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  • 1
    Electronic Resource
    Electronic Resource
    Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster (1974)
    Springer
    Development genes and evolution 174 (1974), S. 313-332 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In ring/rod-X-chromosome heterozygotes the ring-X-chromosome is frequently lost in the early cleavage mitoses. The resulting gynandromorphs are mosaics with female XX- and male XO-areas. The phenotypes of the recessive alleles on the rod-X-chromosome are expressed in the XO-areas. The genemaroonlike (mal) on the X-chromosome influences the activity of the enzyme aldehyde oxidase. This fact was used to test the cell autonomy of aldehyde oxidase activity by histochemical methods in gynandromorphs of the genotypesR(1)2,In(1)w vC /y w mal andR(1)2,In(1)w vC /y w sn 3 lz 50e mal. The results show that in the cells of the imaginal Malpighian tubules the phenotypes ofwhite (w) andmaroonlike (mal) always occur together; XX-cells are pigmented and show aldehyde oxidase activity, whereas colorless XO-cells have no such enzyme activity (Figs. 1 and 2). This cell autonomy of aldehyde oxidase activity most likely applies also to the imaginal gut and the inner genitalia. The distribution of XX- and XO-areas in the Malpighian tubules, the gut and the inner genitalia was examined in 355 gynandromorphs. Approximately half of the gynanders have Malpighian tubules with an XX/XO-mosaic (Table 1, 2 and 3). A large fraction of the mosaic tubules (62%; Table 4) shows a pattern of alternating small cell clusters of different genotypes. It is supposed that this pattern develops during the formation of the tubes, especially during their elongation. The number of primitive Malpighian cells is estimated to be about 140. 72% of the gynanders have mosaic guts (Table 1 and 5). The border between tissues of different genotypes is found very frequently in the posterior third of the anterior midgut (Fig. 3) and may correspond to the border between the tissues which develop from the anterior and posterior midgut rudiments. The estimates of the numbers of primitive cells for the gut structures are 2–3, as far as the crop, the cardia and the rectal valve are concerned, whereas a number of several hundred is estimated for the anterior as well as for the posterior midgut. Mosaics were also found in the inner genitalia consisting of combinations of male and female structures. In 16 gynandromorphs the paragonia or the ductus ejaculatorius were mosaic (Fig. 4); i.e. in male structures with XO-genotype areas with aldehyde oxidase activity were found. Nothing is known about the origin of these XX-cells, but the possibility must be considered that in gynandromorphs cells of female genotype can participate in the development of male genital structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00579119
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  • 2
    Electronic Resource
    Electronic Resource
    Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster (1974)
    Springer
    Development genes and evolution 174 (1974), S. 349-359 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Die Verteilung von XX- und XO-Bereichen auf der Kutikula und in den inneren Organen wurde bei 355 adulten Gynandern des GenotypsR(1)2,In(1)w vC /y w sn 3 lz 50e mal registriert. XO-Bereiche konnten an den Phänotypen der rezessiven Allele des Stab-X-Chromosoms erkannt werden. Der prozentuale Anteil der Gynander, bei denen jeweils zwei betrachtete Strukturen unterschiedlichen Genotyp haben, gilt als Maß (in Sturt-Einheiten) für den Abstand präsumptiver Bereiche dieser Strukturen in frühen Entwicklungsstadien. Der Vergleich der hier gefundenen Abstände zwischen Kutikularstrukturen mit den von Hotta und Benzer (1972) berechneten ergab eine große Übereinstimmung (Tabelle 2). Daher wurden die Strukturen der untersuchten inneren Organe in den Anlageplan von Hotta und Benzer eingeordnet. Dieser erweiterte morphogenetische Plan (Abb. 1) wird im Vergleich mit Poulson's embryonalem Anlageplan diskutiert. Für die kritische Beurteilung des Manuskripts danke ich Dr. H. J. Becker, Dr. A. Garcia-Bellido, Dr. K. Heckmann und Dr. R. Nöthiger sehr. Mein Dank gilt ebenso Herrn cand. rer. nat. B. Eickenscheidt für die Computerauswertung, Frl. R. Münster und Frl. A. Termathe für ihre ausgezeichnete technische Assistenz, Frau M. Kleine-Schonnefeld für die Ausführung der Abbildungen und der Deutschen Forschungsgemeinschaft für die finanzielle Unterstützung.
