@article{6778, abstract = {An important adaptation during colonization of land by plants is gravitropic growth of roots, which enabled roots to reach water and nutrients, and firmly anchor plants in the ground. Here we provide insights into the evolution of an efficient root gravitropic mechanism in the seed plants. Architectural innovation, with gravity perception constrained in the root tips along with a shootward transport route for the phytohormone auxin, appeared only upon the emergence of seed plants. Interspecies complementation and protein domain swapping revealed functional innovations within the PIN family of auxin transporters leading to the evolution of gravitropism-specific PINs. The unique apical/shootward subcellular localization of PIN proteins is the major evolutionary innovation that connected the anatomically separated sites of gravity perception and growth response via the mobile auxin signal. We conclude that the crucial anatomical and functional components emerged hand-in-hand to facilitate the evolution of fast gravitropic response, which is one of the major adaptations of seed plants to dry land.}, author = {Zhang, Yuzhou and Xiao, G and Wang, X and Zhang, Xixi and Friml, Jiří}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Evolution of fast root gravitropism in seed plants}}, doi = {10.1038/s41467-019-11471-8}, volume = {10}, year = {2019}, } @article{6821, abstract = {To determine the visual sensitivities of an organism of interest, quantitative reverse transcription–polymerase chain reaction (qRT–PCR) is often used to quantify expression of the light‐sensitive opsins in the retina. While qRT–PCR is an affordable, high‐throughput method for measuring expression, it comes with inherent normalization issues that affect the interpretation of results, especially as opsin expression can vary greatly based on developmental stage, light environment or diurnal cycles. We tested for diurnal cycles of opsin expression over a period of 24 hr at 1‐hr increments and examined how normalization affects a data set with fluctuating expression levels using qRT–PCR and transcriptome data from the retinae of the cichlid Pelmatolapia mariae. We compared five methods of normalizing opsin expression relative to (a) the average of three stably expressed housekeeping genes (Ube2z, EF1‐α and β‐actin), (b) total RNA concentration, (c) GNAT2, (the cone‐specific subunit of transducin), (d) total opsin expression and (e) only opsins expressed in the same cone type. Normalizing by proportion of cone type produced the least variation and would be best for removing time‐of‐day variation. In contrast, normalizing by housekeeping genes produced the highest daily variation in expression and demonstrated that the peak of cone opsin expression was in the late afternoon. A weighted correlation network analysis showed that the expression of different cone opsins follows a very similar daily cycle. With the knowledge of how these normalization methods affect opsin expression data, we make recommendations for designing sampling approaches and quantification methods based upon the scientific question being examined.}, author = {Yourick, Miranda R. and Sandkam, Benjamin A. and Gammerdinger, William J and Escobar-Camacho, Daniel and Nandamuri, Sri Pratima and Clark, Frances E. and Joyce, Brendan and Conte, Matthew A. and Kocher, Thomas D. and Carleton, Karen L.}, issn = {1755-0998}, journal = {Molecular Ecology Resources}, number = {6}, pages = {1447--1460}, publisher = {Wiley}, title = {{Diurnal variation in opsin expression and common housekeeping genes necessitates comprehensive normalization methods for quantitative real-time PCR analyses}}, doi = {10.1111/1755-0998.13062}, volume = {19}, year = {2019}, } @article{6788, abstract = {We consider the Nelson model with ultraviolet cutoff, which describes the interaction between non-relativistic particles and a positive or zero mass quantized scalar field. We take the non-relativistic particles to obey Fermi statistics and discuss the time evolution in a mean-field limit of many fermions. In this case, the limit is known to be also a semiclassical limit. We prove convergence in terms of reduced density matrices of the many-body state to a tensor product of a Slater determinant with semiclassical structure and a coherent state, which evolve according to a fermionic version of the Schrödinger–Klein–Gordon equations.