scholarly journals Long-term evolution of the roo transposable element copy number in mutation accumulation lines of Drosophila melanogaster

2011 ◽  
Vol 93 (3) ◽  
pp. 181-187 ◽  
Author(s):  
JULIA DÍAZ-GONZÁLEZ ◽  
J. FERNANDO VÁZQUEZ ◽  
JESÚS ALBORNOZ ◽  
ANA DOMÍNGUEZ
Keyword(s):  
Drosophila Melanogaster ◽  
De Novo ◽  
Accumulation Rate ◽  
Mutation Accumulation ◽  
Fundamental Parameter ◽  
Highly Active ◽  
Transposition Rate ◽  
Transposable Element Copy

SummaryThe rate of insertion of transposable elements (TEs) is a fundamental parameter to understand both their dynamics and role in the evolution of the eukaryotic genome. Nonetheless, direct estimates of insertion rates are scarce because transposition is in general a rare phenomenon. A great deal of our previous work on transposition was based on a set of long-term mutation accumulation (MA) lines of Drosophila melanogaster started in 1987 (Oviedo lines), where roo was found highly active, with a rate of insertion of 7×10−4 insertions per element and generation, as compared with other 15 TE families that presented transposition rates around 10−5. Here, we study the evolution of the roo transposition rate, by in situ hybridization, after 60–75 additional generations of MA in two subsets of the Oviedo lines, O and O′, which had achieved average numbers of roo insertions of 77 and 84, respectively. In the O lines, insertions accumulated at a rate that remained constant (7×10−4 insertions per element and generation); however, the subset of lines O′ showed a lower accumulation rate of 4×10−4 insertions per element per generation, suggesting a regulation of transposition that depends on the number of elements. However, one of the O′ lines reached a number of 103 insertions, departing from the group mean by 4·6 sd, and showing that it escapes regulation. Hence, ‘de novo’ mutations affecting the regulation of transposition are relatively common. These results are discussed in relation to the possible mechanisms of containment of TEs.

scholarly journals Rates of movement of transposable elements on the second chromosome of Drosophila melanogaster

2000 ◽  
Vol 75 (3) ◽  
pp. 275-284 ◽  
Author(s):  
XULIO MASIDE ◽  
STAVROULA ASSIMACOPOULOS ◽  
BRIAN CHARLESWORTH
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Polytene Chromosomes ◽  
Mutation Accumulation ◽  
Long Terminal Repeats ◽  
Significant Difference ◽  
Transposable Element Copy ◽  
Excision Rate

The rates of movement of 11 families of transposable elements of Drosophila melanogaster were studied by means of in situ hybridization of probes to polytene chromosomes of larvae from a long-term mutation accumulation experiment. Replicate mutation-accumulation lines carrying second chromosomes derived from a single common ancestral chromosome were maintained by backcrosses of single males heterozygous for a balancer chromosome and a wild-type chromosome, and were scored after 116 generations. Twenty-seven transpositions and 1 excision were detected using homozygous viable and fertile second chromosomes, for a total of 235056 potential sources of transposition events and a potential 252880 excision events. The overall transposition rate per element per generation was 1·15×10−4 and the excision rate was 3·95×10−6. The single excision (of a roo element) was due to recombination between the element's long terminal repeats. A survey of the five most active elements among nine homozygous lethal lines revealed no significant difference in the estimates of transposition and excision rates from those from viable lines. The excess of transposition over excision events is in agreement with the results of other in situ hybridization experiments, and supports the conclusion that replicative increase in transposable element copy number is opposed by selection. These conclusions are compared with those from other studies, and with the conclusions from population surveys of element frequencies.

scholarly journals Transmission pattern of hobo transposable element in transgenic lines of Drosophila melanogaster

1998 ◽  
Vol 71 (2) ◽  
pp. 97-107 ◽  
Author(s):  
VERONIQUE LADEVEZE ◽  
IBO GALINDO ◽  
NICOLE CHAMINADE ◽  
LUIS PASCUAL ◽  
GEORGES PERIQUET ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Population Studies ◽  
Insertion Site ◽  
Molecular Analyses ◽  
Transgenic Lines ◽  
Genomic Dnas ◽  
Insertion Sites ◽  
Method Show

This study is an attempt to trace the fate of hobo elements in the genomes of E strains of Drosophila melanogaster that have been transfected with pHFL1, a plasmid containing an autonomous hobo. Such long-term population studies (over 105 generations) could be very useful for better understanding the population and genomic dynamics of transposable elements and their pattern of insertions. Molecular analyses of hobo elements in the transfected lines were performed using Southern blots of XhoI-digested genomic DNAs. The complete element was observed in all six injected lines. In two lines we observed, at generation 100, two deleted elements, which did not correspond to Th1 and Th2. The results obtained by the in situ method show that the number of hybridization sites increases in each line and prove that the hobo element may be amplified in an RM genome. The hobo activity does not seem to be systematically correlated with the number of hobo elements. After generation 85, the evolution of the hobo element's insertion site number depends on the injected line. In all lines, the total number of insertions remains quite small, between 0 and 11. Hobo elements are located on each of the chromosomal arms. We describe ‘hotspots’ – insertion sites present in all lines and in all generations. On the 3R arm, a short inversion appeared once at generation 85.

