@article{421, abstract = {Cell shape is determined by a balance of intrinsic properties of the cell as well as its mechanochemical environment. Inhomogeneous shape changes underlie many morphogenetic events and involve spatial gradients in active cellular forces induced by complex chemical signaling. Here, we introduce a mechanochemical model based on the notion that cell shape changes may be induced by external diffusible biomolecules that influence cellular contractility (or equivalently, adhesions) in a concentration-dependent manner—and whose spatial profile in turn is affected by cell shape. We map out theoretically the possible interplay between chemical concentration and cellular structure. Besides providing a direct route to spatial gradients in cell shape profiles in tissues, we show that the dependence on cell shape helps create robust mechanochemical gradients.}, author = {Dasbiswas, Kinjal and Hannezo, Claude-Edouard B and Gov, Nir}, journal = {Biophysical Journal}, number = {4}, pages = {968 -- 977}, publisher = {Biophysical Society}, title = {{Theory of eppithelial cell shape transitions induced by mechanoactive chemical gradients}}, doi = {10.1016/j.bpj.2017.12.022}, volume = {114}, year = {2018}, } @article{422, abstract = {We show that a rather simple, steady modification of the streamwise velocity profile in a pipe can lead to a complete collapse of turbulence and the flow fully relaminarizes. Two different devices, a stationary obstacle (inset) and a device which injects fluid through an annular gap close to the wall, are used to control the flow. Both devices modify the streamwise velocity profile such that the flow in the center of the pipe is decelerated and the flow in the near wall region is accelerated. We present measurements with stereoscopic particle image velocimetry to investigate and capture the development of the relaminarizing flow downstream these devices and the specific circumstances responsible for relaminarization. We find total relaminarization up to Reynolds numbers of 6000, where the skin friction in the far downstream distance is reduced by a factor of 3.4 due to relaminarization. In a smooth straight pipe the flow remains completely laminar downstream of the control. Furthermore, we show that transient (temporary) relaminarization in a spatially confined region right downstream the devices occurs also at much higher Reynolds numbers, accompanied by a significant local skin friction drag reduction. The underlying physical mechanism of relaminarization is attributed to a weakening of the near-wall turbulence production cycle.}, author = {Kühnen, Jakob and Scarselli, Davide and Schaner, Markus and Hof, Björn}, journal = {Flow Turbulence and Combustion}, number = {4}, pages = {919 -- 942}, publisher = {Springer}, title = {{Relaminarization by steady modification of the streamwise velocity profile in a pipe}}, doi = {10.1007/s10494-018-9896-4}, volume = {100}, year = {2018}, } @article{423, abstract = {Herd immunity, a process in which resistant individuals limit the spread of a pathogen among susceptible hosts has been extensively studied in eukaryotes. Even though bacteria have evolved multiple immune systems against their phage pathogens, herd immunity in bacteria remains unexplored. Here we experimentally demonstrate that herd immunity arises during phage epidemics in structured and unstructured Escherichia coli populations consisting of differing frequencies of susceptible and resistant cells harboring CRISPR immunity. In addition, we develop a mathematical model that quantifies how herd immunity is affected by spatial population structure, bacterial growth rate, and phage replication rate. Using our model we infer a general epidemiological rule describing the relative speed of an epidemic in partially resistant spatially structured populations. Our experimental and theoretical findings indicate that herd immunity may be important in bacterial communities, allowing for stable coexistence of bacteria and their phages and the maintenance of polymorphism in bacterial immunity.