Alejandro Garciarrubio

The Enigmatic LEA Proteins and Other Hydrophilins

Water limitation affects all types of organisms at some stage during their life cycle; therefore, many strategies have been selected through evolution to cope with water deficit, including changes in enzyme activities and in gene expression, among others. In plants, a group of very hydrophilic

The genomes of four tapeworm species reveal adaptations to parasitism.

Tapeworms (Cestoda) cause neglected diseases that can be fatal and are difficult to treat, owing to inefficient drugs. Here we present an analysis of tapeworm genome sequences using the human-infective species Echinococcus multilocularis, E. granulosus, Taenia solium and the laboratory model Hymenolepis microstoma as examples. The 115- to 141-megabase genomes offer insights into the evolution of parasitism. Synteny is maintained with distantly related blood flukes but we find extreme losses of genes and pathways that are ubiquitous in other animals, including 34 homeobox families and several determinants of stem cell fate. Tapeworms have specialized detoxification pathways, metabolism that is finely tuned to rely on nutrients scavenged from their hosts, and species-specific expansions of non-canonical heat shock proteins and families of known antigens. We identify new potential drug targets, including some on which existing pharmaceuticals may act. The genomes provide a rich resource to underpin the development of urgently needed treatments and control.

Abscisic acid inhibits germination of mature Arabidopsis seeds by limiting the availability of energy and nutrients

Abstract. The addition of abscisic acid (ABA) to mature non-dormant seeds inhibits their germination. This effect of ABA might be related to its natural function as an endogenous inhibitor of precocious germination during seed formation. In this work, we studied how ABA affects the germination of mature seeds and the growth of nascent seedlings of Arabidopsisthaliana (L.) Heynh. Our findings were as follows: (i) inhibition by ABA was gradual, dose-dependent, and did not disappear after germination; (ii) inhibition of germination was relieved by the addition of metabolizable sugars or amino acids to the plating media; (iii) the effect of sugars and amino acids was cooperative, indicating that these two groups of metabolites relieve different deficiencies; (iv) ABA caused appreciable alterations in energy and nitrogen metabolism; and (v) ABA prevented the degradation of the seed storage proteins. In summary, ABA appears to inhibit seed germination by restricting the availability of energy and metabolites. This mechanism seems consistent with other known effects of ABA.

Functional Analysis of the Group 4 Late Embryogenesis Abundant Proteins Reveals Their Relevance in the Adaptive Response during Water Deficit in Arabidopsis

Late-Embryogenesis Abundant (LEA) proteins accumulate to high levels during the last stages of seed development, when desiccation tolerance is acquired, and in vegetative and reproductive tissues under water deficit, leading to the hypothesis that these proteins play a role in the adaptation of plants to this stress condition. In this work, we obtained the accumulation patterns of the Arabidopsis (Arabidopsis thaliana) group 4 LEA proteins during different developmental stages and plant organs in response to water deficit. We demonstrate that overexpression of a representative member of this group of proteins confers tolerance to severe drought in Arabidopsis plants. Moreover, we show that deficiency of LEA proteins in this group leads to susceptible phenotypes upon water limitation, during germination, or in mature plants after recovery from severe dehydration. Upon recovery from this stress condition, mutant plants showed a reduced number of floral and axillary buds when compared with wild-type plants. The lack of these proteins also correlates with a reduced seed production under optimal irrigation, supporting a role in fruit and/or seed development. A bioinformatic analysis of group 4 LEA proteins from many plant genera showed that there are two subgroups, originated through ancient gene duplication and a subsequent functional specialization. This study represents, to our knowledge, the first genetic evidence showing that one of the LEA protein groups is directly involved in the adaptive response of higher plants to water deficit, and it provides data indicating that the function of these proteins is not redundant to that of the other LEA proteins.

Characterization of Phaseolus vulgaris cDNA clones responsive to water deficit: identification of a novel late embryogenesis abundant-like protein.

