scholarly journals THE GENETIC ANALYSIS OF A UNIQUELY DOSE-SENSITIVE CHROMOSOMAL REGION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1976 ◽  
Vol 84 (2) ◽  
pp. 193-210
Author(s):  
R E Denell
Keyword(s):  
Drosophila Melanogaster ◽  
Normal Development ◽  
Chromosomal Region ◽  
Adult Stage ◽  
Chromosome Region ◽  
Extensive Analysis ◽  
Large Numbers ◽  
Segmental Aneuploidy ◽  
Per Se ◽  
Linkage Relationships

ABSTRACT In their extensive analysis of the effects of segmental aneuploidy on development to the adult stage, Lindsley and Sandler et al. (1972) identified salivary chromosome region 83D-E as apparently uniquely dose-sensitive. Neither the hypoploid nor hyperploid classes appeared to survive to the adult stage, although segmental hyperploidy of all other regions of the genome is compatible with normal or quasi-normal development. In the present investigation, this genetic behavior is shown to be a concomitant of region 83D-E itself, and independent of the particular Y-autosome translocations utilized to generate aneuploid classes. Newly induced chromosomal duplications including 83D-E are recovered by their ability to complement the corresponding deficiency; these aberrations indicate that the phenomenon depends on genetic dosage per se and is independent of linkage relationships. Further tests involving the generation of large numbers of aneuploid zygotes support the conclusion that these individuals very rarely and possibly never survive to the adult stage. Finally, crosses yielding hypertriploid females and intersexes indicate that these aneuploids often survive and, in the former case, are fertile. No viable hypotriploid female or intersex was recovered.

Localization of Intracisternal a Particle Antigens in Neoplastic Cells and Preimplantation Mouse Embryos

1980 ◽  
Vol 38 ◽  
pp. 696-697
Author(s):  
Thomas T.F. Huang ◽  
Patricia G. Calarco
Keyword(s):  
Endoplasmic Reticulum ◽  
Normal Development ◽  
Mouse Embryos ◽  
Neoplastic Cells ◽  
Large Numbers ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Intracisternal A Particle ◽  
Normal Feature

The stage specific appearance of a retravirus, termed the Intracisternal A particle (IAP) is a normal feature of early preimplantation development. To date, all feral and laboratory strains of Mus musculus and even Asian species such as Mus cervicolor and Mus pahari express the particles during the 2-8 cell stages. IAP form by budding into the endoplasmic reticulum and appear singly or as groups of donut-shaped particles within the cisternae (fig. 1). IAP are also produced in large numbers in several neoplastic cells such as certain plasmacytomas and rhabdomyosarcomas. The role of IAP, either in normal development or in neoplastic behavior, is unknown.

Genetic analysis of oxygen defense mechanisms in Drosophila melanogaster and identification of a novel behavioural mutant with a Shaker phenotype

Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 749-757 ◽  
Author(s):  
James M. Humphreys ◽  
Brenda Duyf ◽  
Mei-Ling A. Joiner ◽  
John P. Phillips ◽  
Arthur J. Hilliker
Keyword(s):  
Drosophila Melanogaster ◽  
Defense Mechanisms ◽  
Chromosome Region ◽  
Recessive Mutation ◽  
Ether Anaesthesia ◽  
Ros Metabolism ◽  
Chromosome Mutations ◽  
New Gene ◽  
New Alleles

Mutants of Drosophila melanogaster that lack Cu/Zn superoxide dismutase or urate are hypersensitive to reactive oxygen species (ROS) generated in vivo by the redox-cycling agent paraquat. We have subsequently employed paraquat as a selective agent to identify adult viable mutants potentially defective in other, perhaps unknown, components of ROS metabolism. Paraquat screening of ethyl methanesulfonate-induced second- and third-chromosome mutations yielded 24 paraquat hypersensitive mutants. Two mutants were identified as being new alleles of the previously identified doublesex (dsx) and pink (p) genes. The remainder of the mutations identified previously undescribed genes, including one second chromosome paraquat hypersensitive mutant that was found to exhibit shaking legs, abdomen pulsations, and body shuddering under ether anaesthesia. This recessive mutation was mapped to the polytene chromosome region of 48A5–48B2 and defines a new gene we named quiver (qvr). This mutation is similar in phenotype to the Shaker (Sh), ether-a-gogo (eag), and Hyperkinetic (Hk) mutations, all of which affect potassium channel function in D. melanogaster. Key words : Drosophila, paraquat, EMS-mutagenesis, Shaker, oxidative-stress.

