Presence of multiple group I introns closely related to bacteria and fungi in plastid 23S rRNAs of lichen-forming Trebouxia

The chloroplast-encoded large subunit ribosomal RNA gene of several free-living green algae contains group I introns at Escherichia coli genic positions 1917, 1931, 1951, and 2449. Herein we report the presence of group I introns at these positions within the chloroplast-encoded large subunit ribosomal RNA gene of several lichen-forming green algae belonging to the Trebouxia genus. In contrast to the introns inserted at position 2449, all introns inserted at positions 1917, 1931, and 1951 contained LAGLIDADG homing endonuclease genes. Phylogenetic analyses show that: (i) introns inserted at positions 1917, 1931, and 1951 are closely related to introns located at homologous insertion sites in bacterial rDNA genes; and (ii) introns inserted at position 2449 are closely related to fungal introns located at homologous insertion sites in mitochondrial rDNA genes. The symbiogenetic thalli of some lichens are proposed as the likely setting of horizontal transfer of genetic material among distantly related organisms such as bacteria, fungi, and green [email protected]; [email protected]

Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea

[EN] The precise boundary delineations between taxa in symbiotic associations are very important for evolutionary and ecophysiological studies. Growing evidence indicates that in many cases, the use of either morphological characters or molecular markers results in diversity underestimation. In lichen symbioses. Trebouxia is the most common genus of lichen phycobionts, however, the diversity within this genus has been poorly studied and as such there is no clear species concept. This study constitutes a multifaceted approach incorporating aspects of ultrastructural characterization by TEM and phylogenomics to evaluate the morphological and genetic diversity of phycobionts within the sexually reproducing lichen Ramalina fraxinea in the context of Mediterranean and temperate populations. Results reveal an association with at least seven different Trebouxia lineages belonging to at least two species. T. decolorans and T. jamesii, and diverse combinations of such lineages coexisting within the same thallus depending on the analysed sample. Some of these lineages are shared by several other non-related lichen taxa. Our findings indicate the existence of a highly diverse assemblage of Trebouxia algae associating with R. fraxinea and suggest a possible incipient speciation within T. decolorans rendering a number of lineages or even actual species. This study stresses the importance of coordinated ultrastructural and molecular analyses to improve estimates of diversity and reveal the coexistence of more than one Trebouxia species within the same thallus. lt is also necessary to have clearer species delimitation criteria within the genus Trebouxia and microalgae in general.This study was funded by the Ministerio de Economia y Competitividad (MINECO CGL2012-40058-0O2-01/02), FEDER, the Generalitat Valenciana (PROMETEOII2013/021, GVA) and the Direccion General de Universidades e Investigacion de la Consejeria de Educacion de la Comunidad de Madrid - Universidad de Alcala (CCG10-UAH/GEN-5904). Drs. Arantxa Matins and Patricia Moya (Universitat de Valencia) made helpful comments on the manuscript.Català, S.; Campo, ED.; Barreno, E.; García-Breijo, F.; Reig Armiñana, J.; Casano, L. (2016). Coordinated ultrastructural and phylogenomic analyses shed light on the hidden phycobiont diversity of Trebouxia microalgae in Ramalina fraxinea. Molecular Phylogenetics and Evolution. 94:765-777. https://doi.org/10.1016/j.ympev.2015.10.021S7657779

Infant gut microbiota modulation by human milk disaccharides in humanized microbiome mice

