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32 results for “pleiotrope”
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La structure des réseaux de régulation explique l'évolution et l'héritabilité des phénotypes complexes
De nombreux phénotypes humains sont polygéniques, déterminés par plusieurs gènes et éléments régulateurs : la taille à l’âge adulte, le métabolisme, l’immunité, la prédisposition génétique à de nombreuses maladies, y compris des cancers et des maladies auto-immunes, des troubles psychiatriques et des maladies neurodégénératives. Ces gènes sont souvent pléiotropes, déterminant simultanément différents phénotypes. Cela s’explique par le grand nombre d’interactions au niveau moléculaire dans chaque cellule, où des réseaux complexes régulent finement l’expression des gènes. Étant donné l’intrication des bases génétiques des différents phénotypes complexes, nous nous sommes demandé comment un phénotype complexe peut évoluer en réponse aux contraintes environnementales, sans altérer les autres phénotypes.
#ideev #gqelemoulon #maudfagny @hal_fr @officialSMBE #mbe #phenotype #regulation #polygenic @inrae_france
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When processing color images from my 2600MC taken with a dual-band HaO3 filter, I found that debayering in #PixInsight using DrizzleIntegration (CFA checked, 1x scale, 0.9x shrink) resulted in better color rendition and less green noise than the non-drizzle images. This worked even though my data weren’t undersampled (though they were still well-dithered).
Thought that was interesting.
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A false-color #multispectral photo I took of a larkspur with UV and IR light mapped on top of a regular visible-color photo. Inner parts of the flower petals reflect more UV than others and thus show up in blue. Other parts absorb UV but reflect IR, resulting in the red colors seen in the inner part of the flower and stems. Many flowers use this contrast to help pollinators (who often can see UV) to distinguish key parts of the flower.
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Another #multispectrum image showing #infrared and #ultraviolet light in red and blue, respectively. Note how the blue UV light glitters and reflects from the edges of the petals, while the interior of the petals and the stalk in the background glows red from reflected IR (the “Wood Effect”).
#IRphotography #infraredphotography #uvphotography #photography
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Latest #multispectrum image, showing what a flower might look like if we saw beyond visible light into the UV and IR spectra.
I’ve mapped IR light to red and UV light to blue, and added them to the existing red and blue data from the ordinary RGB image (included for comparison). Notice how the spots on the petals reflect IR light (and thus glow red), and how outer parts of the petals reflect more UV (blue).
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A #outrun-style, false color infrared image.
Here, IR = red, red = blue, green = cyan, and blue = green. #IRphotography #photography
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My first image from my hacked-together #multispectral (IR, UV, and visible light) camera. Near IR is in red, visible light is in green, and UV is in blue.
The camera itself is a monochrome camera I normally use for solar imaging, while the lens is just a regular Nikon 50 f/1.8D. Between the two is an electronic filter wheel with IR pass, IR cut, and UV pass filters.
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Walking my dog last night and thought the full moon looked a little lopsided. Turns out it was grazing the edge of the Earth’s shadow- I’d completely forgotten about the penumbral lunar eclipse!
(Also a shout-out to the #lightroom app’s camera- this was first time I’ve ever been able to get a properly exposed picture of the moon from my iPhone)
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Some picules, the tendrils rising above the surface of the solar chromosphere, visible through an H-alpha filter.
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‘Vertical’ #pleiotropy is when a variant affects a phenotype that has its own downstream effects on another phenotype
‘Horizontal’ pleiotropy is where a variant has multiple independent effects; no phenotype mediates another
Needless terminology! Easily represented in simple #DAGs as chaining and common cause, respectively. #Genetics should avoid making up new terms for simple stuff.
The interesting twist for genetics is #LinkageDisequilibrium because it can masquerade as pleiotropy
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STATGEN 2024
Pleiotropy-robust methods for high-dimensional multivariable Mendelian randomization (HDMR)
Nathan LaPierre presenting, co-authors: Matthew Stephens, Xin HeIn HDMR, we have many genetically correlated exposures, which may be explained by unobserved shared factors. These can be inferred by factor analysis.