}, author = {Payne, Pavel and Geyrhofer, Lukas and Barton, Nicholas H and Bollback, Jonathan P}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{CRISPR-based herd immunity can limit phage epidemics in bacterial populations}}, doi = {10.7554/eLife.32035}, volume = {7}, year = {2018}, } @article{425, abstract = {We show that the following algorithmic problem is decidable: given a 2-dimensional simplicial complex, can it be embedded (topologically, or equivalently, piecewise linearly) in R3? By a known reduction, it suffices to decide the embeddability of a given triangulated 3-manifold X into the 3-sphere S3. The main step, which allows us to simplify X and recurse, is in proving that if X can be embedded in S3, then there is also an embedding in which X has a short meridian, that is, an essential curve in the boundary of X bounding a disk in S3 \ X with length bounded by a computable function of the number of tetrahedra of X.}, author = {Matoušek, Jiří and Sedgwick, Eric and Tancer, Martin and Wagner, Uli}, journal = {Journal of the ACM}, number = {1}, publisher = {ACM}, title = {{Embeddability in the 3-Sphere is decidable}}, doi = {10.1145/3078632}, volume = {65}, year = {2018}, } @article{426, abstract = {Sperm cells are the most morphologically diverse cells across animal taxa. Within species, sperm and ejaculate traits have been suggested to vary with the male's competitive environment, e.g., level of sperm competition, female mating status and quality, and also with male age, body mass, physiological condition, and resource availability. Most previous studies have based their conclusions on the analysis of only one or a few ejaculates per male without investigating differences among the ejaculates of the same individual. This masks potential ejaculate-specific traits. Here, we provide data on the length, quantity, and viability of sperm ejaculated by wingless males of the ant Cardiocondyla obscurior. Males of this ant species are relatively long-lived and can mate with large numbers of female sexuals throughout their lives. We analyzed all ejaculates across the individuals' lifespan and manipulated the availability of mating partners. Our study shows that both the number and size of sperm cells transferred during copulations differ among individuals and also among ejaculates of the same male. Sperm quality does not decrease with male age, but the variation in sperm number between ejaculates indicates that males need considerable time to replenish their sperm supplies. Producing many ejaculates in a short time appears to be traded-off against male longevity rather than sperm quality.}, author = {Metzler, Sina and Schrempf, Alexandra and Heinze, Jürgen}, journal = {Journal of Insect Physiology}, pages = {284--290}, publisher = {Elsevier}, title = {{Individual- and ejaculate-specific sperm traits in ant males}}, doi = {10.1016/j.jinsphys.2017.12.003}, volume = {107}, year = {2018}, } @article{427, abstract = {We investigate the quantum interference induced shifts between energetically close states in highly charged ions, with the energy structure being observed by laser spectroscopy. In this work, we focus on hyperfine states of lithiumlike heavy-Z isotopes and quantify how much quantum interference changes the observed transition frequencies. The process of photon excitation and subsequent photon decay for the transition 2s→2p→2s is implemented with fully relativistic and full-multipole frameworks, which are relevant for such relativistic atomic systems. We consider the isotopes Pb79+207 and Bi80+209 due to experimental interest, as well as other examples of isotopes with lower Z, namely Pr56+141 and Ho64+165. We conclude that quantum interference can induce shifts up to 11% of the linewidth in the measurable resonances of the considered isotopes, if interference between resonances is neglected. The inclusion of relativity decreases the cross section by 35%, mainly due to the complete retardation form of the electric dipole multipole. However, the contribution of the next higher multipoles (e.g., magnetic quadrupole) to the cross section is negligible. This makes the contribution of relativity and higher-order multipoles to the quantum interference induced shifts a minor effect, even for heavy-Z elements.