Cytomolecular identification of individual wheat-wheat chromosome arm associations in wheat-rye hybrids

Chromosome pairing in the meiotic metaphase I of wheatrye hybrids has been characterized by sequential genomic and fluorescent in situ hybridization allowing not only the discrimination of wheat and rye chromosomes, but also the identification of the individual wheat and rye chromosome arms involved in the chromosome associations. The majority of associations (93.8%) were observed between the wheat chromosomes. The largest number of wheat-wheat chromosome associations (53%) was detected between the A and D genomes, while the frequency of B-D and A-B associations was significantly lower (32 and 8%, respectively). Among the A-D chromosome associations, pairing between the 3AL and 3DL arms was observed with the highest frequency, while the most frequent of all the chromosome associations (0.113/ cell) was found to be the 3DS-3BS. Differences in the pairing frequency of the individual chromosome arms of wheat-rye hybrids have been discussed in relation to the homoeologous relationships between the constituent genomes of hexaploid wheat

Studies on the maize cold tolerance tests in the Martonvásár phytotron

The climatic conditions in Hungary and in the countries to which seed is exported makes the study of maize cold tolerance and constant improvements in the cold tolerance of Martonvásár hybrids especially important. An improvement in the early spring cold tolerance of maize would allow it to be grown in more northern areas with a cooler climate, while on traditional maize-growing areas the profitability of maize production could be improved by earlier sowing, leading to a reduction in transportation and drying costs and in diseases caused by Fusarium sp. The recognition of this fact led Martonvásár researchers to start investigating this subject nearly four decades ago. The phytotron has proved an excellent tool for studying and improving the cold tolerance of maize. The review will give a brief summary of the results achieved in the field of maize cold tolerance in the Martonvásár institute in recent decades

Vulnerabilidad climática de Puerto Iguazú, Argentina: Camino hacia la adaptación

Las ciudades ocupan un papel vital en el combate contra el cambio climático. Su importancia como actores esenciales se basa en el hecho de que concentran gran parte de la actividad económica y se espera que alberguen a dos terceras partes de la población del planeta para mediados de siglo. En este sentido, las acciones que las ciudades pueden realizar para enfrentar este desafío son significativas. Estas acciones incluyen esfuerzos para mitigar los efectos adversos del calentamiento global, así como gestiones para protegerse y adaptarse a eventos climáticos extremos, los cuales es probable que se tornen más intensos y frecuentes en un futuro. Hasta el momento, la atención se ha volcado predominantemente hacia las grandes metrópolis, dejando a un lado las ciudades medianas y pequeñas, las cuales a menudo son las que registran los niveles de crecimiento más altos y las que carecen de recursos de diversa índole para hacer frente a este desafío. Bajo este contexto, el presente artículo se enfoca a examinar la vulnerabilidad climática de Puerto Iguazú, una ciudad argentina situada en la llamada región de la "Triple Frontera", ya que comparte límites territoriales con Ciudad del Este (Paraguay) y Foz do Iguaçu (Brasil). El análisis se base en un enfoque de métodos mixtos. En términos cuantitativos, se desarrolló un Índice de Vulnerabilidad Urbana (IVU), el cual incluye 73 indicadores económicos, sociales, físicos, climáticos y ambientales, con el propósito de cuantificar la sensitividad de la ciudad a eventos climáticos extremos, así como su capacidad para responder y adaptarse. En términos cualitativos, información derivada de entrevistas fue utilizada para complementar los hallazgos. Este estudio forma parte de la iniciativa Ciudades Resilientes al Clima (CRC) en América Latina. El artículo, en este sentido, también hace una reflexión sobre la experiencia de conducir un proyecto bajo dicha iniciativa, y sobre las lecciones que estos resultados ofrecen a otras ciudades en contextos similares en América Latina

EBI2 is highly expressed in multiple sclerosis lesions and promotes early CNS migration of encephalitogenic CD4 T cells

Arrival of encephalitogenic T cells at inflammatory foci represents a critical step in development of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis. EBI2 and its ligand, 7{alpha},25-OHC, direct immune cell localization in secondary lymphoid organs. CH25H and CYP7B1 hydroxylate cholesterol to 7{alpha},25-OHC. During EAE, we found increased expression of CH25H by microglia and CYP7B1 by CNS-infiltrating immune cells elevating the ligand concentration in the CNS. Two critical pro-inflammatory cytokines, interleukin-23 (IL-23) and interleukin-1 beta (IL-1{beta}), maintained expression of EBI2 in differentiating Th17 cells. In line with this, EBI2 enhanced early migration of encephalitogenic T cells into the CNS in a transfer EAE model. Nonetheless, EBI2 was dispensable in active EAE. Human Th17 cells do also express EBI2, and EBI2 expressing cells are abundant within multiple sclerosis (MS) white matter lesions. These findings implicate EBI2 as a mediator of CNS autoimmunity and describe mechanistically its contribution to the migration of autoreactive T cells into inflamed organs

