| 1. |
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| 2. |
- Andersson, Dan I., et al.
(författare)
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Evolution of New Functions De Novo and from Preexisting Genes
- 2015
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 7:6
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Forskningsöversikt (refereegranskat)abstract
- How the enormous structural and functional diversity of new genes and proteins was generated (estimated to be 10^10-€“10^12 different proteins in all organisms on earth [Choi I-G, Kim S-H. 2006. Evolution of protein structural classes and protein sequence families. Proc Natl Acad Sci 103: 14056–14061] is a central biological question that has a long and rich history. Extensive work during the last 80 years have shown that new genes that play important roles in lineage-specific phenotypes and adaptation can originate through a multitude of different mechanisms, including duplication, lateral gene transfer, gene fusion/fission, and de novo origination. In this review, we focus on two main processes as generators of new functions: evolution of new genes by duplication and divergence of pre-existing genes and de novo gene origination in which a whole protein-coding gene evolves from a noncoding sequence.
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| 3. |
- Aubier, Thomas G., et al.
(författare)
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Negative Coupling: The Coincidence of Premating Isolating Barriers Can Reduce Reproductive Isolation : Negative coupling of reproductive isolation
- 2024
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Ingår i: Cold Spring Harbor Perspectives in Biology. - 1943-0264.
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Tidskriftsartikel (refereegranskat)abstract
- Speciation can be mediated by a variety of reproductive barriers, and the interaction among different barriers has often been shown to enhance overall reproductive isolation, a process referred to as “coupling.” Here, we analyze a population genetics model to study the establishment of linkage disequilibrium (LD) among loci involved in multiple premating barriers, an aspect that has received little theoretical attention to date. We consider a simple genetic framework underlying two distinct premating barriers, each encoded by a preference locus and its associated mating trait locus. We show that their interaction can lead to a decrease in overall reproductive isolation relative to a situation with a single barrier, a process we call “negative coupling.” More specifically, in our model, negative coupling results either from sexual selection that reduces divergence at all loci, or from reduced LD that occurs because the presence of many females with “mismatched” preferences causes the mating success of recombinant males to become high. Interestingly, the latter effect may even cause LD among preference loci to become negative when recombination rates among loci are low. We conclude that coincident reproductive barriers may not necessarily reinforce each other, and that the underlying loci may not necessarily develop a positive association.
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| 4. |
- Bergmann, O, et al.
(författare)
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Adult Neurogenesis in Humans
- 2015
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Ingår i: Cold Spring Harbor perspectives in biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 7:7, s. a018994-
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Casanova, Ruben, et al.
(författare)
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Auxin Metabolism in Plants
- 2021
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- The major natural auxin in plants, indole-3-acetic acid (IAA), orchestrates a plethora of developmental responses that largely depend on the formation of auxin concentration gradients within plant tissues. Together with inter- and intracellular transport, IAA metabolism-which comprises biosynthesis, conjugation, and degradation-modulates auxin gradients and is therefore critical for plant growth. It is now very well established that IAA is mainly produced from Trp and that the IPyA pathway is a major and universally conserved biosynthetic route in plants, while other redundant pathways operate in parallel. Recent findings have shown that metabolic inactivation of IAA is also redundantly performed by oxidation and conjugation processes. An exquisite spatiotemporal expression of the genes for auxin synthesis and inactivation have been shown to drive several plant developmental processes. Moreover, a group of transcription factors and epigenetic regulators controlling the expression of auxin metabolic genes have been identified in past years, which are illuminating the road to understanding the molecular mechanisms behind the coordinated responses of local auxin metabolism to specific cues. Besides transcriptional regulation, subcellular compartmentalization of the IAA metabolism and posttranslational modifications of the metabolic enzymes are emerging as important contributors to IAA homeostasis. In this review, we summarize the current knowledge on (1) the pathways for IAA biosynthesis and inactivation in plants, (2) the influence of spatiotemporally regulated IAA metabolism on auxin-mediated responses, and (3) the regulatory mechanisms that modulate IAA levels in response to external and internal cues during plant development.
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| 6. |
- Delmore, Kira, et al.
