Schlagwort: evolutionary

Scientists discover ‘lost world’ of our early ancestors in billion-year-old rocks

8. Juni 2023
Newly discovered biomarker signatures point to a whole range of previously unknown organisms that dominated complex life on Earth about a billion years ago. They differed from complex eukaryotic life as we know it, such as animals, plants and algae in their cell structure and likely metabolism, which was adapted to a world that had far less oxygen in the atmosphere than today. Benjamin Nettersheim from the MARUM – Center for Marine Environmental Sciences, University of Bremen and Faculty of Geosciences at the University of Bremen and an international team of researchers now report on this breakthrough for the field of evolutionary geobiology in the journal Nature.

Quelle: IDW Informationsdienst Wissenschaft

African rhinos share retroviruses not found in Asian rhinos or other related species

10. Mai 2023
Rhinoceros belong to a mammalian order called odd-toed ungulates that also include horses and tapirs. They are found in Africa and Asia. Until recently, evidence suggested that throughout their evolutionary history, gammaretroviruses such as Murine leukemia virus had not colonised their genomes, unlike most other mammalian orders.

Quelle: IDW Informationsdienst Wissenschaft

Scientists “revive” Stone Age molecules

5. Mai 2023
Breakthroughs in ancient genome reconstruction and biotechnology are now revealing the rich molecular secrets of Paleolithic microorganisms. In a new study published in Science, a transdisciplinary team of researchers led by the Leibniz Institute for Natural Product Research and Infection Biology, the Max Planck Institute for Evolutionary Anthropology, and Harvard University reconstructed bacterial genomes of previously unknown bacteria dating to the Pleistocene. Using their genetic blueprints, they built a biotechnology platform to revive the ancient bacteria’s natural products.

Quelle: IDW Informationsdienst Wissenschaft

Genetic heritage from the Stone Age influences our chance to have a long life

13. April 2023
Researchers at Kiel University have studied the evolutionary history of the longevity gene APOE. To do this, they analysed data obtained from human skeletons that are up to 12,000 years old.

Quelle: IDW Informationsdienst Wissenschaft

New eyes discovered in trilobites

22. März 2023
Researchers at the Universities of Cologne and Edinburgh have detected previously overlooked eyes whose form and function could help to improve the evolutionary classification of archaic arthropods / publication in ‘Scientific Reports – Nature’

Quelle: IDW Informationsdienst Wissenschaft

How fishermen benefit from reversing evolution of cod

17. März 2023
Intense fishing and overexploitation have led to evolutionary changes in fish stocks like cod, reducing both their productivity and value on the market. These changes can be reversed by more sustainable and far-sighted fisheries management. The new study by researchers from the German Centre for Integrative Biodiversity Research (iDiv), Leipzig University and the Institute of Marine Research in Tromsø, which was published in Nature Sustainability, shows that reversal of evolutionary change would only slightly reduce the profit of fishing, but would help regain and conserve natural genetic diversity.

Quelle: IDW Informationsdienst Wissenschaft

The dual face of photoreceptors during seed germination

4. März 2023
Seed germination depends on light in many plants. But not always: Aethionema arabicum, a plant adapted to challenging environmental conditions, does it its own way. Here, the phytochromes, the receptors for red and far-red light, play an unexpected role in seed germination and time this process to the optimal season. These findings, now published in “Plant Physiology”, are a compelling example of the evolutionary rewiring of signaling modules that help plants adapt to their habitats. The study was led by researchers at the Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences.

Quelle: IDW Informationsdienst Wissenschaft

Genetic switch makes the eyes of male bees large and of female bees small

13. Februar 2023
Biology: Publication in Nature Communications

Bee researchers at Heinrich Heine University Düsseldorf (HHU) headed by Professor Dr Martin Beye have identified a new gene in honeybees, which is responsible for the dimorphic eye differentiation between males and females of the species. The researchers have now presented this gene and the evolutionary genetic conclusions they have drawn from it in the scientific journal Nature Communications.

