scholarly journals Dissection of complex, fitness-related traits in multiple Drosophila mapping populations offers insight into the genetic control of stress resistance

2018 ◽  
Author(s):  
Elizabeth Everman ◽  
Casey McNeil ◽  
Jennifer Hackett ◽  
Clint Bain ◽  
Stuart J Macdonald
Keyword(s):  
Activity Level ◽  
Phenotypic Correlation ◽  
Starvation Resistance ◽  
Physiological Mechanisms ◽  
Mapping Panel ◽  
Fitness Trait ◽  
Drosophila Genetic Reference Panel ◽  
Insight Into ◽  
Mapping Populations ◽  
Qtl Effects

We leverage two complementary Drosophila melanogaster mapping panels to genetically dissect starvation resistance, an important fitness trait. Using >1600 genotypes from the multiparental Drosophila Synthetic Population Resource (DSPR) we map numerous starvation stress QTL that collectively explain a substantial fraction of trait heritability. Mapped QTL effects allowed us to estimate DSPR founder phenotypes, predictions that were correlated with the actual phenotypes of these lines. We observe a modest phenotypic correlation between starvation resistance and triglyceride level, traits that have been linked in previous studies. However, overlap among QTL identified for each trait is low. Since we also show that DSPR strains with extreme starvation phenotypes differ in desiccation resistance and activity level, our data imply multiple physiological mechanisms contribute to starvation variability. We additionally exploited the Drosophila Genetic Reference Panel (DGRP) to identify sequence variants associated with starvation resistance. Consistent with prior work these sites rarely fall within QTL intervals mapped in the DSPR. We were offered a unique opportunity to directly compare association mapping results across labs since two other groups previously measured starvation resistance in the DGRP. We found strong phenotypic correlations among studies, but extremely low overlap in the sets of genomewide significant sites. Despite this, our analyses revealed that the most highly-associated variants from each study typically showed the same additive effect sign in independent studies, in contrast to otherwise equivalent sets of random variants. This consistency provides evidence for reproducible trait-associated sites in a widely-used mapping panel, and highlights the polygenic nature of starvation resistance.

Setal morphology of grooming appendages in blue crabs Callinectes sapidus Rathbun, 1896 and stone crabs Menippe mercenaria (Say, 1818) (Decapoda: Brachyura: Portunidae, Menippidae)

2019 ◽  
Vol 39 (4) ◽  
pp. 357-377
Author(s):  
Jen L Wortham ◽  
Stephanie Pascual
Keyword(s):  
Light Microscopy ◽  
Functional Morphology ◽  
Sensory Input ◽  
Callinectes Sapidus ◽  
Time Budget ◽  
Activity Level ◽  
Body Regions ◽  
Electron And Light Microscopy ◽  
Insight Into ◽  
Scanning Electron

Abstract Respiration, sensory input, movement, and molting rely on crustacean body regions being free of fouling. While the grooming appendages of shrimps have been described, few studies have documented the functional morphology of grooming appendages in brachyuran crabs. Because shrimps and brachyurans have very different body morphology and grooming behaviors, their grooming setae may vary. The morphology of grooming appendages of blue (Callinectes sapidusRathbun, 1896) and stone (Menippe mercenaria (Say, 1818)) crabs were investigated to gain better insight into their efficiencies in decreasing fouling. Callinectes sapidus is an active swimmer, migrates through currents across estuaries, spends less time grooming, and is exposed to more environmental variants in contrast to M. mercenaria, which has a lower activity level and spends more time grooming. To compensate for this higher activity level and lower grooming time budget, C. sapidus was predicted to have more setal types on its grooming appendages as compared to M. mercenaria. Thirteen different body appendages/regions involved in grooming are described in both species by using scanning electron and light microscopy. We documented the morphology, presence or absence of setal patches, and types of setae in 104 different grooming appendages and groomed body regions. Of 25 types of setae, nine are unique to C. sapidus, rejecting the hypothesis that C. sapidus have more diverse grooming setae. Menippe mercenaria has denser setal patches and less fouling than C. sapidus. Nine new setal types are described. Fouling, setal diversities, and functions that correspond to grooming behaviors are discussed.