scholarly journals Short and long-lasting behavioral consequences of agonistic encounters between male Drosophila melanogaster

2016 ◽  
Vol 113 (17) ◽  
pp. 4818-4823 ◽  
Author(s):  
Séverine Trannoy ◽  
Jill Penn ◽  
Kenia Lucey ◽  
David Popovic ◽  
Edward A. Kravitz
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Behavioral Changes ◽  
Behavioral Consequences ◽  
Behavioral Interactions ◽  
Varying Environments ◽  
De Novo Protein Synthesis ◽  
Agonistic Encounters

In many animal species, learning and memory have been found to play important roles in regulating intra- and interspecific behavioral interactions in varying environments. In such contexts, aggression is commonly used to obtain desired resources. Previous defeats or victories during aggressive interactions have been shown to influence the outcome of later contests, revealing loser and winner effects. In this study, we asked whether short- and/or long-term behavioral consequences accompany victories and defeats in dyadic pairings between male Drosophila melanogaster and how long those effects remain. The results demonstrated that single fights induced important behavioral changes in both combatants and resulted in the formation of short-term loser and winner effects. These decayed over several hours, with the duration depending on the level of familiarity of the opponents. Repeated defeats induced a long-lasting loser effect that was dependent on de novo protein synthesis, whereas repeated victories had no long-term behavioral consequences. This suggests that separate mechanisms govern the formation of loser and winner effects. These studies aim to lay a foundation for future investigations exploring the molecular mechanisms and circuitry underlying the nervous system changes induced by winning and losing bouts during agonistic encounters.

scholarly journals Deep sequencing of natural and experimental populations of Drosophila melanogaster reveals biases in the spectrum of new mutations

2016 ◽  
Author(s):  
Zoe June Assaf ◽  
Susanne Tilk ◽  
Jane Park ◽  
Mark L. Siegal ◽  
Dmitri A. Petrov
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Selection ◽  
De Novo ◽  
Natural Populations ◽  
Gc Content ◽  
Mutation Accumulation ◽  
Sequencing Error ◽  
Low Frequencies ◽  
Nucleotide Mutation ◽  
New Mutations

AbstractMutations provide the raw material of evolution, and thus our ability to study evolution depends fundamentally on whether we have precise measurements of mutational rates and patterns. Here we explore the rates and patterns of mutations using i) de novo mutations from Drosophila melanogaster mutation accumulation lines and ii) polymorphisms segregating at extremely low frequencies. The first, mutation accumulation (MA) lines, are the product of maintaining flies in tiny populations for many generations, therefore rendering natural selection ineffective and allowing new mutations to accrue in the genome. In addition to generating a novel dataset of sequenced MA lines, we perform a meta-analysis of all published MA studies in D. melanogaster, which allows more precise estimates of mutational patterns across the genome. In the second half of this work, we identify polymorphisms segregating at extremely low frequencies using several publicly available population genomic data sets from natural populations of D. melanogaster. Extremely rare polymorphisms are difficult to detect with high confidence due to the problem of distinguishing them from sequencing error, however a dataset of true rare polymorphisms would allow the quantification of mutational patterns. This is due to the fact that rare polymorphisms, much like de novo mutations, are on average younger and also relatively unaffected by the filter of natural selection. We identify a high quality set of ~70,000 rare polymorphisms, fully validated with resequencing, and use this dataset to measure mutational patterns in the genome. This includes identifying a high rate of multi-nucleotide mutation events at both short (~5bp) and long (~1kb) genomic distances, showing that mutation drives GC content lower in already GC-poor regions, and finding that the context-dependency of the mutation spectrum predicts long-term evolutionary patterns at four-fold synonymous sites. We also show that de novo mutations from independent mutation accumulation experiments display similar patterns of single nucleotide mutation, and match well the patterns of mutation found in natural populations.

scholarly journals A de novo strategy to develop NIR precipitating fluorochrome for long-term in situ cell membrane bioimaging

2021 ◽  
Vol 118 (8) ◽  
pp. e2018033118
Author(s):  
Ke Li ◽  
Yifan Lyu ◽  
Yan Huang ◽  
Shuai Xu ◽  
Hong-Wen Liu ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Fluorescent Probes ◽  
Near Infrared ◽  
De Novo ◽  
Membrane Surface ◽  
In Situ Monitoring ◽  
Fluorescence Signal ◽  
In Situ Imaging