Quelle: IDW Informationsdienst Wissenschaft

Autophagy: The molecular regulation of self-eating

11. Februar 2023
Autophagy, or “self-eating”, is an essential cellular quality control mechanism that clears the cell of protein aggregates and damaged organelles. This mechanism is inactive under normal conditions and only triggered upon persistent cellular stress. Researchers from the Gregor Mendel Institute of Molecular Plant Biology (GMI) of the Austrian Academy of Sciences and the Max Perutz Labs uncover a molecular switch that regulates autophagy in plants. Combining evolutionary analysis with a mechanistic experimental approach, they demonstrate that this regulatory mechanism is conserved in eukaryotes. The findings were published on February 10th in the EMBO Journal.

Quelle: IDW Informationsdienst Wissenschaft

1 billion years of abstinence: chloroplasts finally can hope for sex!

17. Januar 2023
Scientists at the Max Planck Institute of Molecular Plant Physiology in Potsdam (Germany) analyzed the inheritance of chloroplasts under different environmental conditions in almost 4 million tobacco plants. Contrary to the prevailing view that chloroplasts are only passed on by the mother plant, paternal chloroplasts can also be transmitted to the offspring under cold conditions, raising the possibility that the chloroplasts of the two parents exchange genetic material with each other. The new findings will facilitate the targeted use of chloroplast-encoded traits in plant breeding, and they also open up new perspectives for evolutionary research. The study was published in Nature Plants.

Quelle: IDW Informationsdienst Wissenschaft

Extraordinary flight artists. Hummingbird’s hovering flight likely evolved because of a lost gene

13. Januar 2023
Hummingbirds, native to North and South America, are among the smallest and most agile birds in the world. Often barely larger than a thumb, they are the only bird species that can fly not only forwards, but also backwards or sideways. Their characteristic hovering flight makes that possible. However, hovering is extremely energy-demanding. In a genomic study published in the journal Science, an international team of scientists led by Prof. Michael Hiller at the LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG) in Frankfurt, Germany, investigated the evolutionary adaptations of the metabolism that may have enabled the hummingbirds‘ unique flying abilities.

Quelle: IDW Informationsdienst Wissenschaft

Two-billion-year-old enzyme reconstructed – Detective work by molecular biologists and bioinformatics researchers

5. Dezember 2022
Basic researchers at Leipzig University have solved a puzzle in the evolution of bacterial enzymes. By reconstructing a candidate for a special RNA polymerase as it existed about two billion years ago, they were able to explain a hitherto puzzling property of the corresponding modern enzymes. Unlike their ancestors, they do not work continuously and are thus significantly more effective – these pauses in activity constitute evolutionary progress. The reconstruction of the protein from prehistoric times was made possible thanks to interdisciplinary cooperation between molecular biochemistry and bioinformatics.

Quelle: IDW Informationsdienst Wissenschaft

FAU biologist discovers evidence for intentional communication in female putty-nosed monkeys

16. November 2022
Female putty-nosed monkeys deliberately use alarm calls to recruit males to defend the group. This is the conclusion reached by Claudia Stephan, an evolutionary biologist at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), together with colleagues from the Wildlife Conservation Society after conducting observations in the Republic of the Congo. The females kept up their chirping calls until the male took action to defend the group against the predator. This is the first time that intentional vocalization such as this has been observed in the animal kingdom. The researcher has now published her findings in the scientific journal “Animal Behavior and Cognition“.

Quelle: IDW Informationsdienst Wissenschaft

Vocal Communication Originated over 400 Million Years Ago

26. Oktober 2022
Acoustic communication is not only widespread in land vertebrates like birds and mammals, but also in reptiles, amphibians, and fishes. Many of them are usually considered mute, but in fact show broad and complex acoustic repertoires. According to researchers at University of Zurich, the evolutionary origin of vocal communication dates back more than 400 million years.

Quelle: IDW Informationsdienst Wissenschaft

Gut microbes and humans on a joint evolutionary journey

16. September 2022
The human gut microbiome is composed of thousands of different bacteria and archaea that vary widely between populations and individuals. Scientists from the Max Planck Institute for Biology in Tübingen have now discovered gut microbes that share a parallel evolutionary history with their human hosts: the microorganisms co-evolved in the human gut environment over hundreds of thousands of years. In addition, some microbes exhibit genomic and functional features making them dependent on their host. Now published in Science, the researchers present the results of their study conducted with data from 1225 individuals out of Africa, Asia and Europe.