(författare)
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Genomic Approaches Are Improving Taxonomic Representation in Genetic Studies of Speciation
- 2024
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Ingår i: Cold Spring Harbor Perspectives in Biology. - 1943-0264. ; 16:2
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Forskningsöversikt (refereegranskat)abstract
- Until recently, our understanding of the genetics of speciation was limited to a narrow group of model species with a specific set of characteristics that made genetic analysis feasible. Rapidly advancing genomic technologies are eliminating many of the distinctions between laboratory and natural systems. In light of these genomic developments, we review the history of speciation genetics, advances that have been gleaned from model and non-model organisms, the current state of the field, and prospects for broadening the diversity of taxa included in future studies. Responses to a survey of speciation scientists across the world reveal the ongoing division between the types of questions that are addressed in model and non-model organisms. To bridge this gap, we suggest integrating genetic studies from model systems that can be reared in the laboratory or greenhouse with genomic studies in related non-models where extensive ecological knowledge exists.
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| 7. |
- Friberg, Urban, et al.
(författare)
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Sexually Antagonistic Zygotic Drive: A New Form of Genetic Conflict between the Sex Chromosomes
- 2015
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. - 1943-0264. ; 7:3, s. a017608-
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Tidskriftsartikel (refereegranskat)abstract
- Sisters and brothers are completely unrelated with respect to the sex chromosomes they inherit from their heterogametic parent. This has the potential to result in a previously unappreciated form of genetic conflict between the sex chromosomes, called sexually antagonistic zygotic drive (SA-ZD). SA-ZD can arise whenever brothers and sisters compete over limited resources or there is brother-sister mating coupled with inbreeding depression. Although theory predicts that SA-ZD should be common and influence important evolutionary processes, there is little empirical evidence for its existence. Here we discuss the current understanding of SA-ZD, why it would be expected to elude empirical detection when present, and how it relates to other forms of genetic conflict.
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| 8. |
- Guy, Lionel, et al.
(författare)
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The Archaeal Legacy of Eukaryotes : A Phylogenomic Perspective
- 2014
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 6:10, s. a016022-
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Tidskriftsartikel (refereegranskat)abstract
- The origin of the eukaryotic cell can be regarded as one of the hallmarks in the history of life on our planet. The apparent genomic chimerism in eukaryotic genomes is currently best explained by invoking a cellular fusion at the root of the eukaryotes that involves one archaeal and one or more bacterial components. Here, we use a phylogenomics approach to reevaluate the evolutionary affiliation between Archaea and eukaryotes, and provide further support for scenarios in which the nuclear lineage in eukaryotes emerged from within the archaeal radiation, displaying a strong phylogenetic affiliation with, or even within, the archaeal TACK superphylum. Further taxonomic sampling of archaeal genomes in this superphylum will certainly provide a better resolution in the events that have been instrumental for the emergence of the eukaryotic lineage.
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| 9. |
- Heldin, Carl-Henrik, et al.
(författare)
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Signaling Receptors for TGF-beta Family Members
- 2016
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 8:8
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor beta (TGF-beta) family members signal via heterotetrameric complexes of type I and type II dual specificity kinase receptors. The activation and stability of the receptors are controlled by posttranslational modifications, such as phosphorylation, ubiquitylation, sumoylation, and neddylation, as well as by interaction with other proteins at the cell surface and in the cytoplasm. Activation of TGF-beta receptors induces signaling via formation of Smad complexes that are translocated to the nucleus where they act as transcription factors, as well as via non-Smad pathways, including the Erk1/2, JNK and p38 MAP kinase pathways, and the Src tyrosine kinase, phosphatidylinositol 30-kinase, and Rho GTPases.
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| 10. |
- Heldin, Carl-Henrik, et al.
(författare)
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Signals and Receptors
- 2016
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- Communication between cells in a multicellular organism occurs by the production of ligands (proteins, peptides, fatty acids, steroids, gases, and other low-molecular-weight compounds) that are either secreted by cells or presented on their surface, and act on receptors on, or in, other target cells. Such signals control cell growth, migration, survival, and differentiation. Signaling receptors can be single-span plasma membrane receptors associated with tyrosine or serine/threonine kinase activities, proteins with seven transmembrane domains, or intracellular receptors. Ligand-activated receptors convey signals into the cell by activating signaling pathways that ultimately affect cytosolic machineries or nuclear transcriptional programs or by directly translocating to the nucleus to regulate transcription.
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| 11. |
- Heldin, Carl-Henrik, et al.