Six cDNA clones from Phaseolus vulgaris, whose expression is induced by water deficit and ABA treatment (rsP cDNAs) were identified and characterized. The sequence analyses of the isolated clones suggest that they encode two types of late-embryogenesis abundant (LEA) proteins, a class-1 cytoplasmic low-molecular-weight heat shock protein (lmw-HSP), a lipid transfer protein (LTP), and two different proline-rich proteins (PRP). One of the putative LEA proteins identified corresponds to a novel 9.3 kDa LEA-like protein. During the plant response to a mild water deficit (Ψw= −0.35 MPa) all genes identified present a maximal expression at around 16 or 24 h of treatment, followed by a decline in expression levels. Rehydration experiments revealed that those genes encoding PRPs and LTP transiently re-induce or maintain their expression when water is added to the soil after a dehydration period. This is not the case for the lea genes whose transcripts rapidly decrease, reaching basal levels a few hours after rehydration (4 h). Under water deficit and ABA treatments, the highest levels of expression for most of the genes occur in the root, excluding the ltp gene whose maximum expression levels are found in the aerial regions of the plant. This indicates that for these genes, both water deficit and ABA-dependent expression are under organ-specific control. The data presented here support the importance of these proteins during the plant response to water deficit.

Cell-Wall Proteins Induced by Water Deficit in Bean (Phaseolus vulgaris L.) Seedlings.

In the last few years, much attention has been given to the role of proteins that accumulate during water deficit. In this work, we analyzed the electrophoretic patterns of basic protein extracts, enriched for a number of cell-wall proteins, from bean (Phaseolus vulgaris L.) seedlings and 21-d-old plants subjected to water deficit. Three major basic proteins accumulated in bean seedlings exposed to low water potentials, with apparent molecular masses of 36, 33, and 22 kD, which we refer to as p36, p33, and p22, respectively. Leaves and roots of 21-d-old plants grown under low-water-availability conditions accumulated only p36 and p33 proteins. In 21-d-old plants subjected to a fast rate of water loss, both p33 and p36 accumulated to approximately the same levels, whereas if the plants were subjected to a gradual loss of water, p33 accumulated to higher levels. Both p36 and p33 were glycosylated and were found in the cell-wall fraction. In contrast, p22 was not glycosylated and was found in the soluble fraction. The accumulation of these proteins was also induced by abscisic acid (0.1–1.0 mM) treatment but not by wounding or by jasmonate treatment.

Structural organization of the genes that encode two glutamate synthase subunits of Escherichia coli

Plasmid pRSP20, a recombinant plasmid isolated from the Clarke-Carbon Escherichia coli gene bank, contains the two genes coding for the subunits of glutamate synthase (GOGAT). We have constructed several derivatives of pRSP20, and analyzed the direction of transcription and genetic organization of these genes. Unexpectedly, we have found that although they are tightly linked and are transcribed in the same direction, each of them has its own promoter.

Demographic history and biologically relevant genetic variation of Native Mexicans inferred from whole-genome sequencing

Understanding the genetic structure of Native American populations is important to clarify their diversity, demographic history, and to identify genetic factors relevant for biomedical traits. Here, we show a demographic history reconstruction from 12 Native American whole genomes belonging to six distinct ethnic groups representing the three main described genetic clusters of Mexico (Northern, Southern, and Maya). Effective population size estimates of all Native American groups remained below 2,000 individuals for up to 10,000 years ago. The proportion of missense variants predicted as damaging is higher for undescribed (~ 30%) than for previously reported variants (~ 15%). Several variants previously associated with biological traits are highly frequent in the Native American genomes. These findings suggest that the demographic and adaptive processes that occurred in these groups shaped their genetic architecture and could have implications in biological processes of the Native Americans and Mestizos of today.People of Mexico have diverse historical and genetic background. Here, Romero-Hidalgo and colleagues sequence whole genomes of Native Americans of Mexico, and show demographic history and genetic variation shared among subgroups of Native Americans.

