Botánica macaronésica y el viaje del Endeavour: las colecciones y observaciones de Joseph Banks y Daniel Solander de Madeira

Se examinaron, en el herbario del Museo de Historia Natural de Londres, las recolecciones de plantas vasculares, briófitos, hongos, algas y líquenes realizadas por Joseph Banks y Daniel Solander en Madeira durante el primer viaje de James Cook alrededor del mundo (1768-1771). El diario de Banks (en la Biblioteca Estatal de Nueva Gales del Sur, Australia) aporta detalles sobre las especies observadas en esta expedición y también incluye un registro de 330 entradas con las especies que se observaron durante su estancia en dicha isla portuguesa. Las especies de esta lista se estudiaron y cotejaron, cuando fue posible, con los ejemplares correspondientes del herbario del Museo de Historia Natural de Londres, donde se encuentra el herbario de Joseph Banks. Se hicieron comparaciones de este registro con datos de dos documentos que también se encuentran en este museo, a saber: la flora inédita que Solander preparó para Madeira (Primitiae Florae Maderensis, sive catalogus Plantarum en Insula Madera) y el inventario hecho por Banks y Solander de los especímenes recolectados durante la expedición que fueron preservados dentro de los libros que se usaron para secar plantas durante el viaje.The efforts of Joseph Banks and Daniel Solander to document the vascular plant, bryophyte, fungal, algal, and lichen flora of Madeira during the first circumnavigation of James Cook on Her Majesty’s Bark Endeavour (1768-1771) are documented. Banks’s journal (at the State Library of New South Wales, Australia) provides accounts pertinent to the species observed in this visit and also includes a list of 330 entries that were recorded during their stay in this Portuguese island. Where possible, the species documented in this list were matched with corresponding herbarium collections held in the herbarium of the Natural History Museum, London, where the herbarium of Joseph Banks is now housed. Comparisons were made with two documents also housed in this Museum, namely: Solander’s unpublished flora of Madeira (Primitiae Florae Maderensis, sive catalogus Plantarum in Insula Madera) and an inventory of specimens that were collected and stored inside drying books during the expedition

Approximate Bayesian Computation Reveals the Crucial Role of Oceanic Islands for the Assembly of Continental Biodiversity

The perceived low levels of genetic diversity, poor interspecific competitive and defensive ability, and loss of dispersal capacities of insular lineages have driven the view that oceanic islands are evolutionary dead ends. Focusing on the Atlantic bryophyte flora distributed across the archipelagos of the Azores, Madeira, the Canary Islands, Western Europe, and northwestern Africa, we used an integrative approach with species distribution modeling and population genetic analyses based on approximate Bayesian computation to determine whether this view applies to organisms with inherent high dispersal capacities. Genetic diversity was found to be higher in island than in continental populations, contributing to mounting evidence that, contrary to theoretical expectations, island populations are not necessarily genetically depauperate. Patterns of genetic variation among island and continental populations consistently fitted those simulated under a scenario of de novo foundation of continental populations from insular ancestors better than those expected if islands would represent a sink or a refugium of continental biodiversity. We, suggest that the northeastern Atlantic archipelagos have played a key role as a stepping stone for transoceanic migrants. Our results challenge the traditional notion that oceanic islands are the end of the colonization road and illustrate the significant role of oceanic islands as reservoirs of novel biodiversity for the assembly of continental flora

The Madeiran plants collected by Sir Hans Sloane in 1687, and his descriptions

The Macaronesian Islands comprise the Atlantic archipelagos of Azores, Madeira, Selvagens, Canaries and Cape Verde. These islands were a major focus for plant exploration during the 17th and 18th centuries. Sir Hans Sloane (1660–1753), one of the most important patrons and sponsors of natural sciences and botanical research, visited Madeira on his way to Jamaica in 1687. Although he stayed in Madeira for only three days, he collected plant specimens of 38 taxa (including one brown alga) and made important observations concerning the flora and fauna of Madeira from near Funchal. Sixty-six polynomial names of plants from the island are recorded in Sloane’s published work along with 18 copperplate engravings, ostensibly from Madeira, although our study shows that only thirteen of them are of taxa occurring on the island. Fourteen of the sixty-six polynomials reported by Sloane relate to Macaronesian endemic taxa, six of them restricted to Madeira. Our study shows that nine of the fifteen polynomials that he putatively recorded for Madeira and/or the Antilles or for which he was unsure of their origin are from the West Indies and do not occur on this Macaronesian island. Two of the taxa that are listed for Madeira and the Carib bean Islands were likely to be present in both insular systems. Although there is evidence of earlier botanical explorations in Macaronesia, the herbarium collections made by Sloane in Madeira represent the earliest documented plant hunting expedition to Macaronesia, and Sir Hans Sloane can be considered as one of the pioneers of botanical exploration in these Atlantic Islands. Sloane’s records provide an early floristic study of a diverse island flora.info:eu-repo/semantics/publishedVersio

Translational adaptation to heat stress is mediated by RNA 5-methylcytosine in Caenorhabditis elegans.

