Identification and mapping of quantitative trait loci for kernel-related traits in in a durum wheat x T. dicoccum segregating population

[ES] El trigo duro (Triticum turgidum ssp. durum), materia prima de la pasta, es el décimo cereal más importante a nivel mundial. A fin de satisfacer su futura demanda a pesar del cambio climático, es necesario entender la base genética de uno de los principales componentes de su rendimiento, el peso del grano (en inglés TKW). Una estrategia para alcanzar dicho objetivo, es el estudio de nuevos recursos genéticos, como el farro (T. turgidum ssp. dicoccum), con el fin de descubrir alelos favorables que controlan los caracteres morfológicos del grano, los cuales tienen un rol determinante sobre el peso del grano. Con dicho contexto, el presente estudio tuvo como objetivo explorar la red genética responsable de los factores del tamaño (longitud, ancho, perímetro y área) y forma (relación ancho-longitud y coeficiente de forma) del grano y sus relaciones con el peso del grano y la fecha de espigado. Se realizó un mapeo de locus de rasgo cuantitativo (QTL) en una población segregante de 110 líneas endogámicas recombinantes, derivadas de la cruza entre T. dicoccum accessión MG5323 x T. durum variedad Latino, y cultivada en 4 ambientes. Un total de 20 QTL fueron detectados estables entre los ambientes y agrupados en 6 clusters en los cromosomas 2B, 3A, 3B, 4B, 6B y 7A. Entre ellos, destaca el cluster localizado en el cromosoma 4B y relacionado con los caracteres del tamaño del grano y el peso del grano, cuyo alelo favorable fue donado por el parental T. dicoccum. Las posiciones físicas de los clusters, definidas por la proyección de los marcadores en el genoma de referencia, coincidieron con las posiciones de genes ya descritos, por ejemplo, BIG GRAIN PROTEIN 1 en el cromosoma 4B. Dichos resultados proporcionan información genómica de T. dicoccum para facilitar su uso como donador de alelos favorables en el trigo, aplicados a la mejora de su rendimiento por medio de marcadores moleculares.[EN] Durum wheat (Triticum turgidum ssp. durum), which constitutes the raw material of pasta, is the 10th most important cereal worldwide. A key goal in order to meet its upcoming demand while coping with climate change, is to understand the genetic control behind thousand kernel weight (TKW), a major component of grain-yield. A strategy to achieve this is to explore new genetic resources as domesticated emmer (T. turgidum ssp. dicoccum) to discover favorable alleles that affect kernel morphological factors, which have a determining role on TKW. Therefore, the present study aimed to explore the genetic network responsible for kernel size components (length, width, perimeter and area) and kernel shape (width-length ratio and form coefficient) and their relationships with kernel weight and heading date. QTL mapping was performed on a segregating population of 110 recombinant inbred lines, derived from a cross between T. dicoccum accession MG5323 x T. durum cv. Latino, evaluated in 4 different environments. A total of 20 QTL were found environmentally stable and further grouped in 6 clusters on chromosomes 2B, 3A, 3B, 4B, 6B and 7A. Among them, a QTL cluster on 4B chromosome was associated with kernel size traits and TKW, where the parental MG5323 contributed the favorable allele, highlighting its potential to improve durum wheat germplasm. Further, the physical positions of the clusters, defined by the projection on the T. durum reference genome, overlapped with already known genes, such as BIG GRAIN PROTEIN 1 on chromosome 4B. These results might provide genome-based guidance for the efficient exploitation of T. dicoccum variability in wheat, possibly through yield-related molecular markers.Valladares García, AP. (2021). Identification and mapping of quantitative trait loci for kernel-related traits in in a durum wheat x T. dicoccum segregating population. Universitat Politècnica de València. http://hdl.handle.net/10251/174573TFG

The heterocyst differentiation transcriptional regulator HetR of the filamentous cyanobactrium Anabaena forms tetramers and can be regulated by phosphorylation

Many filamentous cyanobacteria respond to the external cue of nitrogen scarcity by the differentiation of heterocysts, cells specialized in the fixation of atmospheric nitrogen in oxic environments. Heterocysts follow a spatial pattern along the filament of two heterocysts separated by ca. 10–15 vegetative cells performing oxygenic photosynthesis. HetR is a transcriptional regulator that directs heterocyst differentiation. In the model strain Anabaena sp. PCC 7120, the HetR protein was observed in various oligomeric forms in vivo, including a tetramer that peaked with maximal hetR expression during differentiation. Tetramers were not detected in a hetR point mutant incapable of differentiation, but were conspicuous in an over-differentiating strain lacking the PatS inhibitor. In differentiated filaments the HetR tetramer was restricted to heterocysts, being undetectable in vegetative cells. HetR co-purified with RNA polymerase from Anabaena mainly as a tetramer. In vitro, purified recombinant HetR was distributed between monomers, dimers, trimers and tetramers, and it was phosphorylated when incubated with (γ-32P)ATP. Phosphorylation and PatS hampered the accumulation of HetR tetramers and impaired HetR binding to DNA. In summary, tetrameric HetR appears to represent a functionally relevant form of HetR, whose abundance in the Anabaena filament could be negatively regulated by phosphorylation and by PatS.Peer Reviewe