}, author = {Amaro, Pedro and Loureiro, Ulisses and Safari, Laleh and Fratini, Filippo and Indelicato, Paul and Stöhlker, Thomas and Santos, José}, journal = { Physical Review A - Atomic, Molecular, and Optical Physics}, number = {2}, publisher = {American Physical Society}, title = {{Quantum interference in laser spectroscopy of highly charged lithiumlike ions}}, doi = {10.1103/PhysRevA.97.022510}, volume = {97}, year = {2018}, } @article{428, abstract = {The plant hormone gibberellic acid (GA) is a crucial regulator of growth and development. The main paradigm of GA signaling puts forward transcriptional regulation via the degradation of DELLA transcriptional repressors. GA has also been shown to regulate tropic responses by modulation of the plasma membrane incidence of PIN auxin transporters by an unclear mechanism. Here we uncovered the cellular and molecular mechanisms by which GA redirects protein trafficking and thus regulates cell surface functionality. Photoconvertible reporters revealed that GA balances the protein traffic between the vacuole degradation route and recycling back to the cell surface. Low GA levels promote vacuolar delivery and degradation of multiple cargos, including PIN proteins, whereas high GA levels promote their recycling to the plasma membrane. This GA effect requires components of the retromer complex, such as Sorting Nexin 1 (SNX1) and its interacting, microtubule (MT)-associated protein, the Cytoplasmic Linker-Associated Protein (CLASP1). Accordingly, GA regulates the subcellular distribution of SNX1 and CLASP1, and the intact MT cytoskeleton is essential for the GA effect on trafficking. This GA cellular action occurs through DELLA proteins that regulate the MT and retromer presumably via their interaction partners Prefoldins (PFDs). Our study identified a branching of the GA signaling pathway at the level of DELLA proteins, which, in parallel to regulating transcription, also target by a nontranscriptional mechanism the retromer complex acting at the intersection of the degradation and recycling trafficking routes. By this mechanism, GA can redirect receptors and transporters to the cell surface, thus coregulating multiple processes, including PIN-dependent auxin fluxes during tropic responses.}, author = {Salanenka, Yuliya and Verstraeten, Inge and Löfke, Christian and Tabata, Kaori and Naramoto, Satoshi and Glanc, Matous and Friml, Jirí}, journal = {PNAS}, number = {14}, pages = { 3716 -- 3721}, publisher = {National Academy of Sciences}, title = {{Gibberellin DELLA signaling targets the retromer complex to redirect protein trafficking to the plasma membrane}}, doi = {10.1073/pnas.1721760115}, volume = {115}, year = {2018}, } @article{43, abstract = {The initial amount of pathogens required to start an infection within a susceptible host is called the infective dose and is known to vary to a large extent between different pathogen species. We investigate the hypothesis that the differences in infective doses are explained by the mode of action in the underlying mechanism of pathogenesis: Pathogens with locally acting mechanisms tend to have smaller infective doses than pathogens with distantly acting mechanisms. While empirical evidence tends to support the hypothesis, a formal theoretical explanation has been lacking. We give simple analytical models to gain insight into this phenomenon and also investigate a stochastic, spatially explicit, mechanistic within-host model for toxin-dependent bacterial infections. The model shows that pathogens secreting locally acting toxins have smaller infective doses than pathogens secreting diffusive toxins, as hypothesized. While local pathogenetic mechanisms require smaller infective doses, pathogens with distantly acting toxins tend to spread faster and may cause more damage to the host. The proposed model can serve as a basis for the spatially explicit analysis of various virulence factors also in the context of other problems in infection dynamics.}, author = {Rybicki, Joel and Kisdi, Eva and Anttila, Jani}, journal = {PNAS}, number = {42}, pages = {10690 -- 10695}, publisher = {National Academy of Sciences}, title = {{Model of bacterial toxin-dependent pathogenesis explains infective dose}}, doi = {10.1073/pnas.1721061115}, volume = {115}, year = {2018}, } @article{430, abstract = {In this issue of GENETICS, a new method for detecting natural selection on polygenic traits is developed and applied to sev- eral human examples ( Racimo et al. 2018 ). By de fi nition, many loci contribute to variation in polygenic traits, and a challenge for evolutionary ge neticists has been that these traits can evolve by small, nearly undetectable shifts in allele frequencies across