Methylation of carbon-5 of cytosines (m5 C) is a post-transcriptional nucleotide modification of RNA found in all kingdoms of life. While individual m5 C-methyltransferases have been studied, the impact of the global cytosine-5 methylome on development, homeostasis and stress remains unknown. Here, using Caenorhabditis elegans, we generated the first organism devoid of m5 C in RNA, demonstrating that this modification is non-essential. Using this genetic tool, we determine the localisation and enzymatic specificity of m5 C sites in the RNome in vivo. We find that NSUN-4 acts as a dual rRNA and tRNA methyltransferase in C. elegans mitochondria. In agreement with leucine and proline being the most frequently methylated tRNA isoacceptors, loss of m5 C impacts the decoding of some triplets of these two amino acids, leading to reduced translation efficiency. Upon heat stress, m5 C loss leads to ribosome stalling at UUG triplets, the only codon translated by an m5 C34-modified tRNA. This leads to reduced translation efficiency of UUG-rich transcripts and impaired fertility, suggesting a role of m5 C tRNA wobble methylation in the adaptation to higher temperatures

Diversidad, rareza, evolución y conservación de la flora endémica de las Islas Canarias

The endemic vascular flora of the Canary Islands comprises over 680, taxa collectively accounting for more than 50% of the total native flora. To investigate geographical patterns of diversity within the endemic flora, distribution data from published sources together with other field observation and herbarium data were used to compile a data matrix comprising the distributions of ca. 90% of endemic taxa scored on a 10 × 10km UTM grid. WORLDMAP was then used to investigate patterns of endemic diversity, range size rarity (a measure of endemicity), phylogenetic diversity and threatened taxon richness. Endemic taxon richness was found to be highly heterogeneous across the archipelago, with cells containing between one and 139 taxa each (0.05-22.82% of endemic diversity). Patterns of variation in range size rarity and phylogenetic diversity were found to be largely congruent with endemic diversity, although some cells exhibited markedly higher range size rarity scores than would be predicted by their endemic diversity scores. In contrast, the pattern of endangered taxon richness across the archipelago differed markedly from endemic taxon richness. Many cells in Lanzarote, Fuerteventura and Gran Canaria exhibit higher endangered taxon richness scores than would be predicted from their endemic richness scores whereas in Tenerife, El Hierro, La Palma and La Gomera, the converse is generally true. The implications of the results both for understanding the evolution of Canary Island endemic diversity and for the conservation of the region’s unique and vulnerable flora are considered.La flora vascular endémica de las Islas Canarias comprende unos 680 táxones, lo que viene a representar más del 50% de la flora nativa. Con objeto de investigar patrones geográficos de diversidad en la flora endémica, se recopilaron los datos publicados que, junto con otras observaciones de campo y datos de herbario, sirvieron para completar una matriz de datos que abarca la distribución de cerca del 90% de los táxones endémicos usando cuadrículas UTM de10 × 10 km. A continuación, se utilizó el programa WORLDMAP para investigar los patrones de diversidad de los endemismos, el rango del grado de rareza (una medida de endemicidad), la diversidad filogenética y la riqueza en táxones amenazados. Se observó que la riqueza en endemismos es muy heterogénea a lo largo del archipiélago, con unos valores por cuadrícula que oscilan entre 1 y 139 táxones (0,05-22,82% de la diversidad de táxones endémicos). Los patrones de variación del rango del grado de la rareza y la diversidad filogenética resultaron ser en gran parte congruentes con la diversidad en endemismos, aunque algunas cuadrículas mostraron valores mucho más altos de rareza de los que podían ser predichos dada su diversidad de endemismos. En contraste, los patrones de riqueza en especies amenazadas en el archipiélago difirieron marcadamente de la riqueza en táxones endémicos. Muchas cuadrículas de Lanzarote, Fuerteventura y Gran Canaria mostraron valores más altos de riqueza en especies amenazadas que las que pudieran ser predichas sobre la base de su riqueza en táxones endémicos, mientras que en Tenerife, El Hierro y La Gomera la regla fue generalmente lo contrario. Se consideran las implicaciones que estos resultados suponen para la comprensión de la evolución de la diversidad de endemismos canaria y para la conservación de su singular y vulnerable flora

