scholarly journals GONADAL DYSGENESIS DETERMINANTS IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1986 ◽  
Vol 114 (3) ◽  
pp. 897-918
Author(s):  
Gail M Simmons
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Gonadal Dysgenesis ◽  
Population Genetic ◽  
Genetic Models ◽  
Hybrid Dysgenesis ◽  
Northern California ◽  
Evolutionary Force ◽  
Over Time ◽  
Balancer Chromosome

ABSTRACT Three populations of Drosophila melanogaster from northern California were surveyed for the ability to produce and resist gonadal dysgenesis in the P-M system of hybrid dysgenesis. Males from all three populations produced low to moderate levels of gonadal dysgenesis in crosses to Oregon-R M females. Most females had the P cytotype, but the M cytotype occurred occasionally. The three populations could not be statistically differentiated from one another, but were easily distinguished from populations from Australia and Wisconsin on the basis of gonadal dysgenesis potential. The California populations had higher levels of M cytotype than did the Wisconsin population. Thirteen Χ chromosomes and 11 pairs of autosomes were extracted from one of the California populations, using a modification of the standard balancer chromosome technique to suppress hybrid dysgenesis during extraction. All lines produced strongly skewed sterility distributions in crosses to M-strain females, and mean levels of sterility were less than 50%. There was evidence of nonadditive interactions between the autosomes. Most extraction lines had the P cytotype, but M and intermediate cytotypes were observed. Some of the intermediate cytotypes were stable over time. Lines were tested at two different times after extraction. Some lines evolved higher sterility potential as they were kept in the laboratory, even in the presence of P cytotype. The results point out a number of deficiencies in current genetic and population genetic models of hybrid dysgenesis and imply that gonadal dysgenesis is unlikely to be an important evolutionary force in this population.

scholarly journals Sterility-mutability correlation: On the correlation between sterility and mutability during P-M hybrid dysgenesis in Drosophila melanogaster

1987 ◽  
Vol 50 (1) ◽  
pp. 73-76 ◽  
Author(s):  
Gail M. Simmons
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Gonadal Dysgenesis ◽  
Hybrid Dysgenesis ◽  
Positive Correlations ◽  
The Relationship

SummaryTwelve isogenic X chromosome lines from a single natural population of Drosophila melanogaster were tested for their potential to induce gonadal dysgenesis and singed-weak mutability in P-M hybrid dysgenesis. The correlation between sterility and mutability was significantly positive for Cross A, confirming the results reported by Engels (1984) and Kocur, Drier & Simmons (1986). In Cross A* cytotype tests, however, two of the lines gave strikingly different results when measured by the gonadal dysgenesis test as compared to the singed-weak test. Positive correlations between traits within a given line were generally not observed. The results suggest that the relationship between gonadal dysgenesis production and the mobilization of P elements in singed-weak mutability is more complicated than that proposed by Engels (1984). The two phenomena may be separable under certain conditions. Neither test can be taken as an adequate characterization of the hybrid dysgenesis ‘profile’ of a line of flies.

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 Hybrid dysgenesis in Drosophila melanogaster: partial sterility associated with embryo lethality in the P-M system

1984 ◽  
Vol 44 (1) ◽  
pp. 11-28 ◽  
Author(s):  
Margaret G. Kidwell
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
Gonadal Development ◽  
Hybrid Dysgenesis ◽  
Sensitive Period ◽  
Temperature Sensitive ◽  
Hybrid Progeny ◽  
Partial Sterility ◽  
Embryo Lethality ◽  
Response To Temperature

SummaryVariable frequencies of unhatched eggs were observed to be produced by a number of F1 interstrain hybrids. This type of partial sterility resulting from F2 embryo death was found to be associated with the P-M system of hybrid dysgenesis. Dysgenic hybrid progeny of crosses between M strain females and P strain males may therefore have reduced fertility due to the disruption of development at two different stages: early F1 gonadal development and early F2 embryo development. These disruptions result in the previously described F1 gonadal dysgenesis (GD sterility) and F2 embryo lethality (EL sterility) respectively. The two morphologically distinct types of P-M-associated sterility differ in their patterns of response to F1 developmental temperature, and the temperature-sensitive period for EL sterility occurs considerably later in F1 development than for GD sterility. EL sterility is similar to SF sterility, which is associated with the I–R system of hybrid dysgenesis in that both result from death during early F2 embryogenesis. However, EL sterility differs from SF sterility in not being restricted to hybrids of the female sex and in showing different patterns of response to temperature and ageing in the F1 generation. Some implications of the existence of EL sterility for methods of strain classification in the I–R system are explored.

