The SUN Protein Mps3 Is Required for Spindle Pole Body Insertion into the Nuclear Membrane and Nuclear Envelope Homeostasis

The budding yeast spindle pole body (SPB) is anchored in the nuclear envelope so that it can simultaneously nucleate both nuclear and cytoplasmic microtubules. During SPB duplication, the newly formed SPB is inserted into the nuclear membrane. The mechanism of SPB insertion is poorly understood but likely involves the action of integral membrane proteins to mediate changes in the nuclear envelope itself, such as fusion of the inner and outer nuclear membranes. Analysis of the functional domains of the budding yeast SUN protein and SPB component Mps3 revealed that most regions are not essential for growth or SPB duplication under wild-type conditions. However, a novel dominant allele in the P-loop region, MPS3-G186K, displays defects in multiple steps in SPB duplication, including SPB insertion, indicating a previously unknown role for Mps3 in this step of SPB assembly. Characterization of the MPS3-G186K mutant by electron microscopy revealed severe over-proliferation of the inner nuclear membrane, which could be rescued by altering the characteristics of the nuclear envelope using both chemical and genetic methods. Lipid profiling revealed that cells lacking MPS3 contain abnormal amounts of certain types of polar and neutral lipids, and deletion or mutation of MPS3 can suppress growth defects associated with inhibition of sterol biosynthesis, suggesting that Mps3 directly affects lipid homeostasis. Therefore, we propose that Mps3 facilitates insertion of SPBs in the nuclear membrane by modulating nuclear envelope composition