Human milk glycans present a unique diversity of structures that suggest different mechanisms by which they may affect the infant microbiome development. A humanized mouse model generated by infant fecal transplantation was utilized here to evaluate the impact of fucosyl-α1,3-GlcNAc (3FN), fucosyl-α1,6-GlcNAc, lacto-N-biose (LNB) and galacto-N-biose on the fecal microbiota and host-microbiota interactions. 16S rRNA amplicon sequencing showed that certain bacterial genera significantly increased (Ruminococcus and Oscillospira) or decreased (Eubacterium and Clostridium) in all disaccharide-supplemented groups. Interestingly, cluster analysis differentiates the consumption of fucosyl-oligosaccharides from galactosyl-oligosaccharides, highlighting the disappearance of Akkermansia genus in both fucosyl-oligosaccharides. An increment of the relative abundance of Coprococcus genus was only observed with 3FN. As well, LNB significantly increased the relative abundance of Bifidobacterium, whereas the absolute levels of this genus, as measured by quantitative real-time PCR, did not significantly increase. OTUs corresponding to the species Bifidobacterium longum, Bifidobacterium adolescentis and Ruminococcus gnavus were not present in the control after the 3-week intervention, but were shared among the donor and specific disaccharide groups, indicating that their survival is dependent on disaccharide supplementation. The 3FN-feeding group showed increased levels of butyrate and acetate in the colon, and decreased levels of serum HDL-cholesterol. 3FN also down-regulated the pro-inflammatory cytokine TNF-α and up-regulated the anti-inflammatory cytokines IL-10 and IL-13, and the Toll-like receptor 2 in the large intestine tissue. The present study revealed that the four disaccharides show efficacy in producing beneficial compositional shifts of the gut microbiota and in addition, the 3FN demonstrated physiological and immunomodulatory roles

Coexistence of different intrathalline symbiotic algae and bacterial biofilms in the foliose Canarian lichen Parmotrema pseudotinctorum

[EN] Parmotrema pseudotinctorum (des Abb.) Hale is a foliose lichen able to colonize large areas on rock surfaces in semiarid and warm localities in the Canary Islands. In this contribution, we investigate the phycobionts of this successful lichen under these extreme environmental conditions using ultrastructural and genetic methodologies. Two populations from La Gomera and La Palma islands were analyzed. After TEM analyses, three algal types were clearly distinguished in intrathalline symbiosis, provisionally named Ph1, Ph2, and Ph3. Two of them (Ph1 and Ph2) were Trebouxia showing a well visible pyrenoid corticolatype the chloroplast thylakoids being very different in both. The type Ph3 could be a taxon included in the genus Asterochloris. Our molecular approach consisted in sequencing two different DNA loci: a portion of the chloroplast psbA gene and nuclear ITS. Sequences of the psbA gene resulted in electrophoretograms showing double peaks when DNA extracted from the whole lichen thallus was used as template. Such double peaks were interpreted as single nucleotide polymorphisms (SNPs). This interpretation was confirmed by cloning. However, no intrathalline polymorphisms were detected among the nrITS sequences. Phylogenetic analyses on the basis of the psbA gene revealed three distinct clades. It is likely that these clades corresponded to the the three different morphotypes revealed by TEM. One of these clades, was closely related to T. corticola, other was related to Asterochloris glomerata and the third did not grouped with any specific taxa. These results are the first piece of evidence that algal coexistence may even be established between species of different genera of the Trebouxiophyceae (Asterochloris and Trebouxia at least). Moreover, the coexistence of several microalgal taxa evidenced in this study appears as a consistent character among the populations of this foliose lichen. Further isolation and cultivation of the three different algal types and physiological studies should shed light on the ecological plasticity of the entire holobiont. Along with such variety of intrathalline coexisting algae, another unexpected result was the observation of an almost continuous layer of bacterial-communities coating the lower cortex in all the studied samples of P. pseudotinctorum. The function of these biofilms in the lichen symbiosis remains to be elucidated. The existence of such particular symbiosis involving different algal species and bacteria could be explained by an increased fitness in particular habitats or under specific environmental conditions[ES] Parmotrema pseudotinctorum (des Abb.) Hale es un liquen foliáceo que coloniza roquedos volcánicos y es frecuente en localidades semiáridas y cálidas de las islas Canarias. En este trabajo, se investigan los ficobiontes de este liquen utilizando métodos ultraestructurales y genéticos. Se analizaron dos poblaciones de La Gomera y La Palma. Mediante análisis TEM, se han distinguido claramente tres tipos de algas en simbiosis intratalinas, llamados provisionalmente Ph1, Ph2 y Ph3. Dos de ellas (Ph1 y Ph2), pertenecientes al género Trebouxia, muestran un pirenoide bien visible del tipo corticola, pero los tilacoides del cloroplasto son muy diferentes en ambos. El tipo Ph3 podría ser un taxón incluido en el género Asterochloris. El enfoque molecular consistió en la secuenciación de dos loco diferentes de ADN: una porción del gen psbA del cloroplasto e ITS nuclear. Las secuencias del gen psbA proporcionaron electroforetogramas que mostraban dobles picos cuando se usó como patrón el ADN extraído de los talos completos. Estos dobles picos se interpretaron como polimorfismos de nucleótido simple (SNP). Esta interpretación se confirmó mediante técnicas de clonación. Sin embargo, no se detectaron polimorfismos intratalinos con las secuencias nrITS. Los análisis filogenéticos basados en las secuencias del gen psbA constataron la presencia de tres clados diferenciados. Es probable que éstos correspondan a los tres diferentes morfotipos puestos en evidencia por TEM. Uno de ellos está estrechamente relacionado con T. corticola, otro con Asterochloris glomerata, y el tercero no se agrupaba a ningún taxón especifico. Estos resultados son la primera evidencia de que en los líquenes la coexistencia de algas intratalinas se puede establecer incluso entre especies de difierentes géneros de Trebouxiophyceae (Asterochloris y Trebouxia al menos). Por otra parte, la coexistencia de varios taxones de microalgas, constatada en este estudio, puede considerarse como una sólida característica entre las poblaciones de este liquen foliáceo. Posteriores aislamientos y el cultivo de los tres tipos de algas, además de estudios fisiológicos, podrán explicar la plasticidad ecológica que muestra el holobionte. Otro resultado inesperado fue la observación de una capa casi continua de comunidades bacterianas que recubren el córtex inferior en todas las muestras estudiadas de P. pseudotinctorum. Está por determinar la función que estos biofilms puedan tener en las simbiosis liquénicas. La existencia de estos tipos de simbiosis tan particulares, que involucran tanto a diferentes especies de algas como a bacterias, podría explicarse por un incremento en la capacidad de colonizar hábitats peculiares o con condiciones ambientales específicasThis study was funded by the Spanish Ministry of Economy and Innovation (MINECO CGL2012-40058-C02-01/02), FEDER and the Generalitat Valenciana (PROMETEO 021/2013 GVA).Molins, A.; García-Breijo, F.; Reig Armiñana, J.; Del Campo, EM.; Casano, L.; Barreno Rodriguez, E. (2013). Coexistence of different intrathalline symbiotic algae and bacterial biofilms in the foliose Canarian lichen Parmotrema pseudotinctorum. Vieraea. Folia Scientarum Biologicarum Canariensium. 41:349-370. http://hdl.handle.net/10251/77348S3493704