(författare)
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Structural and functional properties of platelet-derived growth factor and stem cell factor receptors
- 2013
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 5:8, s. UNSP a009100-
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Tidskriftsartikel (refereegranskat)abstract
- The receptors for platelet-derived growth factor (PDGF) and stem cell factor (SCF) are members of the type III class of PTK receptors, which are characterized by five Ig-like domains extracellularly and a split kinase domain intracellularly. The receptors are activated by ligand-induced dimerization, leading to autophosphorylation on specific tyrosine residues. Thereby the kinase activities of the receptors are activated and docking sites for downstream SH2 domain signal transduction molecules are created; activation of these pathways promotes cell growth, survival, and migration. These receptors mediate important signals during the embryonal development, and control tissue homeostasis in the adult. Their overactivity is seen in malignancies and other diseases involving excessive cell proliferation, such as atherosclerosis and fibrotic diseases. In cancer, mutations of PDGF and SCF receptors-including gene fusions, point mutations, and amplifications-drive subpopulations of certain malignancies, such as gastrointestinal stromal tumors, chronic myelomonocytic leukemia, hypereosinophilic syndrome, glioblastoma, acute myeloid leukemia, mastocytosis, and melanoma.
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| 12. |
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| 13. |
- Johannes, Ludger, et al.
(författare)
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Endocytic Roles of Glycans on Proteins and Lipids
- 2024
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Ingår i: Cold Spring Harbor perspectives in biology. - 1943-0264. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Most cell surface proteins are decorated by glycans, and the plasma membrane is rich in glycosylated lipids. The mechanisms by which the enormous complexity of these glycan structures on proteins and lipids is exploited to control glycoprotein activity by setting their cell surface residence time and the ways by which they are taken up into cells are still under active investigation. Here, two mechanisms are presented, termed galectin lattices and gly-colipid-lectin (GL-Lect)-driven endocytosis, which are among the most prominent to establish a link between glycan information and endocytosis. Types of glycans on glycoproteins and glycolipids are reviewed from the angle of their interaction with glycan-binding proteins that are at the heart of galectin lattices and GL-Lect-driven endocytosis. Examples are given to show how these mechanisms affect cellular functions ranging from cell migration and signaling to vascularization and immune modulation. Finally, outstanding challenges on the link between glycosylation and endocytosis are discussed.
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| 14. |
- Johansson, Erik, et al.
(författare)
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Replicative DNA polymerases
- 2013
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 5:6, s. a012799-
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Tidskriftsartikel (refereegranskat)abstract
- In 1959, Arthur Kornberg was awarded the Nobel Prize for his work on the principles by which DNA is duplicated by DNA polymerases. Since then, it has been confirmed in all branches of life that replicative DNA polymerases require a single-stranded template to build a complementary strand, but they cannot start a new DNA strand de novo. Thus, they also depend on a primase, which generally assembles a short RNA primer to provide a 3'-OH that can be extended by the replicative DNA polymerase. The general principles that (1) a helicase unwinds the double-stranded DNA, (2) single-stranded DNA-binding proteins stabilize the single-stranded DNA, (3) a primase builds a short RNA primer, and (4) a clamp loader loads a clamp to (5) facilitate the loading and processivity of the replicative polymerase, are well conserved among all species. Replication of the genome is remarkably robust and is performed with high fidelity even in extreme environments. Work over the last decade or so has confirmed (6) that a common two-metal ion-promoted mechanism exists for the nucleotidyltransferase reaction that builds DNA strands, and (7) that the replicative DNA polymerases always act as a key component of larger multiprotein assemblies, termed replisomes. Furthermore (8), the integrity of replisomes is maintained by multiple protein-protein and protein-DNA interactions, many of which are inherently weak. This enables large conformational changes to occur without dissociation of replisome components, and also means that in general replisomes cannot be isolated intact.
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| 15. |
- Kahata, Kaoru, et al.