Influence of Traction Battery Arrangement on Risk of Thermal Runaway and Loads Suffered by Electric Vehicle Occupant during Side Collision

In the current electric vehicles, the purpose of the traction battery is to store energy. When designing this battery, different parameters are considered to arrange the battery/module/cells in the mechanically and thermally safest configuration. Moreover, the battery layout must produce correct dynamic behavior during collisions. In the present study, different battery configurations plus added energy absorbers were analyzed. To achieve this, an internal combustion vehicle modeled with finite elements was applied as the reference model. The structural behavior of the different battery configurations in the event of a side collision was examined. First, the safest arrangement was established with respect to both cabin intrusion and thermal runaway propagation. Second, the safest arrangement that guarantees the safety of the occupants in the event of a side collision was analyzed using MADYMO. This software includes experimentally validated dummies that allow insight into the stresses experienced by occupants. The results of the analysis showed that battery pack inclusion in the vehicle increases the stiffness of the car floor, resulting in fewer intrusions into the passenger compartment. Therefore, safety of the occupants is increased. However, none of the configurations analyzed showed sufficient safety against thermal runaway. This study contains sufficient contributions to the new body of knowledge, since there is no study that analyzes the safest configuration in terms of battery behavior with respect to intrusion into the passenger compartment and the effect of thermal runaway, together with the fact that this is the safest configuration for occupants after analyzing the injuries they experience in a side collision for the different configurations

ZipN is an essential FtsZ membrane tether and contributes to the septal localization of SepJ in the flamentous cyanobacterium Anabaena

The organismic unit of heterocyst-forming cyanobacteria is a filament of communicating cells connected by septal junctions, proteinaceous structures bridging the cytoplasms of contiguous cells. This distinct bacterial organization is preserved during cell division. In Anabaena, deletion of the zipN gene could not be segregated. We generated strain CSL109 that expresses zipN from a synthetic regulatable promoter. Under conditions of ZipN depletion, cells progressively enlarged, reflecting restricted cell division, and showed drastic morphological alterations including cell detachment from the filaments, to finish lysing. In contrast to the wild-type localization in midcell Z-rings, FtsZ was found in delocalized aggregates in strain CSL109. Consistently, the proportion of membrane-associated to soluble FtsZ in fractionated cell extracts was lower in CSL109. Bacterial two-hybrid analysis showed that ZipN interacts with FtsZ and other cell-division proteins including cytoplasmic Ftn6 and SepF, and polytopic FtsW, FtsX, FtsQ and FtsI. Additionally, ZipN interacted with the septal protein SepJ, and in CSL109 depletion of ZipN was concomitant with a progressive loss of septal specificity of SepJ. Thus, in Anabaena ZipN represents an essential FtsZ membrane tether and an organizer of the divisome, and it contributes to the conformation of septal structures for filament integrity and intercellular communication.Agencia Estatal de Investigación BFU2013-44686-P, BFU2016-77097-

The heterocyst differentiation transcriptional regulator HetR of the filamentous cyanobactrium Anabaena forms tetramers and can be regulated by phosphorylation

Many filamentous cyanobacteria respond to the external cue of nitrogen scarcity by the differentiation of heterocysts, cells specialized in the fixation of atmospheric nitrogen in oxic environments. Heterocysts follow a spatial pattern along the filament of two heterocysts separated by ca. 10–15 vegetative cells performing oxygenic photosynthesis. HetR is a transcriptional regulator that directs heterocyst differentiation. In the model strain Anabaena sp. PCC 7120, the HetR protein was observed in various oligomeric forms in vivo, including a tetramer that peaked with maximal hetR expression during differentiation. Tetramers were not detected in a hetR point mutant incapable of differentiation, but were conspicuous in an over-differentiating strain lacking the PatS inhibitor. In differentiated filaments the HetR tetramer was restricted to heterocysts, being undetectable in vegetative cells. HetR co-purified with RNA polymerase from Anabaena mainly as a tetramer. In vitro, purified recombinant HetR was distributed between monomers, dimers, trimers and tetramers, and it was phosphorylated when incubated with (γ-32P)ATP. Phosphorylation and PatS hampered the accumulation of HetR tetramers and impaired HetR binding to DNA. In summary, tetrameric HetR appears to represent a functionally relevant form of HetR, whose abundance in the Anabaena filament could be negatively regulated by phosphorylation and by PatS.España, Gobierno BFU2010-17980 and BFU2013-44686-

Cyt c6-3: A new isoform of photosynthetic Cyt c6 exclusive to heterocyst-forming cyanobacteria