A Phaseolus vulgaris cDNA encoding a putative aquaporin

Trabajo presentado en AIChE Annual Meeting, celebrado en Salt Lake City (Estados Unidos) del 8 al 13 de noviembre de 2015.The authors acknowledge the financial support of CINVESTAV and CONACYT (project number 39557-Y), both from Mexico. Berenice Fernandez-Arguijo thanks Eng. Felipe de Jesus Marquez-Torres of CINVESTAV-Saltillo for his assistance in the preparation of samples for SEM observations, as well as Eng. Carlos Palacios of Quimica del Rey, MET – MEX Penoles, who supplied the dolomite used in this work.Trabajo presentado en el XXIV Congreso Iberoamericano de Catalisis, celebrado en Medellin (Colombia) del 14 al 19 de septiembre de 2014.El presente trabajo reporta el estudio de la oxidacion catalitica de tolueno (1400 ppm) en catalizadores de Pd y Pt soportados en alumina promovida con 1 y 10% en peso de Ce. Los catalizadores se caracterizaron por: adsorcion fisica de N2 (BET), XRD, FTIR de piridina adsorbida, FTIR de la adsorcion de CO, XPS y TPO. Los resultados mostraron disminucion en el numero de sitios acidos con el contenido de cerio en el catalizador. Se observo una mayor dispersion en los catalizadores de Pd que en los de Pt. En los catalizadores de Pt solo se detectaron especies de Pt0 mientras que en Pd se detectaron especies de Pd0 y Pd2+. En ambas series de catalizadores la combustion total se alcanzo a contenidos de 1% peso en Ce, catalizadores Pd/ACe1 y Pt/ACe1, a 300oC. En el caso del Pd la combustion de tolueno dependen de las propiedades redox optimas (Ce3+/ Ce4+, Pd0/ Pd2+) por lo que resulta importante el tiempo de activacion del catalizador. La combustion catalitica de tolueno en Pt se vio favorecida en una superficie reductora por un proceso de demetilacion. El deposito de carbono en el catalizador disminuyo con el contenido de cerio en el catalizador debido a las propiedades redox del oxido de cerioPartial financial support from the Ministry of Science and Technology (Spain) (GrantMAT2002-04529-C03) and from CONACYT (Mexico) (fellowship to A.K. Cuentas-Gallegos) are gratefully acknowledged.Trabajo presentado en el XXIV Congreso Iberoamericano de Catalisis, celebrado en Medellin (Colombia) del 14 al 19 de septiembre de 2014.Tesis doctoral presentada por Kilian Laclavetine. Programa de doctorado de Fisica Nuclear, en el Departamento de Fisica Atomica, Molecular y Nuclear de la Universidad de Sevilla.Se propone la localizacion de fugas en redes de distribucion de agua medianteclasificadores basados en el metodo de los vecinos mas cercanos (k-NN) con metrica de distanciacosenoidal. El uso de distancias cosenoidales mejora la respuesta del clasificador, con relacional que usa metrica Euclidiana. Comparado con las tecnicas de localizacion de fugas basadasen la maxima correlacion de los residuos, se consigue una mayor robustez en condicionesaltamente ruidosas, y una menor dependencia del modelo hidraulico de la red, lo que facilita suimplementacion, pues no requiere del calculo de la matriz de sensibilidad. La tecnica propuestase programo en MATLABR©y se probo con datos sinteticos obtenidos de simulaciones conEPANET. La evaluacion del desempeno reportada se basa en el indice de perdidas (la fraccionde fugas localizadas erroneamente) y en una medida del error de localizacion obtenida de ladistancia topologicaTrabajo presentado en el XI Congreso de la Asociacion Iberica de Endocrinologia Comparada, celebrado en Vigo del 13 al 15 de julio de 2017.Resumen del trabajo presentado al 41st International Symposium on Archaeometry (ISA), celebrado en Kalamata (Grecia) del 15 al 21 de mayo de 2016.This study was financed by CONACYT-CB grant 240447 and logistically supported by MARN-El Salvador.Lanthanum chromite nano-particles, with a composition of La0.9Ca0.1CrO3 and La0.8Ca0.2CrO3, were produced by 1 h of hydrothermal reaction at 400 and 425??C respectively. The sintering of the powders was conducted using a spark plasma apparatus over the temperature range 1300-1550oC for 1 min with a constant loading pressure of 45 MPa. Additional sintering experiments using conventional firing were carried out for comparison. Fully densified (98 % r.d.) lanthanum chromite pellets with fine equiaxial grains 2.3 ?Em in size were obtained using the SPS (spark plasma sintering) method. n contrast, a maximum relative density of 97 % was produced using La0.8Ca0.2CrO3 sintered conventionally at 1400oC for 300 min, and the average grain size of the resulting sintered sample was 6 ?Em.Trabajo presentado al 