scholarly journals VARIATION OF SPONTANEOUS OCCURRENCE RATES OF CHROMOSOMAL ABERRATIONS IN THE SECOND CHROMOSOMES OF DROSOPHILA MELANOGASTER

Genetics ◽  
1974 ◽  
Vol 78 (4) ◽  
pp. 1209-1221
Author(s):  
Osamu Yamaguchi ◽  
Terumi Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
Structural Change ◽  
Random Distribution ◽  
The Other ◽  
Occurrence Rate ◽  
The Third ◽  
Pericentric Inversions ◽  
Paracentric Inversions ◽  
Spontaneous Occurrence

ABSTRACT After accumulating mutations by the aid of marked inversions, spontaneous occurrence rates of chromosome aberrations were estimated for 1148 chromosome lines that originated from five stem line second chromosomes of Drosophila melanogaster. In chromosome lines originating from three stem chromosomes (CH, PQ, and RT), mutations were accumulated for 7550, 7252, and 7256 chromosome generations, respectively, but no structural change was detected. For the chromosome lines that originated from the other two stem chromosomes, the situation was different: Twenty aberrations (19 paracentric inversions and 1 translocation between the second and the third chromosomes) during 45990 chromosome generations took place in the 500 chromosome lines derived from stem line chromosome (AW), and 92 aberrations (83 paracentric inversions, 6 pericentric inversions, 2 translocations between the second and the third chromosomes and 1 transposition) arose during 45006 chromosome generations in the 500 chromosome lines derived from stem line chromosome (JH). For the AW group the occurrence rate becomes 0.00043 per chromosome per generation for all aberrations and 0.00041 for inversions. For the JH group the corresponding rates are 0.00204 and 0.00198, respectively.—A non-random distribution of the breakpoint on the salivary gland chromosome was observed and the breakpoints were concentrated in the regions 26, 29, 33, and 34.—The cytoplasms and the chromosomes (other than the second chromosomes) were made approximately uniform throughout the experiments. Thus, this remarkable variability in the occurrence rate is most probably due to the differences in one or more chromosomal elements on the original five stem chromosomes. The mutable chromosomes (AW and JH) appear to carry a kind of mutator factor such as hi (Ives 1950).

scholarly journals Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 353-364 ◽  
Author(s):  
Jerry A Coyne
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Species Difference ◽  
The Other ◽  
Chromosome 3 ◽  
Apparent Effect ◽  
The Third ◽  
Hydrocarbon Profile ◽  
The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

scholarly journals An Analysis of Polygenes Affecting Wing Shape on Chromosome 3 in Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 773-786 ◽  
Author(s):  
Kenneth Weber ◽  
Robert Eisman ◽  
Lisa Morey ◽  
April Patty ◽  
Joshua Sparks ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Wing Shape ◽  
The Other ◽  
Chromosome 3 ◽  
Additive Effects ◽  
Data Set ◽  
The Third ◽  
Isogenic Lines ◽  
Negative Interactions

AbstractLoci on the third chromosome of Drosophila melanogaster that affect an index of wing shape were mapped, using recombinant isogenic lines, with transposable elements as markers. Many genes with small subequal effects are dispersed along the whole chromosome. Their alleles act nearly additively in heterozygotes. They have small correlated effects on leg shape, but no detectable effects on halteres. Small negative net interactions occur over most of the chromosome. The data set of 519 recombinant isogenic lines can be explained reasonably well by two models. One model posits an indefinitely large number of loci with no interactions. The other model posits 11 loci with additive effects whose sum equals the total phenotypic range and with large positive and negative interactions that nearly cancel each other.

XIV.—Cytological Analysis of Formaldehyde Induced Chromosomal Changes in Drosophila melanogaster

1957 ◽  
Vol 66 (3) ◽  
pp. 288-304 ◽  
Author(s):  
H. Slizynska
Keyword(s):  
Drosophila Melanogaster ◽  
Salivary Gland ◽  
High Frequency ◽  
Structural Changes ◽  
Random Distribution ◽  
X Rays ◽  
Cytological Analysis ◽  
Very High Frequency ◽  
Chromosomal Changes ◽  
Very High

SynopsisStructural changes induced in male auxocytes after formaldehyde feeding were analysed cytologically. In comparison with the effects of X-rays (on mature sperm) there is: (1) a high proportion of mosaics; (2) an excess of repeats and deficiencies; (3) a shortage of translocations, and (4) fewer breaks in the heterochromatic regions.The very high frequency of mosaics and the low ratio of inter- to intrachromosomal changes may be explained by the delayed opening of potential breaks which tend to open simultaneously in the same chromosome but at different times in different chromosomes. The high number of “isochromatid” breaks (repeats) points to some connection with the reduplication cycle.The shortage of “eu-heterochromatic” changes in which “heterochromatic” breaks in salivary gland analysis are scored, can be similarly explained by a difference in the time of opening of potential breaks in the two types of chromatin.Initial non random distribution of breaks as well as the conditions of rejoining in premeiotic cells may also play some role.

