons
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effects ◽  
X Chromosome ◽  
Gonadal Dysgenesis ◽  
Inbred Lines ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
P Elements ◽  
Two Generations ◽  
Highly Correlated

SummaryTwelve inbred lines derived from an M′ strain of Drosophila melanogaster were used to study the repression of P-element-mediated hybrid dysgenesis. Initial assessments indicated that the lines differed in the ability to repress gonadal dysgenesis, and that this ability was highly correlated with the ability to repress snw hypermutability. Later assessments indicated that most of the lines with low or intermediate repression potential evolved to a state of higher repression potential; however, Southern analyses failed to reveal significant changes in the array of genomic P elements that could account for this evolution. In addition, none of the lines possessed the incomplete P element known as KP, which has been proposed to explain repression in some D. melanogaster strains. One of the lines maintained intermediate repression potential throughout the period of study (52 generations), indicating that the intermediate condition was not intrinsically unstable. Genetic analyses demonstrated that in some of the lines, repression potential was influenced by factors that were inherited maternally through at least two generations; however, these factors were not as influential as those in a classic P cytotype strain. Additional tests with a dysgenesis-inducing X chromosome called T-5 indicated that repression itself was mediated by a combination of maternal effects and paternally inherited factors that were expressed after fertilization. These tests also suggested that in some circumstances, the P transposase, or its message, might be transmitted through the maternal cytoplasm.

scholarly journals STERILITY AND HYPERMUTABILITY IN THE P-M SYSTEM OF HYBRID DYSGENESIS IN DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (4) ◽  
pp. 1147-1163
Author(s):  
Gordon J Kocur ◽  
Eric A Drier ◽  
Michael J Simmons
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Insertion Mutation ◽  
Eastern United States ◽  
X Chromosomes ◽  
P Elements ◽  
Y Chromosomes ◽  
Wild Strains

ABSTRACT Inbred wild strains of Drosophila melanogaster derived from the central and eastern United States were used to make dysgenic hybrids in the P-M system. These strains possessed P elements and the P cytotype, the condition that represses P element transposition. Their hybrids were studied for the mutability of the P element insertion mutation, snw, and for the incidence of gonadal dysgenesis (GD) sterility. All the strains tested were able to induce hybrid dysgenesis by one or both of these assays; however, high levels of dysgenesis were rare. Sets of X chromosomes and autosomes from the inbred wild strains were more effective at inducing GD sterility than were sets of Y chromosomes and autosomes. In two separate analyses, GD sterility was positively correlated with snw mutability, suggesting a linear relationship. However, one strain appeared to induce too much GD sterility for its level of snw destabilization, indicating an uncoupling of these two manifestations of hybrid dysgenesis.

scholarly journals Quantitative effects of P elements on hybrid dysgenesis in Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 124 (3) ◽  
pp. 647-662 ◽  
Author(s):  
K E Rasmusson ◽  
M J Simmons ◽  
J D Raymond ◽  
C F McLarnon
Keyword(s):  
Gonadal Dysgenesis ◽  
Quantitative Relationship ◽  
Inbred Lines ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
Insertion Mutation ◽  
Simple Relationship ◽  
P Elements ◽  
A Cell ◽  
Element Number

Abstract Genetic analyses involving chromosomes from seven inbred lines derived from a single M' strain were used to study the quantitative relationships between the incidence and severity of P-M hybrid dysgenesis and the number of genomic P elements. In four separate analyses, the mutability of snw, a P element-insertion mutation of the X-linked singed locus, was found to be inversely related to the number of autosomal P elements. Since snw mutability is caused by the action of the P transposase, this finding supports the hypothesis that genomic P elements titrate the transposase present within a cell. Other analyses demonstrated that autosomal transmission ratios were distorted by P element action. In these analyses, the amount of distortion against an autosome increased more or less linearly with the number of P elements carried by the autosome. Additional analyses showed that the magnitude of this distortion was reduced when a second P element-containing autosome was present in the genome. This reduction could adequately be explained by transposase titration; there was no evidence that it was due to repressor molecules binding to P elements and inhibiting their movement. The influence of genomic P elements on the incidence of gonadal dysgenesis was also investigated. Although no simple relationship between the number of P elements and the incidence of the trait could be discerned, it was clear that even a small number of elements could increase the incidence markedly. The failure to find a quantitative relationship between P element number and the incidence of gonadal dysgenesis probably reflects the complex etiology of this trait.