(författare)
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TGF-beta Family Signaling in Ductal Differentiation and Branching Morphogenesis
- 2018
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. - 1943-0264. ; 10:3
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Tidskriftsartikel (refereegranskat)abstract
- Epithelial cells contribute to the development of various vital organs by generating tubular and/or glandular architectures. The fully developed forms of ductal organs depend on processes of branching morphogenesis, whereby frequency, total number, and complexity of the branching tissue define the final architecture in the organ. Some ductal tissues, like the mammary gland during pregnancy and lactation, disintegrate and regenerate through periodic cycles. Differentiation of branched epithelia is driven by antagonistic actions of parallel growth factor systems that mediate epithelial-mesenchymal communication. Transforming growth factor-beta (TGF-beta) family members and their extracellular antagonists are prominently involved in both normal and disease-associated (e.g., malignant or fibrotic) ductal tissue patterning. Here, we discuss collective knowledge that permeates the roles of TGF-beta family members in the control of the ductal tissues in the vertebrate body.
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| 16. |
- Kahata, Kaoru, et al.
(författare)
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TGF-beta Family Signaling in Epithelial Differentiation and Epithelial-Mesenchymal Transition
- 2018
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. - 1943-0264. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Epithelia exist in the animal body since the onset of embryonic development; they generate tissue barriers and specify organs and glands. Through epithelial-mesenchymal transitions (EMTs), epithelia generate mesenchymal cells that form new tissues and promote healing or disease manifestation when epithelial homeostasis is challenged physiologically or pathologically. Transforming growth factor-beta s (TGF-beta s), activins, bone morphogenetic proteins (BMPs), and growth and differentiation factors (GDFs) have been implicated in the regulation of epithelial differentiation. These TGF-beta family ligands are expressed and secreted at sites where the epithelium interacts with the mesenchyme and provide paracrine queues from the mesenchyme to the neighboring epithelium, helping the specification of differentiated epithelial cell types within an organ. TGF-beta ligands signal via Smads and cooperating kinase pathways and control the expression or activities of key transcription factors that promote either epithelial differentiation or mesenchymal transitions. In this review, we discuss evidence that illustrates how TGF-beta family ligands contribute to epithelial differentiation and induce mesenchymal transitions, by focusing on the embryonic ectoderm and tissues that form the external mammalian body lining.
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| 17. |
- Krupinski, Pawel, et al.
(författare)
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Modeling Auxin-regulated Development.
- 2010
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Ingår i: Cold Spring Harbor perspectives in biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 2:2, s. 001560-001560
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Tidskriftsartikel (refereegranskat)abstract
- The phytohormone auxin plays an essential role in many aspects of plant growth and development. Its patterning, intercellular transport, and means of signaling have been extensively studied both in experiments and computational models. Here, we present a review of models of auxin-regulated development in different plant tissues. This includes models of organ initiation in the shoot apical meristem, development of vascular strands in leafs and stems, and auxin-related functioning in roots. The examples show how mathematical modeling can help to examine expected and unexpected behavior of the system, challenge our knowledge and hypotheses, obtain quantitative results, or suggest new experiments and ways to approach a problem.
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| 18. |
- Kuhn, Hans-Georg, 1961
(författare)
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Control of Cell Survival in Adult Mammalian Neurogenesis
- 2015
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 7:12
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Tidskriftsartikel (refereegranskat)abstract
- The fact that continuous proliferation of stem cells and progenitors, as well as the production of new neurons, occurs in the adult mammalian central nervous system (CNS) raises several basic questions concerning the number of neurons required in a particular system. Can we observe continued growth of brain regions that sustain neurogenesis? Or does an elimination mechanism exist to maintain a constant number of cells? If so, are old neurons replaced, or are the new neurons competing for limited network access among each other? What signals support their survival and integration and what factors are responsible for their elimination? This review will address these and other questions regarding regulatory mechanisms that control cell-death and cell-survival mechanisms during neurogenesis in the intact adult mammalian brain.
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| 19. |
- Kuhn, Hans-Georg, 1961, et al.
(författare)
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Detection and Phenotypic Characterization of Adult Neurogenesis
- 2016
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- Studies of adult neurogenesis have greatly expanded in the last decade, largely as a result of improved tools for detecting and quantifying neurogenesis. In this review, we summarize and critically evaluate detection methods for neurogenesis in mammalian and human brain tissue. Besides thymidine analog labeling, cell-cycle markers are discussed, as well as cell stage and lineage commitment markers. Use of these histological tools is critically evaluated in terms of their strengths and limitations, as well as possible artifacts. Finally, we discuss the method of radiocarbon dating for determining cell and tissue turnover in humans.
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| 20. |
- Lampugnani, Maria Grazia, et al.
