scholarly journals THE DEVELOPMENT OF PIGMENT GRANULES IN THE EYES OF WILD TYPE AND MUTANT DROSOPHILA MELANOGASTER

1966 ◽  
Vol 29 (2) ◽  
pp. 223-249 ◽  
Author(s):  
Jane Rearick Shoup
Keyword(s):  
Drosophila Melanogaster ◽  
Pigment Cells ◽  
Type I ◽  
Wild Type ◽  
Eye Color ◽  
Type Iv ◽  
Pigment Granules ◽  
Marginal Areas ◽  
Pigment Type ◽  
Variable Morphology

The eye pigment system in Drosophila melanogaster has been studied with the electron microscope. Details in the development of pigment granules in wild type flies and in three eye color mutants are described. Four different types of pigment granules have been found. Type I granules, which carry ommochrome pigment and occur in both primary and secondary pigment cells of ommatidia, are believed to develop as vesicular secretions by way of the Golgi apparatus. The formation of Type II granules, which are restricted to the secondary pigment cells and contain drosopterin pigments, involves accumulation of 60- to 80-A fibers producing an elliptical granule. Type III granules appear to be empty vesicles, except for small marginal areas of dense material; they are thought to be abnormal entities containing ommochrome pigment. Type IV granules are characteristic of colorless mutants regardless of genotype, and during the course of development they often contain glycogen, ribosomes, and show acid phosphatase activity; for these reasons and because of their bizarre and variable morphology, they are considered to be autophagic vacuoles. The 300-A particles commonly found in pigment cells are identified as glycogen on the basis of their morphology and their sensitivity to salivary digestion.

Eye color pigment granules in wild-type and mutant Drosophila melanogaster

1988 ◽  
Vol 66 (6) ◽  
pp. 1301-1308 ◽  
Author(s):  
William S. Stark ◽  
Randall Sapp
Keyword(s):  
Drosophila Melanogaster ◽  
Fruit Fly ◽  
Distal Portion ◽  
Pigment Cells ◽  
High Electron ◽  
Wild Type ◽  
Eye Color ◽  
Pigment Granules ◽  
Color Pigment ◽  
Electron Lucent

Eye color pigment granules were studied in ultrathin sections of the wild-type fruit fly Drosophila melanogaster and the following eye-color mutants, cinnabar (cn), brown (bw), cinnabar brown (cn bw), and white (w). Ommatin-containing granules of the primary pigment cells are electron lucent in newly emerged flies but are dense in aged flies. The intraretinular granules are of intermediate or high electron density and also contain ommatins. The content of these granules was deduced from comparisons between wild type and cn, which blocks ommatin synthesis. The bw mutant was used to show that drosopterins reside throughout the secondary pigment cells while drosopterin granules monopolize the distal portion. The secondary pigment cell's granules, especially the most distal ones, are electron lucent in our work as well as in most earlier publications. Here we show that these granules are manifested as holes in the section. Both ommatins and drosopterins reside more proximally in the compound eye's pigment cells. We show that white-eyed flies have unusually large granules, and the possible function of these structures is discussed.

scholarly journals Polysaccharides and virulence of Burkholderia pseudomallei

2007 ◽  
Vol 56 (8) ◽  
pp. 1005-1010 ◽  
Author(s):  
M. Sarkar-Tyson ◽  
J. E. Thwaite ◽  
S. V. Harding ◽  
S. J. Smither ◽  
P. C. F. Oyston ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Capsular Polysaccharide ◽  
Gene Clusters ◽  
Type I ◽  
Wild Type ◽  
Time To Death ◽  
Type Iii ◽  
Type Iv ◽  
Mutant Strains ◽  
Delayed Time

Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease of humans and animals. Gene clusters which encode capsular polysaccharide (type I O-PS) and LPS (type II O-PS), both of which play roles in virulence, have previously been identified. Here, the identification of two further putative clusters, type III O-PS and type IV O-PS, is reported. Mice challenged with type III O-PS or type IV O-PS mutants showed increased mean times to death (7.8 and 11.6 days) compared to those challenged with wild-type B. pseudomallei (3 days). To investigate the possible roles of polysaccharides in protection, mice were immunized with killed cells of wild-type B. pseudomallei or killed cells of B. pseudomallei with mutations in the O antigen, capsular polysaccharide, type III O-PS or type IV O-PS gene clusters. Immunization with all polysaccharide mutant strains resulted in delayed time to death compared to the naïve controls, following challenge with wild-type B. pseudomallei strain K96243. However, immunization with killed polysaccharide mutant strains conferred different degrees of protection, demonstrating the immunological importance of the polysaccharide clusters on the surface of B. pseudomallei.

Differential elimination of rDNA genes in bobbed mutants of Drosophila melanogaster

1986 ◽  
Vol 6 (4) ◽  
pp. 1023-1031
Author(s):  
R Terracol ◽  
N Prud'homme
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Copy Number ◽  
Rdna Locus ◽  
Gene Copy ◽  
Specific Gene ◽  
Type I ◽  
28S Rrna ◽  
Wild Type ◽  
Y Chromosomes ◽  
Genes Encoding

In Drosophila melanogaster, the multiply repeated genes encoding 18S and 28S rRNA are located on the X and Y chromosomes. A large percentage of these repeats are interrupted in the 28S region by insertions of two types. We compared the restriction patterns from a subcloned wild-type Oregon R strain to those of spontaneous and ethyl methanesulfonate-induced bobbed mutants. Bobbed mutations were found to be deficiencies that modified the organization of the rDNA locus. Genes without insertions were deleted about twice as often as genes with type I insertions. Type II insertion genes were not decreased in number, except in the mutant having the most bobbed phenotype. Reversion to wild type was associated with an increase in gene copy number, affecting exclusively genes without insertions. One hypothesis which explains these results is the partial clustering of genes by type. The initial deletion could then be due either to an unequal crossover or to loss of material without exchange. Some of our findings indicated that deletion may be associated with an amplification phenomenon, the magnitude of which would be dependent on the amount of clustering of specific gene types at the locus.

Die fluoreszierenden Stoffe aus den Malpighischen-Gefäßen der Wildform und verschiedener Augenfarbenmutanten von Drosophila melanogaster

1968 ◽  
Vol 23 (3) ◽  
pp. 376-386 ◽  
Author(s):  
Armin Wessing ◽  
Dieter Eichelberg
Keyword(s):  
Drosophila Melanogaster ◽  
Malpighian Tubules ◽  
Wild Type ◽  
Eye Color ◽  
Eye Color Mutants

The Malpighian tubules of Drosophila melanogaster accumulate a great number of substances, many of which fluoresce. This paper is concerned with the identification of these substances by chromatography and their location by fluorescentmicroscopy (fig. 4, 5). It appears that they mainly belong to the following three groups: Pteridines, tryptophane and some of its metabolites, and riboflavine (tab. 1).The pattern of fluorescent substances of the eye color mutants cn, v, se, st, bw, ry, and w vary significantly. The patterns of these mutants are compared and discussed with that of the wild-type.

scholarly journals Differential elimination of rDNA genes in bobbed mutants of Drosophila melanogaster.

1986 ◽  
Vol 6 (4) ◽  
pp. 1023-1031 ◽  
Author(s):  
R Terracol ◽  
N Prud'homme
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Copy Number ◽  
Rdna Locus ◽  
Gene Copy ◽  
Specific Gene ◽  
Type I ◽  
28S Rrna ◽  
Wild Type ◽  
Y Chromosomes ◽  
Genes Encoding

