scholarly journals Influence of environmental temperature on mouth-form plasticity in Pristionchus pacificus acts through daf-11-dependent cGMP signaling

2021 ◽  
Author(s):  
Masa Lenuzzi ◽  
Hanh Witte ◽  
Metta Riebesell ◽  
Christian Roedelsperger ◽  
Ray L. Hong ◽  
...  

Mouth-form plasticity in the nematode Pristionchus pacificus has become a powerful system to identify the genetic and molecular mechanisms associated with phenotypic (developmental) plasticity. In particular, the identification of developmental switch genes that can sense environmental stimuli and reprogram developmental processes has confirmed long-standing evolutionary theory. Together with the associated gene regulatory networks, these developmental switch genes have been important to show that plasticity is consistent with the Modern Synthesis of evolution. However, how these genes are involved in the direct sensing of the environment, or if the switch genes act downstream of another, primary environmental sensing mechanism, remains currently unknown. Here, we study the influence of environmental temperature on mouth-form plasticity. Using forward and reverse genetic technology including CRISPR/Cas9, we show that mutations in the guanylyl cyclase Ppa-daf-11, the Ppa-daf-25/AnkMy2 and the cyclic nucleotide-gated channel Ppa-tax-2 eliminate the response to elevated temperatures. Together, our study indicates that DAF-11, DAF-25 and TAX-2 have been co-opted for environmental sensing during mouth-form plasticity regulation in P. pacificus. This work suggests that developmental switch genes integrate environmental signals including perception by cGMP signaling.

2021 ◽  
Vol 12 ◽  
Author(s):  
Dagmar Hromadová ◽  
Aleš Soukup ◽  
Edita Tylová

Responsiveness to environmental conditions and developmental plasticity of root systems are crucial determinants of plant fitness. These processes are interconnected at a cellular level with cell wall properties and cell surface signaling, which involve arabinogalactan proteins (AGPs) as essential components. AGPs are cell-wall localized glycoproteins, often GPI-anchored, which participate in root functions at many levels. They are involved in cell expansion and differentiation, regulation of root growth, interactions with other organisms, and environmental response. Due to the complexity of cell wall functional and regulatory networks, and despite the large amount of experimental data, the exact molecular mechanisms of AGP-action are still largely unknown. This dynamically evolving field of root biology is summarized in the present review.


2020 ◽  
Vol 118 (1) ◽  
pp. e2020028118
Author(s):  
Ryoma Tsuchiya ◽  
Aino Kaneshima ◽  
Masakazu Kobayashi ◽  
Maki Yamazaki ◽  
Yoko Takasu ◽  
...  

Diapause represents a major developmental switch in insects and is a seasonal adaptation that evolved as a specific subtype of dormancy in most insect species to ensure survival under unfavorable environmental conditions and synchronize populations. However, the hierarchical relationship of the molecular mechanisms involved in the perception of environmental signals to integration in morphological, physiological, behavioral, and reproductive responses remains unclear. In the bivoltine strain of the silkwormBombyx mori, embryonic diapause is induced transgenerationally as a maternal effect. Progeny diapause is determined by the environmental temperature during embryonic development of the mother. Here, we show that the hierarchical pathway consists of a γ-aminobutyric acid (GABA)ergic and corazonin signaling system modulating progeny diapause induction via diapause hormone release, which may be finely tuned by the temperature-dependent expression of plasma membrane GABA transporter. Furthermore, this signaling pathway possesses similar features to the gonadotropin-releasing hormone (GnRH) signaling system for seasonal reproductive plasticity in vertebrates.