Population and income across time and space /

Premi Extraordinari de Doctorat concedit pels programes de doctorat de la UAB per curs acadèmic 2017-2018En aquesta tesi investigo teòricament i empíricament l'evolució dels nivells de població i ingressos a tot el món. En el primer capítol, titulat "El Globus com a Xarxa", em pregunto: quina importància tenen els costos de transport en caiguda dels patrons de població i creixement dels ingressos des de 1000 CE? Per respondre a aquesta pregunta, edito un model espacial dinàmic quantitatiu amb un sector agrícola i no agrícola, i la fertilitat endogena, la migració, la innovació i la difusió de la tecnologia. En aquest model existeix un llindar endogen per als costos globals de transport, que es caracteritza per una simple estadística de xarxa. Si els costos de transport estan per sobre d'aquest llindar, el món convergeix a un estat de malaltia. Si els costos del transport cauen per sota d'aquest llindar, l'economia mundial entra en un procés de creixement sostingut de la població i els ingressos per càpita. Prenent aquest model a les dades, divideixo el món en 2.249 3 graus en quadrícules de 3 graus. Assigno a cada local un potencial agrícola determinat pel clima exògens i les característiques del sòl. Defecto els costos de transport bilaterals calculant la ruta més barata entre cada parell d'ubicacions, donada la col·locació natural de rius, oceans i muntanyes. Calculem el model perquè, l'any 1000, el món es trobi en estat de malaltia. A continuació, retiro el cost de l'aigua i el transport terrestre de forma exògena de manera coherent amb l'evidència històrica i fa un seguiment de l'evolució endogen de la població i els ingressos fins a l'any 2000. Qualitativament, aquest exercici genera un creixement lent però accelerat tant en la població com en la renda per càpita durant els primers 800 anys, un repunt abrupte en el creixement després de 1800 CE amb Europa al capdavant, i un gran augment en la dispersió d'ingressos per càpita després de 1800 CE. Quantitativament, el model representa el 55% de la variació de la densitat de població en 10 regions majors en 1000 CE, el 44% de la variació en ingressos per càpita entre regions en 1800 CE, i és capaç de generar un 43% de la dispersió total en ingressos per càpita el 2000 CE. El segon capítol es titula "La transició demogràfica a través del temps i l'espai". La transició demogràfica, és a dir, el pas d'un règim d'alta fertilitat / alta mortalitat a un règim de baixa fertilitat / baixa mortalitat és un procés que gairebé tots els països de la Terra han sofert o estan experimentant. Són iguals totes les transicions demogràfiques? Han canviat amb la velocitat i la forma al llarg del temps? I com relacionen el desenvolupament econòmic? Busco respondre aquestes preguntes posant un conjunt de dades de taxes de naixement i mortalitat en 188 països amb més de 250 anys. Després, calculant dates d'inici i dates finals per a les transicions dels països de la nostra mostra, documento 3 fets nous. Em sembla, en primer lloc, que la velocitat mitjana de les transicions ha augmentat constantment amb el pas del temps. En segon lloc, documento que l'ingrés per càpita al començament d'aquestes transicions és més o menys constant al llarg del temps. En tercer lloc, descobrim l'evidència del contagi demogràfic, l'entrada d'un país en la transició demogràfica està fortament relacionada amb els veïns geogràfics i lingüístics que ja han entrat en la transició fins i tot després de controlar altres observables. En el meu tercer capítol "La difusió de la demografia: una exploració quantitativa", construeixo un model transparent de la transició demogràfica en la tradició de Barro, Becker i Lucas amb diversos països. A més del compromís estàndard entre la quantitat i la qualitat entre el nombre de nens i la quantitat d'educació que hi ha, també hi ha difusió tecnològica entre ubicacions. Com a exercici quantitatiu, introduïm un canvi tecnològic esbiaixat per l'habilitat que s'allunya de la Gran Bretanya a la resta del món. Tot i la seva simplicitat, el model té bastant èxit en comparar els patrons observats de la transició demogràfica a tot el món, tant pel que fa al temps com a la ubicació geogràfica.In this thesis I investigate theoretically and empirically the evolution of population and income levels across the world. In the first chapter, titled "The Globe as a Network," I ask: how important are falling transport costs for patterns of population and income growth since 1000 CE? To answer this question, I build a quantitative dynamic spatial model with an agricultural and a non-agricultural sector, and endogenous fertility, migration, innovation and technology diffusion. In this model there exists an endogenous threshold for global transport costs, which is characterized by a simple network statistic. If transport costs are above this threshold, the world converges to a Malthusian steady state. If transport costs fall below this threshold, the world economy enters a process of sustained growth in population and income per capita. Taking this model to the data, I divide the globe into 2,249 3 degree by 3 degree quadrangles. I assign each location an agricultural potential determined by exogenous climate and soil characteristics. I infer bilateral transport costs by calculating the cheapest route between each pair of locations given the natural placement of rivers, oceans and mountains. I calibrate the model so that in the year 1000 the world is in a Malthusian steady state. I then drop the cost of water and land transport exogenously in a way that is consistent with historical evidence and track the endogenous evolution of population and income until the year 2000. Qualitatively, this exercise generates slow but accelerating growth in both population and income per capita for the first 800 years, an abrupt takeoff in growth after 1800 CE with Europe in the lead, and a large increase in the dispersion of income per capita after 1800 CE. Quantitatively, the model accounts for 55% of the variation in population density across 10 major regions in 1000 CE, 44% of the variation in income per capita across regions in 1800 CE, and is able to generate 43% of the overall dispersion in income per capita in 2000 CE. The second chapter is titled "The Demographic Transition Across Time and Space." The demographic transition, i.e., the move from a regime of high fertility/high mortality into a regime of low fertility/low mortality, is a process that almost every country on Earth has undergone or is undergoing. Are all demographic transitions equal? Have they changed in speed and shape over time? And, how do they relate to economic development? I seek to answer these questions by putting together a data set of birth and death rates for 188 countries that spans more than 250 years. Then, by estimating start dates and end dates for the transitions of the countries in our sample, I document 3 new facts. I find, first, that the average speed of transitions has increased steadily over time. Second, I document that income per capita at the start of these transitions is more or less constant over time. Third, we uncover evidence of demographic contagion the entry of a country into the demographic transition is strongly associated with its geographic and linguistic neighbors having already entered into the transition even after controlling for other observables. In my third chapter "The Diffusion of Demography: A Quantitative Exploration," I build a transparent model of the demographic transition in the tradition of Barro, Becker, and Lucas with multiple countries. In addition to the standard quantity-quality trade-off between how many children to have and how much to educate them, there is also technology diffusion between locations. As a quantitative exercise, we introduce a skill-biased technological change that diffuses away from Britain to the rest of the world. Despite its simplicity, the model is quite successful in matching observed patterns of the demographic transition across the globe, both in terms of timing and geographical location