each of many, typically unknown, loci. Recently, a helpful remedy has arisen. Genome-wide associ- ation studies (GWAS) have been illuminating sets of loci that can be interrogated jointly for c hanges in allele frequencies. By aggregating small signal s of change across many such loci, directional natural selection is now in principle detect- able using genetic data, even for highly polygenic traits. This is an exciting arena of progress – with these methods, tests can be made for selection associated with traits, and we can now study selection in what may be its most prevalent mode. The continuing fast pace of GWAS publications suggest there will be many more polygenic tests of selection in the near future, as every new GWAS is an opportunity for an accom- panying test of polygenic selection. However, it is important to be aware of complications th at arise in interpretation, especially given that these studies may easily be misinter- preted both in and outside the evolutionary genetics commu- nity. Here, we provide context for understanding polygenic tests and urge caution regarding how these results are inter- preted and reported upon more broadly.}, author = {Novembre, John and Barton, Nicholas H}, journal = {Genetics}, number = {4}, pages = {1351 -- 1355}, publisher = {Genetics Society of America}, title = {{Tread lightly interpreting polygenic tests of selection}}, doi = {10.1534/genetics.118.300786}, volume = {208}, year = {2018}, } @inproceedings{433, abstract = {A thrackle is a graph drawn in the plane so that every pair of its edges meet exactly once: either at a common end vertex or in a proper crossing. We prove that any thrackle of n vertices has at most 1.3984n edges. Quasi-thrackles are defined similarly, except that every pair of edges that do not share a vertex are allowed to cross an odd number of times. It is also shown that the maximum number of edges of a quasi-thrackle on n vertices is 3/2(n-1), and that this bound is best possible for infinitely many values of n.}, author = {Fulek, Radoslav and Pach, János}, location = {Boston, MA, United States}, pages = {160 -- 166}, publisher = {Springer}, title = {{Thrackles: An improved upper bound}}, doi = {10.1007/978-3-319-73915-1_14}, volume = {10692}, year = {2018}, } @article{434, abstract = {In this paper, we present a formal model-driven design approach to establish a safety-assured implementation of multifunction vehicle bus controller (MVBC), which controls the data transmission among the devices of the vehicle. First, the generic models and safety requirements described in International Electrotechnical Commission Standard 61375 are formalized as time automata and timed computation tree logic formulas, respectively. With model checking tool Uppaal, we verify whether or not the constructed timed automata satisfy the formulas and several logic inconsistencies in the original standard are detected and corrected. Then, we apply the code generation tool Times to generate C code from the verified model, which is later synthesized into a real MVBC chip, with some handwriting glue code. Furthermore, the runtime verification tool RMOR is applied on the integrated code, to verify some safety requirements that cannot be formalized on the timed automata. For evaluation, we compare the proposed approach with existing MVBC design methods, such as BeagleBone, Galsblock, and Simulink. Experiments show that more ambiguousness or bugs in the standard are detected during Uppaal verification, and the generated code of Times outperforms the C code generated by others in terms of the synthesized binary code size. The errors in the standard have been confirmed and the resulting MVBC has been deployed in the real train communication network.}, author = {Jiang, Yu and Liu, Han and Song, Huobing and Kong, Hui and Wang, Rui and Guan, Yong and Sha, Lui}, journal = {IEEE Transactions on Intelligent Transportation Systems}, number = {10}, pages = {3320 -- 3333}, publisher = {IEEE}, title = {{Safety-assured model-driven design of the multifunction vehicle bus controller}}, doi = {10.1109/TITS.2017.2778077}, volume = {19}, year = {2018}, } @article{435, abstract = {It is shown that two fundamentally different phenomena, the bound states in continuum and the spectral singularity (or time-reversed spectral singularity), can occur simultaneously. This can be achieved in a rectangular core dielectric waveguide with an embedded active (or absorbing) layer. In such a system a two-dimensional bound state in a continuum is created in the plane of a waveguide cross section, and it is emitted or absorbed along the waveguide core. The idea can be used for experimental implementation of a laser or a coherent-perfect-absorber for a photonic bound state that resides in a continuous spectrum.