2021 ◽  
Vol 12 ◽  
Author(s):  
Juhyeon Lee ◽  
Myeong Hoon Kang ◽  
Jung Yeon Kim ◽  
Pyung Ok Lim

Leaf senescence is an integrated response of the cells to develop age information and various environmental signals. Thus, some of the genes involved in the response to environmental changes are expected to regulate leaf senescence. Light acts not only as the primary source of energy for photosynthesis but also as an essential environmental cue that directly control plant growth and development including leaf senescence. The molecular mechanisms linking light signaling to leaf senescence have recently emerged, exploring the role of Phytochrome-Interacting Factors (PIFs) as a central player leading to diverse senescence responses, senescence-promoting gene regulatory networks (GRNs) involving PIFs, and structural features of transcription modules in GRNs. The circadian clock is an endogenous time-keeping system for the adaptation of organisms to changing environmental signals and coordinates developmental events throughout the life of the plant. Circadian rhythms can be reset by environmental signals, such as light-dark or temperature cycles, to match the environmental cycle. Research advances have led to the discovery of the role of core clock components as senescence regulators and their underlying signaling pathways, as well as the age-dependent shortening of the circadian clock period. These discoveries highlight the close relationship between the circadian system and leaf senescence. Key issues remain to be elucidated, including the effect of light on leaf senescence in relation to the circadian clock, and the identification of key molecules linking aging, light, and the circadian clock, and integration mechanisms of various senescence-affecting signals at the multi-regulation levels in dynamics point of view.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fengxia Tian ◽  
Xiao-Li Hu ◽  
Tao Yao ◽  
Xiaohan Yang ◽  
Jin-Gui Chen ◽  
...  

A continuous increase in ambient temperature caused by global warming has been considered a worldwide threat. As sessile organisms, plants have evolved sophisticated heat shock response (HSR) to respond to elevated temperatures and other abiotic stresses, thereby minimizing damage and ensuring the protection of cellular homeostasis. In particular, for perennial trees, HSR is crucial for their long life cycle and development. HSR is a cell stress response that increases the number of chaperones including heat shock proteins (HSPs) to counter the negative effects on proteins caused by heat and other stresses. There are a large number of HSPs in plants, and their expression is directly regulated by a series of heat shock transcription factors (HSFs). Therefore, understanding the detailed molecular mechanisms of woody plants in response to extreme temperature is critical for exploring how woody species will be affected by climate changes. In this review article, we summarize the latest findings of the role of HSFs and HSPs in the HSR of woody species and discuss their regulatory networks and cross talk in HSR. In addition, strategies and programs for future research studies on the functions of HSFs and HSPs in the HSR of woody species are also proposed.


2020 ◽  
Vol 13 (3) ◽  
pp. 192-205 ◽  
Author(s):  
Fanghong Lei ◽  
Tongda Lei ◽  
Yun Huang ◽  
Mingxiu Yang ◽  
Mingchu Liao ◽  
...  

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 909
Author(s):  
Anyela Valentina Camargo Rodriguez

Senescence is the final stage of leaf development and is critical for plants’ fitness as nutrient relocation from leaves to reproductive organs takes place. Although senescence is key in nutrient relocation and yield determination in cereal grain production, there is limited understanding of the genetic and molecular mechanisms that control it in major staple crops such as wheat. Senescence is a highly orchestrated continuum of interacting pathways throughout the lifecycle of a plant. Levels of gene expression, morphogenesis, and phenotypic development all play key roles. Yet, most studies focus on a short window immediately after anthesis. This approach clearly leaves out key components controlling the activation, development, and modulation of the senescence pathway before anthesis, as well as during the later developmental stages, during which grain development continues. Here, a computational multiscale modelling approach integrates multi-omics developmental data to attempt to simulate senescence at the molecular and plant level. To recreate the senescence process in wheat, core principles were borrowed from Arabidopsis Thaliana, a more widely researched plant model. The resulted model describes temporal gene regulatory networks and their effect on plant morphology leading to senescence. Digital phenotypes generated from images using a phenomics platform were used to capture the dynamics of plant development. This work provides the basis for the application of computational modelling to advance understanding of the complex biological trait senescence. This supports the development of a predictive framework enabling its prediction in changing or extreme environmental conditions, with a view to targeted selection for optimal lifecycle duration for improving resilience to climate change.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Dong Won Kim ◽  
Kai Liu ◽  
Zoe Qianyi Wang ◽  
Yi Stephanie Zhang ◽  
Abhijith Bathini ◽  
...  