10th Summer Workshop on Interval Methods, and 3rd International Symposium on Set Membership - Applications, Reliability and Theory, celebrado en Manchester (UK) del 14 al 16 de junio de 2017.The Application of Ixodicidas has been considered for a long time the alternative for control of the cattle tick Boophilus microplus, however, its use is currently limited in reducing tick infestations, due to the appearance of resistant field tick populations. Ixodicide resistance is a growing problem that needs to be attended, because, it is currently affecting the competitiveness of the Mexican Cattle industry in general and in particular the income of cattle producers. The solution to this problem needs to increase the budget dedicated to basic research in order to elucidate the molecular mechanisms of ixodicide resistance leading to the discovery of new molecular targets for ixodicide resistance detection and recombinant vaccine development. The recent use of new genomic tools, as well as reverse genetics approaches, will provide an extraordinary contribution to the improvement of tick control strategies and ixodicide resistance mitigation programs. The aim of the present review is to make a compilation of different topics related with acaricide resistance in the cattle tick Boophilus microplus, starting with some biological and molecular considerations on its new classification, to the analysis of ixodicide resistance, its impact on the Mexican cattle industry and the perspective of the genomic research in order to solve the problems associated to tick control, new diagnostic tools and development of tick vaccines.The present paper shows an interesting Optical Microscopy (OM) and Scanning Electron microscopy coupled with energy dispersive X-ray analysis (SEM/EDX) application to study degradation crust formation processes in Fort San Pedro, a historical building located at the colonial City of San Francisco de Campeche, Mexico; and the Cathedral of Seville, at Seville, Spain. The results show that while in Seville the crusts are consequence of sulfur dioxide reaction whit calcareous stone, leading to gypsum crystal formation (CaSO4 . 2H2O), in San Francisco de Campeche, deterioration crust are consequence of natural recrystallization processes of CaCO3 induced by excessive environmental humidity.Trabajo realizado en el Departamento de Biologia Molecular, CABIMER, y en el Departamento de Genetica, Facultad de Biologia, Universidad de Sevilla, para optar al grado de Doctor en Genetica Molecular y Biomedicina, por el Licenciado Andres Cruz Garcia.Proteases from the tentacles of the sea cucumber Isostichopusfuscus were partially purified and used to produce antioxidant peptides from body wall proteins of this marine species. Three proteins (105, 68, and 39 kDa) were identified by SDS-PAGE in the proteolytic extract of the tentacles. Protein hydrolyzates were generated with gelatin and crude protein substrates from body wall, and peptidic fractions lower and higher than 3 kDa were obtained to evaluate their oxygen radical scavenging capacity (ORAC). The 3 kDa-fraction obtained from the crude protein hydrolyzate showed the highest ORAC value (0.92 +/- 0.04 micromol Trolox equivalent/mg protein). This fraction was selected to purify peptides potentially responsible for the activity that might be used as ingredients for development of functional foods.The periphery of the archaeological city of Teotihuacan is going through a gradual process of destruction due to the unorganized urban growth of its neighboring communities; this has caused clashes between the National Institute of Archaeology and History (INAH) and said communities. This is a multifactorial problem that requires coordinated actions on behalf of the three levels of government involved. However, this article discusses the problem from a generational perspective, based on the fact that at this moment groups of schoolchildren and youth from these communities are creating their own opinions of the problem, learning from the placement of the people in conflict. In this context, we present the origin, development and current state of a scholastic archaeological news report called Archaeologists in a Jam, created with puppets and reported by the schoolchildren themselves, intended to stimulate critical thinking about the value, use and future of the conversation of this heritage.espanolCatalizadores de Pd, PdFe y PdCo fueron preparados por el metodo de impregnacion, usando borohidruro de sodio (NaBH4) como agente