A Genetic Tool to Identify Predators Responsible for Livestock Attacks in South America and Recommendations for Human-Wildlife Conflict Mitigation.

Livestock predation induces global human-wildlife conflict, triggering the retaliatory killing of large carnivores. Although domestic dogs (Canis familiaris) contribute to livestock depredation, blame primarily falls on wild predators. Dogs can also transmit pathogens between wildlife, domestic animals, and humans. Therefore, the presence of free-ranging dogs can have negative consequences for biodiversity conservation, smallholder economy, food supply, and public health, four of the United Nations' Sustainable Developed Goals (SDGs) for 2030. In Ecuador, where livestock sustains rural households, retaliatory poaching threatens Andean bear (Tremarctos ornatus), jaguar (Panthera onca), and puma (Puma concolor) populations. However, the role of dogs in these incidents remains underexplored. The present study evaluates the possibility of reliable molecular identification of predatory species from DNA traces in bite wounds. Our results revealed the presence of dog saliva on four out of six livestock carcasses presumably attacked by wild predators. These findings highlight the importance of rectifying misinformation about large carnivores in Ecuador and the need to control dog populations. We recommend that local administrations incorporate DNA analysis into livestock predation events to examine how common the problem is, and to use the analysis to develop conflict mitigation strategies which are essential for the conservation of large carnivores.

Evidence of population genetic structure in Ecuadorian Andean bears.

Wildlife conservation in Andean countries is a global priority because of the high levels of biodiversity and endemism. Historically, these countries have had limited resources to monitor wildlife (e.g., through genetic tools) and establish conservation programs. Focusing on the study and emblematic use of a few charismatic species has been a strategic approach to direct efforts for conservation and development planning. Consequently, the Andean bear is a flagship and umbrella species for highly biodiverse Andean countries like Ecuador. The few studies exploring the population genetics of this species have concluded that it has low genetic diversity and few units for conservation as populations appear to be well connected. However, these results might be attributed to ascertainment bias as studies have been performed with heterologous molecular markers. Here, using both mtDNA sequences and species-specific microsatellite markers, we show that Andean bears in Ecuador have population structure. Additionally, we found through the study of three Ecuadorian populations that the species might have a higher genetic diversity than we previously thought. These results could support the revision of research priorities, conservation, and planning strategies to improve connectivity for this species which occurs in crucial biodiversity hotspots.

Impact of bacterial and fungal inoculants on the resident rhizosphere microbiome and the volatilome of tomato plants under leaf herbivory stress.

Various studies have addressed the impact of microbial inoculants on the composition of the resident microbiome. How microbial inoculants impact plant metabolism and interact with the resident rhizobiota under herbivory stress remains elusive. Here, we investigated the impact of two bacterial and two fungal inoculants, inoculated as single species and as a synthetic community, on the rhizosphere microbiome and volatilome of tomato plants (Solanum lycopersicum) comparing nonstress conditions to exposed to leaf herbivory by Spodoptera exigua. Based on amplicon sequencing analysis, rhizobacterial community composition was significantly affected by all four inoculants and the magnitude of this effect was dependent on herbivory stress. Fungal community composition was altered by the microbial inoculants but independent of herbivory stress. The rhizosphere volatilome was impacted by the microbial inoculation and differences between treatments were evened under herbivory stress. Each microbial inoculant caused unique changes in the volatilome of stressed plants but also shared similar responses, in particular the enhanced production of dimethyl disulfide and benzothiazole. In conclusion, the introduction of microbial inoculants in the tomato rhizosphere caused unique as well as common changes in the rhizosphere microbiome and volatilome, but these changes were minor compared to the microbiome changes induced by herbivory stress.

First genetic insights of Gonatodescaudiscutatus (Reptilia, Gekkota) in the Galapagos Islands and mainland Ecuador.