(författare)
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Vascular Endothelial (VE)-Cadherin, Endothelial Adherens Junctions, and Vascular Disease
- 2018
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : COLD SPRING HARBOR LAB PRESS, PUBLICATIONS DEPT. - 1943-0264. ; 10:10
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Tidskriftsartikel (refereegranskat)abstract
- Endothelial cell - cell adherens junctions (AJs) supervise fundamental vascular functions, such as the control of permeability and transmigration of circulating leukocytes, and the maintenance of existing vessels and formation of new ones. These processes are often dysregulated in pathologies. However, the evidence that links dysfunction of endothelial AJs to human pathologies is mostly correlative. In this review, we present an update of the molecular organization of AJ complexes in endothelial cells (ECs) that is mainly based on observations from experimental models. Furthermore, we report in detail on a human pathology, cerebral cavernous malformation (CCM), which is initiated by loss-of-function mutations in the genes that encode the three cytoplasmic components of AJs (CCM1, CCM2, and CCM3). At present, these represent a unique example of mutations in components of endothelial AJs that cause human disease. We describe also how studies into the defects of AJs in CCM are shedding light on the crucial regulatory mechanisms and signaling activities of these endothelial structures. Although these observations are specific for CCM, they support the concept that dysfunction of endothelial AJs can directly contribute to human pathologies.
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| 21. |
- Lane, DP, et al.
(författare)
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p53-based cancer therapy
- 2010
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Ingår i: Cold Spring Harbor perspectives in biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 2:9, s. a001222-
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Tidskriftsartikel (refereegranskat)
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| 22. |
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| 23. |
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| 24. |
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| 25. |
- Lindvall, Olle, et al.
(författare)
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Neurogenesis following Stroke Affecting the Adult Brain.
- 2015
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Ingår i: Cold Spring Harbor perspectives in biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 7:11, s. 019034-019034
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Tidskriftsartikel (refereegranskat)abstract
- A bulk of experimental evidence supports the idea that the stroke-damaged adult brain makes an attempt to repair itself by producing new neurons also in areas where neurogenesis does not normally occur (e.g., the striatum and cerebral cortex). Knowledge about mechanisms regulating the different steps of neurogenesis after stroke is rapidly increasing but still incomplete. The functional consequences of stroke-induced neurogenesis and the level of integration of the new neurons into existing neural circuitries are poorly understood. To have a substantial impact on the recovery after stroke, this potential mechanism for self-repair needs to be enhanced, primarily by increasing the survival and differentiation of the generated neuroblasts. Moreover, for efficient repair, optimization of neurogenesis most likely needs to be combined with promotion of other endogenous neuroregenerative responses (e.g., protection and sprouting of remaining mature neurons, transplantation of neural stem/progenitor cells [NSPC]-derived neurons and glia cells, and modulation of inflammation).
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| 26. |
- Lucek, Kay, et al.
(författare)
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The Impact of Chromosomal Rearrangements in Speciation: From Micro- to Macroevolution : A Macroevolutionary View on Chromosomal Speciation
- 2023
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Ingår i: Cold Spring Harbor Perspectives in Biology. - 1943-0264. ; 15:11
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Tidskriftsartikel (refereegranskat)abstract
- Chromosomal rearrangements (CRs) have been known since almost the beginning of genetics. While an important role for CRs in speciation has been suggested, evidence primarily stems from theoretical and empirical studies focusing on the microevolutionary level (i.e., on taxon pairs where speciation is often incomplete). Although the role of CRs in eukaryotic speciation at a macroevolutionary level has been supported by associations between species diversity and rates of evolution of CRs across phylogenies, these findings are limited to a restricted range of CRs and taxa. Now that more broadly applicable and precise CR detection approaches have become available, we address the challenges in filling some of the conceptual and empirical gaps between micro- and macroevolutionary studies on the role of CRs in speciation. We synthesize what is known about the macroevolutionary impact of CRs and suggest new research avenues to overcome the pitfalls of previous studies to gain a more comprehensive understand- ing of the evolutionary significance of CRs in speciation across the tree of life.
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| 27. |
- Morikawa, Masato, et al.