Cancer-Induced Fatigue and Skeletal Muscle Wasting: The Role of Exercise

2001 ◽  
Vol 2 (3) ◽  
pp. 186-197 ◽  
Author(s):  
Sadeeka Al-Majid ◽  
Donna O. McCarthy
Keyword(s):  
Skeletal Muscle ◽  
Resistance Exercise ◽  
Muscle Wasting ◽  
Activity Level ◽  
Future Research ◽  
Physiological Mechanisms ◽  
Cancer Related Fatigue ◽  
Skeletal Muscle Wasting ◽  
Clinical Conditions

Fatigue is the most frequently reported symptom by cancer patients. Many of these patients perceive fatigue as the most distressing symptom associated with their illness because it imposes limitations on their physical activity level. Skeletal muscle wasting, which occurs as part of cancer cachexia, is one of the mechanisms that contribute to fatigue. Cancerinduced skeletal muscle wasting may occur despite normal food intake and is not prevented by nutritional supplementation. Evidence suggests that endurance exercise ameliorates cancer-related fatigue. There is no compelling evidence to support that exerciseinduced reduction in fatigue is related to preservation of muscle mass. Resistance exercise attenuates muscle wasting associated with a variety of catabolic conditions. However, its effects on cancer-induced muscle wasting have not been adequately studied. This article describes the physiological mechanisms implicated in the induction of cancer-related muscle wasting, summarizes findings from endurance and resistance exercise studies in relation to fatigue and muscle wasting during cancer and selected clinical conditions, and proposes directions for future research.

Complex evaluations in the political context: Engaging stakeholders in evaluation design

2018 ◽  
Vol 18 (2) ◽  
pp. 122-131 ◽  
Author(s):  
Rhian Stack ◽  
Nerida Leal ◽  
Sarah Stamp ◽  
Bianca Reveruzzi ◽  
Katrina Middlin ◽  
...  
Keyword(s):  
Lessons Learned ◽  
Evaluation Framework ◽  
Activity Level ◽  
Multiple Stakeholders ◽  
Program Outcomes ◽  
Consultation Process ◽  
Complex Evaluation ◽  
Variable Nature ◽  
Implementation Progress ◽  
Insight Into

While evaluators can often access examples of complex evaluation frameworks and reports, detailed information about the processes used to develop these frameworks is less available. This article provides insight into the development of an evaluation framework for a whole-of-government multi-component reform program, being implemented by stakeholders over a 10-year period. This program incorporates multiple tiers (activity-level and program-level) of evaluations, planned at critical points of implementation. This article focuses on the consultation process adopted in developing an evaluation framework to capture implementation progress and program outcomes and impacts at three different time points. A consultative, iterative approach, emphasizing stakeholder engagement, was adopted to mitigate the effects of challenges of responding to the variable nature of the program and multiple stakeholders with a vested interest in its implementation. Continual reflection and quality improvement allowed these challenges to be addressed, and will continue to allow lessons learned from earlier evaluations to inform the design of future studies.

scholarly journals 298 Can phenomics contribute to improved livelihood and food security in South Africa?

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 29-29
Author(s):  
Carina Visser ◽  
Allan De Freitas ◽  
Este Van Marle Koster ◽  
Herman Myburgh
Keyword(s):  
South Africa ◽  
Farming Systems ◽  
Activity Level ◽  
Mating Period ◽  
Livestock Sector ◽  
Small Holder Farmers ◽  
Nutritional Needs ◽  
Small Holder ◽  
Insight Into ◽  
Extension Support

Abstract In South Africa, there are almost 14 million cattle, which constitute 1.6 million dairy and 12.5 million beef cattle. Of the latter, approximately 53% are kept in commercial systems and the remaining 47% in informal systems. Phenotypic and pedigree recording of livestock faces constraints in terms of the extensive nature of the farming systems and the large informal livestock sector consisting of communal and small-holder farmers, which is characterized by a general lack of resources such as financial, infrastructural and extension support. Animal recording thus remains a challenge in both the commercial and informal agricultural sectors. This review will evaluate the use of precision phenotyping in the beef and dairy cattle industries of South Africa, and highlight the challenges, limitations and possible impact of the technology. Measuring objective, relevant phenotypes, such as activity level, temperature, and weight of an individual animal over time, could assist in detecting sickness before it exacerbates to the point of death. Weight measurement would be especially useful in the developing sector, where infrastructure is not available and could provide insight into the nutritional needs of the livestock, timing of the mating period, the possibility of disease or internal and external parasites. Measuring vital parameters and using them to predict various future occurrences would empower emerging farmers to optimize productivity by providing critical information to the farmer at any given time. Phenomics will provide new and emerging farmers the opportunity to participate in the agriculture economy, which will have a lasting effect of upliftment and empowerment and also contribute to the country’s agriculture output and its gross domestic product. Farmers will benefit from the use of automated technologies in terms of improved animal welfare and economic sustainability in resource-poor areas.