James Cook y la botánica macaronésica: notas nomenclaturales de las nuevas especies descritas por Johann R. Forster and J. Georg A. Forster

Johann Reinhold Forster y su hijo John Georg Adam Forster (entonces con 17 años) se unieron, respectivamente como botánico y artista, al segundo viaje de circunnavegación de James Cook (1772-1775). Aquí proporcionamos un estudio nomenclatural de las seis nuevas especies que ellos describieron para la Macaronesia. Se revisan tipificaciones anteriores y designamos lectotipos para Aytonia rupestris J.R. Forst. & G. Forst. (Aytoniaceae), Borago tristis G. Forst. (Boraginaceae) y Teucrium canescens G. Forst. (Lamiaceae). Designamos epitipos para A. rupestris y Epibaterium pendulum J.R. Forst & G. Forst. Nuestro estudio indica que Teucrium betonicifolium Jacq. es el nombre que se debe aceptar para este endemismo de Madeira. También se designan lectotipos con epitipos para T. betonicifolium y T. betonicum L’Hér.Johann Reinhold Forster and his teenaged son John Georg Adam Forster (then 17) joined James Cook’s second voyage (1772-1775), as botanist and artist, respectively. Upon their return they described six species that are pertinent to the study of the Macaronesian flora. Previous typifications are revisited and we designate lectotypes for Aytonia rupestris J.R. Forst. & G. Forst. (Aytoniaceae), Borago tristis G. Forst. (Boraginaceae), and Teucrium canescens G. Forst. (Lamiaceae). We designate epitypes for A. rupestris and Epibaterium pendulum J.R. Forst & G. Forst. Our study indicates that Teucrium betonicifolium Jacq. is the accepted name for this Madeiran endemic. Lectotypes, along with epitypes, are also designated for T. betonicifolium and T. betonicum L’Hér

Timing and Tempo of Early and Successive Adaptive Radiations in Macaronesia

The flora of Macaronesia, which encompasses five Atlantic archipelagos (Azores, Canaries, Madeira, Cape Verde, and Salvage), is exceptionally rich and diverse

Acquired resistance to oxaliplatin is not directly associated with increased resistance to DNA damage in SK-N-ASrOXALI4000, a newly established oxaliplatin-resistant sub-line of the neuroblastoma cell line SK-N-AS

The formation of acquired drug resistance is a major reason for the failure of anti-cancer therapies after initial response. Here, we introduce a novel model of acquired oxaliplatin resistance, a sub-line of the non-MYCN-amplified neuroblastoma cell line SK-N-AS that was adapted to growth in the presence of 4000 ng/mL oxaliplatin (SK-N-ASrOXALI4000). SK-N-ASrOXALI4000 cells displayed enhanced chromosomal aberrations compared to SK-N-AS, as indicated by 24-chromosome fluorescence in situ hybridisation. Moreover, SK-N-ASrOXALI4000 cells were resistant not only to oxaliplatin but also to the two other commonly used anti-cancer platinum agents cisplatin and carboplatin. SK-N-ASrOXALI4000 cells exhibited a stable resistance phenotype that was not affected by culturing the cells for 10 weeks in the absence of oxaliplatin. Interestingly, SK-N-ASrOXALI4000 cells showed no cross resistance to gemcitabine and increased sensitivity to doxorubicin and UVC radiation, alternative treatments that like platinum drugs target DNA integrity. Notably, UVC-induced DNA damage is thought to be predominantly repaired by nucleotide excision repair and nucleotide excision repair has been described as the main oxaliplatin-induced DNA damage repair system. SK-N-ASrOXALI4000 cells were also more sensitive to lysis by influenza A virus, a candidate for oncolytic therapy, than SK-N-AS cells. In conclusion, we introduce a novel oxaliplatin resistance model. The oxaliplatin resistance mechanisms in SK-N-ASrOXALI4000 cells appear to be complex and not to directly depend on enhanced DNA repair capacity. Models of oxaliplatin resistance are of particular relevance since research on platinum drugs has so far predominantly focused on cisplatin and carboplatin