Flexible, modular framework: Factor-Augmented MR
1. Factor Analysis
2. Regression/Variable Selection#Genetics #StatisticalGenetics #MendelianRandomization #STATGEN2024
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Uzezi Okinedo and Brook Moyers characterized pleiotropy in local adaptation in endemic sunflower populations that exhibit bimodal life-history strategies. Their results support a model of ecotypic divergence under gene flow.
🔗 doi.org/10.1093/gbe/evag098
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Mappes was expecting valkea gene to be pleiotropically linked to life-history, but data said otherwise. Moreover, melanin patterning is genetically independent of valkea. OTOH, the melanin locus associates with male behaviour. #ESEB2025
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Early-life rotavirus infection susceptibility & later gastrointestinal #cancer protection: Reverse antagonistic pleiotropy & potential vaccine benefits.
Severe #rotavirus links to SNPs under selection that raise infection risk yet may lower later cancer risk.
https://davidojcius.blogspot.com/2026/03/early-life-rotavirus-infection.html
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Deep #mutational #scanning of #influenza A virus #NEP reveals pleiotropic #mutations in its N-terminal domain http://biorxiv.org/cgi/content/short/2024.05.16.594574v1?rss=1
The influenza A virus nuclear export protein (NEP) is a multifunctional protein that is essential for the viral life cycle and has very high sequence conservation.
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Breeding for adaptation to global climate change via selection for _local_ adaptation: "#Environment‐specific selection alters #flowering‐time plasticity and results in pervasive #pleiotropic responses in #maize" https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18769#.Y9M_VAgLNvU.twitter by @ndeleongatti @DrSethMurray et al.
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Breeding for adaptation to global climate change via selection for _local_ adaptation: "#Environment‐specific selection alters #flowering‐time plasticity and results in pervasive #pleiotropic responses in #maize" https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18769#.Y9M_VAgLNvU.twitter by @[email protected] @[email protected] et al.
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🚨 new #preprint 🚨
The evolutionary emergence of #EcologicalNetworks has been studied for decades but usually focussing on one type of interaction at a time, even though organisms naturally engage in multiple interaction types simultaneously. The combined effect of different interaction types on diversification thus remains unclear - until now. 😜
I hope you enjoy reading this fascinating story about ecological #pleiotropy and how it shapes #diversification patterns!
https://www.biorxiv.org/content/10.64898/2026.03.16.712075v1
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(1/2) Very happy to announce the publication of our latest work by my former student Sylvain Pouzet in @journal-evo.bsky.social: "Gene network topology drives the mutational landscape of gene expression". Based on simulations, we show that the size and pleiotropy of mutations affecting gene expression heavily depend on the structure of the underlying gene network.
#GeneRegulatoryNetworks
#PopulationGenetics
#EvolutionarySystemsBiology -
Key #genes for #corn #architecture revealed, identifying future #breeding targets.
#agriculture #food-security #genomics #gene_regulation #pleiotropy #transcription_factors #transcriptomics #funded_by_NSF #funded_by_us
https://phys.org/news/2025-03-key-genes-corn-architecture-revealed.html
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Key #genes for #corn #architecture revealed, identifying future #breeding targets.
#agriculture #food-security #genomics #gene_regulation #pleiotropy #transcription_factors #transcriptomics #funded_by_NSF #funded_by_us
https://phys.org/news/2025-03-key-genes-corn-architecture-revealed.html
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Key #genes for #corn #architecture revealed, identifying future #breeding targets.
#agriculture #food-security #genomics #gene_regulation #pleiotropy #transcription_factors #transcriptomics #funded_by_NSF #funded_by_us
https://phys.org/news/2025-03-key-genes-corn-architecture-revealed.html
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Key #genes for #corn #architecture revealed, identifying future #breeding targets.
#agriculture #food-security #genomics #gene_regulation #pleiotropy #transcription_factors #transcriptomics #funded_by_NSF #funded_by_us
https://phys.org/news/2025-03-key-genes-corn-architecture-revealed.html
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Key #genes for #corn #architecture revealed, identifying future #breeding targets.
#agriculture #food-security #genomics #gene_regulation #pleiotropy #transcription_factors #transcriptomics #funded_by_NSF #funded_by_us
https://phys.org/news/2025-03-key-genes-corn-architecture-revealed.html
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Two stages of evolution... @grantkinsler @gsherloc @petrovadmitri use #ExperimentalEvolution in yeast to show that while 1st-step mutants appear pleiotropic in nature, 2nd-step mutations show a shift towards modular adaptation #PLOSBiology https://plos.io/4glXoXJ
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Chemical engineer by training and profession. Spent my last working decade in the network and transport layers, plus security architecture. Retired now.