Infant Gut Microbial Metagenome Mining of α-l-Fucosidases with Activity on Fucosylated Human Milk Oligosaccharides and Glycoconjugates

The gastrointestinal microbiota members produce α-l-fucosidases that play key roles in mucosal, human milk, and dietary oligosaccharide assimilation. Here, 36 open reading frames (ORFs) coding for putative α-l-fucosidases belonging to glycosyl hydrolase family 29 (GH29) were identified through metagenome analysis of breast-fed infant fecal microbiome. Twenty-two of those ORFs showed a complete coding sequence with deduced amino acid sequences displaying the highest degree of identity with α-l-fucosidases from Bacteroides thetaiotaomicron, Bacteroides caccae, Phocaeicola vulgatus, Phocaeicola dorei, Ruminococcus gnavus, and Streptococcus parasanguinis. Based on sequence homology, 10 α-l-fucosidase genes were selected for substrate specificity characterization. The α-l-fucosidases Fuc18, Fuc19A, Fuc35B, Fuc39, and Fuc1584 showed hydrolytic activity on α1,3/4-linked fucose present in Lewis blood antigens and the human milk oligosaccharide (HMO) 3-fucosyllactose. In addition, Fuc1584 also hydrolyzed fucosyl-α-1,6-N-acetylglucosamine (6FN), a component of the core fucosylation of N-glycans. Fuc35A and Fuc193 showed activity on α1,2/3/4/6 linkages from H type-2, Lewis blood antigens, HMOs and 6FN. Fuc30 displayed activity only on α1,6-linked l-fucose, and Fuc5372 showed a preference for α1,2 linkages. Fuc2358 exhibited a broad substrate specificity releasing l-fucose from all the tested free histo-blood group antigens, HMOs, and 6FN. This latest enzyme also displayed activity in glycoconjugates carrying lacto-N-fucopentaose II (Lea) and lacto-N-fucopentaose III (Lex) and in the glycoprotein mucin. Fuc18, Fuc19A, and Fuc39 also removed l-fucose from neoglycoproteins and human α-1 acid glycoprotein. These results give insight into the great diversity of α-l-fucosidases from the infant gut microbiota, thus supporting the hypothesis that fucosylated glycans are crucial for shaping the newborn microbiota composition