scholarly journals A hobo Transgene That Encodes the P-Element Transposase in Drosophila melanogaster: Autoregulation and Cytotype Control of Transposase Activity

Genetics ◽  
2002 ◽  
Vol 161 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Michael J Simmons ◽  
Kevin J Haley ◽  
Craig D Grimes ◽  
John D Raymond ◽  
Jarad B Niemi
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
P Element ◽  
Hsp70 Gene ◽  
Alternate Splicing ◽  
Male And Female ◽  
P Elements ◽  
Male Germline ◽  
Female Germline ◽  
Transposase Expression

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.

scholarly journals A novel repressor of P element transposition in Drosophila melanogaster

1998 ◽  
Vol 71 (1) ◽  
pp. 21-30 ◽  
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.

scholarly journals A particular P-element insertion is correlated to the P-induced hybrid dysgenesis repression in Drosophila melanogaster

1992 ◽  
Vol 60 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Dominique Higuet ◽  
Dominique Anxolabéhére ◽  
Danielle Nouaud
Keyword(s):  
Drosophila Melanogaster ◽  
Promoter Activity ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
P Elements ◽  
Element Insertion ◽  
Element Number

SummaryTransposable P elements in Drosophila melanogaster cause hybrid dysgenesis if their mobility is not repressed. The ability to regulate the dysgenic activity of the P elements depends on several mechanisms, one of which hypothesized that a particular deleted P element (the KP element) results in a non-susceptibility which is biparentally transmitted. In this study totally nonsusceptible lines, and susceptible lines containing exclusively KP elements (IINS2 line and IIS2 line) were isolated from a M' strain. We show that non-susceptibility is correlated with a particular insertion of one KP element located at the cytological site 47D1. The repression ability of the GD sterility is determined by a recessive chromosomal factor, and cannot be due to the KP-element number. Here the repression of the P mobility is associated with reduction of the P transcripts and the inhibition of P promoter activity.

Molecular analysis of the P-M gonadal dysgenesis cline in eastern Australian Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 119 (4) ◽  
pp. 889-902
Author(s):  
I A Boussy ◽  
M J Healy ◽  
J G Oakeshott ◽  
M G Kidwell
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Element ◽  
Gonadal Dysgenesis ◽  
Molecular Techniques ◽  
P Element ◽  
Latitudinal Cline ◽  
Deletion Derivative ◽  
P Elements ◽  
Regulatory Ability ◽  
Eastern Australia

Abstract The latitudinal cline in P-M gonadal dysgenesis potential in eastern Australia has been shown to comprise three regions which are, from north to south respectively, P, Q, and M, with the P-to-Q and Q-to-M transitions occurring over relatively short distances. The P element complements of 30 lines from different regions of the cline were determined by molecular techniques. The total amount of P element-hybridizing DNA was high in all lines, and it did not correlate in any obvious way with the P-M phenotypes of individual lines. The number of potentially full-sized P elements per genome was high in lines from the P regions, but variable or low among lines from the Q and M regions, and thus declined overall from north to south. A particular P element deletion-derivative, the KP element, occurred in all the tested lines. The number of KP elements was low in lines from the P region, much higher in lines from the Q region, and highest among lines from the M region, thus forming a cline reciprocal to that of the full-sized P elements. Another transposable element, hobo, which has been described as causing dysgenic traits similar to those of P-M hybrid dysgenesis, was shown to be present in all lines and to vary among them in number, but not in any latitudinal pattern. The P-M cline in gonadal dysgenesis potential can be inferred to be based on underlying clinal patterns of genomic P element complements. P activity of a line was positively correlated with the number of full-sized P elements in the line, and negatively correlated with the number of KP elements. Among Q and M lines, regulatory ability was not correlated with numbers of KP elements.

scholarly journals Comparison of the regulation of P elements in M and M′ strains of Drosophila melanogaster