(författare)
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TGF-beta and the TGF-beta Family : Context-Dependent Roles in Cell and Tissue Physiology
- 2016
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 8:5
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Tidskriftsartikel (refereegranskat)abstract
- The transforming growth factor-beta (TGF-beta) is the prototype of the TGF-beta family of growth and differentiation factors, which is encoded by 33 genes in mammals and comprises homo- and heterodimers. This review introduces the reader to the TGF-beta family with its complexity of names and biological activities. It also introduces TGF-beta as the best-studied factor among the TGF-beta family proteins, with its diversity of roles in the control of cell proliferation and differentiation, wound healing and immune system, and its key roles in pathology, for example, skeletal diseases, fibrosis, and cancer.
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| 28. |
- Nyberg, Lars, et al.
(författare)
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Working Memory : Maintenance, Updating, and the Realization of Intentions
- 2016
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- "Working memory" refers to avast set of mnemonic processes and associated brain networks, relates to basic intellectual abilities, and underlies many real-world functions. Working-memory maintenance involves frontoparietal regions and distributed representational areas, and can be based on persistent activity in reentrant loops, synchronous oscillations, or changes in synaptic strength. Manipulation of content of working memory depends on the dorsofrontal cortex, and updating is realized by a frontostriatal '"gating" function. Goals and intentions are represented as cognitive and motivational contexts in the rostrofrontal cortex. Different working-memory networks are linked via associative reinforcement-learning mechanisms into a self-organizing system. Normal capacity variation, as well as working-memory deficits, can largely be accounted for by the effectiveness and integrity of the basal ganglia and dopaminergic neurotransmission.
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| 29. |
- Reifova, Radka, et al.
(författare)
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Mechanisms of Intrinsic Postzygotic Isolation : From Traditional Genic and Chromosomal Views to Genomic and Epigenetic Perspectives
- 2023
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Ingår i: Cold Spring Harbor Perspectives in Biology. - 1943-0264. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- Intrinsic postzygotic isolation typically appears as reduced viability or fertility of interspecific hybrids caused by genetic incompatibilities between diverged parental genomes. Dobzhansky-Muller interactions among individual genes, and chromosomal rearrangements causing problems with chromosome synapsis and recombination in meiosis, have both long been considered as major mechanisms behind intrinsic postzygotic isolation. Recent research has, however, suggested that the genetic basis of intrinsic postzygotic isolation can be more complex and involves, for example, overall divergence of the DNA sequence or epigenetic changes. Here, we review the mechanisms of intrinsic postzygotic isolation from genic, chromosomal, genomic, and epigenetic perspectives across diverse taxa. We provide empirical evidence for these mechanisms, discuss their importance in the speciation process, and highlight questions that remain unanswered.
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| 30. |
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| 31. |
- Shaw, Kerry L., et al.
(författare)
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How Important Is Sexual Isolation to Speciation?
- 2024
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Ingår i: Cold Spring Harbor perspectives in biology. - 1943-0264. ; 16:4
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Forskningsöversikt (refereegranskat)abstract
- A central role for sexual isolation in the formation of new species and establishment of species boundaries has been noticed since Darwin and is frequently emphasized in the modern literature on speciation. However, an objective evaluation of when and how sexual isolation plays a role in speciation has been carried out in few taxa. We discuss three approaches for assessing the importance of sexual isolation relative to other reproductive barriers, including the relative evolutionary rate of sexual trait differentiation, the relative strength of sexual isolation in sympatry, and the role of sexual isolation in the long-term persistence of diverging forms. First, we evaluate evidence as to whether sexual isolation evolves faster than other reproductive barriers during the early stages of divergence. Second, we discuss available evidence as to whether sexual isolation is as strong or stronger than other barriers between closely related sympatric species. Finally, we consider the effect of sexual isolation on long-term species persistence, relative to other reproductive barriers. We highlight challenges to our knowledge of and opportunities to improve upon our understanding of sexual isolation from different phases of the speciation process.
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| 32. |
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| 33. |
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| 34. |
- Sundberg, Eva
(författare)
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Distinct and Dynamic Auxin Activities During Reproductive Development
- 2009
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 1, s. 1-14
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Forskningsöversikt (refereegranskat)abstract
- Flowering plants have evolved sophisticated and complicated reproductive structures to ensure optimal conditions for the next generation. Successful reproduction relies on careful timing and coordination of tissue development, which requires constant communication between these tissues. Work on flower and fruit development over the last decade places the phytohormone auxin in a key role as a master of patterning and tissue specification of reproductive organs. Although many questions still remain, it is now clear that auxin mediates its function in flowers and fruits through an integrated process of biosynthesis, transport, and signaling, as well as interaction with other hormonal pathways. In addition, the knowledge obtained so far about auxin function already allows researchers to develop tools for crop improvement and precision agriculture.