}, author = {Leopold, Nikolai K and Petrat, Sören P}, issn = {1424-0661}, journal = {Annales Henri Poincare}, number = {10}, pages = {3471–3508}, publisher = {Springer Nature}, title = {{Mean-field dynamics for the Nelson model with fermions}}, doi = {10.1007/s00023-019-00828-w}, volume = {20}, year = {2019}, } @article{6795, abstract = {The green‐beard effect is one proposed mechanism predicted to underpin the evolu‐tion of altruistic behavior. It relies on the recognition and the selective help of altruists to each other in order to promote and sustain altruistic behavior. However, this mechanism has often been dismissed as unlikely or uncommon, as it is assumed that both the signaling trait and altruistic trait need to be encoded by the same gene or through tightly linked genes. Here, we use models of indirect genetic effects (IGEs) to find the minimum correlation between the signaling and altruistic trait required for the evolution of the latter. We show that this correlation threshold depends on the strength of the interaction (influence of the green beard on the expression of the altruistic trait), as well as the costs and benefits of the altruistic behavior. We further show that this correlation does not necessarily have to be high and support our analytical results by simulations.}, author = {Trubenova, Barbora and Hager, Reinmar}, issn = {20457758}, journal = {Ecology and Evolution}, number = {17}, pages = {9597--9608}, publisher = {Wiley}, title = {{Green beards in the light of indirect genetic effects}}, doi = {10.1002/ece3.5484}, volume = {9}, year = {2019}, } @article{6793, abstract = {The Regge symmetry is a set of remarkable relations between two tetrahedra whose edge lengths are related in a simple fashion. It was first discovered as a consequence of an asymptotic formula in mathematical physics. Here, we give a simple geometric proof of Regge symmetries in Euclidean, spherical, and hyperbolic geometry.}, author = {Akopyan, Arseniy and Izmestiev, Ivan}, issn = {14692120}, journal = {Bulletin of the London Mathematical Society}, number = {5}, pages = {765--775}, publisher = {London Mathematical Society}, title = {{The Regge symmetry, confocal conics, and the Schläfli formula}}, doi = {10.1112/blms.12276}, volume = {51}, year = {2019}, } @article{6831, abstract = {* Understanding the mechanisms causing phenotypic differences between females and males has long fascinated evolutionary biologists. An extensive literature exists on animal sexual dimorphism but less information is known about sex differences in plants, particularly the extent of geographical variation in sexual dimorphism and its life‐cycle dynamics. * Here, we investigated patterns of genetically based sexual dimorphism in vegetative and reproductive traits of a wind‐pollinated dioecious plant, Rumex hastatulus, across three life‐cycle stages using open‐pollinated families from 30 populations spanning the geographic range and chromosomal variation (XY and XY1Y2) of the species. * The direction and degree of sexual dimorphism was highly variable among populations and life‐cycle stages. Sex‐specific differences in reproductive function explained a significant amount of temporal change in sexual dimorphism. For several traits, geographical variation in sexual dimorphism was associated with bioclimatic parameters, likely due to the differential responses of the sexes to climate. We found no systematic differences in sexual dimorphism between chromosome races. * Sex‐specific trait differences in dioecious plants largely result from a balance between sexual and natural selection on resource allocation. Our results indicate that abiotic factors associated with geographical context also play a role in modifying sexual dimorphism during the plant life‐cycle.}, author = {Puixeu Sala, Gemma and Pickup, Melinda and Field, David and Barrett, Spencer C.H.}, issn = {1469-8137}, journal = {New Phytologist}, number = {3}, pages = {1108--1120}, publisher = {Wiley}, title = {{Variation in sexual dimorphism in a wind-pollinated plant: The influence of geographical context and life-cycle dynamics}}, doi = {10.1111/nph.16050}, volume = {224}, year = {2019}, } @article{6828, abstract = {In this paper we construct a family of exact functors from the category of Whittaker modules of the simple complex Lie algebra of type to the category of finite-dimensional modules of the graded affine Hecke algebra of type . Using results of Backelin [2] and of Arakawa-Suzuki [1], we prove that these functors map standard modules to standard modules (or zero) and simple modules to simple modules (or zero). Moreover, we show that each simple module of the graded affine Hecke algebra appears as the image of a simple Whittaker module. Since the Whittaker category contains the BGG category as a full subcategory, our results generalize results of Arakawa-Suzuki [1], which in turn generalize Schur-Weyl duality between finite-dimensional representations of and representations of the symmetric group .