1989 ◽  
Vol 54 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Stéphane Ronsseray ◽  
Monique Lehmann ◽  
Georges Periquet
Keyword(s):  
Drosophila Melanogaster ◽  
Copy Number ◽  
Gonadal Dysgenesis ◽  
Mixed Cultures ◽  
Hybrid Dysgenesis ◽  
P Elements ◽  
Copy Numbers ◽  
P Factor ◽  
P Type

SummaryM and M′ strains of Drosophila melanogaster in the P-M system of hybrid dysgenesis were compared in two series of tests, with the following results. (1) The singed-weak hypermutability regulation test showed that M′ strains had lower P excision rates than M strains, suggesting that P-elements repression must occur in M′ strains although it is not detectable by gonadal dysgenesis assays. (2) The evolution of mixed P + M and mixed P + M′ populations was compared, using a strong P strain. The P + M cultures invariably evolved in a few generations into strong P cultures, while the P + M′ cultures evolved into P-type cultures with reduced P-factor potentials. However, after 30 generations of culture, both these types of mixed cultures had similar P copy numbers, suggesting that regulation of copy number had occurred in them.

scholarly journals Maternal repression of the P element promoter in the germline of Drosophila melanogaster: a model for the P cytotype.

Genetics ◽  
1993 ◽  
Vol 135 (1) ◽  
pp. 149-160 ◽  
Author(s):  
B Lemaitre ◽  
S Ronsseray ◽  
D Coen
Keyword(s):  
Drosophila Melanogaster ◽  
Maternal Effect ◽  
Molecular Mechanisms ◽  
Maternal Inheritance ◽  
P Element ◽  
Fusion Genes ◽  
P Elements ◽  
Somatic Tissues ◽  
By Products

Abstract The transposition of P elements in Drosophila melanogaster is regulated by products encoded by the P elements themselves. The P cytotype, which represses transposition and associated phenomena, exhibits both a maternal effect and maternal inheritance. The genetic and molecular mechanisms of this regulation are complex and not yet fully understood. In a previous study, using P-lacZ fusion genes, we have shown that P element regulatory products were able to inhibit the activity of the P promoter in somatic tissues. However, the repression observed did not exhibit the maternal effect characteristic of the P cytotype. With a similar approach, we have assayed in vivo the effect of P element regulatory products in the germline. We show that the P cytotype is able to repress the P promoter in the germline as well as in the soma. Furthermore, this repression exhibits a maternal effect restricted to the germline. On the basis of these new observations, we propose a model for the mechanism of P cytotype repression and its maternal inheritance.

scholarly journals Har-P, a short P-element variant, weaponizes P-transposase to severely impair Drosophila development

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Satyam P Srivastav ◽  
Reazur Rahman ◽  
Qicheng Ma ◽  
Jasmine Pierre ◽  
Saptaparni Bandyopadhyay ◽  
...  
Keyword(s):  
Gonadal Dysgenesis ◽  
De Novo ◽  
Full Length ◽  
P Element ◽  
Drosophila Development ◽  
P Elements ◽  
Transposon Silencing ◽  
Somatic Transposition

Without transposon-silencing Piwi-interacting RNAs (piRNAs), transposition causes an ovarian atrophy syndrome in Drosophila called gonadal dysgenesis (GD). Harwich (Har) strains with P-elements cause severe GD in F1 daughters when Har fathers mate with mothers lacking P-element-piRNAs (i.e. ISO1 strain). To address the mystery of why Har induces severe GD, we bred hybrid Drosophila with Har genomic fragments into the ISO1 background to create HISR-D or HISR-N lines that still cause Dysgenesis or are Non-dysgenic, respectively. In these lines, we discovered a highly truncated P-element variant we named ‘Har-P’ as the most frequent de novo insertion. Although HISR-D lines still contain full-length P-elements, HISR-N lines lost functional P-transposase but retained Har-P’s that when crossed back to P-transposase restores GD induction. Finally, we uncovered P-element-piRNA-directed repression on Har-P’s transmitted paternally to suppress somatic transposition. The Drosophila short Har-P’s and full-length P-elements relationship parallels the MITEs/DNA-transposase in plants and SINEs/LINEs in mammals.

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