scholarly journals Genetic trade-offs between male reproductive traits in Drosophila melanogaster

2018 ◽  
Vol 14 (10) ◽  
pp. 20180474 ◽  
Author(s):  
David C. S. Filice ◽  
Tristan A. F. Long

In Drosophila melanogaster , males engage in both extensive pre- and post-copulatory competition for the opportunity to mate with females and subsequently sire offspring. The selection pressure for increased male reproductive success has resulted in the evolution of a wide diversity of sexual traits. However, despite strong selection, individuals often exhibit considerable phenotypic variation in the expression of these traits, and it is unclear if any of this variation is owing to underlying genetic trade-offs. Here, using hemiclonal flies, we examine how male reproductive success covaries with their ability to induce long-term stimulation of oogenesis and oviposition in their mates, and how this relationship may change over time. We found that males from hemiclone lines with phenotypes that were more successful in a short-term reproductive ‘scramble’ environment were less effective at stimulating long-term fecundity in females. Furthermore, we observed that males from hemiclone lines which showed the most improvement over a longer reproductive interaction period also tended to stimulate higher long-term fecundity in females. Together, these results indicate the presence of genetic trade-offs between different male reproductive traits and offer insights into the maintenance of their variation.

2021 ◽  
pp. 1-10
Author(s):  
Michihiro Osumi ◽  
Daisuke Shimizu ◽  
Yuki Nishi ◽  
Shu Morioka

Background: Patients with brachial plexus avulsion (BPA) usually experience phantom sensations and phantom limb pain (PLP) in the deafferented limb. It has been suggested that evoking the sensation of touch in the deafferented limb by stimulating referred sensation areas (RSAs) on the cheek or shoulder might alleviate PLP. However, feasible rehabilitation techniques using this approach have not been reported. Objective: The present study sought to examine the analgesic effects of simple electrical stimulation of RSAs in BPA patients with PLP. Methods: Study 1: Electrical stimulation of RSAs for 60 minutes was conducted for six BPA patients suffering from PLP to examine short-term analgesic effects. Study 2: A single case design experiment was conducted with two BPA patients to investigate whether electrical stimulation of RSAs was more effective for alleviating PLP than control electrical stimulation (electrical stimulation of sites on side opposite to the RSAs), and to elucidate the long-term effects of electrical stimulation of RSAs. Results: Study 1: Electrical stimulation of RSAs evoked phantom touch sensations in the deafferented limb, and significantly alleviated PLP (p <  0.05). Study 2: PLP was alleviated more after electrical stimulation on RSAs compared with control electrical stimulation (p <  0.05). However, the analgesic effects of electrical stimulation on RSAs were observed only in the short term, not in the long term (p >  0.05). Conclusions: Electrical stimulation of RSAs not only evoked phantom touch sensation but also alleviated PLP in the short term. The results indicate that electrical stimulation of RSAs may provide a useful practical rehabilitation technique for PLP. Future studies will be required to clarify the mechanisms underlying immediate PLP alleviation via electrical stimulation of RSAs.


2005 ◽  
Vol 36 (4) ◽  
pp. 306-312 ◽  
Author(s):  
François Criscuolo ◽  
Olivier Chastel ◽  
Fabrice Bertile ◽  
Geir Wing Gabrielsen ◽  
Yvon Le Maho ◽  
...  

2012 ◽  
Vol 8 (6) ◽  
pp. 1050-1054 ◽  
Author(s):  
H. Colinet ◽  
D. Renault

Immobilization of insects is necessary for various experimental purposes, and CO 2 exposure remains the most popular anaesthetic method in entomological research. A number of negative side effects of CO 2 anaesthesia have been reported, but CO 2 probably brings about metabolic modifications that are poorly known. In this work, we used GC/MS-based metabolic fingerprinting to assess the effect of CO 2 anaesthesia in Drosophila melanogaster adults. We analysed metabolic variation of flies submitted to acute CO 2 exposure and assessed the temporal metabolic changes during short- and long-term recovery. We found that D. melanogaster metabotypes were significantly affected by the anaesthetic treatment. Metabolic changes caused by acute CO 2 exposure were still manifested after 14 h of recovery. However, we found no evidence of metabolic alterations when a long recovery period was allowed (more than 24 h). This study points to some metabolic pathways altered during CO 2 anaesthesia (e.g. energetic metabolism). Evidence of short-term metabolic changes indicates that CO 2 anaesthesia should be used with utmost caution in physiological studies when a short recovery is allowed. In spite of this, CO 2 treatment seems to be an acceptable anaesthetic method provided that a long recovery period is allowed (more than 24 h).


2020 ◽  
Vol 77 (6) ◽  
pp. 2033-2042 ◽  
Author(s):  
Arthur N Popper

Abstract Collaboration is integral to most scientific research today, and it has certainly been important in my career and for my career path. However, not all collaborations are “equal”. Most, in fact, are short term or transient, with collaborators working on one project and then moving on to other projects and perhaps other collaborations. There are, however, a few collaborations, such as the three I describe here, that are long term and that not only resulted in a large number of collaborative projects but that also strongly influenced career paths. Indeed, these three collaborations resulted in all of us undertaking new paths that we were not likely to have taken alone or without the stimulation of working with someone we know well and have learned to trust.


2018 ◽  
Vol 36 (6_suppl) ◽  
pp. 505-505
Author(s):  
Brian Christopher Baumann ◽  
Wei-Ting Hwang ◽  
Sharadha Srinivasan ◽  
Xingmei Wang ◽  
Ronac Mamtani ◽  
...  

