scholarly journals Adaptive phenotypic response to climate enabled by epigenetics in a K-strategy species, the fish Leucoraja ocellata (Rajidae)

2016 ◽  
Vol 3 (10) ◽  
pp. 160299 ◽  
Author(s):  
Jackie Lighten ◽  
Danny Incarnato ◽  
Ben J. Ward ◽  
Cock van Oosterhout ◽  
Ian Bradbury ◽  
...  

The relative importance of genetic versus epigenetic changes in adaptive evolution is a hotly debated topic, with studies showing that some species appear to be able to adapt rapidly without significant genetic change. Epigenetic mechanisms may be particularly important for the evolutionary potential of species with long maturation times and low reproductive potential (‘K-strategists’), particularly when faced with rapidly changing environmental conditions. Here we study the transcriptome of two populations of the winter skate ( Leucoraja ocellata ), a typical ‘K-strategist’, in Atlantic Canada; an endemic population in the southern Gulf of St Lawrence and a large population on the Scotian Shelf. The endemic population has been able to adapt to a 10°C higher water temperature over short evolutionary time (7000 years), dramatically reducing its body size (by 45%) significantly below the minimum maturation size of Scotian Shelf and other populations of winter skate, as well as exhibiting other adaptations in life history and physiology. We demonstrate that the adaptive response to selection has an epigenetic basis, cataloguing 3653 changes in gene expression that may have enabled this species to rapidly respond to the novel environment. We argue that the epigenetic augmentation of species evolutionary potential (its regulation though gene expression) can enable K-strategists to survive and adapt to different environments, and this mechanism may be particularly important for the persistence of sharks, skates and rays in the light of future climate change.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Wei Zhang ◽  
You Zhai ◽  
Guanzhang Li ◽  
Tao Jiang

Abstract Background Glioma is the most common and fatal type of nerve neoplasm in the central nervous system. Several biomarkers have been considered for prognosis prediction, which is not accurate enough. We aimed to carry out a gene signature related to the expression of immune checkpoints which was enough for its performance in prediction. Methods Gene expression of immune checkpoints in TGGA database was filtrated. The 5 selected genes underwent verification by COX and Lasso-COX regression. Next, the selected genes were included to build a novel signature for further analysis. Results Patients were sub-grouped into high and low risk according to the novel signature. Immune response, clinicopathologic characters, and survival showed significant differences between those 2 groups. Terms including “naive,” “effector,” and “IL-4” were screened out by GSEA. The results showed strong relevance between the signature and immune response. Conclusions We constructed a gene signature with 5 immune checkpoints. The signature predicted survival effectively. The novel signature performed more functional than previous biomarkers.


Author(s):  
Barbara Elizabeth Hanna ◽  
Peter Cowley

China Miéville’s 2009 'Weird' detective novel The City and The City is a tale of two city states, culturally distinct, between which unpoliced contact is forbidden. While residents of each city can learn about the other’s history, geography, politics, see photographs and watch news footage of the other city, relations between the two are tightly monitored and any direct contact requires a series of protocols, some of which might seem reasonable, or at least familiar: entry permits, international mail, international dialing codes, intercultural training courses. What complicates these apparently banal measures is the relative positioning of the two cities, each one around, within, amongst the other. The two populations live side by side, under a regime which requires ostentatious and systematic disregard or 'unnoticing' of the other in any context but a tightly regulated set of encounters. For all that interculturality is endemic to everyday life in the 21st century, what is striking is that critical and popular uptake of this novel so frequently decries the undesirability, the immorality even, of the cultural separation between the two populations, framing it as an allegory of unjust division within a single culture, and thus by implication endorsing the erasure of intercultural difference. We propose an alternative reading which sees this novel as exploring the management of intercultural encounters, and staging the irreducibility of intercultural difference. We examine how the intercultural is established in the novel, and ask how it compares to its representations in prevalent theoretical models, specifically that of the Third Place.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
James Alexander Briggs ◽  
Victor C Li ◽  
Seungkyu Lee ◽  
Clifford J Woolf ◽  
Allon Klein ◽  
...  

In embryonic development, cells differentiate through stereotypical sequences of intermediate states to generate particular mature fates. By contrast, driving differentiation by ectopically expressing terminal transcription factors (direct programming) can generate similar fates by alternative routes. How differentiation in direct programming relates to embryonic differentiation is unclear. We applied single-cell RNA sequencing to compare two motor neuron differentiation protocols: a standard protocol approximating the embryonic lineage, and a direct programming method. Both initially undergo similar early neural commitment. Later, the direct programming path diverges into a novel transitional state rather than following the expected embryonic spinal intermediates. The novel state in direct programming has specific and uncharacteristic gene expression. It forms a loop in gene expression space that converges separately onto the same final motor neuron state as the standard path. Despite their different developmental histories, motor neurons from both protocols structurally, functionally, and transcriptionally resemble motor neurons isolated from embryos.


