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Se presenta un catálogo de 25 especies de hepáticas foliosas pertenecientes a 9 familias: Adelanthaceae, Balantiopsidaceae, Calypogeiaceae, Frullaniaceae, Herbertaceae, Lejeuneaceae, Lophocoleaceae, Porellaceae y Radulaceae, recolectadas en bosques neotropicales húmedos-hiperhúmedos del NE y NO de la Argentina. Once taxones son exclusivos del Dominio Amazónico de la Región Neotropical; 5 presentan una distribución Neotropical en los Dominios Amazónico y Chaqueño; Isotachis serrulata, Triandrophyllum subtrifidum var. trifidum, Heteroscyphus integrifolius y Radula voluta tienen una distribución disyunta Neotropical (Dominio Amazónico)-Antártica. Por último, para Frullania ericoides, Frullania glomerata, Lophocolea leptantha, Leptoscyphus expansus y Syzygiella sonderi, se amplía su área de distribución a los tres dominios fitogeográficos en la Argentina: Amazónico y Chaqueño de la Región Neotropical y Subantártico, de la Región Antártica. Se indica la preferencia de hábitat, distribución en Argentina por provincias administrativas y distribución fitogeográfica de cada taxón, así como mapas de distribución de algunas especies. Se aportan seis nuevas citas provinciales para Jujuy, tres para Salta y siete para Tucumán

Struthiopteris (Blechnaceae) has recently been classified on the basis of molecular and morphological evidence, and some of its species are now included in the sister genus Spicantopsis. However, the lack of studies on several important morphological features impedes a sound assessment of their congruence with this new systematic arrangement, as well as of their range of variation and taxonomic value in this group of ferns. Here we present a study on the spores and sporangia using both light and scanning electron microscopy in Struthiopteris and Spicantopsis, using samples of all their species, and almost all their varieties. We provide full morphological descriptions of the spores and sporangia of all these taxa. We point out that the perispore structure and ornamentation and the number and the thickness of stomium cells in the sporangium clearly distinguish both genera.

espanolSe presenta una lista de 32 especies de hepaticas foliosas pertenecientes a 16 familias: Acrobolbaceae, Adelanthaceae, Balantiopsidaceae, Blepharidophyllaceae, Cephaloziaceae, Frullaniaceae, Jungermanniaceae, Lepico­leaceae, Lepidolaenaceae, Lepidoziaceae, Lophocoleaceae, Lophoziaceae, Porellaceae, Radulaceae, Schistochilaceae y Trichocoleaceae, recolectadas en los bosques humedos-hiperhumedos andino-patagonicos de la Provincia Biogeo­grafica Subantartica situada al S-SO de la Argentina (provincias de Neuquen, Rio Negro, Chubut, Santa Cruz y Tierra del Fuego). La mayoria de las especies son endemicas o frecuentes en el Dominio Subantartico, otras presentan una distribucion disyunta en las Regiones Austral y Neotropical de la Argentina. Se actualiza la taxonomia de las especies y se incluyen comentarios sobre antecedentes bibliograficos, ecologia y corologia de cada taxon. Heterogemma pata­gonica y Hepatostolonophora abnormis se citan por primera vez para la brioflora argentina, y se aportan 10 novedades provinciales y 6 departamentales. EnglishWe present a list of 32 leafy liverworts belonging to 16 families: Acrobolbaceae, Adelanthaceae, Balantiop­sidaceae, Blepharidophyllaceae, Cephaloziaceae, Frullaniaceae, Jungermanniaceae, Lepicoleaceae, Lepidolaenaceae, Lepidoziaceae, Lophocoleaceae, Lophoziaceae, Porellaceae, Radulaceae, Schistochilaceae and Trichocoleaceae. All have been collected in the humid-hyperhumid Andean-Patagonian mountain forests of the Subantartic biogeographic province of the S-SW of the Argentina (Neuquen, Rio Negro, Chubut, Santa Cruz and Tierra del Fuego provinces). Many of them are endemic or frequent in the Subantartic Domain, whereas others show a disjunct distribution in areas of the Austral and Neotropical Regions of Argentina. The taxonomy and nomenclature of the species are updated, and comments are included on bibliographical background, ecology and chorology of each taxon. Heterogemma pata­gonica and Hepatostolonophora abnormis are cited for the first time for the Argentinean bryoflora, and 10 provincial and 6 departmental new records are provided.

