Dissection of the major late blight resistance cluster on potato linkage group IV

Potato is consumed worldwide and represents the fourth most important staple food crop after rice and wheat. Potato cultivars display a large variety of color, shape, taste, cooking properties and starch content but are all derived from the same species; Solanum tuberosum. Potato breeding is an economic important activity for international breeding companies, but also plays an important role in breaking the circle of poverty for small farmers. In the Andean region, most farmers use many different potato genotypes combined with farming practices transmitted orally over thousands of years. The most prominent menace to potato production is Late Blight caused by the oomycete Phytophthora infestans which destroys leaves, stems and tubers. Differences of breeding methods between the potato grown in South America and in the rest of the world is related to differences in the consequences of Late Blight infection. In the 19th, century, entire potato fields in Ireland were devastated while in South America P. infestans proliferation was readily inhibited. This difference is found in the biodiversity reserve such as that of the Chiloé archipelago in Chile where local people cultivate about 200 varieties of native potato. Obviously, the genetic diversity of cultivated native potato acts as a shield against this versatile pathogen. Inspired by this model to solve the problems raised by the extensive use of potato monoculture, growers and breeders need to maintain genetic diversity in the European staple food crops. In exploring the South American native potato collection, Solanum demissum and later on Solanum bulbocastanum appeared to be a source of resistance genes (Rpi) to P. infestans. The S. demissum Rpi genes were transmitted to potato breeding clones by traditional introgression breeding. However the fading of their ability in providing effective resistance against Late Blight infection was witnessed within a decade. In the pursuit to provide a hopefully more durable protection in existing potato cultivars, plant breeding scientists proposed to directly introduce South American native potato Rpi genes in modern potato varieties by using a so-called cisgenic approach. This in contrast to transgenic plants which can contain genes which have originated from non related genera or even different kingdoms. Breeding of cisgenic plants is on its way to public acceptance because of its inherent resemblance to natural crossing and because efforts are made by the scientific community to explain the principles of cisgenesis. Lessons were learned from the flexibility of P. infestans to overcome the effect of newly introduced Rpi genes and, therefore, efforts are still ongoing to discover and clone new Rpi genes from native potatoes. With this in mind, a new family of Rpi genes represented by Rpi-blb3, Rpi-abpt, R2, R2-like and Rpi-mcd1.1 were characterized in clones derived from S. bulbocastanum, S. demissum, S. edinense and S. microdontum. We accomplished in this research the physical isolation of these genes, the molecular characterization of their functionality and the allelic distribution in the Petota collection. Rpi-blb3, Rpi-abpt, R2, R2-like and Rpi-mcd1.1 belong to the potato linkage group IV and all contain signature sequences characteristic of LZ-NBS-LRR proteins. The closest known R gene so far is RPP13 from Arabidopsis thaliana which shares an amino-acid sequence similarity of 35%. The LRR domains of Rpi-blb3, Rpi-abpt, R2 and R2-like proteins are highly homologous, whilst LZ and NBS domains are more polymorphic with those of R2 being the most divergent. All four Rpi genes recognize the recently identified RXLR effector protein PiAVR2 which is secreted by P.infestans in the cytoplasm of plant cells during the infection process. Unlike Rpi-blb3, Rpi-abpt, R2 and R2-like , the S. microdontum resistance gene Rpi-mcd1.1 does not interact with PiAVR2 and provides a different resistance spectrum. Rpi-mcd1.1 shares 90% nucleotide identity with Rpi-blb3 and polymorphic nucleotides are mainly located in the LRR region. The S. bulbocastanum haplotypes of Rpi-blb1, Rpi-blb2 and Rpi-blb3 were discovered in several Mexican diploid as well as polyploid species closely related to S. bulbocastanum. These three resistance genes occurred in different combinations and frequencies in S. bulbocastanum accessions and their distribution is confined to Central America. A selected set of genotypes was tested for their response to the avirulence effectors IPIO-2, Avr-blb2 and Pi-Avr2, which interact with Rpi-blb1, Rpi-blb2 and Rpi-blb3, respectively, as well as by disease assays with a diverse set of isolates. Using this approach some accessions could be identified that contain novel, yet unknown, Late Blight resistance factors in addition to the Rpi-blb1, Rpi-blb2 and Rpi-blb3 genes Analysis of the sequences obtained in different allele mining strategies suggests an evolution of the major late blight locus on linkage group IV through recombination and point mutations. By making use of the sequence information provided by the alleles, we identified the repeats and amino acids in the LRR domain which are specific for PiAVR2 recognition. Finally, we discussed the results described in this thesis in a potato/ P. infestans co-evolution context. <br/