}, author = {Midya, Bikashkali and Konotop, Vladimir}, journal = {Optics Letters}, number = {3}, pages = {607 -- 610}, publisher = {Optica Publishing Group}, title = {{Coherent-perfect-absorber and laser for bound states in a continuum}}, doi = {10.1364/OL.43.000607}, volume = {43}, year = {2018}, } @article{436, abstract = {There has been significant interest recently in using complex quantum systems to create effective nonreciprocal dynamics. Proposals have been put forward for the realization of artificial magnetic fields for photons and phonons; experimental progress is fast making these proposals a reality. Much work has concentrated on the use of such systems for controlling the flow of signals, e.g., to create isolators or directional amplifiers for optical signals. In this Letter, we build on this work but move in a different direction. We develop the theory of and discuss a potential realization for the controllable flow of thermal noise in quantum systems. We demonstrate theoretically that the unidirectional flow of thermal noise is possible within quantum cascaded systems. Viewing an optomechanical platform as a cascaded system we show here that one can ultimately control the direction of the flow of thermal noise. By appropriately engineering the mechanical resonator, which acts as an artificial reservoir, the flow of thermal noise can be constrained to a desired direction, yielding a thermal rectifier. The proposed quantum thermal noise rectifier could potentially be used to develop devices such as a thermal modulator, a thermal router, and a thermal amplifier for nanoelectronic devices and superconducting circuits.}, author = {Barzanjeh, Shabir and Aquilina, Matteo and Xuereb, André}, journal = {Physical Review Letters}, number = {6}, publisher = {American Physical Society}, title = {{Manipulating the flow of thermal noise in quantum devices}}, doi = {10.1103/PhysRevLett.120.060601}, volume = {120}, year = {2018}, } @article{437, abstract = {Dendritic cells (DCs) are sentinels of the adaptive immune system that reside in peripheral organs of mammals. Upon pathogen encounter, they undergo maturation and up-regulate the chemokine receptor CCR7 that guides them along gradients of its chemokine ligands CCL19 and 21 to the next draining lymph node. There, DCs present peripherally acquired antigen to naïve T cells, thereby triggering adaptive immunity.}, author = {Leithner, Alexander F and Renkawitz, Jörg and De Vries, Ingrid and Hauschild, Robert and Haecker, Hans and Sixt, Michael K}, journal = {European Journal of Immunology}, number = {6}, pages = {1074 -- 1077}, publisher = {Wiley-Blackwell}, title = {{Fast and efficient genetic engineering of hematopoietic precursor cells for the study of dendritic cell migration}}, doi = {10.1002/eji.201747358}, volume = {48}, year = {2018}, } @article{438, abstract = {The MazF toxin sequence-specifically cleaves single-stranded RNA upon various stressful conditions, and it is activated as a part of the mazEF toxin–antitoxin module in Escherichia coli. Although autoregulation of mazEF expression through the MazE antitoxin-dependent transcriptional repression has been biochemically characterized, less is known about post-transcriptional autoregulation, as well as how both of these autoregulatory features affect growth of single cells during conditions that promote MazF production. Here, we demonstrate post-transcriptional autoregulation of mazF expression dynamics by MazF cleaving its own transcript. Single-cell analyses of bacterial populations during ectopic MazF production indicated that two-level autoregulation of mazEF expression influences cell-to-cell growth rate heterogeneity. The increase in growth rate heterogeneity is governed by the MazE antitoxin, and tuned by the MazF-dependent mazF mRNA cleavage. Also, both autoregulatory features grant rapid exit from the stress caused by mazF overexpression. Time-lapse microscopy revealed that MazF-mediated cleavage of mazF mRNA leads to increased temporal variability in length of individual cells during ectopic mazF overexpression, as explained by a stochastic model indicating that mazEF mRNA cleavage underlies temporal fluctuations in MazF levels during stress.