Balanced gene losses, duplications and intensive rearrangements led to an unusual regularly sized genome in Arbutus unedo chloroplasts

Completely sequenced plastomes provide a valuable source of information about the duplication, loss, and transfer events of chloroplast genes and phylogenetic data for resolving relationships among major groups of plants. Moreover, they can also be useful for exploiting chloroplast genetic engineering technology. Ericales account for approximately six per cent of eudicot diversity with 11,545 species from which only three complete plastome sequences are currently available. With the aim of increasing the number of ericalean complete plastome sequences, and to open new perspectives in understanding Mediterranean plant adaptations, a genomic study on the basis of the complete chloroplast genome sequencing of Arbutus unedo and an updated phylogenomic analysis of Asteridae was implemented. The chloroplast genome of A. unedo shows extensive rearrangements but a medium size (150,897 nt) in comparison to most of angiosperms. A number of remarkable distinct features characterize the plastome of A. unedo: five-fold dismissing of the SSC region in relation to most angiosperms; complete loss or pseudogenization of a number of essential genes; duplication of the ndhH-D operon and its location within the two IRs; presence of large tandem repeats located near highly re-arranged regions and pseudogenes. All these features outline the primary evolutionary split between Ericaceae and other ericalean families. The newly sequenced plastome of A. unedo with the available asterid sequences allowed the resolution of some uncertainties in previous phylogenies of Asteridae

Different strategies to achieve Pb-tolerance by the two Trebouxia algae coexisting in the lichen Ramalina farinacea

Lichen thalli are permeable to airborne substances, including heavy metals, which are harmful to cell metabolism. Ramalina farinacea shows a moderate tolerance to Pb. This lichen comprises two Trebouxia phycobionts, provisionally referred to as TR1 and TR9, with distinct physiological responses to acute oxidative stress. Thus, there is a more severe decay in photosynthesis and photosynthetic pigments in TR1 than in TR9. Similarly, under oxidative stress, antioxidant enzymes and HSP70 protein decrease in TR1 but increase in TR9. Since Pb toxicity is associated with increased ROS formation, we hypothesized greater Pb tolerance in this phycobiont. Accordingly, the aim of the present study was to characterize the physiological differences in the responses of TR1 and TR9 to Pb exposure. Liquid cultures of isolated phycobionts were incubated for 7 days in the presence of Pb(NO3)2. Thereafter, extracellular and intracellular Pb accumulation, photosynthetic pigments, and photosynthesis (as modulated chlorophyll fluorescence) were analyzed along with the antioxidant enzymes glutathione reductase (GR), superoxide dismutase (SOD), ascorbate peroxidase (APx), and catalase (CAT), and the stress-related protein HSP70. Pb uptake increased with the amount of supplied Pb in both algae. However, while significantly more metal was immobilized extracellularly by TR9, the amount of intracellular Pb accumulation was three times higher in TR1. In neither of the phycobionts were significant effects on photosynthetic pigments or photosynthetic electron transport observed. While under control conditions GR, SOD, and APx levels were significantly higher in TR1 than in TR9, only in the latter were these enzymes induced by Pb. This resulted in quantitatively similar antioxidant activities in the two algae when exposed to Pb. In conclusion, the phycobionts of R. farinacea make use of two different strategies against stress, in which the integration of distinct anatomical and physiological features affords similar levels of Pb tolerance.This study was supported by the Spanish Ministry of Science and Innovation (CGL2009-13429-C02-01/02) and the Generalitat Valenciana (PROMETEO 174/2008 and GVACOMP2011-205). We are grateful to the Central Support Service in Experimental Research (SCSIE), University of Valencia (Spain), for the TEM studies. We acknowledge Dr. Said Agouram (SCSIE, University of Valencia, Spain) for TEM-EDXS characterizations and for helpful discussions during the TEM investigations. We thank Wendy Ran and Daniel Sheerin for the English revision of the manuscript.Álvarez, R.; Del Hoyo, A.; García Breijo, FJ.; Reig Armiñana, J.; Del Campo, EM.; Guéra, A.; Barreno, E.... (2012). Different strategies to achieve Pb-tolerance by the two Trebouxia algae coexisting in the lichen Ramalina farinacea. Journal of Plant Physiology. 169(18):1797-1806. https://doi.org/10.1016/j.jplph.2012.07.005S179718061691