The Post-embryonic Development of the Tracheal System in Drosophila melanogaster

1957 ◽  
Vol s3-98 (41) ◽  
pp. 123-150
Author(s):  
JOAN M. WHITTEN
Keyword(s):  
Drosophila Melanogaster ◽  
Adult Stage ◽  
Larval Instar ◽  
Pupal Stage ◽  
Tracheal System ◽  
True Nature ◽  
The Third ◽  
Air Sacs ◽  
Abdominal Region ◽  
Pupal Cuticle

The fate of the tracheal system is traced from the first larval instar to the adult stage. The basic larval pattern conforms to that shown for other Diptera Cyclorrhapha (Whitten, 1955), and is identical in all three instars. According to previous accounts the adult system directly replaces the larval: the larval system is partly shed, partly histolysed, and the adult system arises from imaginal cell clusters independently of the preceding larval system. In contrast, it is shown here that in the cephalic, thoracic, and anterior abdominal region there is a definite continuity in the tracheal system, from larval, through pupal to the adult stage, whereas in the posterior abdominal region the larval system is histolysed, and the adult system is independent of it in origin. Moreover, in the pupal stage this region is tracheated by tracheae arising from the anterior abdominal region and belonging to a distinct pupal system. Moulting of the tracheal linings is complete at the first and second larval ecdyses, but incomplete at the third larval-pupal and pupal-adult ecdyses. In consequence, in both pupal and adult systems there are tracheae which are secreted around preexisting tracheae, others formed as new ‘branch’ tracheae, and those which have been carried over from the previous instar. In the adult the newly formed tracheae of the posterior abdominal region fall into a fourth category. Most of the adult thoracic air sacs correspond to new ‘branch’ tracheae of other instars. The pre-pupal moult and instar are discussed with reference to the tracheal system and tentative suggestions are made concerning the true nature of the pre-pupal cuticle. There is no pre-pupal tracheal system. Events traced for Drosophila would seem to be general for Cyclorrhapha, both Acalypterae and Calypterae. The separate fates of the anterior and posterior abdom inal systems, in contrast with the straightforward development in Dipterc Nematocera, would appear to mark a distinct step in the evolution of the system in Diptera.

scholarly journals Behavior Individuality: A Focus on Drosophila melanogaster

2021 ◽  
Vol 12 ◽  
Author(s):  
Rubén Mollá-Albaladejo ◽  
Juan A. Sánchez-Alcañiz
Keyword(s):  
Gene Expression ◽  
Drosophila Melanogaster ◽  
High Throughput ◽  
High Throughput Sequencing ◽  
Great Effort ◽  
Behavioral Differences ◽  
Adult Behavior ◽  
Large Numbers ◽  
Environmental Variations ◽  
And Function

Among individuals, behavioral differences result from the well-known interplay of nature and nurture. Minute differences in the genetic code can lead to differential gene expression and function, dramatically affecting developmental processes and adult behavior. Environmental factors, epigenetic modifications, and gene expression and function are responsible for generating stochastic behaviors. In the last decade, the advent of high-throughput sequencing has facilitated studying the genetic basis of behavior and individuality. We can now study the genomes of multiple individuals and infer which genetic variations might be responsible for the observed behavior. In addition, the development of high-throughput behavioral paradigms, where multiple isogenic animals can be analyzed in various environmental conditions, has again facilitated the study of the influence of genetic and environmental variations in animal personality. Mainly, Drosophila melanogaster has been the focus of a great effort to understand how inter-individual behavioral differences emerge. The possibility of using large numbers of animals, isogenic populations, and the possibility of modifying neuronal function has made it an ideal model to search for the origins of individuality. In the present review, we will focus on the recent findings that try to shed light on the emergence of individuality with a particular interest in D. melanogaster.

scholarly journals Linkage relationships of markers on chromosome 17 of the house mouse