505 Background: Patients with high-risk muscle-invasive bladder cancer (MIBC) who are borderline medically operable for radical cystectomy (RC) face a difficult decision between RC which has higher short-term treatment-related morbidity/mortality & chemoradiotherapy (CRT) which is better tolerated in the short-term but may have worse long-term cancer control outcomes. There are no existing decision support tools to assist patients & providers in understanding these trade-offs. Herein, we developed a visualization tool to inform patients & providers how the relative risks & benefits of RC & CRT vary over time with respect to overall survival (OS). Methods: We identified cT2-3 N0 M0 urothelial bladder cancer patients ≥65 y/o treated with RC +/- chemo (n = 5981) or definitive-dose CRT after TURBT (n = 793) in the National Cancer Database, 2003-2011. The database was split into a development & validation cohort. Multivariate Cox regression with time-varying hazard ratio was performed to assess pre-treatment factors associated with OS. The inverse probability of treatment weighting method using the propensity score was employed to reduce selection bias. External validation was performed. Visualization tool showing adjusted survival curves based on pre-op patient features was generated with input from patients & a multidisciplinary expert panel. Tool calculates median OS & the “break-even point,” where the short-term OS disadvantage of RC equals the long-term advantage of RC (i.e. the point where the restricted mean survival for RC & CRT are equal). Results: On MVA, significant predictors of OS were age, Charlson Deyo comorbidity index, & cT stage (p < 0.001 for all). Using these results, we iteratively developed a web application that utilizes clinical inputs to generate patient-specific survival curves that display estimated OS differences over time. Median OS, the break-even point, & percent alive at the break-even point are provided. Conclusions: This is the first decision-support tool developed to assist high-risk borderline operable MIBC patients & their providers in understanding the short-term & long-term trade-offs between RC & CRT. Additional testing is underway.


2018 ◽  
Vol 103 ◽  
pp. 1-10 ◽  
Author(s):  
Hanna Ruhmann ◽  
Mareike Koppik ◽  
Mariana F. Wolfner ◽  
Claudia Fricke

2006 ◽  
Vol 2 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Reinmar Hager ◽  
Rufus A Johnstone

Recent studies on mammals investigating parent-of-origin-specific effects such as genomic imprinting and maternal effects have demonstrated their impact on short-term measures of fitness, for example offspring growth. However, the long-term fitness consequences of parent-of-origin-specific effects and their role outside the immediate mother–offspring interaction remain largely unexplored. Here, we show that female mice mated to males that inherited the same set of paternal and maternal genes as themselves have a higher reproductive success than females mated to males of reciprocal genotype. Furthermore, we demonstrate that the early social environment experienced by an individual influences its reproductive success. Females raised with unrelated siblings in a mixed litter had a subsequent lower reproductive success than those that were fostered together with all their biological siblings in unmixed litters. Our results highlight the important influence of parent-of-origin-specific effects and conditions in early development on long-term reproductive success in mammals and suggest that parent-of-origin-specific effects may provide the underlying mechanism for beneficial coadaptation between genotypes, for example, in mate choice.


2017 ◽  
Vol 34 (2) ◽  
pp. 164-189
Author(s):  
Daniel Austin Green ◽  
Roberta Q. Herzberg

Abstract:What is progress and what is not progress? We can talk about progress in lots of different arenas; we will focus primarily on economic and scientific progress, but also make brief reference to cultural and moral progress. In our discussion, we want to distinguish, especially, between overall, long-term progress and narrower, shorter-term progress or regress. We will refer to these as “global” and “local” progress, respectively. Of course, one can also regress; therefore, we will also look at instances where progress, along some dimension, slows or even moves backwards. Generally, such regress is local, and often still in a context of broader, global progress. In scientific progress, for example, there are many instances of short-term progress which, if not completely discarded or disproved, are at least substantially modified or fundamentally challenged. And yet, those research paths, even when later abandoned, still contributed to the overall progress of the field. In that sense, the regress (that is, rejection or modification of previous theories) is corrected by, but not in conflict with, the overall progress. In the case of economic progress, the concept of regress usually takes on a different form in which things that aren’t advancing progress don’t necessarily stop it, but are simply retarding progress — that is, making the rate of progress less efficient. The consequence, we suggest, is that when talking about economic progress, objections to certain consequences of economic progress (for instance, income inequality — a type of regress, in our terminology) should not be cordoned off and dealt with independently, but should be incorporated into the way we think about economic progress itself — as instances of local regress within a context of global progress. We explore the effects of these different relations between progress and regress to suggest some of the challenges those seeking to broaden the standard measure, GDP, to incorporate other social values of well-being will face moving forward.


2021 ◽  
pp. 2150008
Author(s):  
MARIIA BELAIA ◽  
JUAN B. MORENO-CRUZ ◽  
DAVID W. KEITH

We introduce solar geoengineering (SG) and carbon dioxide removal (CDR) into an integrated assessment model to analyze the trade-offs between mitigation, SG, and CDR. We propose a novel empirical parameterization of SG that disentangles its efficacy, calibrated with climate model results, from its direct impacts. We use a simple parameterization of CDR that decouples it from the scale of baseline emissions. We find that (a) SG optimally delays mitigation and lowers the use of CDR, which is distinct from moral hazard; (b) SG is deployed prior to CDR while CDR drives the phasing out of SG in the far future; (c) SG deployment in the short term is relatively independent of discounting and of the long-term trade-off between SG and CDR over time; (d) small amounts of SG sharply reduce the cost of meeting a [Formula: see text]C target and the costs of climate change, even with a conservative calibration for the efficacy of SG.


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