Cell membrane–targeted bioimaging is a prerequisite for studying the roles of membrane-associated biomolecules in various physiological and pathological processes. However, long-term in situ bioimaging on the cell membrane with conventional fluorescent probes leads to diffusion into cells from the membrane surface. Therefore, we herein proposed a de novo strategy to construct an antidiffusion probe by integrating a fluorochrome characterized by strong hydrophobicity and low lipophilicity, with an enzyme substrate to meet this challenge. This precipitating fluorochrome HYPQ was designed by conjugating the traditionally strong hydrophobic solid-state fluorochrome 6-chloro–2-(2-hydroxyphenyl) quinazolin-4(3H)-one (HPQ) with a 2-(2-methyl–4H-chromen–4-ylidene) malononitrile group to obtain closer stacking to lower lipophilicity and elongate emission to the far-red to near-infrared wavelength. As proof-of-concept, the membrane-associated enzyme γ-glutamyltranspeptidase (GGT) was selected as a model enzyme to design the antidiffusion probe HYPQG. Then, benefiting from the precipitating and stable signal properties of HYPQ, in situ imaging of GGT on the membrane was successfully realized. Moreover, after HYPQG was activated by GGT, the fluorescence signal on the cell membrane remained unchanged, with incubation time even extending to 6 h, which is significant for in situ monitoring of enzymatic activity. In vivo testing subsequently showed that the tumor region could be accurately defined by this probe after long-term in situ imaging of tumor-bearing mice. The excellent performance of HYPQ indicates that it may be an ideal alternative for constructing universal antidiffusion fluorescent probes, potentially providing an efficient tool for accurate imaging-guided surgery in the future.

Antiretroviral Treatment-Associated Labia Majora Lipohypertrophy: A Rare Case and Plastic Surgical Treatment Options

2017 ◽  
Vol 2 (1) ◽  
pp. 43
Author(s):  
Akmal Hisham ◽  
Devananthan Ilenghoven ◽  
Wan Syazli Wan Ahmad Kamal ◽  
Salina Ibrahim ◽  
Shah Jumaat Mohd Yussof
Keyword(s):  
Highly Active Antiretroviral Therapy ◽  
Daily Living ◽  
Treatment Options ◽  
Hiv Positive ◽  
Highly Active ◽  
Labia Majora ◽  
The Face ◽  
Central Fat

The emergence of highly active antiretroviral therapy (HAART) has revolutionized the prognosis of HIV-infected patients. However, the extended use of HAART is associated with a disfiguring complication termed lipodystrophy, a disorder of body fat maldistribution causing peripheral fat loss (lipoatrophy) and central fat accumulation (lipohypertrophy). Lipoatrophy commonly affects the face, legs, buttocks and arm, whilst lipohypertrophy frequently favours the abdomen, breast and dorsocervical region. To our knowledge, we present only the second documented case in the literature of a labia majora lipohypertrophy in a HIV-positive patient receiving long-term HAART. The severity of labial abnormality caused significant physical and functional morbidities. Labiaplasty with dermolipectomy of the labia majora and excisional lipectomy of the mons pubis was successfully performed. At a 6-month follow-up, patient had no recurrence with resolution of symptoms and resumption of normal activities of daily living (ADL).

Is 3 years adequate for tracking completely occluded coiled aneurysms?

2020 ◽  
Vol 133 (3) ◽  
pp. 758-764
Author(s):  
Eung Koo Yeon ◽  
Young Dae Cho ◽  
Dong Hyun Yoo ◽  
Su Hwan Lee ◽  
Hyun-Seung Kang ◽  
...  
Keyword(s):  
De Novo ◽  
Careful Monitoring ◽  
Surveillance Period ◽  
Radiological Data ◽  
De Novo Aneurysm ◽  
Low Probability ◽  
Almost All ◽  
Annual Risk

OBJECTIVEThe authors conducted a study to ascertain the long-term durability of coiled aneurysms completely occluded at 36 months’ follow-up given the potential for delayed recanalization.METHODSIn this retrospective review, the authors examined 299 patients with 339 aneurysms, all shown to be completely occluded at 36 months on follow-up images obtained between 2011 and 2013. Medical records and radiological data acquired during the extended monitoring period (mean 74.3 ± 22.5 months) were retrieved, and the authors analyzed the incidence of (including mean annual risk) and risk factors for delayed recanalization.RESULTSA total of 5 coiled aneurysms (1.5%) occluded completely at 36 months showed recanalization (0.46% per aneurysm-year) during the long-term surveillance period (1081.9 aneurysm-years), 2 surfacing within 60 months and 3 developing thereafter. Four showed minor recanalization, with only one instance of major recanalization. The latter involved the posterior communicating artery as an apparent de novo lesion, arising at the neck of a firmly coiled sac, and was unrelated to coil compaction or growth. Additional embolization was undertaken. In a multivariate analysis, a second embolization for a recurrent aneurysm (HR = 22.088, p = 0.003) independently correlated with delayed recanalization.CONCLUSIONSAlmost all coiled aneurysms (98.5%) showing complete occlusion at 36 months postembolization proved to be stable during extended observation. However, recurrent aneurysms were predisposed to delayed recanalization. Given the low probability yet seriousness of delayed recanalization and the possibility of de novo aneurysm formation, careful monitoring may be still considered in this setting but at less frequent intervals beyond 36 months.

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