}, author = {Nikolic, Nela and Bergmiller, Tobias and Vandervelde, Alexandra and Albanese, Tanino and Gelens, Lendert and Moll, Isabella}, journal = {Nucleic Acids Research}, number = {6}, pages = {2918--2931}, publisher = {Oxford University Press}, title = {{Autoregulation of mazEF expression underlies growth heterogeneity in bacterial populations}}, doi = {10.1093/nar/gky079}, volume = {46}, year = {2018}, } @article{44, abstract = {Recent realization of a kinetically constrained chain of Rydberg atoms by Bernien et al., [Nature (London) 551, 579 (2017)] resulted in the observation of unusual revivals in the many-body quantum dynamics. In our previous work [C. J. Turner et al., Nat. Phys. 14, 745 (2018)], such dynamics was attributed to the existence of “quantum scarred” eigenstates in the many-body spectrum of the experimentally realized model. Here, we present a detailed study of the eigenstate properties of the same model. We find that the majority of the eigenstates exhibit anomalous thermalization: the observable expectation values converge to their Gibbs ensemble values, but parametrically slower compared to the predictions of the eigenstate thermalization hypothesis (ETH). Amidst the thermalizing spectrum, we identify nonergodic eigenstates that strongly violate the ETH, whose number grows polynomially with system size. Previously, the same eigenstates were identified via large overlaps with certain product states, and were used to explain the revivals observed in experiment. Here, we find that these eigenstates, in addition to highly atypical expectation values of local observables, also exhibit subthermal entanglement entropy that scales logarithmically with the system size. Moreover, we identify an additional class of quantum scarred eigenstates, and discuss their manifestations in the dynamics starting from initial product states. We use forward scattering approximation to describe the structure and physical properties of quantum scarred eigenstates. Finally, we discuss the stability of quantum scars to various perturbations. We observe that quantum scars remain robust when the introduced perturbation is compatible with the forward scattering approximation. In contrast, the perturbations which most efficiently destroy quantum scars also lead to the restoration of “canonical” thermalization.}, author = {Turner, C J and Michailidis, Alexios and Abanin, D A and Serbyn, Maksym and Papić, Z}, journal = {Physical Review B}, number = {15}, publisher = {American Physical Society}, title = {{Quantum scarred eigenstates in a Rydberg atom chain: Entanglement, breakdown of thermalization, and stability to perturbations}}, doi = {10.1103/PhysRevB.98.155134}, volume = {98}, year = {2018}, } @article{442, abstract = {The rapid auxin-triggered growth of the Arabidopsis hypocotyls involves the nuclear TIR1/AFB-Aux/IAA signaling and is accompanied by acidification of the apoplast and cell walls (Fendrych et al., 2016). Here, we describe in detail the method for analysis of the elongation and the TIR1/AFB-Aux/IAA-dependent auxin response in hypocotyl segments as well as the determination of relative values of the cell wall pH.}, author = {Li, Lanxin and Krens, Gabriel and Fendrych, Matyas and Friml, Jirí}, issn = {2331-8325}, journal = {Bio-protocol}, number = {1}, publisher = {Bio-protocol}, title = {{Real-time analysis of auxin response, cell wall pH and elongation in Arabidopsis thaliana Hypocotyls}}, doi = {10.21769/BioProtoc.2685}, volume = {8}, year = {2018}, } @article{446, abstract = {We prove that in Thomas–Fermi–Dirac–von Weizsäcker theory, a nucleus of charge Z > 0 can bind at most Z + C electrons, where C is a universal constant. This result is obtained through a comparison with Thomas-Fermi theory which, as a by-product, gives bounds on the screened nuclear potential and the radius of the minimizer. A key ingredient of the proof is a novel technique to control the particles in the exterior region, which also applies to the liquid drop model with a nuclear background potential.