    Notes: Summary The distribution of XX- and XO-areas within the cuticle and in the internal organs was examined in 355 adult gynandromorphs of the genotypeR(1)2,In(1)w vC /y w sn 3 lz 50e mal, whereby XO-areas could be recognized by the phenotypes of the recessive alleles on the rod-X-chromosome. The percentage of gynandromorphs in which selected pairs of structures show different genotypes is taken as a measurement (in sturt-units) for the distance between the presumptive areas of these structures in early developmental stages. The calculated distances between cuticular structures (Table 2) agree well with those reported by Hotta and Benzer (1972). The structures of internal organs were therefore localized in the fate map of Hotta and Benzer. The resulting morphogenetic map (Fig. 1) is discussed in comparison with Poulson's embryonic fate map.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00579123
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  • 3
    Electronic Resource
    Electronic Resource
    Entwicklungsgenetische Untersuchungen an Gynandern vonDrosophila melanogaster (1976)
    Springer
    Development genes and evolution 179 (1976), S. 349-372 
    Details
    ISSN: 1432-041X
    Keywords: Insect Development ; Genetic Mosaics ; Fate Maps ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Gynandromorphs with female XX-and male XO-areas result from the loss of an unstable ring-X-chromosome in the early cleavage mitoses of ring/rod-X-chromosome heterozygotes. The phenotypes of the recessive alleles on the rod-X-chromosome are expressed in the XO-areas. 377 larval gynandromorphs of the genotypeR(1)2, In(1)w vC /y w sn3Iz50e mal were examined and scored for the phenotypes of 13 paired and 10 unpaired structures (Table 2, Fig. 2). This was possible mainly by the cell-autonomous expression of aldehyde oxidase activity in soft tissues and by the comparison of the distribution of enzyme activity in wildtype and gynander larvae. The distances between pairs of structures were calculated in sturt-units (Tables 3 and 4). A morphogenetic fate map with the presumptive areas of larval structures was constructed (Fig. 3). The relative positions of the structures agree well with Poulson's fate map (Fig. 4). In addition, the distribution of phenotypes was scored in 380 adult gynandromorphs Table (5). The fate map (Fig. 5) which was constructed from these data is very similar to the fate map of larval structures. This similarity becomes even more pronounced if fate maps are constructed which contain only structures analogous in larva and imago (Table 6, Fig. 6). Therefore an attempt was made to set up an integrated morphogenetic fate map containing the presumptive areas of both larval and imaginal structures (Fig. 7). The possibilities of further blastoderm mapping are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848243
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  • 4
    Electronic Resource
    Electronic Resource
    Clonal analysis of the blastoderm anlage of the Malpighian tubules in Drosophila melanogaster (1986)
    Springer
    Development genes and evolution 195 (1986), S. 22-32 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Cell lineage ; Malpighian tubules ; Compartments ; Cell death
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Genetically marked maroon-like (mal) clones were induced by mitotic recombination with X-rays at the blastoderm stage in mal/mal + heterozygotes and were analysed in differentiated Malpighian tubules (MT). Marked cells were not confined to single anterior (MA) or posterior (MP) tubules, but were distributed among the four tubules. About 70% of the clones with two or more cells were fragmented, i.e. mal cells were separated by wild-type cells. Since the clones contain, on average, 6 cells and the differentiated MT consist of 484 cells (2 × 136 MA cells, 2 × 106 MP cells), we estimate that there are about 80 cells in the blastoderm anlage which on average pass through two to three mitoses. With increasing radiation doses (254 R, 635 R, 1270 R) a linear increase in clone frequency is observed. The mean sizes and size distributions of clones, however, remain unchanged. Since the increasing radiation dose also results in fewer differentiated Malpighi cells, we assume that regeneration does not occur. Therefore, size distributions of marked clones presumably represent real mitotic patterns in normogenesis. We suggest that essentially three successive mitoses take place, with a decreasing fraction of cells showing mitotic activity. Only a small fraction of cells goes through a fourth or even a fifth mitosis. Marked non-Minute clones induced in Minute heterozygotes are more frequent, but are not larger than non-Minute clones in wild-type background. Therefore, compartment boundaries cannot be recognized by this method. However, frequencies of marked cells found simultaneously in MA and MP pairs or in several single tubules of the same individuals are significantly higher than frequencies of multiple recombination events predicted by the Poisson distribution. From this, we conclude that neither the MA pair nor the MP pair nor single tubules represent compartments of the MT anlage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00444038