Response of Wheat Fungal Diseases to Elevated Atmospheric CO2 Level

Infection with fungal pathogens on wheat varieties with different levels of resistance was tested at ambient (NC, 390 ppm) and elevated (EC, 750 ppm) atmospheric CO2 levels in the phytotron. EC was found to affect many aspects of the plant-pathogen interaction. Infection with most fungal diseases was usually found to be promoted by elevated CO2 level in susceptible varieties. Powdery mildew, leaf rust and stem rust produced more severe symptoms on plants of susceptible varieties, while resistant varieties were not infected even at EC. The penetration of Fusarium head blight (FHB) into the spike was delayed by EC in Mv Mambo, while it was unaffected in Mv Regiment and stimulated in Mv Emma. EC increased the propagation of FHB in Mv Mambo and Mv Emma. Enhanced resistance to the spread of Fusarium within the plant was only found in Mv Regiment, which has good resistance to penetration but poor resistance to the spread of FHB at NC. FHB infection was more severe at EC in two varieties, while the plants of Mv Regiment, which has the best field resistance at NC, did not exhibit a higher infection level at EC. The above results suggest that breeding for new resistant varieties will remain a useful means of preventing more severe infection in a future with higher atmospheric CO2 levels

Identification of genes preferentially expressed in wheat egg cells and zygotes

Wheat genes differentially expressed in the egg cell before and after fertilization were identified. The data support zygotic gene activation before the first cell division in wheat. To have an insight into fertilization-induced gene expression, cDNA libraries have been prepared from isolated wheat egg cells and one-celled zygotes. Two-hundred and twenty-six egg cell and 253 zygote-expressed EST sequences were determined. Most of the represented transcripts were detected in the wheat egg cell or zygote transcriptome at the first time. Expression analysis of fourteen of the identified genes and three controls was carried out by real-time quantitative PCR. The preferential expression of all investigated genes in the female gametophyte-derived samples (egg cells, zygotes, two-celled proembryos, and basal ovule parts with synergids) in comparison to the anthers, and the leaves were verified. Three genes with putative signaling/regulatory functions were expressed at a low level in the egg cell but exhibited increased (2-to-33-fold) relative expression in the zygote and the proembryo. Genes with high EST abundance in cDNA libraries exhibited strong expression in the egg cell and the zygote, while the ones coding for unknown or hypothetical proteins exhibited differential expression patterns with preferential transcript accumulation in egg cells and/or zygotes. The obtained data support the activation of the zygotic genome before the first cell division in wheat

Combined loss of the BH3-only proteins Bim and Bmf restores B-cell development and function in TACI-Ig transgenic mice.

Terminal differentiation of B cells depends on two interconnected survival pathways, elicited by the B-cell receptor (BCR) and the BAFF receptor (BAFF-R), respectively. Loss of either signaling pathway arrests B-cell development. Although BCR-dependent survival depends mainly on the activation of the v-AKT murine thymoma viral oncogene homolog 1 (AKT)/PI3-kinase network, BAFF/BAFF-R-mediated survival engages non-canonical NF-κB signaling as well as MAPK/extracellular-signal regulated kinase and AKT/PI3-kinase modules to allow proper B-cell development. Plasma cell survival, however, is independent of BAFF-R and regulated by APRIL that signals NF-κB activation via alternative receptors, that is, transmembrane activator and CAML interactor (TACI) or B-cell maturation (BCMA). All these complex signaling events are believed to secure survival by increased expression of anti-apoptotic B-cell lymphoma 2 (Bcl2) family proteins in developing and mature B cells. Curiously, how lack of BAFF- or APRIL-mediated signaling triggers B-cell apoptosis remains largely unexplored. Here, we show that two pro-apoptotic members of the 'Bcl2 homology domain 3-only' subgroup of the Bcl2 family, Bcl2 interacting mediator of cell death (Bim) and Bcl2 modifying factor (Bmf), mediate apoptosis in the context of TACI-Ig overexpression that effectively neutralizes BAFF as well as APRIL. Surprisingly, although Bcl2 overexpression triggers B-cell hyperplasia exceeding the one observed in Bim(-/-)Bmf(-/-) mice, Bcl2 transgenic B cells remain susceptible to the effects of TACI-Ig expression in vivo, leading to ameliorated pathology in Vav-Bcl2 transgenic mice. Together, our findings shed new light on the molecular machinery restricting B-cell survival during development, normal homeostasis and under pathological conditions. Our data further suggest that Bcl2 antagonists might improve the potency of BAFF/APRIL-depletion strategies in B-cell-driven pathologies

Rapid Regulatory T-Cell Response Prevents Cytokine Storm in CD28 Superagonist Treated Mice

Superagonistic CD28-specific monoclonal antibodies (CD28SA) are highly effective activators of regulatory T-cells (Treg cells) in rats, but a first-in-man trial of the human CD28SA TGN1412 resulted in an unexpected cytokine release syndrome. Using a novel mouse anti-mouse CD28SA, we re-investigate the relationship between Treg activation and systemic cytokine release. Treg activation by CD28SA was highly efficient but depended on paracrine IL-2 from CD28SA-stimulated conventional T-cells. Systemic cytokine levels were innocuous, but depletion of Treg cells prior to CD28SA stimulation led to systemic release of proinflammatory cytokines, indicating that in rodents, Treg cells effectively suppress the inflammatory response. Since the human volunteers of the TGN1412 study were not protected by this mechanism, we also tested whether corticosteroid prophylaxis would be compatible with CD28SA induced Treg activation. We show that neither the expansion nor the functional activation of Treg cells is affected by high-dose dexamethasone sufficient to control systemic cytokine release. Our findings warn that preclinical testing of activating biologicals in rodents may miss cytokine release syndromes due to the rapid and efficacious response of the rodent Treg compartment, and suggest that polyclonal Treg activation is feasible in the presence of antiphlogistic corticosteroid prophylaxis