Studies on genetic variability amongst native and introduced species contribute to a better understanding of the genetic diversity of species along their autochthonous distribution and identify possible routes of introduction. Gonatodescaudiscutatus is a gecko native to western Ecuador and introduced to the Galapagos Islands. Despite being a successful species in human-modified habitats along its native and non-native ranges, neither the colonisation process nor the genetic diversity of this gecko is known. In this study, we analysed 55 individuals from 14 localities in western Ecuador and six localities in San Cristobal Island, Galapagos - the only island with a large, self-sustaining population. We amplified and analysed the genetic variability of two nuclear genes (Cmos and Rag2) and one mitochondrial gene (16S). Cmos and Rag2 sequences presented little to none genetic variability, while 16S allowed us to build a haplotype network. We identified nine haplotypes across mainland Ecuador, two of which are also present in Galapagos. Low genetic diversity between insular and continental populations suggests that the introduction of G.caudiscutatus on the Islands is relatively recent. Due to the widespread geographical distribution of mainland haplotypes, it was not possible to determine the source population of the introduction. This study represents the first exploration of the genetic diversity of Gonatodescaudiscutatus, utilising genetic tools to gain insights into its invasion history in the Galapagos.

Clinical Evidence on a Novel Macrohybrid Design Dental Implant with 12° Angled Platform: A Systematic Review.

Background: Immediate implant placement with immediate esthetics has become a more common procedure over time, though ensuring good emergence of the axis of the implant has been a challenge. A novel macroimplant design with an angled platform (Co-Axis®) has been developed to ensure exit of the head of the implant in the correct prosthetic position. A systematic literature review was carried to determine the survival rate and marginal bone loss associated with these implants. Material and Methods: An electronic and manual literature search was made in accordance with the PRISMA statement. The search strategy was limited to human studies, retrospective and prospective clinical trials, cross-sectional studies, and cohort studies reporting outcomes of a novel macrohybrid implant with a 12° angled implant connection. Results: Three articles met the inclusion criteria and were reviewed in the analysis. The estimated success rate was 95.9%. The global marginal bone loss was estimated to be -0.17 ± 0.58 mm in an environment characterized by great heterogeneity (I2 = 99%). The estimated mean implant stability was 69.6 ± 0.92 (ISQ). As only two studies provided the required information, it was not possible to determine publication bias. Lastly, mean recession was estimated to be practically zero (0.06 ± 0.23 mm), with great heterogeneity. Conclusions: Within the limitations of this systematic review, it can be affirmed that immediate implant treatment with Co-Axis® implants shows a survival rate of 95.9% at one year of follow-up, with low marginal bone loss values, near-zero soft tissue recession, and favorable papilla index values. Nevertheless, the great heterogeneity of the data requires the findings to be interpreted with caution.

Accuracy of static fully guided implant placement in the posterior area of partially edentulous jaws: a cohort prospective study.

OBJECTIVE: A cohort prospective study was conducted to assess the three-dimensional positioning accuracy of the implant between pre-surgical and the final implant position using a static fully guided approach in the posterior area of the jaws. MATERIALS AND METHODS: A total of 60 implants (30 patients) were digitally analyzed after superimposing the Digital Imaging and Communications in Medicine (DICOM) files obtained from the Cone Beam Computed Tomography (CBCT) pre- and post-implant placement. The software calculations included deviations at the implant shoulder and at the implant apex, global deviation (3D offset), and angle deviation. Statistical analysis was performed with α = 0.05. RESULTS: Considering the total number of implants, mesiodistal, buccolingual, and apicocoronal mean deviations at the shoulder and implant apex were equal or below 0.21 ± 0.69 mm, and only the buccolingual mean deviation at the apex reached up to 0.67 ± 1.06 mm. The mesiodistal and apicocoronal deviations were not statistically significant at both the shoulder and apex levels of the implant. The mean total angular deviation was 5.62° ± 4.09. The main limitation of this surgical approach was the requirement for a wide mouth opening. CONCLUSIONS: Static fully guided surgery for dental implant placement exhibits minimum deviations respect to presurgical planning. The main limitation in the posterior areas is the requirement for a wide mouth opening. CLINICAL RELEVANCE: Even with minimum deviations clinically acceptable, precautions and safety margins must be respected when using static full-guided surgery to place dental implants.