Tracing seed to seedling transmission of the wheat blast pathogen Magnaporthe oryzae

Wheat blast caused by Magnaporthe oryzae pathotype Triticum (MoT), initially restricted to South America, is a global threat for wheat after spreading to Asia in 2016 by the introduction of contaminated seeds, raising the question about transmission of the pathogen from seeds to seedlings, a process so far not well understood. We therefore studied the relationship between seed infection and disease symptoms on seedlings and adult plants. To accomplish this objective, we inoculated spikes of wheat cv. Apogee with a transgenic isolate (MoT-DsRed, with the addition of being resistant to hygromycin). We identified MoT-DsRed in experiments using hygromycin resistance for selection or by observation of DsRed fluorescence. The seeds from infected plants looked either apparently healthy or shrivelled. To evaluate the transmission, two experimental designs were chosen (blotter test and greenhouse) and MoT-DsRed was recovered from both. This revealed that MoT is able to colonize wheat seedlings from infected seeds under the ground. The favourable conditions of temperature and humidity allowed a high recovery rate of MoT from wheat shoots when grown in artificial media. Around 42 days after germination of infected seeds, MoT-DsRed could not be reisolated, indicating that fungal progression, at this time point, did not proceed systemically/endophytically. We hypothesize that spike infection might occur via spore dispersal from infected leaves rather than within the plant. Because MoT-DsRed was not only successfully reisolated from seed coats and germinating seeds with symptoms, but also from apparently healthy seeds, urgent attention is needed to minimize the risks of inadvertent dispersal of inoculum.Fil: Martinez, Sergio Ivan. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Biológicas. Centro de Investigaciones de Fitopatología. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones de Fitopatología; ArgentinaFil: Wegner, Alex. Rwth Aachen University; AlemaniaFil: Bohnert, Stefan. Rwth Aachen University; AlemaniaFil: Schaffrath, Ulrich. Rwth Aachen University; AlemaniaFil: Perello, Analia Edith. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Biológicas. Centro de Investigaciones de Fitopatología. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones de Fitopatología; Argentin

Regulation of inducible BALT formation and contribution to immunity and pathology

Inducible bronchus-associated lymphoid tissue (iBALT) is an organized tertiary lymphoid structure that is not preprogrammed but develops in response to infection or under chronic inflammatory conditions. Emerging research has shown that iBALT provides a niche for T-cell priming and B-cell education to assist in the clearance of infectious agents, highlighting the prospect that iBALT may be engineered and harnessed to enhance protective immunity against respiratory pathogens. Although iBALT formation is associated with several canonical factors of secondary lymphoid organogenesis such as lymphotoxin-α and the homeostatic chemokines, CXCL13, CCL19, and CCL21, these cytokines are not mandatory for its formation, even though they influence its organization and function. Similarly, lymphoid tissue inducer cells are not a requisite of iBALT formation. In contrast, dendritic cells are emerging as pivotal players required to form and sustain the presence of iBALT. Regulatory T cells appear to be able to attenuate the development of iBALT, although the underlying mechanisms remain ill-defined. In this review, we discuss facets unique to iBALT induction, the cellular subsets, and molecular cues that govern this process, and the contribution of this ectopic structure toward the generation of immune responses in the pulmonary compartment