All known cyanobacteria contain Cyt c6, a small soluble electron carrier protein whose main function is to transfer electrons from the Cyt b6 f complex to PSI, although it is also involved in respiration. We have previously described a second isoform of this protein, the Cyt c6-like, whose function remains unknown. Here we describe a third isoform of Cyt c6 (here called Cytc6-3), which is only found in heterocyst- forming filamentous cyanobacteria. Cyt c6-3 is expressed in vegetative cells but is specifically repressed in heterocysts cells under diazotrophic growth conditions. Although there is a close structural similarity between Cyt c6-3 and Cyt c6 related to the general protein folding, Cyt c6-3 presents differential electrostatic surface features as compared with Cyt c6, its expression is not copper dependent and has a low reactivity towards PSI. According to the different expression pattern, functional reactivity and structural properties, Cyt c6-3 has to play an as yet to be defined regulatory role related to heterocyst differentiation.Fundación de Investigación de la Universidad de Sevilla FIUS05710000Ministerio de Economía y Competitividad BIO2012-35271, BIO2015-64169-PJunta de Andalucía PAIDI BIO-02

Interactions of PatA with the divisome during heterocyst differentiation in anabaena

The Anabaena organismic unit is a filament of communicating cells. Under conditions of nitrogen scarcity, some cells along the filament differentiate into heterocysts, which are specialized in the fixation of atmospheric N2 and provide the vegetative cells with N2 fixation products. At a certain stage, the differentiation process becomes irreversible, so that even when nitrogen is replenished, no return to the vegetative cell state takes place, possibly as a consequence of loss of cell division capacity. Upon N-stepdown, midcell FtsZ-rings were detected in vegetative cells, but not in differentiating cells, and this was also the case for ZipN, an essential protein that participates in FtsZ tethering to the cytoplasmic membrane and divisome organization. Later, expression of ftsZ was arrested in mature heterocysts. PatA is a protein required for the differentiation of intercalary heterocysts in Anabaena. The expression level of the patA gene was increased in differentiating cells, and a mutant strain lacking PatA exhibited enhanced FtsZ-rings. PatA was capable of direct interactions with ZipN and SepF, another essential component of the Anabaena Z-ring. Thus, PatA appears to promote inhibition of cell division in the differentiating cells, allowing progress of the differentiation process. PatA, which in mature heterocysts was detected at the cell poles, could interact also with SepJ, a protein involved in production of the septal junctions that provide cell-cell adhesion and intercellular communication in the filament, hinting at a further role of PatA in the formation or stability of the intercellular structures that are at the basis of the multicellular character of Anabaena

La maternidad subrogada en el ordenamiento jurídico español : el impacto de la STS 247/2014 y las recientes propuestas de regulación

La gestación por sustitución es una técnica reproducción mediante la cual una mujer, por encargo de una pareja o un individuo contratante, gesta un embrión para éstos, entregándoles el niño o niña tras el parto. Es un contrato.En España no está regulada de forma eficaz, puesto que la Ley nos indica que sería nulo cualquier contrato de este tipo, pero si las personas lo hacen en otro país, aquí se reconocen los efectos jurídicos derivados de dicho contrato. No existe una regulación uniforme de ámbito internacional ni de la Unión Europea, produciéndose una gran disparidad normativa al respecto de unos Estados a otros.La problemática principal estriba en los conflictos de intereses que confluyen, puesto que se han de tener en cuenta los derechos de la mujer gestante, así como los de los padres de intención, y la especial protección del menor.En el presente trabajo analizo el marco jurídico de esta práctica, tanto internacional como de origen interno, los efectos de la sentencia del Tribunal Supremo 247/2014 de 6 de febrero, y las propuestas legislativas hasta ahora documentadas en España, estudiando de forma comparada sus contenidos y analizando los aspectos más problemático

Transcription activation by NtcA and 2-oxoglutarate of three genes involved in heterocyst differentiation in the cyanobacterium Anabaena sp. strain PCC 7120

In Anabaena sp. strain PCC 7120, differentiation of heterocysts takes place in response to the external cue of combined nitrogen deprivation, allowing the organism to fix atmospheric nitrogen in oxic environments. NtcA, a global transcriptional regulator of cyanobacteria, is required for activation of the expression of multiple genes involved in heterocyst differentiation, including key regulators that are specific to the process. We have set up a fully defined in vitro system, which includes the purified Anabaena RNA polymerase, and have studied the effects of NtcA and its signaling effector 2-oxoglutarate on RNA polymerase binding, open complex formation, and transcript production from promoters of the hetC, nrrA, and devB genes that are activated by NtcA at different stages of heterocyst differentiation. Both RNA polymerase and NtcA could specifically bind to the target DNA in the absence of any effector. 2-Oxoglutarate had a moderate positive effect on NtcA binding, and NtcA had a limited positive effect on RNA polymerase recruitment at the promoters. However, a stringent requirement of both NtcA and 2-oxoglutarate was observed for the detection of open complexes and transcript production at the three investigated promoters. These results support a key role for 2-oxoglutarate in transcription activation in the developing heterocyst.Ministerio de Educación y Ciencia BFU2004-00872 BFU2007-6045

Regulación de la expresión de las oxidasas terminales de la cadena de transporte de electrones de "Pseudomonas putida" y su efecto en represión catabólica

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 25-02-200