Never used the bird, ran from the faceplant and tightly constrain other social. Watched #Explore here for a bit and found interesting and welcoming positivity. Hoping to find a community to exchange and discuss ideas.
Fan of science fiction and original research in mammalian biology, microbiology and systems/network biology.
#biology #microbiology #systemsbiology #networkmedicine #ecoevo #pleiotropy #mechanisms #hiking #olympicweightlifting
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#introduction
👋 :mastodon:,
I'm a researcher at #INRAE-Nouzilly (France) studying #quantitativegenetics of #chicken #behaviour (especially #socialbehavior) to improve #animalwelfareI tackle these questions using my background from #EvolutionaryBiology. I've investigated how #sexualselection and #genetic constraints (#pleiotropy, between life stages & sexes) can drive the #evolution of phenotypes & behaviours in red #junglefowl and #drosophila (some cool stuffs to be published soon!)
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"Intended state" (or sustainable w/in a system) = external influence, so how should we describe it arising from internal dynamics alone? It sounds like you're just describing evolution, but not sure what the specific subject or context is here. #maladaptation #antagonistic-pleiotropy
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#ASHG24 AU: large neuropsychiatric dx associated cnvs share characteristics.
Large. Can be complex with unknown break points.
Example 22q11. 3Mbp. ~50 genes affected. Up to 0.1% of live births. Pleiotropic with high risk of SCZ.
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Tumoral Immune Cell Exploitation in Colorectal Cancer Metastases Can Be Targeted Effectively by Anti-CCR5 Therapy in Cancer Patients
Niels Halama, Inka Zoernig, Anna Berthel, Christoph Kahlert, Fee Klupp, Meggy Suarez-Carmona,Thomas Suetterlin, Karsten Brand, Juergen Krauss, Felix Lasitschka, Tina Lerchl, Claudia Luckner-Minden, Alexis Ulrich, Moritz Koch, Juergen Weitz, Martin Schneider, Markus W. Buechler, Laurence Zitvogel,
Thomas Herrmann, Axel Benner, Christina Kunz, Stephan Luecke, Christoph Springfeld, Niels Grabe, Christine S. Falk, and Dirk JaegerTargeting Tumor-Promoting Microenvironment Through CCR5 Blockade in #Colorectal #Cancer #Liver Metastases
#Cancer progression is a process in which cancer cells and #immune cells interact with each other in a way that can lead to the growth and spread of cancer. In #colorectal cancer, when the cancer has spread to other parts of the body, it is called #metastasis and it is very difficult to treat. Treatments such as PD-1/PD-L1 blockade and #chemokine modulation have been successful in modifying the interactions between the immune system and cancer, leading to the rejection or suppression of progression. Cancer cells can also alter the immune microenvironment, leading to #immunosuppression and #immune evasion. In this research paper, the authors studied the microenvironment in #CRC #liver metastases and identified a network of #tumor cells and immune cells that exploit the CCL5-CCR5 axis. They then investigated and characterized the effects of blocking the CCL5-CCR5 axis.
the microenvironment of #liver metastases of #colorectal cancer (#CRC).
the environment induces migration of T lymphocytes, which produce a #cytokine called CCL5. This CCL5 then supports tumor growth and spread by influencing macrophages and #tumor cells. The environment is immunosuppressive and the tumor cells are exploiting the host's #immune cells to their advantage. In other words, the tumor cells are using the host's immune cells to help them grow and spread.
the effects of CCR5 blockade on the #tissue level.
Tumor #cell death and a specific pattern of #cytokine and #chemokine modulation are observed in the #ExplantModel and in #tumor biopsies from a #ClinicalTrial. Macrophages are the key for these anti-tumoral effects, as they produce IFNs and reactive oxygen species which cause tumor cell death. #CCR5 blockade induces a phenotypic shift in the macrophages, which is referred to as a switch from an M2 to an M1 phenotype. This repolarization also reduces levels of CD163+ cells, reshaping the #myeloid cell composition in the microenvironment. The influx of new effector cells due to CCR5 inhibition can shift the effects of CCL5 towards beneficial effects, such as reduction of #immunosuppression , #angiogenesis, and #chemotherapy resistance.