scholarly journals On a Parasitic Drosophila from Trinidad

1918 ◽  
Vol 9 (2) ◽  
pp. 157-162
Author(s):  
C. G. Lamb
Keyword(s):  
Drosophila Melanogaster ◽  
West Indies ◽  
Normal Forms ◽  
The Other ◽  
The Third ◽  
Number Of Individuals

The material for this paper was forwarded to the author by Dr. Guy Marshall, of the Imperial Bureau of Entomology, and was collected by Mr. C. B. Williams.The insects were said by him to be parasitic on a Cercopid of the genus Clastoptera, which was found attacking cacao trees. This highly unusual habit gives much interest to the species. Unfortunately the number of individuals sent was quite inadequate to enable one to deal satisfactorily with such small and obscure insects, especially as shrivelling takes place to a different extent in various individuals, which renders the provision of a reasonably large number more necessary than in more normal forms of fly. The individuals sent included three pinned ones of a species from Trinidad (West Indies), and one pinned one of a species from Panama, together with the fragments of two others of the latter species in spirit. In spite of the paucity of material, it was felt to be desirable to put on record as fair a description as could be made under the circumstances. Two of the individuals of the Trinidad species were of one sex, and the third was apparently the other sex of the same species. The two former had all the appearance of representing the male, having brighter eyes, darkened wings, and the general facies of that sex. The genitalia were small and hidden in a terminal hood, such as is found in Drosophila melanogaster and Leucophenga maculata, but it was smaller than in either of these, even than in the latter, in which the hood is only moderately open at the tip, while widely so in the former.

Chromosome rearrangement patterns of an SD chromosome (SDKona-2) in Drosophila melanogaster caused by hybrid dysgenesis

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 855-863 ◽  
Author(s):  
Jeffrey G. Ault
Keyword(s):  
Drosophila Melanogaster ◽  
Chromosome Rearrangement ◽  
Chromosome Rearrangements ◽  
Hybrid Dysgenesis ◽  
Reciprocal Translocations ◽  
Segregation Distorter ◽  
Chromosome Mutation ◽  
Pericentric Inversions ◽  
Spontaneous Chromosome ◽  
Paracentric Inversions

The types and frequencies of spontaneous chromosome rearrangements caused by hybrid dysgenesis were studied in a second chromosome autosome of Drosophila melanogaster. This second chromosome, being an SD chromosome, had two important advantages over other autosomes for this study: (i) it had the two inversions characteristic of a standard SD-72 chromosome type, which distinguished it from its homolog in polytene chromosome spreads, and (ii) because of the meiotic drive associated with the segregation distorter system, it was preferentially transmitted to the next generation. The chromosome mutation frequency of this chromosome (given the name SDKona-2) was 8.3 and 11.7% in the F2 and F3 generations, respectively. The types of new chromosome rearrangements observed in the first four generations included paracentric inversions, pericentric inversions, duplications, deletions, reciprocal translocations (involving the third chromosome), and transpositions. Small paracentric inversions were the most common type of new rearrangement. Later, over 35 generations, some of these new rearrangements changed, either by becoming more complex or by being replaced with yet another new chromosome rearrangement. Duplications were unstable and were replaced by paracentric inversions whose breakpoints were on either side of the duplication. Transpositions arose both from a single multibreak event and from a series of two-break events.Key words: chromosome rearrangements, hybrid dysgenesis, segregation distorter, Drosophila melanogaster.

Efficacy of some insecticide modules against major insect pests and spider population of rice, Oryza sativa L.

ENTOMON ◽  
2018 ◽  
Vol 43 (4) ◽  
pp. 257-262
Author(s):  
Atanu Seni ◽  
Bhimasen Naik
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Untreated Control ◽  
Insect Pests ◽  
Oryza Sativa L ◽  
Gall Midge ◽  
Stem Borer ◽  
The Other ◽  
The Third ◽  
Treated Plot