In Drosophila melanogaster, the multiply repeated genes encoding 18S and 28S rRNA are located on the X and Y chromosomes. A large percentage of these repeats are interrupted in the 28S region by insertions of two types. We compared the restriction patterns from a subcloned wild-type Oregon R strain to those of spontaneous and ethyl methanesulfonate-induced bobbed mutants. Bobbed mutations were found to be deficiencies that modified the organization of the rDNA locus. Genes without insertions were deleted about twice as often as genes with type I insertions. Type II insertion genes were not decreased in number, except in the mutant having the most bobbed phenotype. Reversion to wild type was associated with an increase in gene copy number, affecting exclusively genes without insertions. One hypothesis which explains these results is the partial clustering of genes by type. The initial deletion could then be due either to an unequal crossover or to loss of material without exchange. Some of our findings indicated that deletion may be associated with an amplification phenomenon, the magnitude of which would be dependent on the amount of clustering of specific gene types at the locus.

scholarly journals TERMINAL SYNTHESIS OF XANTHOMMATIN IN DROSOPHILA MELANOGASTER. III. MUTATIONAL PLEIOTROPY AND PIGMENT GRANULE ASSOCIATION OF PHENOXAZINONE SYNTHETASE

Genetics ◽  
1973 ◽  
Vol 73 (1) ◽  
pp. 45-56
Author(s):  
John P Phillips ◽  
Hugh S Forrest ◽  
Anil D Kulkarni
Keyword(s):  
Drosophila Melanogaster ◽  
Pigment Granule ◽  
Synthetase Activity ◽  
Type I ◽  
Developmental Control ◽  
Eye Color ◽  
Xanthommatin Synthesis ◽  
Eye Color Mutants ◽  
Low Levels

ABSTRACT Phenoxazinone synthetase, which catalyzes the condensation of 3-hydroxykynurenine to xanthommatin, the brown eye pigment of Drosophila, is shown to exist in association with a particle which resembles the cytologically defined Type I pigment granule. Several classical eye color mutants (v, cn, st, ltd, cd, w), including two which effect other enzymes in the xanthommatin pathway (v, cn), have low levels of phenoxazinone synthetase activity and disrupt the normal association of the enzyme with the pigment granule. A model is proposed depicting several structural and enzymatic interrelationships involved in the developmental control of xanthommatin synthesis in Drosophila.

scholarly journals DEVELOPMENTAL AND GENETIC STUDIES ON KYNURENINE HYDROXYLASE FROM DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 75 (4) ◽  
pp. 651-661
Author(s):  
David T Sullivan ◽  
Robert J Kitos ◽  
Marie C Sullivan
Keyword(s):  
Drosophila Melanogaster ◽  
Bimodal Distribution ◽  
Maximum Activity ◽  
Wild Type ◽  
Genetic Studies ◽  
Eye Color ◽  
Eye Color Mutants ◽  
Puparium Formation ◽  
Kynurenine Hydroxylase ◽  
Short Time

ABSTRACT The level of kynurenine hydroxylase was measured throughout the development of wild type and the eye color mutants v, cn, st, ltd, cd, kar, w, ca, bri and pP of Drosophila melanogaster. In all cases except cn a bimodal distribution of enzyme activity during development was observed. Activity is initially detectable in second instar. A maximum is reached in early third instar. Activity declines prior to puparium formation. Shortly after pupation, activity rises dramatically to reach a maximum about five times the peak larval level. Maximum activity persists for a short time, and then falls sharply prior to emergence. No activity is detectable in cn, cn3, or cn35K. In pupae which have zero, one, two or three doses of the cn  + allele, activity is proportional to the number of the + alleles. This provides further evidence that the cn locus contains the structural gene for kynurenine hydroxylase. Kynurenine hydroxylase is a useful gene product for studying the events of imaginal disc differentiation.

scholarly journals The white gene controls copulation success in Drosophila melanogaster

2016 ◽  
Author(s):  
Chengfeng Xiao ◽  
Shuang Qiu ◽  
R Meldrum Robertson
Keyword(s):  
Drosophila Melanogaster ◽  
Copy Number ◽  
Genetic Background ◽  
Genetic Basis ◽  
Courtship Behavior ◽  
Sexual Experience ◽  
Male Courtship ◽  
Wild Type ◽  
Eye Color ◽  
Male Courtship Behavior