Adaptive Learning Gain in Asset Pricing

This paper delves into the complexities of asset pricing, emphasizing the need to go beyond prevailing paradigms and constant learning gain assumptions. We examine the influence of personal experiences, adaptive learning processes, and subjective return expectations on asset pricing. By incorporating the concept of time-varying learning gain, we provide a more realistic portrayal of asset pricing. Empirical analysis reveals a consistent negative correlation between experienced real payout growth and subsequent returns, indicating counter-cyclical behavior. Our findings also support the mean-reversion hypothesis in stock returns, although caution is needed due to some scenarios lacking statistical significance. Theoretical exploration uncovers that higher uncertainty or variability compels investors to seek additional compensation, thus elevating the equity risk premium. Moreover, the information structure does not form a filtration, leading to no convergence to a specific value in the long run. Agents perceive future increments as negatively serially correlated but lack the memory to effectively exploit this correlation for forecasting. Consequently, the Law of Iterated Expectations does not hold. We propose the resale valuation method as ideal for agents with adaptive learning gains. These findings contribute to an innovative asset pricing model with adaptive learning gains, enhancing our understanding of market dynamics. While this study does not provide calibration or validation, we outline the model’s theoretical foundations and implications for future research. Our work adds to the evolving landscape of asset pricing theory, highlighting the significance of adaptive learning in capturing complex dynamics

Human Breast Milk: From Food to Active Immune Response With Disease Protection in Infants and Mothers

Breastfeeding is associated with long-term wellbeing including low risks of infectious diseases and non-communicable diseases such as asthma, cancer, autoimmune diseases and obesity during childhood. In recent years, important advances have been made in understanding the human breast milk (HBM) composition. Breast milk components such as, non-immune and immune cells and bioactive molecules, namely, cytokines/chemokines, lipids, hormones, and enzymes reportedly play many roles in breastfed newborns and in mothers, by diseases protection and shaping the immune system of the newborn. Bioactive components in HBM are also involved in tolerance and appropriate inflammatory response of breastfed infants if necessary. This review summarizes the current literature on the relationship between mother and her infant through breast milk with regard to disease protection. We will shed some light on the mechanisms underlying the roles of breast milk components in the maintenance of health of both child and mother

Investigation of the evolution of law tranpsortnogo European community

Исследуется эволюция развития транспортного законодательства Европейского сообщества, процессы либерализации транспортного рынка, с целью разработки направлений повышения конкурентоспособности и эффективности деятельности железнодорожного транспорта

Role of Cytotrophoblast Cells and Placenta-Derived Exosomes in Regulatory B Cell Differentiation and Function during Pregnancy

Pregnancy is a particular physiologic stage during which immune regulation is essential. A successful placentation and subsequent fetal development depend on the delicate balance between moderate pro-inflammatory response and immune tolerance. Findings have pointed out a crucial role for regulatory B cells (Bregs) in establishing an immunomodulatory (IM) environment relevant to pregnancy. In a steady state, Bregs represent 10% of B cells in peripheral blood, a proportion that increases during pregnancy, with the highest rate being observed in post-partum. In the context of pregnancy, Bregs seem to be well positioned to perform the mechanisms that accommodate the growing semi-allogenic fetus and also allow the adequate immune response to pathogen. This chapter discusses the mechanism of action of Bregs during human pregnancy. Also, we will evoke interactions between maternal immune cells and fetal annexes that result in hijacking the naïve B cells to educate and to differentiate them into Bregs

Hétérogénéité génétique et résistance des vecteurs du paludisme (Anopheles gambiae s.l) aux insecticides en zone cotonnière au Benin

La résistance des vecteurs du paludisme aux insecticides utilisés dans la lutte anti vectorielle est un obstacle majeur pour les programmes nationaux de lutte contre le paludisme. La présente étude avait pour but d’évaluer la diversité génétique des populations de Anopheles gambiae et la résistance aux insecticides (mutation Kdr et Ace-1) en zone cotonnière au Bénin. Deux méthodes de capture ont été utilisées pour la collecte d’échantillon. La capture sur appât humain et la récolte de la faune résiduelle matinale par spray. La PCR SINE a permis de distinguer deux espèces jumelles et d’obtenir les différents génotypes pour les deux gènes. Deux espèces du complexe An. gambiae s.l ont été trouvées en sympatrie (Anopheles coluzzii et Anopheles gambiae). La résistance kdr et Ace-1 connaissent un flux saisonnier. L’allèle résistant du gène kdr est fixé dans la population de vecteurs (Fis&gt;0). Par contre, un déficit de l’allèle résistant est noté au niveau du gène Ace-1 (Fis&lt;0).Mots clés : Hétérogénéité, génétique, résistance, vecteur, paludisme. English Title: Genetic heterogeneity and resistance to insecticides in malaria vector Anopheles gambiae s.l in the cotton growing area in Benin Resistance of malaria vectors to insecticides used in vector control is a major threat for national malaria control programs. The purpose of this study was to assess the genetic diversity of Anopheles gambiae populations and resistance to insecticides (Kdr Ace-1 mutation) in the cotton growing area in Benin. Two samples methods were used for mosquito collection: Human Landing catch (HLC) and the residual fauna collection by spray. The SINE PCR allow to identify species the different genotypes resistance genes. Two species of the An. gambiae s.l complex have been found in sympatry (Anopheles coluzzii and Anopheles gambiae). kdr and Ace-1 resistance had seasonal variation trend. The kdr resistance allele is fixed in the vector population (Fis&gt; 0). Moreover, a deficit of the Ace-1 resistance allele was observed (Fis &lt;0). Keywords: Heterogeneity, genetic, resistance, vector, malaria