}, author = {Frank, Rupert and Phan Thanh, Nam and Van Den Bosch, Hanne}, journal = {Communications on Pure and Applied Mathematics}, number = {3}, pages = {577 -- 614}, publisher = {Wiley-Blackwell}, title = {{The ionization conjecture in Thomas–Fermi–Dirac–von Weizsäcker theory}}, doi = {10.1002/cpa.21717}, volume = {71}, year = {2018}, } @article{448, abstract = {Around 150 million years ago, eusocial termites evolved from within the cockroaches, 50 million years before eusocial Hymenoptera, such as bees and ants, appeared. Here, we report the 2-Gb genome of the German cockroach, Blattella germanica, and the 1.3-Gb genome of the drywood termite Cryptotermes secundus. We show evolutionary signatures of termite eusociality by comparing the genomes and transcriptomes of three termites and the cockroach against the background of 16 other eusocial and non-eusocial insects. Dramatic adaptive changes in genes underlying the production and perception of pheromones confirm the importance of chemical communication in the termites. These are accompanied by major changes in gene regulation and the molecular evolution of caste determination. Many of these results parallel molecular mechanisms of eusocial evolution in Hymenoptera. However, the specific solutions are remarkably different, thus revealing a striking case of convergence in one of the major evolutionary transitions in biological complexity.}, author = {Harrison, Mark and Jongepier, Evelien and Robertson, Hugh and Arning, Nicolas and Bitard Feildel, Tristan and Chao, Hsu and Childers, Christopher and Dinh, Huyen and Doddapaneni, Harshavardhan and Dugan, Shannon and Gowin, Johannes and Greiner, Carolin and Han, Yi and Hu, Haofu and Hughes, Daniel and Huylmans, Ann K and Kemena, Karsten and Kremer, Lukas and Lee, Sandra and López Ezquerra, Alberto and Mallet, Ludovic and Monroy Kuhn, Jose and Moser, Annabell and Murali, Shwetha and Muzny, Donna and Otani, Saria and Piulachs, Maria and Poelchau, Monica and Qu, Jiaxin and Schaub, Florentine and Wada Katsumata, Ayako and Worley, Kim and Xie, Qiaolin and Ylla, Guillem and Poulsen, Michael and Gibbs, Richard and Schal, Coby and Richards, Stephen and Belles, Xavier and Korb, Judith and Bornberg Bauer, Erich}, journal = {Nature Ecology and Evolution}, number = {3}, pages = {557--566}, publisher = {Springer Nature}, title = {{Hemimetabolous genomes reveal molecular basis of termite eusociality}}, doi = {10.1038/s41559-017-0459-1}, volume = {2}, year = {2018}, } @article{449, abstract = {Auxin is unique among plant hormones due to its directional transport that is mediated by the polarly distributed PIN auxin transporters at the plasma membrane. The canalization hypothesis proposes that the auxin feedback on its polar flow is a crucial, plant-specific mechanism mediating multiple self-organizing developmental processes. Here, we used the auxin effect on the PIN polar localization in Arabidopsis thaliana roots as a proxy for the auxin feedback on the PIN polarity during canalization. We performed microarray experiments to find regulators of this process that act downstream of auxin. We identified genes that were transcriptionally regulated by auxin in an AXR3/IAA17- and ARF7/ARF19-dependent manner. Besides the known components of the PIN polarity, such as PID and PIP5K kinases, a number of potential new regulators were detected, among which the WRKY23 transcription factor, which was characterized in more detail. Gain- and loss-of-function mutants confirmed a role for WRKY23 in mediating the auxin effect on the PIN polarity. Accordingly, processes requiring auxin-mediated PIN polarity rearrangements, such as vascular tissue development during leaf venation, showed a higher WRKY23 expression and required the WRKY23 activity. Our results provide initial insights into the auxin transcriptional network acting upstream of PIN polarization and, potentially, canalization-mediated plant development.}, author = {Prat, Tomas and Hajny, Jakub and Grunewald, Wim and Vasileva, Mina K and Molnar, Gergely and Tejos, Ricardo and Schmid, Markus and Sauer, Michael and Friml, Jirí}, journal = {PLoS Genetics}, number = {1}, publisher = {Public Library of Science}, title = {{WRKY23 is a component of the transcriptional network mediating auxin feedback on PIN polarity}}, doi = {10.1371/journal.pgen.1007177}, volume = {14}, year = {2018}, }