Origin and dispersion pathways of guava in the Galapagos Islands inferred through genetics and historical records.

Guava (Psidium guajava) is an aggressive invasive plant in the Galapagos Islands. Determining its provenance and genetic diversity could explain its adaptability and spread, and how this relates to past human activities. With this purpose, we analyzed 11 SSR markers in guava individuals from Isabela, Santa Cruz, San Cristobal, and Floreana islands in the Galapagos, as well as from mainland Ecuador. The mainland guava population appeared genetically differentiated from the Galapagos populations, with higher genetic diversity levels found in the former. We consistently found that the Central Highlands region of mainland Ecuador is one of the most likely origins of the Galapagos populations. Moreover, the guavas from Isabela and Floreana show a potential genetic input from southern mainland Ecuador, while the population from San Cristobal would be linked to the coastal mainland regions. Interestingly, the proposed origins for the Galapagos guava coincide with the first human settlings of the archipelago. Through approximate Bayesian computation, we propose a model where San Cristobal was the first island to be colonized by guava from the mainland, and then, it would have spread to Floreana and finally to Santa Cruz; Isabela would have been seeded from Floreana. An independent trajectory could also have contributed to the invasion of Floreana and Isabela. The pathway shown in our model agrees with the human colonization history of the different islands in the Galapagos. Our model, in conjunction with the clustering patterns of the individuals (based on genetic distances), suggests that guava introduction history in the Galapagos archipelago was driven by either a single event or a series of introduction events in rapid succession. We thus show that genetic analyses supported by historical sources can be used to track the arrival and spread of invasive species in novel habitats and the potential role of human activities in such processes.

Neuroplasticity and Epilepsy Surgery in Brain Eloquent Areas: Case Report.

Introduction: Neuronal plasticity includes changes in any component of the central nervous system in response to intrinsic or extrinsic stimuli. Brain functions that depend on the epileptogenic cortex pose a challenge in epilepsy surgery because many patients are excluded from pre-surgical evaluation for fear of the possible sequelae. Some of these patients may be rescued by enhancing neuronal plasticity with brain neuromodulation techniques. Case Report: We describe a 6-year-old child with refractory focal motor seizures symptomatic to a neuroepithelial dysembryoblastic tumor in the left temporo-parietal region. He underwent limited resection of the lesion in order to avoid sequelae in his language function. A functional study at age of 17 years revealed an overlap of Wernicke's area with the tumor and areas of incipient language reorganization in the contralateral hemisphere. An invasive neuromodulation procedure was designed to enhance neuroplasticity. After craniotomy, he underwent language training and simultaneous electrical inhibition of language using an electrode grid placed over the lesion. The intensity of the language inhibitory stimulus was increased every day to force the use of accessory language areas in the right hemisphere by neuroplasticity. Results: The language of the patient improved for six consecutive days until he was able to speak and understand while undergoing maximum electrical inhibition. The tumor was resected using a cortical mapping guide. Discussion: Application of direct cortical stimulation techniques and language pre-habilitation before epilepsy surgery can be useful to rescue patients excluded from resective surgery, especially young patients with long-term lesions.

Root-to-shoot signalling in mycorrhizal tomato plants upon Botrytis cinerea infection.

Arbuscular mycorrhizal symbiosis is restricted in roots, but it also improves shoot responses against leaf challenges, a phenomenon known as Mycorrhiza-Induced Resistance (MIR). This study focuses on mycorrhizal root signals that may orchestrate shoot defence responses. Metabolomic analysis of non-mycorrhizal and mycorrhizal plants upon Botrytis cinerea infection showed that roots rearrange their metabolome mostly in response to the symbiosis, whereas in shoots a stronger impact of the infection is observed. Specific clusters of compounds in shoots and roots display a priming profile suggesting an implication in the enhanced resistance observed in mycorrhizal plants. Among the primed pathways in roots, lignans showed the highest number of hits followed by oxocarboxylic acids, compounds of the amino acid metabolism, and phytohormones. The lignan yatein was present at higher concentrations in roots, root efflux and leaves of mycorrhizal plants This lignan displayed in vitro antimicrobial activity against B. cinerea and it was also functional protecting tomato plants. Besides, several JA defence-related genes were upregulated in mycorrhizal roots regardless of the pathogen infection, whereas PIN-II was primed in roots of mycorrhizal infected plants. These observations suggest that the enhanced resistance in shoots during MIR may be coordinated by lignans and oxylipins with the participation of roots.

