scholarly journals Salmonid gene expression biomarkers indicative of physiological responses to changes in salinity, temperature, but not dissolved oxygen

2018 ◽  
Author(s):  
Aimee Lee S. Houde ◽  
Arash Akbarzadeh ◽  
Oliver P. Günther ◽  
Shaorong Li ◽  
David A. Patterson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dissolved Oxygen ◽  
Oncorhynchus Tshawytscha ◽  
Environmental Changes ◽  
Multiple Stressors ◽  
Life Stage ◽  
Skin Pigmentation ◽  
Seawater Temperature ◽  
Life Stages ◽  
Transcriptional Responses

AbstractAn organism’s ability to respond effectively to environmental change is critical to their survival. Yet, life stage and overall condition can dictate tolerance thresholds to heightened environmental stressors, such that stress may not be equally felt across individuals within a species. Environmental changes can induce transcriptional responses in an organism, some of which reflect generalized responses, and others are highly specific to the type of change being experienced. Thus, if transcriptional biomarkers specific to a heightened environmental stressor, even under multi-stressor impacts, can be identified, the biomarkers could be then applied in natural environments to determine when and where individuals are experiencing such stressors. Here, we validate candidate gill gene expression biomarkers by experimentally challenging juvenile Chinook salmon (Oncorhynchus tshawytscha). A sophisticated experimental set-up (four trials) manipulated salinity (freshwater, brackish water, and seawater), temperature (10, 14, and 18°C), and dissolved oxygen (normoxia and hypoxia), in all 18 possible combinations, for up to six days during the pre-smolt, smolt, and de-smolt life stages. In addition, we also describe the changes in juvenile behaviour, plasma variables, gill Na+/K+- ATPase (NKA) activity, body size, body morphology, and skin pigmentation associated with salinity, temperature, dissolved oxygen, mortality, and smolt status. We statistically identified biomarkers specific to salinity and temperature treatments, as well as mortality across multiple stressors and life stages. Similar biomarkers for the dissolved oxygen treatment could not be identified in the data and we discuss our next steps using an RNA-seq study. This work demonstrates the unique power of gene expression biomarkers to identify a specific stressor even under multi-stressor conditions.

scholarly journals Heat hardening capacity in Drosophila melanogaster is life stage-specific and juveniles show the highest plasticity

2019 ◽  
Vol 15 (2) ◽  
pp. 20180628 ◽  
Author(s):  
Neda N. Moghadam ◽  
Tarmo Ketola ◽  
Cino Pertoldi ◽  
Simon Bahrndorff ◽  
Torsten N. Kristensen
Keyword(s):  
Drosophila Melanogaster ◽  
Heat Resistance ◽  
High Temperatures ◽  
Environmental Changes ◽  
Thermal Sensitivity ◽  
Life Stage ◽  
High Plasticity ◽  
Life Stages ◽  
Heat Hardening ◽  
The Impact

Variations in stress resistance and adaptive plastic responses during ontogeny have rarely been addressed, despite the possibility that differences between life stages can affect species' range margins and thermal tolerance. Here, we assessed the thermal sensitivity and hardening capacity of Drosophila melanogaster across developmental stages from larval to the adult stage. We observed strong differences between life stages in heat resistance, with adults being most heat resistant followed by puparia , pupae and larvae . The impact of heat hardening (1 h at 35°C) on heat resistance changed during ontogeny, with the highest positive effect of hardening observed in puparia and pupae and the lowest in adults. These results suggest that immobile life stages ( puparia and pupae ) have evolved high plasticity in upper thermal limits whereas adults and larvae rely more on behavioural responses to heat stress allowing them to escape from extreme high temperatures. While most studies on the plasticity of heat resistance in ectotherms have focused on the adult life stage, our findings emphasize the crucial importance of juvenile life stages of arthropods in understanding the thermal biology and life stage-specific physiological responses to variable and stressful high temperatures. Failure to acknowledge this complication might lead to biased estimates of species' ability to cope with environmental changes, such as climate change.