reductor y un material de carbono comercial, (Vulcan XC-72R) como soporte. Los electrocatalizadores sintetizados fueron probados para la reaccion de oxidacion de acido formico (FAOR, por sus siglas en ingles) en medio acido (H2SO4 0,5 M). La morfologia, la composicion y el tamano de particula de los electrocatalizadores se caracterizaron mediante tecnicas fisico-quimicas como difraccion de rayos X (XRD), microscopia electronica de barrido con espectroscopia por energia dispersiva (SEM-EDS) y microscopia electronica de transmision (TEM). La actividad catalitica se evaluo mediante tecnicas de voltamperometria ciclica (CV) y cronoamperometria (CA) EnglishPd, PdCo and PdFe catalysts were prepared by the impregnation method, using sodium borohydride (NaBH4) as the reducing agent and a commercial carbon material (Vulcan XC-72R) as support. The synthesized electrocatalysts were tested for the formic acid oxidation reaction (FAOR) in acid medium (H2SO4 0.5 M). The morphology, composition and particle size of the electrocatalysts were characterized by physicochemical techniques as X-ray diffraction (XRD), scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The catalytic activity was evaluated by cyclic voltammetry (CV) and chronoamperometry techniques (CA)Al Consejo Nacional de Ciencia y Tecnologia (CONACyT, Mexico), por el apoyo economico (beca 354779) recibida durante parte de esta investigacion.Poster presentado a la 6th International Conference on Food Digestion (ICFD), celebrada en Granada (Espana) del 2 al 4 de abril de 2019.The authors acknowledge the financial support of the Mexican National Council of Science and Technology (CONACYT), through project number 31356-U, as well as through a scholarship granted to M.G.G. to carry out her Ph.D. studies at Cinvestav-Saltillo.The Major Intrinsic Protein (MIP) is a large family of integral membrane proteins with six putative transmembrane domains conserved throughout evolution. Members of this family have been identified in many organisms, ranging from bacteria to mammals. Functional data has been reported for some members of the different subfamilies (Chrispeels and Agre, 1994; Agre et al., 1995). There are MIPs that are thought to constitute relatively simple but selective channels for a variety of ions or small uncharged molecules. In the case of the bacterial glycerol facilitator GlpF, it has been shown that it facilitates glycerol, other polyhidric alcohols, urea and glycine uptake into E. coli (Maurel et al., 1994). For the bovine prototype MIP26, there is data showing that it serves as voltage-dependent anion channel (Ehring et al., 1990). Other MIP members have been shown to facilitate transport of water in plants and animals which are known as aquaporins (Chrispeels and Agre, 1994; Chrispeels and Maurel 1994). Different subfamilies have been identified by sequence comparisons which allows to distinguish animal and plant genes and that may help to recognize different functions of MIPs (Yamada et al., 1995). Interested in the function of proteins involved in water or solutes transport, we isolated a member of the MIP gene-family from common bean (Phaseolus vulgaris) using as probe a pea cDNA encoding a putative turgor responsive MIP (Guerrero et al., 1990). The sequence analysis of the putative PvMip-1 indicated that it can be classified within the subfamily of plant MIP genes encoding aquaporins. Northern-blot analysis showed that the PvMip-1 transcript is present in roots, leaves and stems. In spite of the high homology with the pea turgor responsive PsMip-7a cDNA, drought and ABA treatments doTrabajo presentado en el XXIV Congreso Iberoamericano de Catalisis, celebrado en Medellin (Colombia) del 14 al 19 de septiembre de 2014.Resumen del trabajo presentado al 25th international Congress on X-ray optic and microanalysis (ICXOM), celebrado en EE.UU. del 5 al 9 de agosto de 2019.

Organization of the Rhizobium Phaseoli Genome

In the last few years we have directed our research efforts towards the understanding of the nature of Rhizobium phaseoli and its genome, in particular those features that could be relevant for its symbiotic properties. At the present time we are addresing some questions that we consider relevant to obtain an overall view of the organization of the Rhizobium genome that might contribute to better possibilities of manipulation. In the first part of this paper, we will comment on such questions and summarize results obtained. In the second part we will discuss some perspectives.