}, author = {Brown, Adam}, issn = {0021-8693}, journal = {Journal of Algebra}, pages = {261--289}, publisher = {Elsevier}, title = {{Arakawa-Suzuki functors for Whittaker modules}}, doi = {10.1016/j.jalgebra.2019.07.027}, volume = {538}, year = {2019}, } @misc{9803, abstract = {Understanding the mechanisms causing phenotypic differences between females and males has long fascinated evolutionary biologists. An extensive literature exists on animal sexual dimorphism but less is known about sex differences in plants, particularly the extent of geographical variation in sexual dimorphism and its life-cycle dynamics. Here, we investigate patterns of genetically-based sexual dimorphism in vegetative and reproductive traits of a wind-pollinated dioecious plant, Rumex hastatulus, across three life-cycle stages using open-pollinated families from 30 populations spanning the geographic range and chromosomal variation (XY and XY1Y2) of the species. The direction and degree of sexual dimorphism was highly variable among populations and life-cycle stages. Sex-specific differences in reproductive function explained a significant amount of temporal change in sexual dimorphism. For several traits, geographical variation in sexual dimorphism was associated with bioclimatic parameters, likely due to the differential responses of the sexes to climate. We found no systematic differences in sexual dimorphism between chromosome races. Sex-specific trait differences in dioecious plants largely result from a balance between sexual and natural selection on resource allocation. Our results indicate that abiotic factors associated with geographical context also play a role in modifying sexual dimorphism during the plant life cycle.}, author = {Puixeu Sala, Gemma and Pickup, Melinda and Field, David and Barrett, Spencer C.H.}, publisher = {Dryad}, title = {{Data from: Variation in sexual dimorphism in a wind-pollinated plant: the influence of geographical context and life-cycle dynamics}}, doi = {10.5061/dryad.n1701c9}, year = {2019}, } @article{6836, abstract = {Direct reciprocity is a powerful mechanism for the evolution of cooperation on the basis of repeated interactions1,2,3,4. It requires that interacting individuals are sufficiently equal, such that everyone faces similar consequences when they cooperate or defect. Yet inequality is ubiquitous among humans5,6 and is generally considered to undermine cooperation and welfare7,8,9,10. Most previous models of reciprocity do not include inequality11,12,13,14,15. These models assume that individuals are the same in all relevant aspects. Here we introduce a general framework to study direct reciprocity among unequal individuals. Our model allows for multiple sources of inequality. Subjects can differ in their endowments, their productivities and in how much they benefit from public goods. We find that extreme inequality prevents cooperation. But if subjects differ in productivity, some endowment inequality can be necessary for cooperation to prevail. Our mathematical predictions are supported by a behavioural experiment in which we vary the endowments and productivities of the subjects. We observe that overall welfare is maximized when the two sources of heterogeneity are aligned, such that more productive individuals receive higher endowments. By contrast, when endowments and productivities are misaligned, cooperation quickly breaks down. Our findings have implications for policy-makers concerned with equity, efficiency and the provisioning of public goods.}, author = {Hauser, Oliver P. and Hilbe, Christian and Chatterjee, Krishnendu and Nowak, Martin A.}, issn = {14764687}, journal = {Nature}, number = {7770}, pages = {524--527}, publisher = {Springer Nature}, title = {{Social dilemmas among unequals}}, doi = {10.1038/s41586-019-1488-5}, volume = {572}, year = {2019}, } @article{6844, abstract = {Studying the progression of the proliferative and differentiative patterns of neural stem cells at the individual cell level is crucial to the understanding of cortex development and how the disruption of such patterns can lead to malformations and neurodevelopmental diseases. However, our understanding of the precise lineage progression programme at single-cell resolution is still incomplete due to the technical variations in lineage- tracing approaches. One of the key challenges involves developing a robust theoretical framework in which we can integrate experimental observations and introduce correction factors to obtain a reliable and representative description of the temporal modulation of proliferation and differentiation. In order to obtain more conclusive insights, we carry out virtual clonal analysis using mathematical modelling and compare our results against experimental data. Using a dataset obtained with Mosaic Analysis with Double Markers, we illustrate how the theoretical description can be exploited to interpret and reconcile the disparity between virtual and experimental results.}, author = {Picco, Noemi and Hippenmeyer, Simon and Rodarte, Julio and Streicher, Carmen and Molnár, Zoltán and Maini, Philip K. and Woolley, Thomas E.}, issn = {1469-7580}, journal = {Journal of Anatomy}, number = {3}, pages = {686--696}, publisher = {Wiley}, title = {{A mathematical insight into cell labelling experiments for clonal analysis}}, doi = {10.1111/joa.13001}, volume = {235}, year = {2019}, }