The microenvironment of the invasive margin of #liver metastases.
There was no relevant Th1, Th2, or Th17 #cytokine signature present in any of the samples. However, the authors did find that #chemokines and #macrophage-related cytokines were significantly increased at the invasive margin. Chemokines are molecules that help to attract #immune cells to the area, and macrophage-related cytokines are molecules that help to regulate the activity of #macrophages, which are a type of immune cell. 98% of the CD3+ #lymphocyte s in the resection specimens were positive for PD-1, which is a molecule that helps to regulate the activity of the immune system.
#CCL5 is a protein produced by T cells, which are a type of white blood cell. #CCR5 is a receptor found on metastatic tumor cells, which are cancer cells that have spread from the primary #tumor to other parts of the body. In this research paper, it was found that CCL5 has #pleiotropic tumor-promoting effects on #tumor cells and tumor-associated #macrophage s. This means that CCL5 has multiple effects on both the cancer cells and the macrophages, which are a type of white #blood #cell, that are associated with the #tumor. CCL5 was produced mainly by T cells located at the invasive margin and #peritumoral stroma of metastases, and that CCR5 was dominantly expressed by metastatic tumor cells. CCL5 also had effects on tumor #CellProliferation, invasive tumor #CellBehavior, and increased production of matrix #metalloproteinas es by tumor-associated macrophages. Finally, they found that CCR5 inhibition had an effect on key molecules of #epithelial to #mesenchymal transition ( #EMT ).
The researchers wanted to test the effects of #CCR5 blockade, which is a way of blocking the CCR5 receptor on cells, using a drug called maraviroc. They used human #tumor #explantmodel s, which are samples of #tissue from advanced #CRC patients with #liver metastases. Maraviroc led to morphologically overt tumor #CellDeath in the #explants, which means that the tumor cells died and changed in appearance. The researchers then tested the hypothesis that #macrophage s, (type of white blood cell), were required for the tumor cell death-inducing effects of CCR5 blockade. They used clodronate #liposome s to deplete CD163+ TAMs, ( #macrophage s associated with tumors) and found that combining clodronate with CCR5 inhibition abrogated the immediate tumor cell death-inducing effects of #CCR5 inhibition. This confirmed the role of macrophages in this process. IFN-g induced stromal CD163+ #macrophage #cell death and led to a reconfiguration of the #myeloid cell compartment. Inhibition of macrophage-derived reactive oxygen species could partially block the anti-tumoral effects of CCR5 inhibition. Finally, they tested the effects of CCL5/CCR5 inhibition and found that both a CCL5 neutralizing antibody and a CCR5 blocking #antibody had similar functional effects to maraviroc.
A #ClinicalTrial (MARACON) was conducted to test the effects of a drug called maraviroc on patients with advanced-stage #metastatic colorectal #cancer. The #trial involved taking biopsies of the patients before and after treatment with maraviroc, and the results showed that the drug had beneficial effects on the tumor-promoting #microenvironment and led to objective clinical responses. These responses included induction of central #TumorNecrosis, reduction of tumor cell death, and reduction of key #cytokine s and growth factors that promote tumor growth. The drug was also found to be very well tolerated, with mild elevation of #liver enzymes being the most common side effect. Finally, the trial showed that partial responses were achieved in patients with previously refractory disease.
CCR5 blockade, is a type of #therapy used to treat #cancer.
The MARACON clinical trial, showed that CCR5 blockade had a positive effect on the tumor microenvironment and led to a higher response rate in subsequent chemotherapies. The authors suggest that this effect is not limited to the #liver metastases, but is a systemic feature. They also suggest that the local presence of multiple layers of #immune subversion in cancers depends on the individual tissue, #treatment, tumor type, and the difference between primary #tumor and metastatic lesion. The authors also found that the results of the #ClinicalTrial were in line with the results of a fully human organotypic tumor #ExplantModel, which is a simple model with a straightforward approach. The authors also note that the survival data from the trial is not conclusive due to the limited number of patients, but that the objective treatment responses are very encouraging. They suggest that CCR5 blockade may be a promising approach and needs to be evaluated further scientifically and clinically.