scholarly journals Diurnal and seasonal hsp70 gene expression in a cryptic reef fish, the bluebanded goby Lythrypnus dalli (Gilbert 1890)

Biotecnia ◽  
2021 ◽  
Vol 23 (2) ◽  
Author(s):  
Tania Zenteno-Savín
Keyword(s):  
Gene Expression ◽  
Dissolved Oxygen ◽  
Reef Fish ◽  
Gulf Of California ◽  
Environmental Changes ◽  
Warm Season ◽  
Reef Fishes ◽  
Physical Parameters ◽  
Hsp70 Gene ◽  
Lythrypnus Dalli

Physiological responses of marine organisms are influenced by environmental variations, particularly in dynamic habitats. These variations could be at a diel or seasonal scale and require acclimation responses that, at a molecular level, are facilitated by gene expression regulation. Circadian rhythms allow organisms to adjust to recurring environmental changes and to synchronize physiological processes. Increased Hsp70 gene expression allows organisms to protect themselves against heat and other stressors, conferring them a periodically changing thermotolerance. This study aimed at analyzing whether the variability of exogenous factors (temperature, dissolved oxygen, salinity) in diurnal or seasonal scales affects hsp70 expression in cryptic reef fishes in their natural environment. The study model was Lythrypnus dalli, an endemic cryptic reef fish inhabiting shallow waters throughout the Gulf of California. Physical parameters varied seasonally; temperature increased 6°C during the warm season, salinity and dissolved oxygen remained constant. Minimal changes in temperature (±1 °C) occurred diurnally. Expression levels of hsp70 increased significantly during the warm season (p < 0.05), perhaps related to seasonal thermal changes. No differences in hsp70 were observed during the diurnal cycle (p > 0.05). L. dalli has apparently developed phenotypic plasticity to face environmental variability at diurnal and seasonal scales.

scholarly journals Meta-analysis of RNA-seq studies reveals genes responsible for life stage-dominant functions in Schistosoma mansoni

2018 ◽  
Author(s):  
Zhigang Lu ◽  
Matthew Berriman
Keyword(s):  
Gene Expression ◽  
Schistosoma Mansoni ◽  
Differential Expression ◽  
Meta Analysis ◽  
Life Stage ◽  
Expression Patterns ◽  
Differential Expression Analysis ◽  
Housekeeping Genes ◽  
Life Stages ◽  
Rna Seq

AbstractBackgroundSince the genome of the parasitic flatworm Schistosoma mansoni was sequenced in 2009, various RNA-seq studies have been conducted to investigate differential gene expression between certain life stages. Based on these studies, the overview of gene expression in all life stages can improve our understanding of S. mansoni genome biology.Methodspublicly available RNA-seq data covering all life stages and gonads were mapped to the latest S. mansoni genome. Read counts were normalised across all samples and differential expression analysis was preformed using the generalized linear model (GLM) approach.Resultswe revealed for the first time the dissimilarities among all life stages. Genes that are abundantly-expressed in all life stages, as well as those preferentially-expressed in certain stage(s), were determined. The latter reveals genes responsible for stage-dominant functions of the parasite, which can be a guidance for the investigation and annotation of gene functions. In addition, distinct differential expression patterns were observed between adjacent life stages, which not only correlate well with original individual studies, but also provide additional information on changes in gene expression during parasite transitions. Furthermore, thirteen novel housekeeping genes across all life stages were identified, which is valuable for quantitative studies (e.g., qPCR).Conclusionsthe metaanalysis provides valuable information on the expression and potential functions of S. mansoni genes across all life stages, and can facilitate basic as well as applied research for the community.

scholarly journals Dynamic Changes of Gut Microbial Communities of Bumble Bee Queens through Important Life Stages

mSystems ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Liuhao Wang ◽  
Jie Wu ◽  
Kai Li ◽  
Ben M. Sadd ◽  
Yulong Guo ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Physiological State ◽  
Life Stage ◽  
Animal Health ◽  
Adult Life ◽  
Gut Bacteria ◽  
Egg Laying ◽  
Community Diversity ◽  
Bumble Bee ◽  
Life Stages