Role and mechanisms of callose priming in mycorrhiza-induced resistance.

Mycorrhizal plants display enhanced resistance to several pathogens. However, the molecular mechanisms regulating mycorrhiza-induced resistance (MIR) are still elusive. We aim to study the mechanisms underlying MIR against Botrytis cinerea and the role of callose accumulation during this process. Mycorrhizal tomato plants inoculated with Rhizoglomus irregularis displayed callose priming upon B. cinerea infection. The callose inhibitor 2-deoxy-d-glucose abolished MIR, confirming the relevance of callose in the bioprotection phenomena. While studying the mechanisms underlying mycorrhiza-induced callose priming, we found that mycorrhizal plants display an enhanced starch degradation rate that is correlated with increased levels of ß-amylase1 transcripts following pathogen infection. Starch mobilization in mycorrhizal plants seems coordinated with the increased transcription of sugar transporter and invertase genes. Moreover, the expression levels of genes encoding the vesicular trafficking proteins ATL31 and SYP121 and callose synthase PMR4 were higher in the mycorrhizal plants and further boosted by subsequent pathogen infection. All these proteins play a key role in the priming of callose accumulation in Arabidopsis, suggesting that callose priming is an induced resistance mechanism conserved in different plant species. This evidence highlights the importance of sugar mobilization and vesicular trafficking in the priming of callose as a defence mechanism in mycorrhiza-induced resistance.

Reabsorción Condilar como Complicación Postoperatoria en Pacientes Sometidos a Cirugía Ortognática. Revisión Narrativa / Condylar Resorption as a Postoperative Complication in Patients Undergoing Orthognathic Surgery. Narrative Review

RESUMEN: La reabsorción condilar como complicación postoperatoria en cirugía ortognática es una causa frecuente de recidiva de anomalías dentomaxilares, existiendo diversos factores que se relacionan con su aparición. El objetivo de este estudio fue describir mediante una revisión narrativa la reabsorción condilar como complicación postoperatoria en cirugía ortognática. Se realizó una búsqueda electrónica de la literatura en las bases de datos electrónicas PubMed, EBSCO, TripDatabase y Epistemonikos sin límite de años, en idioma inglés y español, incluyendo revisiones sistemáticas, ensayos clínicos y estudios observacionales. Se excluyeron reportes de casos, estudios en animales y aquellos que no relacionaran la complicación con cirugía ortognática. Se evaluaron los estudios según grado de recomendación y calidad de reporte. Veintiún artículos fueron seleccionados según los criterios de selección establecidos en esta revisión. La literatura reportada sugiere que la reabsorción condilar es una patología de frecuencia relativa en pacientes postoperados de cirugía ortognática (1,4-32 % de los casos) y que está asociada a factores de riesgo preoperatorios tales como género, edad, tipo de anomalía dentomaxilar y técnica quirúrgica utilizada. La reabsorción condilar es una complicación postoperatoria a cirugía ortognática que debemos considerar en la planificación del tratamiento e identificar pacientes con factores de riesgo. Luego de la intervención quirúrgica es de vital importancia realizar un seguimiento estricto a este tipo de pacientes e identificar de forma temprana cambios clínicos y radiográficos. Finalmente, es importante seguir investigando sobre esta materia para establecer criterios de prevención y diagnóstico, con mayor claridad.