1975 ◽  
Vol 26 (2) ◽  
pp. 203-211 ◽  
Author(s):  
Graig Hammerberg ◽  
Jan Klein
Keyword(s):  
House Mouse ◽  
Chromosomal Region ◽  
Recombination Frequency ◽  
Genetic Distances ◽  
Chromosome 17 ◽  
Linkage Data ◽  
Crossing Over ◽  
The Right ◽  
Linkage Relationships ◽  
Important Marker

SUMMARYLinkage data for the following markers on chromosome 17 of the house mouse were obtained: centromere (marked by translocation R67), Brachyury (T), tufted (tf), H-2, and thin fur (thf). The markers were found to be arranged in that order in the genetic map and the combined genetic distances between individual markers were found to be as follows: Rb7…T, 4·5 cM; T…tf, 5·8 cM; tf…H-2, 5·0 cM; H-2…thf, 15·1 cM. The localization of the thf locus on the non-centromeric side of the H-2 complex provides an important marker for this arm of chromosome 17. The map distances in the centromeric portion of chromosome 17 changed drastically in the presence of various t factors. These factors strongly reduce the recombination frequency in the T…tf and tf…H-2 intervals and this crossing-over suppression is most likely responsible for the linkage disequilibrium between t and H-2 reported earlier. Recombinants involving a t chromosome but occurring to the right of the H-2 complex do not change the properties of t factors suggesting that all determinants responsible for the t phenotype are located in the chromosomal region between T and tf (H-2).

Clinical Chemistry

2019 ◽  
Author(s):  
Dan Furmedge
Keyword(s):  
Fluid Balance ◽  
Clinical Chemistry ◽  
Clinical Status ◽  
Serum Biochemistry ◽  
Left Ventricular ◽  
Intravenous Fluids ◽  
Blood Tests ◽  
Large Numbers ◽  
Per Se ◽  
Level 2

With so many tests available and increasingly fast laboratory processors, there is a growing temptation to request large numbers of blood tests on each and every patient. What we should remember is that they should be used as an adjunct to the history and clinical examination. Test results should reinforce the likely diagnosis and rule out our differentials, rather than be used to try and make the diagnosis per se. What makes things easier is to know how serum biochemistry and homeostasis are regulated and then to consider a number of questions: ● Which hormones are involved in the control of this electrolyte? ● What happens when these are increased or decreased? ● Does the patient have any renal or hepatic impairment? ● Are they taking any drugs that might be affecting serum electrolyte levels? ● Have they taken an overdose? ● Is the patient dehydrated/ hypovolaemic/ hypoxic? It can seem daunting at first when results come back unexpectedly out of range. They must be considered in combination with the patient’s clinical status; if the numbers just do not fit, then repeat the test— they may not be right. However, there are a few ‘unmissable’ electrolyte derangements that need to be dealt with immediately. Once detected, they should trigger the thoughts shown in Table 12.1. Interpreting serum values is important, but to prevent iatrogenic derangement, careful use and prescription of intravenous fluids are also needed. Does a patient who looks hypovolaemic, has a low blood pres­sure, and is tachycardic need crystalloids or blood? Colloids, such as ‘Gelofusine®’ or ‘Volplex®’, are now largely out of date, with evidence not supporting their use. Are they frail or do they have cardiac failure and therefore require cautious replacement? Do they have liver failure? Is their fluid balance so critical that close fluid monitoring in a level 2 crit­ical care setting required? Gone are the days when central venous lines are used on the wards for fluid balance. This chapter will help consider­ation of the whole picture before putting pen to paper and (potentially) wrongly prescribing 4 L of fluids a day for a frail older man with left ventricular failure.

scholarly journals The effect of the absence of rumen ciliate protozoa on growing lambs fed on a roughage–concentrate diet

1971 ◽  
Vol 26 (2) ◽  
pp. 155-167 ◽  
Author(s):  
J. Margaret Eadie ◽  
J. C. Gill
Keyword(s):  
Fatty Acids ◽  
Weight Gain ◽  
Volatile Fatty Acids ◽  
Soluble Sugar ◽  
Group Differences ◽  
Rumen Bacteria ◽  
Body Measurements ◽  
Large Numbers ◽  
Per Se ◽  
Ciliate Protozoa