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| 35. |
- Visa, Neus, et al.
(författare)
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Nuclear Functions of Actin
- 2010
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory. - 1943-0264. ; 2:4, s. a000620-
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Tidskriftsartikel (refereegranskat)abstract
- Actin participates in several essential processes in the cell nucleus. Even though the presence of actin in the nucleus was proposed more than 30 years ago, nuclear processes that require actin have been only recently identified. Actin is part of chromatin remodeling complexes; it is associated with the transcription machineries; it becomes incorporated into newly synthesized ribonucleoproteins; and it influences long-range chromatin organization. As in the cytoplasm, nuclear actin works in conjunction with different types of actin-binding proteins that regulate actin function and bridge interactions between actin and other nuclear components.
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| 36. |
- Ålund, Murielle, et al.
(författare)
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Anthropogenic Change and the Process of Speciation
- 2023
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Ingår i: Cold Spring Harbor Perspectives in Biology. - : Cold Spring Harbor Laboratory Press (CSHL). - 1943-0264. ; 15:12
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic impacts on the environment alter speciation processes by affecting both geographical contexts and selection patterns on a worldwide scale. Here we review evidence of these effects. We find that human activities often generate spatial isolation between populations and thereby promote genetic divergence but also frequently cause sudden secondary contact and hybridization between diverging lineages. Human-caused environmental changes produce new ecological niches, altering selection in diverse ways that can drive diversification; but changes also often remove niches and cause extirpations. Human impacts that alter selection regimes are widespread and strong in magnitude, ranging from local changes in biotic and abiotic conditions to direct harvesting to global climate change. Altered selection, and evolutionary responses to it, impacts early-stage divergence of lineages, but does not necessarily lead toward speciation and persistence of separate species. Altogether, humans both promote and hinder speciation, although new species would form very slowly relative to anthropogenic hybridization, which can be nearly instantaneous. Speculating about the future of speciation, we highlight two key conclusions: (1) Humans will have a large influence on extinction and "despeciation" dynamics in the short term and on early-stage lineage divergence, and thus potentially speciation in the longer term, and (2) long-term monitoring combined with easily dated anthropogenic changes will improve our understanding of the processes of speciation. We can use this knowledge to preserve and restore ecosystems in ways that promote (re-)diversification, increasing future opportunities of speciation and enhancing biodiversity.
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| 37. |
- Berlin, Anna
(författare)
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Isolate Specificity and Polygenic Inheritance of Resistance in Barley to the Heterologous Rust Pathogen Puccinia graminis f. sp avenae
- 2016
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Ingår i: Phytopathology. - 0031-949X .- 1943-7684. ; 106, s. 1029-1037
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Tidskriftsartikel (refereegranskat)abstract
- Barley is a near-nonhost to numerous heterologous (nonadapted) rust pathogens because a small proportion of genotypes are somewhat susceptible. We assessed 66 barley accessions and three mapping populations (Vada x SusPtrit, Cebada Capa x SusPtrit, and SusPtrit x Golden Promise) for response to three Swedish oat stem rust (Puccinia graminis f. sp. avenae) fungal isolates and determined that barley is a near-nonhost to P. graminis f. sp. avenae and that resistance was polygenically inherited. The parental genotypes Vada and Golden Promise were immune to all three isolates, whereas Cebada Capa was immune to two isolates and moderately resistant to the third. Phenotypic data from the Vada x SusPtrit mapping population and the barley accessions tested also demonstrated isolate-specific resistance. In particular, the SusPtrit parent and several other accessions allowed sporulation by isolate Ingeberga but were resistant to isolate Evertsholm. Nine chromosomal regions carried quantitative trait loci (QTL) (Rpgaql to Rpgaq9) of varying effect, most of which colocated to previously identified QTL for resistance to other heterologous rust pathogens. Rpgaql on chromosome 1H (Vada and Golden Promise) was effective toward all isolates tested. Microscopic examination indicated that resistance was prehaustorial in Vada whereas, in SusPtrit, both pre- and posthaustorial mechanisms play a role.
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