ABSTRACT: Condylar resorption as a complication following orthognathic surgery is considered to cause dento-facial anomalies, relating to different pre and intra-operative factors. The aim of the research was to describe condylar resorption as a postoperative complication after orthognathic surgery. A review of the literature was made in four databases: PubMed, EBSCO, Trip database and Epistemonikos. The search was carried out without year limiting, articles in English and Spanish, including systematic reviews, observational studies and clinical trials. Exclusion criteria were applied for report cases, animal studies and articles that do not relate condylar resorption with orthognathic surgery. Quality of evidence and strength of the recommendations were assessed for the chosen studies. For this study 21 articles were selected following the inclusion criteria. The literature found reported that condylar resorption is a relatively frequent complication following orthognathic surgery (1.4-32 % of frequency) and that it can be associated with several factors such as genre, age, dento-maxillary anomaly and surgical technique. Condylar resorption is a complication that we must consider in the planning of orthognathic surgery, in order to identify risk factors and patients who are more likely to present this post-surgical complication. Following surgery, strict follow-up is a key factor to determine early clinical and radiographic changes. Finally, further research is needed to establish stronger prevention and diagnostic criteria.

Psidium guajava in the Galapagos Islands: Population genetics and history of an invasive species.

The threat of invasive plant species in island populations prompts the need to better understand their population genetics and dynamics. In the Galapagos islands, this is exemplified by the introduced guava (Psidium guajava), considered one of the greatest threats to the local biodiversity due to its effective spread in the archipelago and its ability to outcompete endemic species. To better understand its history and genetics, we analyzed individuals from three inhabited islands in the Galapagos archipelago with 11 SSR markers. Our results reveal similar genetic diversity between islands, and the populations appear to be distinct: the islands of San Cristobal and Isabela are genetically different while the population of Santa Cruz is a mixture from both. Additional evidence for genetic bottlenecks and the inference of introduction events suggests an original introduction of the species in San Cristobal, from where it was later introduced to Isabela, and finally into Santa Cruz. Alternatively, a second introduction in Isabela might have occurred. These results are contrasted with the historical record, providing a first overview of the history of P. guajava in the Galapagos islands and its current population dynamics.

Microbial Community Composition in Take-All Suppressive Soils.

Gaeumannomyces graminis var. tritici (Ggt) is the main soilborne factor that affects wheat production around the world. Recently we reported the occurrence of six suppressive soils in monoculture areas from indigenous "Mapuche" communities, and evidenced that the suppression relied on the biotic component of those soils. Here, we compare the rhizosphere and endosphere microbial community structure (total bacteria, actinomycetes, total fungi, and ascomycetes) of wheat plants grown in suppressive and conducive soils. Our results suggested that Ggt suppression could be mediated mostly by bacterial endophytes, rather than rhizosphere microorganisms, since the community structure was similar in all suppressive soils as compared with conducive. Interestingly, we found that despite the lower incidence of take-all disease in suppressive soils, the Ggt concentration in roots was not significantly reduced in all suppressive soils compared to those growing in conducive soil. Therefore, the disease suppression is not always related to a reduction of the pathogen biomass. Furthermore, we isolated endophytic bacteria from wheat roots growing in suppressive soils. Among them we identified Serratia spp. and Enterobacter spp. able to inhibit Ggt growth in vitro. Since the disease, but not always pathogen amount, was reduced in the suppressive soils, we propose that take all disease suppressiveness is not only related to direct antagonism to the pathogen.