AbstractGABAergic neurons of the hypothalamus regulate many innate behaviors, but little is known about the mechanisms that control their development. We previously identified hypothalamic neurons that express the LIM homeodomain transcription factor Lhx6, a master regulator of cortical interneuron development, as sleep-promoting. In contrast to telencephalic interneurons, hypothalamic Lhx6 neurons do not undergo long-distance tangential migration and do not express cortical interneuronal markers such as Pvalb. Here, we show that Lhx6 is necessary for the survival of hypothalamic neurons. Dlx1/2, Nkx2-2, and Nkx2-1 are each required for specification of spatially distinct subsets of hypothalamic Lhx6 neurons, and that Nkx2-2+/Lhx6+ neurons of the zona incerta are responsive to sleep pressure. We further identify multiple neuropeptides that are enriched in spatially segregated subsets of hypothalamic Lhx6 neurons, and that are distinct from those seen in cortical neurons. These findings identify common and divergent molecular mechanisms by which Lhx6 controls the development of GABAergic neurons in the hypothalamus.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tarun Karthik Kumar Mamidi ◽  
Jiande Wu ◽  
Chindo Hicks

Background. A majority of prostate cancers (PCas) are indolent and cause no harm even without treatment. However, a significant proportion of patients with PCa have aggressive tumors that progress rapidly to metastatic disease and are often lethal. PCa develops through somatic mutagenesis, but emerging evidence suggests that germline genetic variation can markedly contribute to tumorigenesis. However, the causal association between genetic susceptibility and tumorigenesis has not been well characterized. The objective of this study was to map the germline and somatic mutation interaction landscape in indolent and aggressive tumors and to discover signatures of mutated genes associated with each type and distinguishing the two types of PCa. Materials and Methods. We integrated germline mutation information from genome-wide association studies (GWAS) with somatic mutation information from The Cancer Genome Atlas (TCGA) using gene expression data from TCGA on indolent and aggressive PCas as the intermediate phenotypes. Germline and somatic mutated genes associated with each type of PCa were functionally characterized using network and pathway analysis. Results. We discovered gene signatures containing germline and somatic mutations associated with each type and distinguishing the two types of PCa. We discovered multiple gene regulatory networks and signaling pathways enriched with germline and somatic mutations including axon guidance, RAR, WINT, MSP-RON, STAT3, PI3K, TR/RxR, and molecular mechanisms of cancer, NF-kB, prostate cancer, GP6, androgen, and VEGF signaling pathways for indolent PCa and MSP-RON, axon guidance, RAR, adipogenesis, and molecular mechanisms of cancer and NF-kB signaling pathways for aggressive PCa. Conclusion. The investigation revealed germline and somatic mutated genes associated with indolent and aggressive PCas and distinguishing the two types of PCa. The study revealed multiple gene regulatory networks and signaling pathways dysregulated by germline and somatic alterations. Integrative analysis combining germline and somatic mutations is a powerful approach to mapping germline and somatic mutation interaction landscape.


2014 ◽  
Vol 82 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
Tram N. Cao ◽  
Zhuyun Liu ◽  
Tran H. Cao ◽  
Kathryn J. Pflughoeft ◽  
Jeanette Treviño ◽  
...  

ABSTRACTDespite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogenStreptococcus pyogenes(the group AStreptococcus[GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related α2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in thefasCgene of thefasBCAXregulatory system and an inactivating polymorphism in therivRregulator-encoding gene. ThefasCandrivRmutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of thefasCmutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of therivRmutation in M3 GAS restored the regulation ofgrabmRNA abundance but did not alter capsule mRNA levels. While important, thefasCandrivRmutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted.


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