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  • 5
    Electronic Resource
    Electronic Resource
    Autonome Determination für Pigmentbildung beimwhite-Positionseffekt vonDrosophila melanogaster (1971)
    Springer
    Development genes and evolution 168 (1971), S. 362-366 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Beimwhite-Positionseffekt vonDrosophila melanogaster findet die Determination für Pigmentbildungspotenzen der Augenzellen am Ende des ersten Larvenstadiums statt. Augenimaginalscheiben wurden vor oder nach diesem Zeitpunkt zusammen mit möglichst wenig larvalem Gewebe aus Larven entnommen und in die Abdomina adulter Weibchen transplantiert. Nach einer Kultivierungsdauer von 5–7 Tagen wurden die Implantate in Larven rücktransplantiert, mit denen sie die Metamorphose durchliefen. Es konnte gezeigt werden, daß die Augenanlagezellen auch während der Kultivierungsperiode im Adultabdomen autonom determiniert werden. Ein Einfluß mittransplantierten Larvalgewebes auf die Determination konnte nicht nachgewiesen werden. Dieser Determinationsvorgang ist daher sehr wahrscheinlich unabhängig vom spezifischen Larvalmilieu.
    Notes: Summary Inwhite position-effect ofDrosophila melanogaster, determination for the potential of pigment formation of eye cells takes place at the end of the first larval instar. Eye discs, prior to or after this developmental stage, were transplanted together with some larval tissue into the abdomens of adult females. After a cultivation period of 5 to 7 days, the implants were transplanted back into larvae. Imaginal differentiation occurred in these metamorphosing hosts. It could be shown that eye disc cells become autonomously determined during the cultivation period. An influence of the larval tissues transplanted together with the eye discs on determination could not be demonstrated. Therefore, this determinative event most likely is independent on the specific larval milieu.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00582932
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  • 6
    Electronic Resource
    Electronic Resource
    Cell lineage restrictions in the genital disc ofDrosophila revealed byMinute gynandromorphs (1983)
    Springer
    Development genes and evolution 192 (1983), S. 337-346 
    Details
    ISSN: 1432-041X
    Keywords: Drosophila ; Gynandromorphs ; Genital disc ; Compartments ; Evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The genital imaginal disc ofDrosophila differentiates the terminalia, i.e. the genitalia and analia, of both sexes. It represents a composite anlage, containing a female genital primordium, a male genital primordium and an anal primordium. In normal males and females, only one of the two genital primordia differentiates; the other is developmentally repressed. Therefore, cell-lineage relationships between the male and female genital primordia can only be studied in sexual mosaics which differentiate female and male cells. We producedMinute (M)‖non-Minute(M+) gynandromorphs and selected those with sexually mosaic terminalia for a cell-lineage analysis. In these mosaics, either the male (XO) or female (XX) cells wereM + and thus had a growth advantage. The differential growth rates served as a tool to detect clonal restrictions. In control gynandromorphs (M +‖M +), the amount of female genitalia differentiated was largely independent of the amount of male genitalia present. In contrast, male and female anal structures, as a rule, added up to one full set. The same was true for the experimentalM‖M + gynandromorphs, but the contribution ofXX andXO cells to mosaic terminalia changed drastically due toM + cells competing successfully against the more slowly growingM cells. Specific subsamples ofM‖M + gynandromorphs showed thatM cells in a non-mosaic primordium are shielded from cell competition taking place in the neighbouring mosaic primordium. We conclude that the three primordia of the genital disc represent developmental compartments. In the genital primordia, even developmentally repressedM + cells compete successfully against developmentally activeM cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848814
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  • 7
    Electronic Resource
    Electronic Resource
    Die Häufigkeit röntgeninduzierter mitotischer Rekombination bei Genotypen mit verschiedenen X-Y-Kombinations-Chromosomen von Drosophila melanogaster (1970)
    Springer