2021 ◽  
Author(s):  
Chester J Joyner ◽  
Ariel Ley ◽  
Doan Nguyen ◽  
Muhammad Ali ◽  
Alessia Corrado ◽  
...  

Antibody secreting cells (ASC) circulate after vaccination and migrate to the bone marrow (BM) where a subset known as long-lived plasma cells (LLPC) persist and secrete antibodies for a lifetime. The mechanisms of how circulating ASC become LLPC are not well elucidated. Here, we show that human blood ASCs have distinct morphology, transcriptomes, and epigenetics compared to BM LLPC. LLPC acquire transcriptional and epigenetic changes in the apoptosis pathway to support their survival. Upregulation of pro-survival gene expression accompanies downregulation of pro-apoptotic gene expression in LLPC. While pro-apoptotic gene loci are less accessible, pro-survival gene loci are not always accompanied by accessibility changes. Importantly, we show similar LLPC morphological and transcriptional maturation of blood ASC in response to the novel in vitro BM mimetic. In all, our study demonstrates that blood ASC in the BM microniche must undergo morphological and molecular changes to mature into apoptotic-resistant LLPC.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12298
Author(s):  
Maokai Yan ◽  
Xingyue Jin ◽  
Yanhui Liu ◽  
Huihuang Chen ◽  
Tao Ye ◽  
...  

Background Sugarcane (Saccharum spontaneum L.), the major sugar and biofuel feedstock crop, is cultivated mainly by vegetative propagation worldwide due to the infertility of female reproductive organs resulting in the reduction of quality and output of sugar. Deciphering the gene expression profile during ovule development will improve our understanding of the complications underlying sexual reproduction in sugarcane. Optimal reference genes are essential for elucidating the expression pattern of a given gene by quantitative real-time PCR (qRT-PCR). Method In this study, based on transcriptome data obtained from sugarcane ovule, eighteen candidate reference genes were identified, cloned, and their expression levels were evaluated across five developmental stages ovule (AC, MMC, Meiosis, Mitosis, and Mature). Results Our results indicated that FAB2 and MOR1 were the most stably expressed genes during sugarcane female gametophyte development. Moreover, two genes, cell cycle-related genes REC8 and CDK, were selected, and their feasibility was validated. This study provides important insights into the female gametophyte development of sugarcane and reports novel reference genes for gene expression research on sugarcane sexual reproduction.


Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 360
Author(s):  
Peter Schausberger ◽  
Yukie Sato

Optimal outbreeding and kin selection theories state that the degree of kinship is a fundamental determinant in any mating system. However, the role of kinship in male choice and alternative reproductive tactics (ARTs) is poorly known. We assessed the influence of kinship on male choice and expression of ARTs in two populations of two-spotted spider mites Tetranychus urticae. Male spider mites guard premature females, which is an indicator of mate choice, and may conditionally adopt fighting or sneaking tactics to secure access to females. Males competing with kin or non-kin were offered one kin or non-kin female (experiment 1) and single males were presented a choice of kin and non-kin females (experiment 2). Under kin competition, males of both populations were more prone to guard non-kin than kin females at a 3:1 fighter:sneaker ratio. Under non-kin competition, all males were fighters. Under no-choice, males used novelty as indicator of genetic dissimilarity, serving as absolute decision rule for outbreeding. Under choice, comparative evaluation allowed males to preferentially guard females with higher reproductive potential. Overall, our study suggests that male spider mites can assess kinship of rivals and prospective mates. Kin discrimination allows adaptive, context-specific non-random mating preference and adjustment of ARTs.


2005 ◽  
Vol 289 (4) ◽  
pp. E586-E590 ◽  
Author(s):  
Susan Kralisch ◽  
Johannes Klein ◽  
Ulrike Lossner ◽  
Matthias Bluher ◽  
Ralf Paschke ◽  
...  

Visfatin is a novel adipocytokine exerting insulin-mimetic effects in various insulin-sensitive tissues such as liver, muscle, and fat. In contrast, interleukin (IL)-6 is a proinflammatory adipose-secreted factor that induces insulin resistance and plasma concentrations that correlate with the development of type 2 diabetes mellitus. In the present study, the impact of IL-6 on visfatin gene expression in 3T3-L1 adipocytes was determined by quantitative real-time reverse transcription-polymerase chain reaction. Interestingly, 30 ng/ml IL-6 time-dependently downregulated visfatin synthesis with a significant 40% suppression seen after 4 h of treatment. Furthermore, the addition of IL-6 for 16 h dose-dependently suppressed visfatin mRNA with significant effects first observed at concentrations as low as 3 ng/ml and a maximal 43% reduction at 30 ng/ml effector. Moreover, inhibitor studies suggested that the negative effect of IL-6 on visfatin expression is, at least in part, mediated by p44/42 mitogen-activated protein kinase. In contrast, troglitazone did not reverse the negative effect of IL-6 on visfatin synthesis under these conditions. Taken together, our study suggests that IL-6 might influence glucose tolerance in part by regulation of the novel insulin-mimetic adipocytokine visfatin.


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