Dispositivos de Administración Electrónica de Nicotina y sus Efectos en los Tejidos Periodontales y la Región Orofacial: Revisión de la Literatura / Electronic Nicotine Delivery Systems and their Effect in Periodontal Tissue and the Orofacial Region. A Review

RESUMEN: Los dispositivos de administración electrónica de nicotina aparecieron con el objetivo de reemplazar el uso del tabaco y contribuir al reciente crecimiento de las políticas antitabaco. Actualmente, los efectos que producen los químicos que contiene son desconocidos. El objetivo de este trabajo consistió en describir la información encontrada en la literatura sobre los posibles daños generados por los dispositivos de administración electrónica de nicotina, en la cavidad bucal y los tejidos periodontales. Se realizó una búsqueda electrónica y manual, sin límite de idioma ni año. Se excluyeron, opiniones de expertos y artículos que estudiaran otros dispositivos de administración de nicotina. Se seleccionaron 18 artículos, 7 estudios in-vitro, 2 estudios longitudinales, 2 ensayos clínicos y 7 reportes de caso. Se encontró que existen niveles de citotoxicidad elevados, observando cambios a nivel de morfología y metabolismo celular. Sin embargo, si lo comparamos con el tabaco, se observa que los niveles de toxicidad son menores en los dispositivos de administración electrónica de nicotina. En los estudios longitudinales y ensayos clínicos se observó un aumento del sangramiento al sondaje y de la circulación sanguínea, medida con láser Doppler, al cambiar de cigarro convencional a cigarro electrónico. Los reportes de caso informan de importantes traumatismos en el territorio maxilofacial, causados por la explosión de estos dispositivos, durante su uso. Los dispositivos de administración electrónica de nicotina son tóxicos a nivel de las células periodontales, generando necrosis y daños al ADN celular. Presentan riesgos de uso, reportándose traumatismos graves a nivel oral y maxilofacial, por sobrecalentamiento de las baterías. Los ensayos clínicos y estudios longitudinales no fueron concluyentes, por lo que se debe seguir investigando en la materia.

ABSTRACT: Electronic nicotine delivery systems were introduced to replace tobacco use and contribute to the anti-smoking policies. Today, the effect the chemicals it contains produce in the human body, are unknown. The aim of this work was to describe the information found in the literature about the possible damage produced in the periodontal tissue and the oral cavity, by the electronic nicotine delivery systems. An electronic and manual search was carried by a single reviewer, without year or language limit, excluding expert's opinions and articles that studied other nicotine delivery systems. Eighteen articles were selected; 7 in vitro studies, 2 longitudinal studies, 2 clinical trials and 7 case reports. Toxicity levels were found to be high, showing changes in cellular morphology and metabolism. Comparing with conventional cigarette, toxicity levels were lower in the electronic nicotine delivery systems. Longitudinal studies and clinical trials observed an increase in bleeding on probing and in blood circulation, by using laser doppler velocimetry, when changing from conventional cigarette to electronic cigarette. Also reports about explosions while using these electronic devises were encountered in the literature, with grave consequences in the maxillofacial territory. Electronic nicotine delivery systems show toxic levels, generating necrosis and DNA damage in periodontal ligament and gingival fibroblast cells. The risk of using these devices is high, due to possible explosion following overheating of the lithium battery, causing facial and oral trauma. Clinical trials and longitudinal studies were not conclusive, so investigations should continue in this matter.

Vesicular Delivery of the Antifungal Antibiotics of Lysobacter enzymogenes C3.

Lysobacter enzymogenes C3 is a predatory strain of Gram-negative gliding bacteria that produces antifungal antibiotics by the polyketide synthetic pathway. Outer membrane vesicles (OMV) are formed as a stress response and can deliver virulence factors to host cells. The production of OMV by C3 and their role in antifungal activity are reported here. Vesicles in the range of 130 to 150 nm in diameter were discovered in the cell-free supernatants of C3 cultures. These OMV contain molecules characteristic of bacterial outer membranes, such as lipopolysaccharide and phospholipids. In addition, they contain chitinase activity and essentially all of the heat-stable antifungal activity in cell supernatants. We show here that C3 OMV can directly inhibit growth of the yeast Saccharomyces cerevisiae as well as that of the filamentous fungus Fusarium subglutinans The activity is dependent on physical contact between OMV and the cells. Furthermore, fluorescent lipid labeling of C3 OMV demonstrated transfer of the membrane-associated probe to yeast cells, suggesting the existence of a mechanism of delivery for membrane-associated molecules. Mass spectrometric analysis of C3 OMV extracts indicates the presence of molecules with molecular weights identical to some of the previously identified antifungal products of C3. These data together suggest that OMV act as an important remote mobile component of predation by LysobacterIMPORTANCE The data presented here suggest a newly discovered function of outer membrane vesicles (OMV) that are produced from the outer membrane of the bacterial species Lysobacter enzymogenes strain C3. We show that these OMV can be released from the surface of the cells to deliver antibiotics to target fungal organisms as a mechanism of killing or growth inhibition. Understanding the role of OMV in antibiotic delivery can generally lead to improved strategies for dealing with antibiotic-resistant organisms. These results also add to the evidence that some bacterially produced antibiotics can be discovered and purified using methods designed for isolation of nanoscale vesicles. Information on these systems can lead to better identification of active molecules or design of delivery vehicles for these molecules.