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 Temporal stability of P–M cytotype polymorphism in a natural population of Drosophila melanogaster

1987 ◽  
Vol 50 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Hassan Izaabel ◽  
Stephane Ronsseray ◽  
Dominique Anxolabéhère
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Natural Population ◽  
North Africa ◽  
Temporal Stability ◽  
Genetic Load ◽  
Hybrid Dysgenesis ◽  
P Element ◽  
High Rate ◽  
Genetic Abnormalities

SummaryThe P–M system of hybrid dysgenesis in Drosophila melanogaster is a syndrome of genetic abnormalities which appears in the progeny of crosses between strains different with regard to their possession of ‘P’ transposable elements. Cytotype is an extrachromosomal property which regulates the mobility of the P element. We report here data showing that a cytotype polymorphism previously observed in a natural population from North-Africa is stable over a period of 5 years. A potentially high rate of mutation is associated with this cytotype polymorphism. Explanations of the appearance of a cytotype polymorphism are proposed and the consequences for the genetic load induced by transposable elements are discussed.

scholarly journals Temperature-dependent gonadal hybrid dysgenesis in Drosophila willistoni

1999 ◽  
Vol 22 (2) ◽  
pp. 205-211 ◽  
Author(s):  
Luciana P. Regner ◽  
Eliana Abdelhay ◽  
Cláudia Rohde ◽  
Jaqueline J.S. Rodrigues ◽  
Vera Lucia S. Valente
Keyword(s):  
Transposable Elements ◽  
Natural Population ◽  
Gonadal Dysgenesis ◽  
The Other ◽  
Drosophila Species ◽  
Hybrid Dysgenesis ◽  
Temperature Dependent ◽  
Drosophila Willistoni ◽  
Laboratory Stock ◽  
Two Populations

Temperature-dependent gonadal dysgenesis was shown to occur in the progeny of both inter- and intrastrain crosses involving two populations of Drosophila willistoni, one of which was an old laboratory stock, and the other, freshly collected from a natural population. We propose that the phenomenon observed was caused by the mobilization of transposable elements, as occurs in several other Drosophila species.

scholarly journals The P-M Hybrid Dysgenesis Cline in Eastern Australian Drosophila melanogaster: Discrete P, Q and M Regions Are Nearly Contiguous

Genetics ◽  
1987 ◽  
Vol 115 (4) ◽  
pp. 737-745
Author(s):  
Ian A Boussy ◽  
Margaret G Kidwell
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
East Coast ◽  
New South ◽  
Hybrid Dysgenesis ◽  
Latitudinal Cline ◽  
Sharp Drop ◽  
Smooth Tests ◽  
South Wales ◽  
Two Populations

ABSTRACT The dramatic latitudinal cline in P-M hybrid dysgenesis characteristics along the east coast of Australia is not smooth. Tests of recent collections of Drosophila melanogaster from the southeastern coast define the previously described cline as comprising three discrete, apparently contiguous regions of P, Q and M phenotypes, respectively. Northern populations from Cairns (16.9°SLat) to Ourimbah (33.4°SLat) are phenotypically P; populations from Wollongong (34.4°SLat) to Eden (37.1°SLat) are Q; and populations from Genoa (37.5°SLat) to Cygnet (43.2°SLat) are M. The decline in P activity from northern Queensland (55-60% gonadal dysgenesis (GD) in cross A) to mid-New South Wales (20-30% GD in cross A) is gradual; proceeding south, there then is a sharp drop to Q populations (<10% GD in crosses A and A*). This drop in P activity occurs in only 150 km, across the urban and suburban area of Sydney. Q populations are then found south to Eden, but Genoa, only about 50 km further southeast, is clearly M (48% GD in cross A*), as are two populations further south. The two discontinuities in the P-M cline do not correspond to obvious climatic differences along the coast, nor to obvious barriers to dispersal of D. melanogaster. The cline has apparently not moved between 1983 and 1985-1986.

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