Physiological mechanisms of ovarian follicular growth in pigs — A review

2008 ◽  
Vol 56 (3) ◽  
pp. 369-378 ◽  
Author(s):  
Tomasz Schwarz ◽  
Marcin Kopyra ◽  
Jacek Nowicki
Keyword(s):  
Selection Process ◽  
Follicular Development ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Significant Heterogeneity ◽  
Follicular Growth ◽  
Physiological Mechanisms ◽  
The Relationship ◽  
Ovarian Follicular Growth ◽  
Insight Into

Follicular growth after antrum formation is determined by follicle-stimulating hormone (FSH). Only two ways are possible for recruited follicles, continuing development or atresia. In gilts, intensive ovarian follicular growth begins between 60 and 100 days of age, and fluctuations of the ovarian morphological status last about 20 days; however, at that time there are no really large follicles. Final follicular development is under luteinising hormone (LH) control; this is why the attainment of puberty is related to an increase in serum oestradiol to a level that causes a preovulatory surge of this gonadotropin. The pool of follicles at the beginning of the oestrous cycle is about 30–40, most of which are small (< 3 mm) and growing. Then, the pool of follicles increases to about 80 in the mid-luteal phase but about 50 of them are small and 30 are medium sized (3–6.9 mm). Some of these follicles are in the growing phase, but some are atretic. Between days 7 and 15 of the oestrous cycle the percentage of atretic follicles fluctuates between 12 and 73%. At that time there are no large (> 7 mm) follicles because of the suppressing effect of progesterone. The number of small follicles declines after luteolysis. From the pool of medium follicles, large follicles are selected under the influence of LH, but about 70% of the medium-sized follicles become atretic. Because of the long-lasting selection process there is a significant heterogeneity in the diameter of large follicles in oestrus. However, the number of follicles correlates with the number of corpora lutea after ovulation. Individual follicular development and the relationship between follicles are still poorly known. The use of ultrasonography may give a closer insight into these phenomena.

scholarly journals Genetic and physiological mechanisms of freezing tolerance in locally adapted populations of a winter annual

2019 ◽  
Author(s):  
Brian J. Sanderson ◽  
Sunchung Park ◽  
M. Inam Jameel ◽  
Joshua C. Kraft ◽  
Michael F. Thomashow ◽  
...  
Keyword(s):  
Local Adaptation ◽  
Freezing Tolerance ◽  
Adaptive Response ◽  
Sequence Polymorphism ◽  
Loss Of Function ◽  
Physiological Mechanisms ◽  
Naturally Occurring ◽  
Before And After ◽  
Winter Annual ◽  
Insight Into

ABSTRACTPremise of the studyDespite myriad examples of local adaptation, the phenotypes and genetic variants underlying such adaptive differentiation are seldom known. Recent work on freezing tolerance and local adaptation in ecotypes of Arabidopsis thaliana from Sweden and Italy provides the essential foundation for uncovering the genotype-phenotype-fitness map for an adaptive response to a key environmental stress.MethodsHere we examine the consequences of a naturally occurring loss of function (LOF) mutation in an Italian allele of the gene that encodes the transcription factor CBF2, which underlies a major freezing tolerance locus. We used four lines with a Swedish genetic background, each containing a LOF CBF2 allele. Two lines had introgression segments containing of the Italian CBF2 allele, and two were created using CRISPR-Cas9. We used a growth chamber experiment to quantify freezing tolerance and gene expression both before and after cold acclimation.Key resultsFreezing tolerance was greater in the Swedish (72%) compared to the Italian (11%) ecotype, and all four experimental CBF2 LOF lines had reduced freezing tolerance compared to the Swedish ecotype. Differential expression analyses identified ten genes for which all CBF2 LOF lines and the IT ecotype showed similar patterns of reduced cold responsive expression compared to the SW ecotype.ConclusionsWe identified ten genes that are at least partially regulated by CBF2 that may contribute to the differences in cold acclimated freezing tolerance between the Italian and Swedish ecotypes. These results provide novel insight into the molecular and physiological mechanisms connecting a naturally occurring sequence polymorphism to an adaptive response to freezing conditions.

scholarly journals Identification and Analysis of Zinc Efficiency-Associated Loci in Maize

2021 ◽  
Vol 12 ◽  
Author(s):  
Jianqin Xu ◽  
Xuejie Wang ◽  
Huaqing Zhu ◽  
Futong Yu
Keyword(s):  
Inbred Line ◽  
Genetic Basis ◽  
Crop Yields ◽  
Zn Deficiency ◽  
Zinc Efficiency ◽  
Physiological Mechanisms ◽  
Zn Uptake ◽  
Trait Locus ◽  
Indole 3 Acetic Acid ◽  
Insight Into