Experiments were carried out to assess some insecticide modules against major insect pests of rice. Each module consists of a basal application of carbofuran 3G @ 1 kg a.i ha-1 at 20 DAT and Rynaxypyr 20 SC @ 30 g a.i ha-1 at 45 DAT except untreated control. All modules differ with each other only in third treatment which was applied in 65 DAT. The third treatment includes: Imidacloprid 17.8 SL @ 27 g a.i ha-1, Pymetrozine 50 WG @ 150 g a.i ha-1, Triflumezopyrim 106 SC @ 27 g a.i ha-1, Buprofezin 25 SC @ 250 g a.i ha-1; Glamore (Imidacloprid 40+Ethiprole 40% w/w) 80 WG @ 100 g a.i. ha-1, Thiacloprid 24 SC @ 60 g a.i ha-1, Azadirachtin 0.03 EC @ 8 g a.i ha-1, Dinotefuran 20 SG@ 40 g a.i ha-1 and untreated control. All the treated plots recorded significantly lower percent of dead heart, white ear- head caused by stem borer and silver shoot caused by gall midge. Module with Pymetrozine 50 WG @ 150 g a.i ha-1 treated plot recorded significantly higher per cent reduction of plant hoppers (>80% over untreated control) and produced higher grain yield (50.75 qha-1) than the other modules. Among the different treated modules the maximum number of spiders was found in Azadirachtin 0.03 EC @ 8 g a.i ha-1 treated module plot followed by other treatments.

Retroaktive Neuverhandlung

2018 ◽  
Vol 63 (1) ◽  
Author(s):  
Daniel Martin Feige
Keyword(s):  
Original Work ◽  
The Other ◽  
Final Part ◽  
Critical Reading ◽  
The Third ◽  
Works Of Art ◽  
The Relationship

Der Beitrag widmet sich der Frage historischer Folgeverhältnisse in der Kunst. Gegenüber dem Gedanken, dass es ein ursprüngliches Werk in der Reihe von Werken gibt, das späteren Werken seinen Sinn gibt, schlägt der Text vor, das Verhältnis umgekehrt zu denken: Im Lichte späterer Werke wird der Sinn früherer Werke neu ausgehandelt. Dazu geht der Text in drei Schritten vor. Im ersten Teil formuliert er unter der Überschrift ›Form‹ in kritischer Abgrenzung zu Danto und Eco mit Adorno den Gedanken, dass Kunstwerke eigensinnig konstituierte Gegenstände sind. Die im Gedanken der Neuverhandlung früherer Werke im Lichte späterer Werke vorausgesetzte Unbestimmtheit des Sinns von Kunstwerken wird im zweiten Teil unter dem Schlagwort ›Zeitlichkeit‹ anhand des Paradigmas der Improvisation erörtert. Der dritte und letzte Teil wendet diese improvisatorische Logik unter dem Label ›Neuaushandlung‹ dann dezidiert auf das Verhältnis von Vorbild und Nachbild an. The article proposes a new understanding of historical succession in the realm of art. In contrast to the idea that there is an original work in the series of works that gives meaning to the works that come later, the text proposes to think it exactly the other way round: in the light of later works, the meanings of earlier works are renegotiated. The text proceeds in three steps to develop this idea. Under the heading ›Form‹ it develops in the first part a critical reading of Danto’s and Eco’s notion of the constitution of the artworks and argues with Adorno that each powerful work develops its own language. In the second part, the vagueness of the meaning of works of art presupposed in the idea of renegotiating earlier works in the light of later works is discussed under the term ›Temporality‹ in terms of the logic of improvisation. The third and final part uses this improvisational logic under the label ›Renegotiation‹ to understand the relationship between model and afterimage in the realm of art.

Features of the course and treatment of glaucoma during pregnancy

2020 ◽  
Vol 98 (3) ◽  
pp. 178-184
Author(s):  
T. V. Chernyakova ◽  
A. Yu. Brezhnev ◽  
I. R. Gazizova ◽  
A. V. Kuroyedov ◽  
A. V. Seleznev
Keyword(s):  
Pregnant Women ◽  
Laser Treatment ◽  
Progressive Disease ◽  
Clinical Course ◽  
The Other ◽  
Third Trimester ◽  
The Third ◽  
Chronic Progressive Disease ◽  
Hypotensive Therapy ◽  
Eye Pressure

In the review we have integrated all up-to-date knowledge concerning clinical course and treatment of glaucoma among pregnant women to help specialists choose a proper policy of treatment for such a complicated group of patients. Glaucoma is a chronic progressive disease. It rarely occurs among childbearing aged women. Nevertheless the probability to manage pregnant patients having glaucoma has been recently increasing. The situation is complicated by the fact that there are no recommendations on how to treat glaucoma among pregnant women. As we know, eye pressure is progressively going down from the first to the third trimester, so we often have to correct hypotensive therapy. Besides, it is necessary to take into account the effect of applied medicines on mother health and evaluate possible teratogenic complications for a fetus. The only medicine against glaucoma which belongs to category B according to FDA classification is brimonidine. Medicines of the other groups should be prescribed with care. Laser treatment or surgery may also be a relevant decision when monitoring patients who are planning pregnancy or just bearing a child. Such treatment should be also accompanied by medicines.

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