ABSTRACTCharacteristics of male courtship behavior in Drosophila melanogaster have been well-described, but the genetic basis of male-female copulation is largely unknown. Here we show that the white (w) gene, a classical gene for eye color, is associated with copulation success. 82.5% of wild-type Canton-S flies copulated within 60 minutes in circular arenas, whereas few white-eyed mutants mated successfully. The w+ allele exchanged to the X chromosome or duplicated to the Y chromosome in the white-eyed genetic background rescued the defect of copulation success. The w+-associated copulation success was independent of eye color phenotype. Addition of the mini-white (mw+) gene to the white-eyed mutant rescued the defect of copulation success in a manner that was mw+ copy number-dependent. Lastly, male-female sexual experience mimicked the effects of w+/mw+ in improving successful copulation. These data suggest that the w+ gene controls copulation success in Drosophila melanogaster.

scholarly journals The occurrence of long ribosomal transcripts homologous to type I insertions in bobbed mutants of Drosophila melanogaster

1989 ◽  
Vol 54 (2) ◽  
pp. 127-135 ◽  
Author(s):  
Mohamed Makni ◽  
Mohamed Marrakchi ◽  
Nicole Prud'Homme
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Genes ◽  
Type I ◽  
Wild Type ◽  
Coding Region ◽  
Rdna Genes ◽  
Sandwich Hybridization ◽  
Number Of Genes ◽  
In The Wild ◽  
Two Temperatures

SummaryIn Drosophila melanogaster up to two thirds of the rDNA genes contain insertion sequences of two types in the 28S coding region. Comparison of the ribosomal insertion transcripts in the wild type and in two bobbed mutants reared at two temperatures showed that the level of type I transcripts is dependent on both the number of genes with type I insertions in the bobbed loci and the intensity of bobbed phenotype. Importantly, a long transcript of 8·7 kb hybridized to the ribosomal probe, the INS I probe and also to the restriction fragment of the rDNA downstream of the point of insertion was found in one bobbed mutant. This result and also those from sandwich hybridization indicate that some interrupted ribosomal genes are functional.

scholarly journals A genetic analysis of the Suppressor 2 of zeste complex of Drosophila melanogaster.

Genetics ◽  
1995 ◽  
Vol 140 (1) ◽  
pp. 139-181 ◽  
Author(s):  
C T Wu ◽  
M Howe
Keyword(s):  
Drosophila Melanogaster ◽  
Position Effect ◽  
Molecular Data ◽  
Polycomb Group ◽  
Position Effect Variegation ◽  
Wild Type ◽  
Trithorax Group ◽  
Eye Color ◽  
Multidomain Structure ◽  
Sex Combs

Abstract The zeste1 (z1) mutation of Drosophila melanogaster produces a mutant yellow eye color instead of the wild-type red. Genetic and molecular data suggest that z1 achieves this change by altering expression of the wild-type white gene in a manner that exhibits transvection effects. There exist suppressor and enhancer mutations that modify the z1 eye color, and this paper summarizes our studies of those belonging to the Suppressor 2 of zeste complex [Su(z)2-C]. The Su(z)2-C consists of at least three subregions called Psc (Posterior sex combs), Su(z)2 and Su(z)2D (Distal). The products of these subregions are proposed to act at the level of chromatin. Complementation analyses predict that the products are functionally similar and interacting. The alleles of Psc define two overlapping phenotypic classes, the hopeful and hapless. The distinctions between these two classes and the intragenic complementation seen among some of the Psc alleles are consistent with a multidomain structure for the product of Psc. Psc is a member of the homeotic Polycomb group of genes. A general discussion of the Polycomb and trithorax group of genes, position-effect variegation, transvection, chromosome pairing and chromatin structure is presented.

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