Octodon degus, a new model to study the agonist and plexus-induced response in the urinary bladder.

Urinary bladder function consists in the storage and controlled voiding of urine. Translational studies require animal models that match human characteristics, such as Octodon degus, a diurnal rodent. This study aims to characterize the contractility of the detrusor muscle and the morphology and code of the vesical plexus from O. degus. Body temperature was measured by an intra-abdominal sensor, the contractility of detrusor strips was evaluated by isometric tension recording, and the vesical plexus was studied by electrical field stimulation (EFS) and immunofluorescence. The animals showed a diurnal chronotype as judged from core temperature. The myogenic contractile response of the detrusor muscle to increasing doses of KCl reached its maximum (31.04 mN/mm2) at 60 mM. In the case of cumulative dose-response of bethanecol, the maximum response (37.42 mN/mm2) was reached at 3.2 × 10-4 M. The response to ATP was clearly smaller (3.8 mN/mm2). The pharmacological dissection of the EFS-induced contraction identified ACh and sensory fibers as the main contributors to this response. The neurons of the vesical plexus were located mainly in the trigone area, grouped in big and small ganglia. Out of them, 48.1 % of the neurons were nitrergic and 62.7 % cholinergic. Our results show functional and morphological similarities between the urinary bladder of O. degus and that of humans.

Intra and Inter-Spore Variability in Rhizophagus irregularis AOX Gene.

Arbuscular mycorrhizal fungi (AMF) are root-inhabiting fungi that form mutualistic symbioses with their host plants. AMF symbiosis improves nutrient uptake and buffers the plant against a diversity of stresses. Rhizophagus irregularis is one of the most widespread AMF species in the world, and its application in agricultural systems for yield improvement has increased over the last years. Still, from the inoculum production perspective, a lack of consistency of inoculum quality is referred to, which partially may be due to a high genetic variability of the fungus. The alternative oxidase (AOX) is an enzyme of the alternative respiratory chain already described in different taxa, including various fungi, which decreases the damage caused by oxidative stress. Nevertheless, virtually nothing is known on the involvement of AMF AOX on symbiosis establishment, as well on the existence of AOX variability that could affect AMF effectiveness and consequently plant performance. Here, we report the isolation and characterisation of the AOX gene of R. irregularis (RiAOX), and show that it is highly expressed during early phases of the symbiosis with plant roots. Phylogenetic analysis clustered RiAOX sequence with ancient fungi, and multiple sequence alignment revealed the lack of several regulatory motifs which are present in plant AOX. The analysis of RiAOX polymorphisms in single spores of three different isolates showed a reduced variability in one spore relatively to a group of spores. A high number of polymorphisms occurred in introns; nevertheless, some putative amino acid changes resulting from non-synonymous variants were found, offering a basis for selective pressure to occur within the populations. Given the AOX relatedness with stress responses, differences in gene variants amongst R. irregularis isolates are likely to be related with its origin and environmental constraints and might have a potential impact on inoculum production.

Arbuscular mycorrhizal symbiosis influences strigolactone production under salinity and alleviates salt stress in lettuce plants.

Arbuscular mycorrhizal (AM) symbiosis can alleviate salt stress in plants. However the intimate mechanisms involved, as well as the effect of salinity on the production of signalling molecules associated to the host plant-AM fungus interaction remains largely unknown. In the present work, we have investigated the effects of salinity on lettuce plant performance and production of strigolactones, and assessed its influence on mycorrhizal root colonization. Three different salt concentrations were applied to mycorrhizal and non-mycorrhizal plants, and their effects, over time, analyzed. Plant biomass, stomatal conductance, efficiency of photosystem II, as well as ABA content and strigolactone production were assessed. The expression of ABA biosynthesis genes was also analyzed. AM plants showed improved growth rates and a better performance of physiological parameters such as stomatal conductance and efficiency of photosystem II than non-mycorrhizal plants under salt stress since very early stages - 3 weeks - of plant colonization. Moreover, ABA levels were lower in those plants, suggesting that they were less stressed than non-colonized plants. On the other hand, we show that both AM symbiosis and salinity influence strigolactone production, although in a different way in AM and non-AM plants. The results suggest that AM symbiosis alleviates salt stress by altering the hormonal profiles and affecting plant physiology in the host plant. Moreover, a correlation between strigolactone production, ABA content, AM root colonization and salinity level is shown. We propose here that under these unfavourable conditions, plants increase strigolactone production in order to promote symbiosis establishment to cope with salt stress.

Tempol protects the gallbladder against ischemia/reperfusion.

Impairment in gallbladder emptying, increase in residual volume, and reduced smooth muscle contractility are hallmarks of acute acalculous cholecystitis and seem to be related to ischemia/reperfusion (I/R). This study was designed to determine the effects of tempol, a general antioxidant, on I/R-induced changes in gallbladder contractile capacity, the mechanisms involved in the contractile process, and the level of inflammatory mediators. Experimental gallbladder I/R was induced in male guinea pigs by common bile duct ligation for 2 days, then a deligation of the duct was performed and after 2 days the animals were sacrificed. A group of animals was treated with tempol, administered in the drinking water at 1 mmol/l for 10 days prior the bile duct ligation and until animal sacrifice. Isometric tension recordings showed that KCl and cholecystokinin-induced contractions were impaired by I/R, which correlated with decreased F-actin content and detrimental effects on Ca(2+) influx. In addition, I/R depolarized mitochondrial membrane potential, as indicated by the reduction of the heterogeneity of the rhodamine123 fluorescence signal, and increased the expression of NF-kappaB, COX-2, and iNOS. Tempol treatment improved contractility via normalization of Ca(2+) handling and improvement of F-actin content. Moreover, the antioxidant ameliorated mitochondrial polarity and normalized the expression levels of the inflammatory mediators. These results show that antioxidant treatment protects the gallbladder from I/R, indicating the potential therapeutic benefits of tempol in I/R injury.

Microbial co-operation in the rhizosphere.

Soil microbial populations are immersed in a framework of interactions known to affect plant fitness and soil quality. They are involved in fundamental activities that ensure the stability and productivity of both agricultural systems and natural ecosystems. Strategic and applied research has demonstrated that certain co-operative microbial activities can be exploited, as a low-input biotechnology, to help sustainable, environmentally-friendly, agro-technological practices. Much research is addressed at improving understanding of the diversity, dynamics, and significance of rhizosphere microbial populations and their co-operative activities. An analysis of the co-operative microbial activities known to affect plant development is the general aim of this review. In particular, this article summarizes and discusses significant aspects of this general topic, including (i) the analysis of the key activities carried out by the diverse trophic and functional groups of micro-organisms involved in co-operative rhizosphere interactions; (ii) a critical discussion of the direct microbe-microbe interactions which results in processes benefiting sustainable agro-ecosystem development; and (iii) beneficial microbial interactions involving arbuscular mycorrhiza, the omnipresent fungus-plant beneficial symbiosis. The trends of this thematic area will be outlined, from molecular biology and ecophysiological issues to the biotechnological developments for integrated management, to indicate where research is needed in the future.