1. Lambs were removed form their dams at 2 d of age, and at 5 weeks of age eitht of one group were incoulated with a mixed rumen ciliate and seven in a second group were maintained ciliate-free throughout the 61 weeks of the experiment. Performance of the groups was compared when given a 2:1 roughage:concentrate diet as a set ration and withad lib.roughage.2. Mixed ciliate populations developed in all faunated lambs and average-sized populations were maintained. Large numbers of flagellate protozoa developed in the ciliate-free animals after flagellates had been introduced into the building with the ciliate-free animals after flagellates had been introduced into the building with the ciliate inoculum.3. Higher numbers of rumen bacteria were found in the ciliate-free group.4. Only between the 14th and 21st weeks was there a significant different between groups in weight gain and this was infavour of the faunated group. The only significant different in body measurements was greater girth in the ciliate-free lambs.5. Only minor differences were found between the groups in calorimetric trials, digestibility and nitrogen balanes. There were no differences between groups in concentration of total protein N and soluble sugar in the rumen. The ammonis concentration was significantly higher in the faunated group.6. The concentrations of total rumen volatile fatty acids (VFA) were higher in the faunated group. Differences, between groups, in proportions of VFA were attributed to the activity of the rumen bacteria rather than the ciliatesper se.7. No differences between groups were found in the concentrations of blood sugar and haemoglobin.8. It was concluded that the changes due to the presence of rumen ciliates were not great enough to be reflected in animal performance under the conditions of this experiment.

A CYTOGENETIC ANALYSIS OF THE CHROMOSOMAL REGION SURROUNDING THE α-GLYCEROPHOSPHATE DEHYDROGENASE LOCUS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 105 (2) ◽  
pp. 371-386
Author(s):  
Michael A Kotarski ◽  
Sally Pickert ◽  
Ross J MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosome ◽  
Cytogenetic Analysis ◽  
Chromosomal Region ◽  
Chromosome Band ◽  
Recombination Analysis ◽  
Chromosome 2 ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
Glycerophosphate Dehydrogenase

ABSTRACT The chromosomal region surrounding the structural gene for α-glycerophosphate dehydrogenase (αGpdh, 2-20.5) of Drosophila melanogaster has been studied in detail. Forty-three EMS-induced recessive lethal mutations and five previously identified visible mutations have been localized within the 25A-27D region of chromosome 2 by deficiency mapping and in some cases by a recombination analysis. The 43 lethal mutations specify 17 lethal loci. ?Gpdh has been localized to a single polytene chromosome band, 25F5, and there apparently are no lethals that map to the αGpdh locus.

scholarly journals Artificial light in baited pots substantially increases the catch of cod (Gadus morhua) by attracting active bait, krill (Thysanoessa inermis)

2018 ◽  
Vol 75 (6) ◽  
pp. 2257-2264 ◽  
Author(s):  
Odd-Børre Humborstad ◽  
Anne Christine Utne-Palm ◽  
Michael Breen ◽  
Svein Løkkeborg
Keyword(s):  
Light Source ◽  
North Atlantic ◽  
Coastal Waters ◽  
Gadus Morhua ◽  
Catch Rate ◽  
Light Sources ◽  
The North ◽  
Important Prey ◽  
Large Numbers ◽  
Per Se

Abstract The use of pots in the north Atlantic finfish fisheries is negligible because this fishing method typically has a low capture efficiency. Large numbers of individuals encounter baited pots, but the proportions of fish that enter the pot and become caught are low. Krill, which constitutes an important prey for cod (Gadus morhua), is attracted by light. The catching efficiency of baited cod pots with three light sources with different colours and intensities (white: 9744 mW m−2, white: 23 mW m−2, green: 8 mW m−2) were tested in coastal waters in northern Norway. Pots with the light source of highest intensity gave a 17 times higher catch rate of cod than that of control pots (with bait only). The light source of medium intensity gave about a five times higher catch rate, whereas the weakest light did not influence the catch. Cod caught in pots with light had more krill and arrowworms in their stomach and were observed feeding on these preys inside the pot. We concluded that light sources of increasing intensity attract more krill, and that cod were attracted into the pot by the dense swarms of prey and not the light per se.

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