El género Daldinia (Sordariomycetes, Ascomycota) en México

Background and Aims: The genus Daldinia, with 48 species worldwide, is characterized by perithecia immersed in globose to claviform stromata, which are cupper, violet, wine, brown to black coloured; releasing ochraceous, purple, greenish and gray pigments in KOH. It is characterized by cylindrical stipitate ascii with an apical amyloid pore, and ellipsoid, brown, smooth or ornamented ascospores. The asexual state was described in the genus Nodulisporium. It is now known that the group is mainly endophytic. The objective of the present study is to carry out a taxonomic revision of the genus Daldinia in Mexico, based on macro- and micromorphological characters and the observation of the spores with a SEM to identify the species.Methods: The specimens were studied, described and determined according to the traditional techniques in mycology. In addition, the spores were observed with a scanning electron microscope. The material is deposited in the fungus collection of the ENCB herbarium.Key results: Fourteen species of Daldinia were identified in Mexico, of which D. decipiens, D. cuprea, D. petriniae and D. rehmii are cited for the first time for the country. The species of this genus were mainly associated with the tropical dry forest. Daldinia childiae, D. eschscholtzii and D. vernicosa are the species with major distribution in the national territory.Conclusions: The genus Daldinia is well represented in Mexico, being one of the best studied of the family Hypoxylaceae. The group has a remarkable tropicaldistribution with more than 80% of the species located in tropical dry forest. It has a restricted distribution in temperate regions, as well as a greater specificity for the host, mainly Alnus and Quercus. The state of Oaxaca is the most species-rich entity.Resumen:Antecedentes y Objetivos: El género Daldinia, con 48 especies a nivel mundial, se caracteriza por presentar peritecios inmersos en estromas globosos a clavados de colores cobrizos, violáceos, vináceos, marrones a negros, liberando pigmentos de colores ocráceos, púrpuras, verdosos y grisáceos en KOH. Está caracterizado por ascas cilíndricas estipitadas con poro apical amiloide, y ascosporas elipsoidales marrones lisas u ornamentadas. El estado asexual fue descrito en el género Nodulisporium. Actualmente, se sabe que el grupo es principalmente endófito. El objetivo del presente estudio fue realizar una revisión taxonómica del género Daldinia en México, basada en caracteres macro y micromorfológicos y la observación de las esporas al MEB para identificar a las especies.Métodos: Los ejemplares fueron estudiados, descritos y determinados de acuerdo con las técnicas tradicionales en micología. Adicionalmente, las esporas se observaron al microscopio electrónico de barrido. El material está depositado en la colección de hongos del herbario ENCB.Resultados clave: Se determinaron 14 especies de Daldinia en México; de éstas, D. decipiens, D. cuprea, D. petriniae y D. rehmii se citan por primera vez para el país. De acuerdo con el hábitat, las especies de este género se asociaron principalmente al bosque tropical caducifolio. Daldinia childiae, D. eschscholtzii y D. vernicosa son las especies con mejor distribución en el territorio nacional.Conclusiones: El género Daldinia se encuentra bien representado en México, siendo uno de los mejor estudiados de la familia Hypoxylaceae. El género tiene una distribución principalmente tropical, con más de 80% de las especies descritas. En regiones templadas su distribución es restringida y manifiesta una mayor especificidad por el hospedero, principalmente Alnus y Quercus. El estado de Oaxaca fue la entidad con mayor riqueza de especies.

Cell vacuolation induced by Haemophilus influenzae supernatants in HEp-2 cells

Haemophilus influenzae belongs to respiratory tract microbiota. We observed vacuoles formation in previous studies with H. influenzae culture supernatants, so in this work we characterised that cytotoxic effect. We observed an abundant production of acidic cytoplasmic vacuoles due to the presence of a “vacuolating factor” in H. influenzae supernatants which was characterised as thermolabile. Greatest vacuolating activity was observed when utilizing the fraction > 50 kDa. The presence of a large number of vacuoles in HEp-2 cells was verified by transmission electron microscopy and some vacuoles were identified with a double membrane and/or being surrounded by ribosomes. These results suggest similar behaviour to that of vacuolating effects described by autotransporter proteins an undescribed cytotoxic effect induced by H. influenzae

The conservation status of the world’s reptiles

Effective and targeted conservation action requires detailed information about species, their distribution, systematics and ecology as well as the distribution of threat processes which affect them. Knowledge of reptilian diversity remains surprisingly disparate, and innovative means of gaining rapid insight into the status of reptiles are needed in order to highlight urgent conservation cases and inform environmental policy with appropriate biodiversity information in a timely manner. We present the first ever global analysis of extinction risk in reptiles, based on a random representative sample of 1500 species (16% of all currently known species). To our knowledge, our results provide the first analysis of the global conservation status and distribution patterns of reptiles and the threats affecting them, highlighting conservation priorities and knowledge gaps which need to be addressed urgently to ensure the continued survival of the world’s reptiles. Nearly one in five reptilian species are threatened with extinction, with another one in five species classed as Data Deficient. The proportion of threatened reptile species is highest in freshwater environments, tropical regions and on oceanic islands, while data deficiency was highest in tropical areas, such as Central Africa and Southeast Asia, and among fossorial reptiles. Our results emphasise the need for research attention to be focussed on tropical areas which are experiencing the most dramatic rates of habitat loss, on fossorial reptiles for which there is a chronic lack of data, and on certain taxa such as snakes for which extinction risk may currently be underestimated due to lack of population information. Conservation actions specifically need to mitigate the effects of human-induced habitat loss and harvesting, which are the predominant threats to reptiles