FRECUENCIA DE Neospora caninum EN PERROS DE ESTABLOS LECHEROS DEL VALLE DE LIMA

La neosporosis es una enfermedad parasitaria ocasionada por el Neospora caninum, que cursa con problemas reproductivos en el ganado lechero y signos nerviosos en el perro, el cual es el hospedero definitivo. El objetivo del estudio fue determinar la frecuencia de N. caninum en perros de establos lecheros del valle de Lima. Se evaluaron 104 muestras de suero de caninos mayores a 3 meses de edad, provenientes de 23 establos lecheros, mediante la detección de anticuerpos contra N. caninum a través de la prueba de inmunofluorescencia indirecta. El 32.7 ± 9.0% (34/104) de las muestras fueron positivas a N. caninum en una dilución de 1:50; siendo las provincias del Huaura y Huaral las que tuvieron los mayores niveles de seropositividad (58.8%, 10/17). No se hallaron diferencias estadísticas significativas en las variables edad y sexo.Neosporosis is a parasitic disease caused by Neospora caninum that produces nervous signs in dogs, the definite host, and may affect reproduction in dairy cattle. The objective of the study was to determine the frequency of N. caninum in dogs of dairy farms in the Lima valley. Samples from a total of 104 dogs older than 3 months of age from 23 dairy farms, were collected and analyzed by the indirect immunofluorescense test to detect antibodies against N. caninum. The results indicated that 32.7 ± 9.0% (34/104) were positive to N. caninum in a dilution of 1:50. The Huaura and Huaral provinces had the highest proportion of seropositives (58.8%, 10/17). No significant differences were found due to sex and age

Relevance of gastrointestinal manifestations in a large Spanish cohort of patients with systemic lupus erythematosus: what do we know?

SLE can affect any part of the gastrointestinal (GI) tract. GI symptoms are reported to occur in >50% of SLE patients. To describe the GI manifestations of SLE in the RELESSER (Registry of SLE Patients of the Spanish Society of Rheumatology) cohort and to determine whether these are associated with a more severe disease, damage accrual and a worse prognosis. METHODS: We conducted a nationwide, retrospective, multicentre, cross-sectional cohort study of 3658 SLE patients who fulfil =4 ACR-97 criteria. Data on demographics, disease characteristics, activity (SLEDAI-2K or BILAG), damage (SLICC/ACR/DI) and therapies were collected. Demographic and clinical characteristics were compared between lupus patients with and without GI damage to establish whether GI damage is associated with a more severe disease. RESULTS: From 3654 lupus patients, 3.7% developed GI damage. Patients in this group (group 1) were older, they had longer disease duration, and were more likely to have vasculitis, renal disease and serositis than patients without GI damage (group 2). Hospitalizations and mortality were significantly higher in group 1. Patients in group 1 had higher modified SDI (SLICC Damage Index). The presence of oral ulcers reduced the risk of developing damage in 33% of patients. CONCLUSION: Having GI damage is associated with a worse prognosis. Patients on a high dose of glucocorticoids are at higher risk of developing GI damage which reinforces the strategy of minimizing glucocorticoids. Oral ulcers appear to decrease the risk of GI damage. © The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology