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Abstract Xenopus laevis are able to regenerate the spinal cord during larvae stages through the activation of neural stem progenitor cells (NSPCs). Here we use high-resolution expression profiling to characterize the early transcriptome changes induced after spinal cord injury, aiming to identify the signals that trigger NSPC proliferation. The analysis delineates a pathway that starts with a rapid and transitory activation of immediate early genes, followed by migration processes and immune response genes, the pervasive increase of NSPC-specific ribosome biogenesis factors, and genes involved in stem cell proliferation. Western blot and immunofluorescence analysis showed that mTORC1 is rapidly and transiently activated after SCI, and its pharmacological inhibition impairs spinal cord regeneration and proliferation of NSPC through the downregulation of genes involved in the G1/S transition of cell cycle, with a strong effect on PCNA. We propose that the mTOR signaling pathway is a key player in the activation of NPSCs during the early steps of spinal cord regeneration.

Hedgehog proteins (Hhs) secretion from apical and/or basolateral domains occurs in different epithelial cells impacting development and tissue homeostasis. Palmitoylation and cholesteroylation attach Hhs to membranes, and Dispatched-1 (Disp-1) promotes their release. How these lipidated proteins are handled by the complex secretory and endocytic pathways of polarized epithelial cells remains unknown. We show that polarized Madin–Darby canine kidney cells address newly synthesized sonic hedgehog (Shh) from the TGN to the basolateral cell surface and then to the apical domain through a transcytosis pathway that includes Rab11-apical recycling endosomes (Rab11-ARE). Both palmitoylation and cholesteroylation contribute to this sorting behavior, otherwise Shh lacking these lipid modifications is secreted unpolarized. Disp-1 mediates first basolateral secretion from the TGN and then transcytosis from Rab11-ARE. At the steady state, Shh predominates apically and can be basolaterally transcytosed. This Shh trafficking provides several steps for regulation and variation in different epithelia, subordinating the apical to the basolateral secretion.

El conocimiento detallado de la biodiversidad constituye un insumo imprescindible para un diseño adecuado de estrategias de conservación. En cuanto a la diversidad de briófitos, Chile aún carece de información florística en grandes extensiones del país. Como contribución al conocimiento de la historia natural de la zona central, presentamos un catálogo de los briófitos del Parque Nacional La Campana, ubicado en la Región de Valparaíso. Se reportan 148 taxones de briófitos, correspondientes a 111 especies de musgos, 33 hepáticas y cuatro antocerotes. Entre éstos se encuentran nuevos registros regionales y provinciales, además de extensiones de límites de distribución. Se reporta Bryum klinggraeffii por primera vez para Chile. Se discute la composición biogeográfica de la flora local y se comentan las particularidades ecológicas de la flora briofítica del área de estudio.

Abstract Background The efficient regenerative abilities at larvae stages followed by a non-regenerative response after metamorphosis in froglets makes Xenopus an ideal model organism to understand the cellular responses leading to spinal cord regeneration. Methods We compared the cellular response to spinal cord injury between the regenerative and non-regenerative stages of Xenopus laevis. For this analysis, we used electron microscopy, immunofluorescence and histological staining of the extracellular matrix. We generated two transgenic lines: i) the reporter line with the zebrafish GFAP regulatory regions driving the expression of EGFP, and ii) a cell specific inducible ablation line with the same GFAP regulatory regions. In addition, we used FACS to isolate EGFP+ cells for RNAseq analysis. Results In regenerative stage animals, spinal cord regeneration triggers a rapid sealing of the injured stumps, followed by proliferation of cells lining the central canal, and formation of rosette-like structures in the ablation gap. In addition, the central canal is filled by cells with similar morphology to the cells lining the central canal, neurons, axons, and even synaptic structures. Regeneration is almost completed after 20 days post injury. In non-regenerative stage animals, mostly damaged tissue was observed, without clear closure of the stumps. The ablation gap was filled with fibroblast-like cells, and deposition of extracellular matrix components. No reconstruction of the spinal cord was observed even after 40 days post injury. Cellular markers analysis confirmed these histological differences, a transient increase of vimentin, fibronectin and collagen was detected in regenerative stages, contrary to a sustained accumulation of most of these markers, including chondroitin sulfate proteoglycans in the NR-stage. The zebrafish GFAP transgenic line was validated, and we have demonstrated that is a very reliable and new tool to study the role of neural stem progenitor cells (NSPCs). RNASeq of GFAP::EGFP cells has allowed us to clearly demonstrate that indeed these cells are NSPCs. On the contrary, the GFAP::EGFP transgene is mainly expressed in astrocytes in non-regenerative stages. During regenerative stages, spinal cord injury activates proliferation of NSPCs, and we found that are mainly differentiated into neurons and glial cells. Specific ablation of these cells abolished proper regeneration, confirming that NSPCs cells are necessary for functional regeneration of the spinal cord. Conclusions The cellular response to spinal cord injury in regenerative and non-regenerative stages is profoundly different between both stages. A key hallmark of the regenerative response is the activation of NSPCs, which massively proliferate, and are differentiated into neurons to reconstruct the spinal cord. Also very notably, no glial scar formation is observed in regenerative stages, but a transient, glial scar-like structure is formed in non-regenerative stage animals.

Here we present a multi-taxa inventory of naturalized alien species recorded on continental Chile and adjacent marine habitats, including eight taxonomic groups. We identified 1,122 species. These comprise 790 vascular plants (terrestrial and aquatic); 31 nonvascular plants [Bryophyta (mosses), Marchantiophyta (liverworts) and Anthocerotophyta (hornworts)]; 18 marine and freshwater macro and micro algae; 71 fungi; 39 terrestrial vertebrates (amphibians, reptiles, mammals and birds); 108 insects; 37 marine and freshwater invertebrates and vertebrates (6 polychaetes, 3 mollusks and 28 Pisces); and 28 terrestrial gastropods. For all taxonomic groups, naturalized species were found to mainly be distributed in regions with Mediterranean and temperate climates, with few at either extreme of the country. The invasion curves show that naturalized species first underwent a positive increment, followed by an apparent plateau phase, mainly in vascular plants, insects and vertebrates. In fungi, marine and freshwater macro and microalgae, vertebrates and invertebrates, the cumulative number of naturalized species increased sharply starting in the early 20th century; the lack of collections before 1900 is also evident. When considering naturalized species as a whole, this inventory highlights that the rate of new naturalizations consistently increased after 1950, especially for some taxonomic groups such as insects, fungi, and vascular plants. This multi-taxa inventory of naturalized species provides a platform for national reporting on biodiversity indicators and highlights areas where Chile must invest resources to manage biological invasions.

PREMISE New sequencing technologies facilitate the generation of large‐scale molecular data sets for constructing the plant tree of life. We describe a new probe set for target enrichment sequencing to generate nuclear sequence data to build phylogenetic trees with any flagellate land plants, including hornworts, liverworts, mosses, lycophytes, ferns, and all gymnosperms. METHODS We leveraged existing transcriptome and genome sequence data to design the GoFlag 451 probes, a set of 56,989 probes for target enrichment sequencing of 451 exons that are found in 248 single‐copy or low‐copy nuclear genes across flagellate plant lineages. RESULTS Our results indicate that target enrichment using the GoFlag451 probe set can provide large nuclear data sets that can be used to resolve relationships among both distantly and closely related taxa across the flagellate land plants. We also describe the GoFlag 408 probes, an optimized probe set covering 408 of the 451 exons from the GoFlag 451 probe set that is commercialized by RAPiD Genomics. CONCLUSIONS A target enrichment approach using the new probe set provides a relatively low‐cost solution to obtain large‐scale nuclear sequence data for inferring phylogenetic relationships across flagellate land plants.

The Chilean endemic genus Costesia belongs to the Gigaspermaceae, one of the most basal groups of arthrodontous mosses. While none of the species in this family has a peristome, earlier stages of sporophyte development often disclose its basic structure. The study of Costesia sporophytes at the early stages of development was conducted to identify possible similarities with Diphyscium, the genus sister to Gigaspermaceae plus all other arthrodontous mosses in the moss phylogenetic tree. Diphyscium shares a strongly unequal cell division pattern with the Dicranidae. In groups more closely related to Diphyscium, as it is the case of Costesia, this pattern is not known. Our study of Costesia found only irregular presence of slightly unequal cell divisions that may then be considered as a plesiomorphic state in peristomate mosses. The most frequently present pattern revealed in Costesia is common with the Polytrichaceae, a more basal moss group with nematodontous peristomes.

This is the final report on the moss flora of the Bío-Bío Region (Región VIII) in south-central Chile where collections were made in 2001–2003. Reported in this paper are one species new to South America, four species new to Chile and 16 species new to the Region. With these new additions the total number of taxa in the Bío-Bío Region is 343, corresponding to 331 species and 12 infraspecific taxa. A complete checklist of the mosses for all the provinces in the Region is presented.

Xenopus laevis frogs are a widely used organism to study aspects of modern biology (Harland and Grainger, 2011). Its central nervous system is particularly interesting, because in certain stages of metamorphosis the spinal cord can regenerate after injury and recover swimming. With this in mind, automatic gait analysis could help evaluate the regenerative performance by means of a method that automatically and quantitatively establishes the degree in froglets' limb movement. Here, we present an algorithm that characterizes spinal cord damage in froglets. The proposed method tracks the position of the limbs throughout videos and extracts kinematic features, which posteriorly serve to differentiate froglets with different levels of damage to the spinal cord. The detection algorithm and kinematic features chosen were validated in a pattern recognition experiment in which 90 videos (divided equally in three classes: uninjured, hemisected and transected) were classified. We conclude that our system is effective in the characterization of damage to the spinal cord through video analysis of a swimming froglet with a 97% accuracy. These results potentially validate this methodology to automatically compare the recovery of spinal cord function after different treatments without the need to manually process videos. In addition, the procedure could be used to measure the kinematics and behavioral response of froglets to different experimental conditions such as nutritional state, stress, genetic background and age.

El Santuario de la Naturaleza “Serranía El Ciprés” es un sitio prioritario para la conservación de la biodiversidad al nivel regional y nacional en Chile. Se ubica administrativamente en la Región de Valparaíso, en la ecorregión mediterránea. El objetivo de este trabajo es estudiar la riqueza y la composición de su flora vascular. Los resultados indican que en el área existen al menos 297 taxa, pertenecientes a 293 especies, 183 géneros y 74 familias. Las familias mejor representadas son Asteraceae, Fabaceae y Poaceae. La riqueza de especies en relación con la superficie es mayor a la esperada en Chile central (226-272), donde 272 (92,8%) son nativas, de las que 145 (53,3%) son endémicas de Chile y 21 (7,2%), alóctonas asilvestradas. Las formas de vida de Raunkiaer predominantes fueron las hemicriptófitas (26,4%), las terófitas (23,5%) y las caméfitas (17,7%). Se encontraron diez especies clasificadas oficialmente en alguna categoría de conservación, cinco de ellas como “vulnerable”, ellas son Citronella mucronata, Eriosyce aurata, Placea ornata, Porlieria chilensis y Prosopis chilensis. Se registran, además, siete especies nuevas para la Región.

The bryophytes play a key role in the peat bogs. However, knowledge of this group is scarce in southern South America. We present an identification key for peat moss from the Isla Grande de Chiloé (Chile). The key is separated for each group with similar characters.

The systematic placement of Frullania herzogii has been contentious since its description six decades ago. Over the years it has been interpreted as either a member of the genus Frullania or segregated into its own genus, Neohattoria, due to morphological similarities with both Frullania and Jubula. Here we provide molecular evidence that supports the recognition of the genus Neohattoria and its inclusion within the Jubulaceae, together with Jubula and Nipponolejeunea. Jubulaceae are placed sister to Lejeuneaceae rather than to the monogeneric Frullaniaceae.

Mammals are unable to regenerate its spinal cord after a lesion, meanwhile, anuran amphibians are capable of spinal cord regeneration only as larvae, and during metamorphosis, this capability is lost. Sox2/3+ cells present in the spinal cord of regenerative larvae are required for spinal cord regeneration. Here we evaluate the effect of the transplantation of spinal cord cells from regenerative larvae into the resected spinal cord of non-regenerative stages (NR-stage). Donor cells were able to survive up to 60 days after transplantation in the injury zone. During the first 3-weeks, transplanted cells organize in neural tube-like structures formed by Sox2/3+ cells. This was not observed when donor cells come from non-regenerative froglets. Mature neurons expressing NeuN and Neurofilament-H were detected in the grafted tissue 4 weeks after transplantation concomitantly with the appearance of axons derived from the donor cells growing into the host spinal cord, suggesting that Sox2/3+ cells behave as neural stem progenitor cells. We also found that cells from regenerative animals provide a permissive environment that promotes growth and regeneration of axons coming from the host. These results suggest that Sox2/3 cells present in the spinal cord of regenerative stage (R-stage) larvae are most probably neural stem progenitor cells that are able to survive, proliferate, self-organize and differentiate into neurons in the environment of the non-regenerative host. In addition, we have established an experimental paradigm to study the biology of neural stem progenitor cells in spinal cord regeneration.

Lorentziella (Gigaspermaceae, Bryophyta) nuevo para Chile, y lectotipificación del género. El género Lorentziella es reportado por primera vez para Chile sobre la base de múltiples colecciones realizadas durante los meses de julio y septiembre de 2016. Se entrega información acerca de la ecología de la especie y su distribución mundial conocida, así como un mapa de distribución. Un lectotipo para el género Lorentziella es aquí seleccionado y se corrige la autoría del nombre.

Se presenta una lista de plantas no vasculares para la Estancia Cerro Paine, predio particular ubicado en el centro del Parque Nacional Torres del Paine. La lista incluye dos antocerotes, 29 hepáticas y 93 especies de musgos, totalizando 124 especies de briófitos. Se reportan 32 nuevos registros para la provincia de Última Esperanza, 11 para la Región de Magallanes y tres nuevos registros para Chile (Bryum apiculatum, Tortella fragilis y Valdonia microcarpa). Se extienden hacia el norte los límites de distribución de seis taxones, mientras que los de siete se extienden hacia el sur. Este es el primer listado de briófitos realizado dentro de los límites del Parque Nacional Torres del Paine.

Bryophytes and lichens are an important component of biodiversity. Nevertheless, these cryptogamic groups are rarely included in floristic and ecological studies in southern South America. We present the first comparison of patterns of alpha and beta diversity of bryophytes and macrolichens in peatlands and Tepualia stipularis forests (TF) on Isla Grande de Chiloé, Chile. Two kinds of Sphagnum peatlands were studied, which were defined according to their origin and their vegetation, natural peatlands (GP) and anthropogenic peatlands (AP). A total of 86 species were found: 42 liverworts, 29 mosses and 14 lichens. The most species-rich sites were AP with a total of 52 species, followed by TF with 45 species, and GP with 21 species. The total bryo-lichenic diversity reported in this study was considerably higher than that reported in other studies for Patagonian peatlands. The three types of studied habitats showed significant differences in species richness and diversity indices. We found clear distinctions between the three habitat types, with significant differences in the floristic composition of GP, AP, and TP. Moreover, AP presented a species composition that has not been previously documented in TF or GP. They are the result of human action, but do not depend on continued human intervention for their maintenance. Therefore, here we propose to denominate AP as a novel ecosystem.

We report the finding of a population of Frullania weberbaueri in Parque Nacional Pan de Azúcar, Antofagasta Province, Chile. This taxon was previously known only from the type specimen collected by August Weberbauer in Lima in 1901. The new gathering is fertile so we describe here its sexuality and perianths, together with the oil bodies and the habitat used by the species, and we provide a map of its known distribution. A lectotype for the name is here designated. This is the first record of a liverwort for the deserts of northern Chile, and the southernmost record for Frullania sect. Meteoriopsis.

The heterobasidiomycete fungus Eocronartium muscicola is an obligate parasite recorded on about 21 moss species, mainly from the Northern Hemisphere. It interacts with its hosts mainly by replacing the sporophyte and obtaining water and nutrients from the gametophyte through specialized tissues. This work reports for the first time E. muscicola on the native mosses Eurhynchium corralense and Eurhynchiella acanthophylla in central and southern Chile, in different forest formations. Also, associations between fungi and bryophytes as well as the taxonomic status of Chilean host mosses and its relationship with E. muscicola are discussed.El hongo heterobasidiomycete Eocronartium muscicola es un parásito obligado registrado en alrededor de 21 especies de musgos, principalmente del hemisferio norte. Interactúa con los musgos reemplazando el esporofito y de esta forma aprovechando el flujo de agua y nutrientes que va desde el gametofito a través de tejidos especializados. Este trabajo reporta E. muscicola por primera vez en Chile central y sur con los musgos nativos Eurhynchium corralense y Eurhynchiella acanthophylla en diferentes tipos de formaciones boscosas. Además, se comentan los tipos de relaciones entre hongos y briófitas y se discute el estatus taxonómico de los musgos chilenos hospedantes y su relación con E. muscicola.

El olvidado nombre Racomitrium stenocladum Dusén es revalidado luego de ser considerado un sinónimo de R. orthotrichaceum (Müll. Hal.) Paris (=Bucklandiella orthotrichacea (Müll. Hal.) Bednarek-Ochyra & Ochyra) por más de 25 años. La especie se distingue de B. orthotrichacea por las hojas fuertemente adpresas a los tallos en seco, la forma de la costa en sección transversal y la lámina mayoritariamente de un solo estrato de células. El nombre es lectotipificado y se propone la nueva combinación Bucklandiella stenoclada (Dusén) Larraín. Se presenta además una clave para las especies de Bucklandiella del sur de Sudamérica (al sur de los 30°S).

Proliferation and cell fate determination in the developing embryo are extrinsically regulated by multiple interactions among diverse secreted factors, such as Sonic Hedgehog (SHh), which act in a concentration-dependent manner. The fact that SHh is secreted as a lipid-modified protein suggests the existence of a mechanism to regulate its movement across embryonic fields. We have previously shown that heparan sulfate proteoglycans (HSPGs) are required for SHh binding and signalling. However, it was not determined which specific HSPG was responsible for these functions. Here we evaluated the contribution of perlecan on SHh localization and activity. To understand the mechanism of action of perlecan at the cellular level, we studied the role of perlecan-SHh interaction in SHh activity using both cell culture and biochemical assays. Our findings show that perlecan is a crucial anchor and modulator of SHh activity acting as an extracellular positive regulator of SHh.

Son reportadas dos nuevas criptógamas para el altiplano de la Provincia de Parinacota en el norte de Chile: el liquen Caloplacafragillima Poelt, conocido previamente en Chile sólo de la localidad tipo en la provincia de Valparaíso, y el musgo Grimmia trinervis R.S.Wilhams, reportado anteriormente como endémico del altiplano de Perú y Bolivia.

Las turberas son ecosistemas reconocidos mundialmente por actuar como grandes reservorios de agua dulce, afectando el clima y la hidrología local; por ser sumideros de carbono; por albergar especies únicas, contribuyendo así a la biodiversidad; y porque significan un recurso económico para la sociedad. La vegetación de las turberas es dominada por plantas que crecen a ras de suelo formando densas poblaciones, en especial musgos del género Sphagnum o plantas vasculares de la familia de las Ciperáceas o Juncáceas. Presentan altos niveles freáticos y una profunda capa de materia orgánica (turba) bajo la capa viva de plantas. La tala y quema de bosques en sitios con drenaje pobre han generado un tipo de ecosistema similar a las turberas donde crece principalmente el musgo Sphagnum (turberas antropogénicas o "pomponales"), pero donde la acumulación de turba aún es muy baja. Mientras las turberas naturales son utilizadas para la extracción de turba, en las turberas antropogénicas se cosecha el musgo vivo que se encuentra en la superficie. Las consecuencias ecológicas después de ambas actividades extractivas son distintas. El objetivo de este trabajo es hacer una comparación de la composición florística y de los niveles freáticos entre turberas naturales y antropogénicas. Fueron estudiadas turberas naturales y antropogénicas con y sin extracción de Sphagnum. Se registraron 74 taxa (ocho liqúenes, 19 briófitas y 47 de plantas vasculares). Las diferencias en composición florística nos permiten distinguir entre turberas naturales y antropogénicas. Los niveles freáticos también difieren entre sitios, siendo menos superficiales en turberas naturales y antropogénicas sin extracción, que en turberas antropogénicas con extracción de Sphagnum. Debido a la inexistencia de nieves eternas en la Isla de Chiloé, la alteración hidrológica de estos reservorios de agua dulce proveniente de las lluvias puede traer graves consecuencias ecológicas.Peatlands are globally known as major deposits of fresh water and carbón, affecting the planet's weather and local hydrology; for bearing unique plant and animal species, contributing to biodiversity; and because they represent a major economic resource to humanity. Peatlands are dominated by plants forming dense populations, especially Sphagnum moss and vascular plants belonging to the Cyperaceae and Juncaceae. They present high water table levéis and a deep organic matter layer (peat) below the living layer of plants. The use of fire and logging to clear forests in poor drainage soils have generated a kind of ecosystem similar to peatlands, dominated by Sphagnum moss, where peat accumulation is very low or absent (anthropogenic peatlands or "pomponales"). Compared with natural peatlands, they share the presence of Sphagnum, but they are very different in the use human beings give to them. While natural peatlands are used for peat extraction, anthropogenic peatlands are harvested for the superficial layer of living moss. The ecological consequences after both extractive activities are also different. The aim of this work is to compare the floristic composition and water table levéis between natural and anthropogenic peatlands. We sampled natural and anthropogenic peatlands with and without Sphagnum extraction. We registered 74 taxa (eight lichens, 19 bryophytes and 47 vascular plants). Differences in floristic composition allow us to distinguish between natural and anthropogenic peatlands. Water table levéis also differ between study sites, being less superficial in natural and anthropogenic peatlands without moss extraction. The hydrological alterations after peatland exploitation would bring serious ecological consequences to Chiloé island, since its only source of water comes from rainfall and is stored in these large reservoirs called peatlands.