    Molecular genetics and genomics 107 (1970), S. 150-157 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In first and second instar larvae of Drosophila melanogaster mitotic recombination has been induced by X-rays. Resulting mosaic spots were analysed in the eyes of adult females. The five examined genotypes varied in the combination of different X-chromosomes and in the presence or absence of the duplication Dp(1;3)N 264-58. X-chromosomes used have been elongated by proximally or distally linked arms of the Y-chromosome. The portion of Y-heterochromatin in the genome is negatively correlated with the frequency of twin mosaic spots (Fig. 1). The frequency of these spots is lower in flies bearing the duplication than in those without the duplication. With respect to the X-chromosome combinations, there are no marked differences in the frequencies of single mosaic spots (Fig. 2); with respect to the duplication they are absent. In the genotype Y S X/X.Y S prophases of neuroblast mitoses (Fig. 4) show normal pairing of homologous chromosome sections. Reasons for the different spot frequencies are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00333630
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  • 8
    Electronic Resource
    Electronic Resource
    Bestimmung des Heterochromatisierungsstadiums beim white-Positionseffekt mittels röntgeninduzierter mitotischer Rekombination in der Augenanlage von Drosophila melanogaster (1970)
    Springer
    Molecular genetics and genomics 107 (1970), S. 128-149 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Position-effect variegation of eye pigmentation in the examined Dp(1;3)N 264-58 females is due to an insertion of a X-chromosome section including the white-locus into the proximal heterochromatic region of the third chromosome. The light and dark pigmented areas have a cell lineage basis (Fig. 2). Flies bearing the w +-duplication had two X-chromosomes marked with w a lz 50 e and w a rb rux 2 respectively (Fig. 3). X-ray induced mitotic recombination in presumptive eye cells of larvae resulted in w a lz 50e /w a rb rux 2 twin mosaic spots in the adult eyes. After young larvae were treated twin spots appeared, which had one partner light colored and one dark. Such combinations were rarely found after older larvae were treated. Treatment of young larvae in addition produced twin spots with one or both partners variegated (Figs. 5 and 6). Sometime after the stage at which younger larvae were treated and before the stage at which older larvae were treated the translocated w +-gene in each cell was determined for function or no function. As a result the progeny of each of these cells synthesized pigment or not during the pupal stage. At a temperature of 25.5° C the developmental phase during which determination, i.e. “heterochromatization” of the white gene, takes place, begins not earlier than 39 hours after egg laying and ends about 8 hours later (Fig. 7). In females heterozygous for the short arm of the heterochromatic Y-chromosome linked distally to the X-chromosome (Y S X/X) one twin spot partners is homozygous for this arm (Y SX/YS X), the other lacks it (X/X; Fig.4a). The Y SX/YS X-partner were more frequently dark pigmented than the X/X-partners (Tables 3 and 4). This shows that heterochromatization of the translocated w +-genes is markedly influenced by the genotype of the single cell. When two genotypes with varied amounts of heterochromatin were compared (Fig. 4) no difference in the phases of heterochromatization could be observed (Table 5). Therefore, when position-effect variegation is modified by varying the amount of heterochromatin in the genome the modification is probably not due to a shift in the phase of heterochromatization.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00333629
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  • 9
    Electronic Resource
    Electronic Resource
    Heterochromatin of the Drosophila melanogaster Y chromosome as modifier of position effect variegation: The time of its action (1977)
    Springer
    Molecular genetics and genomics 151 (1977), S. 111-114 
    Details
    ISSN: 1617-4623
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Addition of heterochromatin suppresses while subtraction enhances position effect variegation. The heterochromatin-sensitive period has been determined in white/white-apricot variegated eyes of Y S w a /w a ; Dp (1;3) w 265-58 flies. When such larvae, carrying a Y-short (Y S ) arm at the distal end of one X chromosome, are X-rayed, mitotic recombination leads to one daughter cell with two Y S arms and an adjacent daughter cell with no Y S arm. When induced after clonal initiation, the frequency of dark clones developing from daughter cells with two Y S arms is significantly higher than the frequency of dark clones in the rest of the eye; and this frequency is. even higher when induced before clonal initiation. The modifying action of the Y-heterochromatin is exerted, therefore, during and after clonal initiation. Surprisingly, the frequency of dark clones developing from cells with no Y S arm is not lower than the frequency of dark clones in the rest of the eye.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00338684
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  • 10
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    FlyMove – a new way to look at development of Drosophila (2003)
    Cell Press
    Details
    Publication Date: 2003-06-01
    Print ISSN: 0168-9525
    Electronic ISSN: 1362-4555
    Topics: Biology
    Published by Cell Press
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