ABSTRACT Bumble bees are important pollinators in natural and agricultural ecosystems. Their social colonies are founded by individual queens, which, as the predominant reproductive females of colonies, contribute to colony function through worker production and fitness through male and new queen production. Therefore, queen health is paramount, but even though there has been an increasing emphasis on the role of gut microbiota for animal health, there is limited information on the gut microbial dynamics of bumble bee queens. Employing 16S rRNA amplicon sequencing and quantitative PCR, we investigate how the adult life stage and physiological state influence a queen’s gut bacterial community diversity and composition in unmated, mated, and ovipositing queens of Bombus lantschouensis. We found significant shifts in total gut microbe abundance and microbiota composition across queen states. There are specific compositional signatures associated with different stages, with unmated and ovipositing queens showing the greatest similarity in composition and mated queens being distinct. The bacterial genera Gilliamella, Snodgrassella, and Lactobacillus were relatively dominant in unmated and ovipositing queens, with Bifidobacterium dominant in ovipositing queens only. Bacillus, Lactococcus, and Pseudomonas increased following queen mating. Intriguingly, however, further analysis of unmated queens matching the mated queens in age showed that changes are independent of the act of mating. Our study is the first to explore the gut microbiome of bumble bee queens across key life stages from adult eclosion to egg laying and provides useful information for future studies of the function of gut bacteria in queen development and colony performance. IMPORTANCE Bumble bee queens undergo a number of biological changes as they transition through adult emergence, mating, overwintering, foraging, and colony initiation including egg laying. Therefore, they represent an important system to understand the link between physiological, behavioral, and environmental changes and host-associated microbiota. It is plausible that the bumble bee queen gut bacteria play a role in shaping the ability of the queen to survive environmental extremes and reproduce, due to long-established coevolutionary relationships between the host and microbiome members.

scholarly journals Transcriptional responses to social isolation : characterization of the neuropeptide parathyroid hormone 2

2021 ◽  
Author(s):  
◽  
Lukas Anneser
Keyword(s):  
Gene Expression ◽  
Parathyroid Hormone ◽  
Social Isolation ◽  
Environmental Changes ◽  
Model Organism ◽  
Transcriptional Response ◽  
Transcriptional Responses ◽  
Physiological Level ◽  
Brain Gene Expression ◽  
Social Species

Across the entire animal kingdom, sociality, i.e. the tendency of individual animals to form a group with conspecifics, is a common trait. Environmental changes have to be met with corresponding, quick adaptations. For social species, the presence of conspecifics is important for survival and if social animals are deprived of access to conspecifics, this can lead to strong and lasting changes on a physiological level as well as behaviour. Gene expression changes responsible for these adaptations have so far not been understood in detail. As social isolation leads to changes on a neuronal level, it is important to investigate the gene expression changes that are induced in the brain. In this thesis, next-generation RNA-sequencing was applied to zebrafish, a well-established model organism characterized by its high degree of companionship. Within the entire brain, gene expression was analysed in zebrafish that were raised either with conspecifis or in isolation, ranging from 5 to 21 days post fertilization. Using this approach, several genes were identified that were downregulated by social isolation. In this thesis, I focused on one of these consistently downregulated genes, parathyroid hormone 2 (pth2). The expression of pth2 was demonstrated to be bidirectionally regulated by the number of conspecifics present and to be responsive to changes in the social environment within 30 minutes. Regulation of pth2 does not occur by visual or chemosensory access to conspecifcs, but is mediated by mechanosensory perception of other fish via the lateral line. In an experiment using an artificial mechanical stimulation paradigm, it was shown that the features necessary to elicit pth2 transcription closely mimick the locomotion of actual zebrafish. Other, similar stimulation paradigms are not capable to induce this transcriptional response.

scholarly journals Coping with a changing environment: the effects of early life stress