Son reportados por primera vez para la Isla Grande de Chiloé 42 especies de musgos, 17 géneros y cuatro familias (Cryphaeaceae, Racopilaceae, Vittiaceae y Daltoniaceae), sobre la base de colecciones del autor en localidades previamente poco exploradas de la Isla y material depositado en el herbario CONC. Once especies extienden sus límites de distribución conocidos en el país y cuatro taxa son citados por primera vez para la X Región. Con estos nuevos registros, la flora muscinal del archipiélago se eleva a 162 especies y tres taxa subespecíficos.Forty-two moss species, 17 genera and four families (Cryphaeaceae, Racopilaceae, Vittiaceae y Daltoniaceae) are reported for the first time for Chiloé Island, based on collections made by the author in scarcely explored localities of the Island and material housed at CONC. Eleven species extend their distribution limits known for the country and 4 taxa are reported for the first time for the Lake District (10th Region). With these new records, the Archipelago moss flora is increased to 162 species and three subspecific taxa.

One hundred and twenty-nine taxa of bryophytes and lichens were found in peatlands (Sphagnum bogs) and swamp forests of Tepualia stipularis of Isla Grande de Chiloé (Chile) (41°-43°S, 73°-74°W). Forty eight percent of these species are endemic to southern South America. The range of most species spans from Los Rios Region to Magallanes Region. Fifty mosses, 52 liverworts, and 27 macrolichens were reported. Global and national distributions and habitat preferences are given for each species.

In bryophytes a morphological species concept is still most commonly employed, but delimitation of closely related species based on morphological characters is often difficult. Here we test morphological species circumscriptions in a species complex of the moss genus Racomitrium, the R. canescens complex, based on variable DNA sequence markers from the plastid (rps4-trnT-trnL region) and nuclear (nrITS) genomes. The extensive morphological variability within the complex has led to different opinions about the number of species and intraspecific taxa to be distinguished. Molecular phylogenetic reconstructions allowed to clearly distinguish all eight currently recognised species of the complex plus a ninth species that was inferred to belong to the complex in earlier molecular analyses. The taxonomic significance of intraspecific sequence variation is discussed. The present molecular data do not support the division of the R. canescens complex into two groups of species (subsections or sections). Most morphological characters, albeit being in part difficult to apply, are reliable for species identification in the R. canescens complex. However, misidentification of collections that were morphologically intermediate between species questioned the suitability of leaf shape as diagnostic character. Four partitions of the molecular markers (rps4-trnT, trnT-trnL, ITS1, ITS2) that could potentially be used for molecular species identification (DNA barcoding) performed almost equally well concerning amplification and sequencing success. Of these, ITS1 provided the highest species discrimination capacity and should be considered as a DNA barcoding marker for mosses, especially in complexes of closely related species. Molecular species identification should be complemented by redefining morphological characters, to develop a set of easy-to-use molecular and non-molecular identification tools for improving biodiversity assessments and ecological research including mosses.