Zinc (Zn) deficiency, a globally predominant micronutrient disorder in crops and humans, reduces crop yields and adversely impacts human health. Despite numerous studies on the physiological mechanisms underlying Zn deficiency tolerance, its genetic basis of molecular mechanism is still poorly understood. Thus, the Zn efficiency of 20 maize inbred lines was evaluated, and a quantitative trait locus (QTL) analysis was performed in the recombination inbred line population derived from the most Zn-efficient (Ye478) and Zn-inefficient inbred line (Wu312) to identify the candidate genes associated with Zn deficiency tolerance. On this basis, we analyzed the expression of ZmZIP1-ZmZIP8. Thirteen QTLs for the traits associated with Zn deficiency tolerance were detected, explaining 7.6–63.5% of the phenotypic variation. The genes responsible for Zn uptake and transport across membranes (ZmZIP3, ZmHMA3, ZmHMA4) were identified, which probably form a sophisticated network to regulate the uptake, translocation, and redistribution of Zn. Additionally, we identified the genes involved in the indole-3-acetic acid (IAA) biosynthesis (ZmIGPS) and auxin-dependent gene regulation (ZmIAA). Notably, a high upregulation of ZmZIP3 was found in the Zn-deficient root of Ye478, but not in that of Wu312. Additionally, ZmZIP4, ZmZIP5, and ZmZIP7 were up-regulated in the Zn-deficient roots of Ye478 and Wu312. Our findings provide a new insight into the genetic basis of Zn deficiency tolerance.

scholarly journals Drug delivery across the blood–brain barrier: recent advances in the use of nanocarriers

Nanomedicine ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 205-214 ◽  
Author(s):  
John JE Mulvihill ◽  
Eoghan M Cunnane ◽  
Aisling M Ross ◽  
Jason T Duskey ◽  
Giovanni Tosi ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Blood Brain Barrier ◽  
Significant Contribution ◽  
Rapid Development ◽  
Brain Barrier ◽  
Preclinical Studies ◽  
Physiological Mechanisms ◽  
Blood Brain ◽  
Insight Into ◽  
Made In

The blood–brain barrier (BBB) has a significant contribution to homeostasis and protection of the CNS. However, it also limits the crossing of therapeutics and thereby complicates the treatment of CNS disorders. To overcome this limitation, the use of nanocarriers for drug delivery across the BBB has recently been exploited. Nanocarriers can utilize different physiological mechanisms for drug delivery across the BBB and can be modified to achieve the desired kinetics and efficacy. Consequentially, several nanocarriers have been reported to act as functional nanomedicines in preclinical studies using animal models for human diseases. Given the rapid development of novel nanocarriers, this review provides a comprehensive insight into the most recent advancements made in nanocarrier-based drug delivery to the CNS, such as the development of multifunctional nanomedicines and theranostics.

scholarly journals Dissection of Complex, Fitness-Related Traits in Multiple Drosophila Mapping Populations Offers Insight into the Genetic Control of Stress Resistance

Genetics ◽  
2019 ◽  
Vol 211 (4) ◽  
pp. 1449-1467 ◽  
Author(s):  
Elizabeth R. Everman ◽  
Casey L. McNeil ◽  
Jennifer L. Hackett ◽  
Clint L. Bain ◽  
Stuart J. Macdonald
Keyword(s):  
Genetic Control ◽  
Stress Resistance ◽  
Insight Into ◽  
Mapping Populations

Mitochondria: a multimodal hub of hypoxia tolerance

2014 ◽  
Vol 92 (7) ◽  
pp. 569-589 ◽  
Author(s):  
Matthew E. Pamenter
Keyword(s):  
Brain Function ◽  
Energy Production ◽  
Oxygen Availability ◽  
Hypoxia Tolerance ◽  
Low Oxygen ◽  
Physiological Mechanisms ◽  
Oxygen Stress ◽  
Cellular Energy ◽  
Selective Pressures ◽  
Insight Into

Decreased oxygen availability impairs cellular energy production and, without a coordinated and matched decrease in energy consumption, cellular and whole organism death rapidly ensues. Of particular interest are mechanisms that protect brain from low oxygen injury, as this organ is not only the most sensitive to hypoxia, but must also remain active and functional during low oxygen stress. As a result of natural selective pressures, some species have evolved molecular and physiological mechanisms to tolerate prolonged hypoxia with no apparent detriment. Among these mechanisms are a handful of responses that are essential for hypoxia tolerance, including (i) sensors that detect changes in oxygen availability and initiate protective responses; (ii) mechanisms of energy conservation; (iii) maintenance of basic brain function; and (iv) avoidance of catastrophic cell death cascades. As the study of hypoxia-tolerant brain progresses, it is becoming increasingly apparent that mitochondria play a central role in regulating all of these critical mechanisms. Furthermore, modulation of mitochondrial function to mimic endogenous neuroprotective mechanisms found in hypoxia-tolerant species confers protection against otherwise lethal hypoxic stresses in hypoxia-intolerant organs and organisms. Therefore, lessons gleaned from the investigation of endogenous mechanisms of hypoxia tolerance in hypoxia-tolerant organisms may provide insight into clinical pathologies related to low oxygen stress.

Sign in / Sign up

Export Citation Format

Share Document