2016 ◽  
Vol 3 (10) ◽  
pp. 160382 ◽  
Author(s):  
Marco A. Vindas ◽  
Angelico Madaro ◽  
Thomas W. K. Fraser ◽  
Erik Höglund ◽  
Rolf E. Olsen ◽  
...  
Keyword(s):  
Stress Responses ◽  
Growth Rates ◽  
Life Stress ◽  
Early Life ◽  
Environmental Changes ◽  
Acute Stress ◽  
Life Stage ◽  
Early Life Stress ◽  
Life Stages ◽  
Artificial Rearing

Ongoing rapid domestication of Atlantic salmon implies that individuals are subjected to evolutionarily novel stressors encountered under conditions of artificial rearing, requiring new levels and directions of flexibility in physiological and behavioural coping mechanisms. Phenotypic plasticity to environmental changes is particularly evident at early life stages. We investigated the performance of salmon, previously subjected to an unpredictable chronic stress (UCS) treatment at an early age (10 month old parr), over several months and life stages. The UCS fish showed overall higher specific growth rates compared with unstressed controls after smoltification, a particularly challenging life stage, and after seawater transfer. Furthermore, subjecting fish to acute stress at the end of the experiment, we found that UCS groups had an overall lower hypothalamic catecholaminergic and brain stem serotonergic response to stress compared with control groups. In addition, serotonergic activity was negatively correlated with final growth rates, which implies that serotonin responsive individuals have growth disadvantages. Altogether, our results may imply that a subdued monoaminergic response in stressful farming environments may be beneficial, because in such situations individuals may be able to reallocate energy from stress responses into other life processes, such as growth.

Linking transcription, RNA polymerase II elongation and alternative splicing

2020 ◽  
Vol 477 (16) ◽  
pp. 3091-3104 ◽  
Author(s):  
Luciana E. Giono ◽  
Alberto R. Kornblihtt
Keyword(s):  
Gene Expression ◽  
Alternative Splicing ◽  
Rna Polymerase Ii ◽  
Environmental Changes ◽  
Transcription Elongation ◽  
Single Gene ◽  
Regulation Of Gene Expression ◽  
Regulation Of Transcription ◽  
Stepping Stones ◽  
Eukaryotic Transcription

Gene expression is an intricately regulated process that is at the basis of cell differentiation, the maintenance of cell identity and the cellular responses to environmental changes. Alternative splicing, the process by which multiple functionally distinct transcripts are generated from a single gene, is one of the main mechanisms that contribute to expand the coding capacity of genomes and help explain the level of complexity achieved by higher organisms. Eukaryotic transcription is subject to multiple layers of regulation both intrinsic — such as promoter structure — and dynamic, allowing the cell to respond to internal and external signals. Similarly, alternative splicing choices are affected by all of these aspects, mainly through the regulation of transcription elongation, making it a regulatory knob on a par with the regulation of gene expression levels. This review aims to recapitulate some of the history and stepping-stones that led to the paradigms held today about transcription and splicing regulation, with major focus on transcription elongation and its effect on alternative splicing.

‘And all my children?’

2018 ◽  
Author(s):  
Charlotte Scott
Keyword(s):  
Early Modern ◽  
Life Stage ◽  
Early Modern Period ◽  
Life Stages ◽  
Cultural Imagination ◽  
Modern Period

Beginning with an exploration of the role of the child in the cultural imagination, Chapter 1 establishes the formative and revealing ways in which societies identify themselves in relation to how they treat their children. Focusing on Shakespeare and the early modern period, Chapter 1 sets out to determine the emotional, symbolic, and political registers through which children are depicted and discussed. Attending to the different life stages and representations of the child on stage, this chapter sets out the terms of the book’s enquiry: what role do children play in Shakespeare’s plays; how do we recognize them as such—age, status, parental dynamic—and what are the effects of their presence? This chapter focuses on how the early moderns understood the child, as a symbolic figure, a life stage, a form of obligation, a profound bond, and an image of servitude.

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