Quelle: IDW Informationsdienst Wissenschaft

The wax flowers and their complex relationship

26. August 2022
Wax flowers and numerous plant genera related to them evolved about 33 million years ago. Shortly thereafter, they split into three independent evolutionary lineages, according to a new international study led by Bayreuth plant systematist Prof. Dr. Sigrid Liede-Schumann. A total of 37 genera and 740 species emerged, distributed over the tropics and subtropics worldwide. Only the combination of well-established morphological studies with the latest molecular genetic analysis methods ensures a correct taxonomic description and classification. The research results have been published in the journal „Taxon“.

Quelle: IDW Informationsdienst Wissenschaft

Genetic time travel back 50 million years: Scientific team reveals the correct evolutionary relationships among possums

19. August 2022
Reunion in the animal kingdom. For decades separated Australasian possums can look forward to a joint future. A study of jumping genes shows that all possums share a common ancestry. In detail, the “presence (1)” or “absence (0) of 61 jumping genes indicates a common origin of all Possums (Phalangeroidea and Petauroidea) and only a distant relationship to kangaroos.

Quelle: IDW Informationsdienst Wissenschaft

A two-step adaptive walk in the wild

19. Mai 2022
An international team led by Angela Hancock at the Max Planck Institute for Plant Breeding Research in Cologne (Germany) and scientists from the Associação Projecto Vitó and Parque Natural do Fogo (Cape Verde), the University of Nottingham (UK), and the University of Bochum (Germany) studied a wild thale cress (Arabidopsis thaliana) population that colonized the base of an active stratovolcano. They found that a two-step molecular process rewired nutrient transport in the population. The study, published today in the journal Science Advances, reveal an exceptionally clear case of an adaptive walk in a wild population with broader implications for evolutionary biology and crop improvement.

Quelle: IDW Informationsdienst Wissenschaft

New social organization evolved in one species of fire ants before spreading to other species

11. März 2022
An international research team led by Queen Mary University of and Dr. Eckart Stolle from the Leibniz-Institute for the Analysis of Biodiversity Change (LIB) has discovered that a new form of ant society spread across species. They found that after the new form of social organization evolved in one species of fire ants, a „social supergene“ carrying the genetic information for the new social form, spread into other species. This spread occurred through hybridisation, i.e., breeding between ants of different species. The alternate way of life provides the ants with an evolutionary advantage and makes them more successful than with just the original social form.

Quelle: IDW Informationsdienst Wissenschaft

James W. Lightfoot commended with the Heidelberg Academy Award

3. März 2022
Max Planck researcher honored for outstanding achievements in evolutionary biology

Neuroscientist and Max Planck Research Group Leader James Lightfoot is awarded the Academy Award of the Heidelberg Academy of Sciences and Humanity. Lightfoot is recognized for his scientific findings on how a predatory nematode species is able to recognize its own offspring and kin. This turned out to be dependent on a small peptide that provides an identification signal. The Academy Award will be presented at a special ceremony on May 22.

Quelle: IDW Informationsdienst Wissenschaft

When synapse building blocks became scarce: Bayreuth biologists explain protein exchange during vertebrate evolution

1. März 2022
The electrical synapses in vertebrates are made of different, but by no means more powerful proteins than the electrical synapses in far older invertebrates. Animal physiologists at the University of Bayreuth have now found an explanation for this evolutionary puzzle. In the early phase of vertebrate evolution, there was a loss of diversity in precisely those proteins that had been used for signal transmission in older invertebrates. The scientists have published their discovery in the journal eLife.

Quelle: IDW Informationsdienst Wissenschaft

Microorganism sheds new light on cancer resistance

24. Dezember 2021
Scientists describe T. adhaerens‘ unusual behavior, including its capacity to repair its DNA even after significant radiation damage and to extrude injured cells, which later die. The findings advance scientific investigations of natural cancer-suppression mechanisms across life. Insights gleaned from these evolutionary adaptations may find their way into new and more effective therapies for this leading killer.

Quelle: Sciencedaily

Mitochondria and the evolutionary roots of cancer

23. Februar 2015

Cancer is a group of almost 200 diseases that involve variety of changes in cell structure, morphology, and physiology. Cancer phenotype is underlying several alterations in cellular dynamics with three most critical features, which includes self-sufficiency in growth signals and insensitivity to inhibitory signals, evasion of programmed cell death and limitless replicative potential with a potential for the invasion of other organs. Cancer disease is widespread among metazoans. Some properties of cancer cells such as uncontrolled cell proliferation, lack of apoptosis, hypoxia, fermentative metabolism and free cell motility, i.e. metastasis, resemble a prokaryotic lifestyle, which leads to the assumption of a reversal like evolution from eucariotic back to proteobacterial state. This phenotype matches the phenotype of the last universal common ancestor (LUCA) that resulted from the endosymbiosis between archaebacteria and α-proteobacteria, which later became the mitochondria.

 Davila AF and Zamorano P (2013) Mitochondria and the evolutionary roots of cancer. Phys. Biol. 10 (2013) 026008, doi:10.1088/1478-3975/10/2/026008

A Mitochondrial Paradigm of Metabolic and Degenerative Diseases, Aging, and Cancer: A Dawn for Evolutionary Medicine

23. Februar 2015
Progressive increase in mtDNA 3243A>G heteroplasmy causes abrupt transcriptional reprogramming

Wallace hypothesized mitochondrial dysfunction as a central role in a wide range of age-related disorders and various forms of cancer. Steadily rising increases in mitochondrial DNA mutations cause abrupt shifts in diseases. Discrete changes in nuclear gene expression in response to small increases in DNA mutant level are analogous to the phase shifts that is well known in physics: As heat is added, the ice abruptly turns to water or with more heat abruptly to steam. Therefore, a quantitative change that is an increasing proportion of mitochondrial DNA mutation results in a qualitative change  which coordinate changes in nuclear gene expression together with discrete changes in clinical symptoms.

 Wallace DC (2005) A Mitochondrial Paradigm of Metabolic and Degenerative Diseases, Aging, and Cancer: A Dawn for Evolutionary Medicine. Annu Rev Genet. 2005 ; 39: 359. doi:10.1146/annurev.genet.39.110304.095751

Picard M et. Al (2014) Progressive increase in mtDNA 3243A>G heteroplasmy causes abrupt transcriptional reprogramming. PNAS E4033–E4042, doi: 10.1073/pnas.1414028111

Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci

22. Februar 2015
3D-SIM-based DAPI intensity classification in the Barr body versus the entire nucleus of C2C12 cells. (A) Mid z-section of a DAPI-stained nucleus. The area below the dashed line illustrates the resolution level obtained by wide-field deconvolution microscopy, for comparison. Inset magnifications show the non-uniformly compacted structure of the Barr body resolvable with 3D-SIM (1) and an arbitrary autosomal region with CDCs (2). Scale bars: 5 μm, insets 1 μm. (B) X chromosome-specific painting (green) of Xi (left) and Xa territories (right) of the same nucleus in different z-sections. Note the high convergence between the painted Xi and the DAPI visualized Barr body (arrowheads). Scale bars: 2 μm, insets 1 μm. (C) 3D DAPI intensity classification exemplified for the nucleus shown in (A). Seven DAPI intensity classes displayed in false-color code ranging from class 1 (blue) representing pixels close to background intensity, largely representing the IC, up to class 7 (white) representing pixels with highest density, mainly associated with chromocenters. Framed areas of the Barr body (inset 1) and a representative autosomal region (inset 2) are shown on the right at resolution levels of 3D-SIM, deconvolution and conventional wide-field microscopy. The Xi territory pervaded by lower DAPI intensities becomes evident only at 3D-SIM resolution, whereas both wide-field and deconvolution microscopy imply a concentric increase of density in the Barr body. In the autosomal region, chromatin assigned to classes 2 to 3 lines compacted CDCs, represented by classes 4 to 6. (D) Left: average DAPI intensity classification profiles with standard deviations evaluated for entire nuclear volumes or the Barr body region only (dark grey bars). Right: over/underrepresentation of the average DAPI intensity class fraction sizes in the Barr body versus entire nuclear volumes (n = 12). Distribution differences on classes between Xi and entire nucleus P <0.001. 3D-SIM, three-dimensional structured illumination microscopy; CDC, chromatin domain cluster; DAPI, 4',6-diamidino-2-phenylindole; FISH, fluorescence in situ hybridization; IC, interchromatin compartment; Xa, active X chromosome; Xi, inactive X chromosome. Smeets et al. Epigenetics & Chromatin 2014 7:8 doi:10.1186/1756-8935-7-8
3D-SIM-based DAPI intensity classification in the Barr body versus the entire nucleus of C2C12 cells. (A) Mid z-section of a DAPI-stained nucleus. The area below the dashed line illustrates the resolution level obtained by wide-field deconvolution microscopy, for comparison. Inset magnifications show the non-uniformly compacted structure of the Barr body resolvable with 3D-SIM (1) and an arbitrary autosomal region with CDCs (2). Scale bars: 5 μm, insets 1 μm. (B) X chromosome-specific painting (green) of Xi (left) and Xa territories (right) of the same nucleus in different z-sections. Note the high convergence between the painted Xi and the DAPI visualized Barr body (arrowheads). Scale bars: 2 μm, insets 1 μm. (C) 3D DAPI intensity classification exemplified for the nucleus shown in (A). Seven DAPI intensity classes displayed in false-color code ranging from class 1 (blue) representing pixels close to background intensity, largely representing the IC, up to class 7 (white) representing pixels with highest density, mainly associated with chromocenters. Framed areas of the Barr body (inset 1) and a representative autosomal region (inset 2) are shown on the right at resolution levels of 3D-SIM, deconvolution and conventional wide-field microscopy. The Xi territory pervaded by lower DAPI intensities becomes evident only at 3D-SIM resolution, whereas both wide-field and deconvolution microscopy imply a concentric increase of density in the Barr body. In the autosomal region, chromatin assigned to classes 2 to 3 lines compacted CDCs, represented by classes 4 to 6. (D) Left: average DAPI intensity classification profiles with standard deviations evaluated for entire nuclear volumes or the Barr body region only (dark grey bars). Right: over/underrepresentation of the average DAPI intensity class fraction sizes in the Barr body versus entire nuclear volumes (n = 12). Distribution differences on classes between Xi and entire nucleus P Smeets et al. Epigenetics & Chromatin 2014 7:8 doi:10.1186/1756-8935-7-8

Daniel Smeets, Yolanda Markaki, Volker J Schmid, Felix Kraus, Anna Tattermusch, Andrea Cerase, Michael Sterr, Susanne Fiedler, Justin Demmerle, Jens Popken, Heinrich Leonhardt, Neil Brockdorff, Thomas Cremer1, Lothar Schermelleh and Marion Cremer

Abstract

Background

A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super-resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs).

Results

We demonstrate that all CTs are composed of structurally linked chromatin domain clusters (CDCs). In active CTs the periphery of CDCs harbors low-density chromatin enriched with transcriptionally competent markers, called the perichromatin region (PR). The PR borders on a contiguous channel system, the interchromatin compartment (IC), which starts at nuclear pores and pervades CTs. We propose that the PR and macromolecular complexes in IC channels together form the transcriptionally permissive active nuclear compartment (ANC). The Barr body differs from active CTs by a partially collapsed ANC with CDCs coming significantly closer together, although a rudimentary IC channel system connected to nuclear pores is maintained. Distinct Xist RNA foci, closely adjacent to the nuclear matrix scaffold attachment factor-A (SAF-A) localize throughout Xi along the rudimentary ANC. In early differentiating ESCs initial Xist RNA spreading precedes Barr body formation, which occurs concurrent with the subsequent exclusion of RNA polymerase II (RNAP II). Induction of a transgenic autosomal Xist RNA in a male ESC triggers the formation of an ‘autosomal Barr body’ with less compacted chromatin and incomplete RNAP II exclusion.

Conclusions

3D-SIM provides experimental evidence for profound differences between the functional architecture of transcriptionally active CTs and the Barr body. Basic structural features of CT organization such as CDCs and IC channels are however still recognized, arguing against a uniform compaction of the Barr body at the nucleosome level. The localization of distinct Xist RNA foci at boundaries of the rudimentary ANC may be considered as snap-shots of a dynamic interaction with silenced genes. Enrichment of SAF-A within Xi territories and its close spatial association with Xist RNA suggests their cooperative function for structural organization of Xi.

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