espanol"Parablechnum" es el genero mas diverso de las Blechnaceae (ca. 65 especies), con una distribucion pantropical y dos centros de diversidad, en America y en la region austro-pacifica. Las especies son dimorfas, con rizomas normalmente erguidos y escamas rizomaticas, frondas pinnadas, con hoja truncada en la base, de apice conforme y pinnas pecioluladas. Este grupo presenta muchos problemas taxonomicos, por lo que se necesitan estudios mas detallados para resolver conflictos de separacion entre especies. Este trabajo trata del complejo americano de P. cordatum en el que se incluyen las especies P. cordatum, P. schiedeanum, P. chilense, P. falciforme y Blechnum varians. Se ha llevado a cabo un analisis biometrico de los esporangios y las esporas, estructuras taxonomicamente importantes en la distincion de los helechos. Los datos se sometieron a un analisis unidireccional de la varianza y a un analisis discriminante. Ademas, las esporas se observaron bajo un microscopio electronico de barrido para estudiar su ornamentacion. De los caracteres que hemos estudiado, el grosor del arco, el numero de celulas en el arco, el numero de celulas en el hipostomio y el diametro mayor ecuatorial de la espora han apoyado estadisticamente su importancia taxonomica y, por lo tanto, son utiles para la separacion de especies. English"Parablechnum" is the most diverse genus of Blechnaceae (ca. 65 species), with a pantropical distribution and two centers of diversity, in America and in the Austro-Pacific region. The species are dimorphic, with often erect rhizomes and rhizomatic scales, 1-pinnate fronds, with truncate blade at base, conform apex and stalked pinnae. This group presents many taxonomic problems, needing more detailed studies to resolve these conflicts of separation between species. This work deals with the American complex of P. cordatum in which the species P. cordatum, P. schiedeanum, P. chilense, P. falciforme and Blechnum varians are included. A biometric analysis of sporangia and spores, important taxonomic structures in the distinction of ferns, has been carried out. The data were subjected to a one-way analysis of variance and a discriminant analysis. In addition, the spores were observed under a scanning electron microscope to study their ornamentation. Of the characters we have studied thickness of the arcus, number of cells in the arcus, number of cells in the hypostome and major equatorial diameter of the spore have statisticalParablechnum is the most diverse genus of Blechnaceae (ca. 65 species), with a pantropical distribution and two centers of diversity, in America and in the Austro-Pacific region. The species are dimorphic, with often erect rhizomes and rhizomatic scales, 1-pinnate fronds, with truncate blade at base, conform apex and stalked pinnae. This group presents many taxonomic problems, needing more detailed studies to resolve these conflicts of separation between species. This work deals with the American complex of P. cordatum in which the species P. cordatum, P. schiedeanum, P. chilense, P. falciforme and Blechnum varians are included. A biometric analysis of sporangia and spores, important taxonomic structures in the distinction of ferns, has been carried out. The data were subjected to a one-way analysis of variance and a discriminant analysis. In addition, the spores were observed under a scanning electron microscope to study their ornamentation. Of the characters we have studied thickness of the arcus, number of cells in the arcus, number of cells in the hypostome and major equatorial diameter of the spore have statistically supported taxonomic significance and are therefore useful for species separation.

espanol"Cranfillia opaca" es una especie de helecho presente en Nueva Caledonia, para la que se registra una gran variacion morfologica. Otras especies, como Blechnum deplanchei han sido propuestas en el pasado, y se sinonimizaron mas tarde con C. opaca. En este trabajo, hemos estudiado este taxon tanto a nivel morfologico como anatomico, asi como su ecologia y distribucion geografica. Encontramos diferencias entre C. opaca s.s. y B. deplanchei en la morfologia tanto de frondas esteriles como fertiles, y en rasgos morfo-anatomicos como son la forma, longitud y distribucion de los tricomas y la longitud y/o forma de diferentes estructuras relativas a esporas y esporangios. La distribucion de ambos taxones tambien fue distinta, aunque siendo simpatricos en algunas localidades. Todas estas evidencias apoyan el reconocimiento de ambos taxones, y la combinacion de Cranfillia deplanchei (Baker) Vazquez Ferreira & Gabriel y Galan, la cual proponemos aqui. Tambien proporcionamos descripciones taxonomicas para ambas especies. English"Cranfillia opaca" is a fern species present in New Caledonia, for which a great variation in morphology is reported. Some other species such as Blechnum deplanchei have been proposed, but those were later synonymized with C. opaca. In this work, we have studied this taxon at both the morphological and the anatomical level, as well as its ecology and geographical distribution. We found differences between C. opaca s.s. and B. deplanchei in the morphology of the sterile and fertile fronds, in several morphoanatomical features such as trichome shape, length, and distribution, and length and/or shape of different structures of sporangia and spores. The distribution of both taxa was also different, but they are sympatric at some localities. The differences identified in this study support the recognition of both taxa, and the combination of Cranfillia deplanchei (Baker) Vazquez Ferreira & Gabriel y Galan, which we propose here. A new taxonomic description is provided for both species.

espanolLas plantas vasculares que no forman semillas son conocidas con el nombre vulgar de helechos, presentando unas 120 especies en la peninsula iberica, mas abundantes en ambientes forestales humedos y saxicolas. En entornos urbanos y semiurbanos no suelen ser muy numerosos, un hecho que parece estar unido a la escasa presencia de sus esporas en la atmosfera de estas zonas, en comparacion con otras particulas biologicas como las esporas fungicas o los granos de polen. El objetivo de este trabajo es proporcionar una clave de determinacion de los tipos de esporas de licofitos y helechos mas comunes en los entornos urbanos o sus proximidades, discriminando para ello 12 generos. Se pretende asi facilitar su identificacion en muestras aerobiologicas y permitir, con ello, un mayor conocimiento de estos tipos esporales y sus dinamicas atmosfericas urbanas. EnglishVascular plants that do not form seeds are known by the common name of ferns, with about 120 species in the Iberian Peninsula, which are more abundant in humid forests and saxicolous environments. In urban and semi-urban environments they are usually not very common, a fact that seems to be linked to the low presence of their spores in the atmosphere in these areas, compared to other biological particles such as fungal spores or pollen grains. The aim of this work is to provide a key to determine the spore types of the most common lycophytes and ferns in or near urban environments, discriminating 12 genera. In addition, it is intended to facilitate their identification in aerobiological samples and thus allow a better understanding of these spore types and their urban atmospheric dynamics.

Spore morphology of 25 Mexican and Central American species in Pteris were studied. This was accomplished using scanning electron and light microscopy. Spores are trilete, tetrahedral, with plane or slightly convex proximal faces, concave only occasionally, and convex or hemispherical distal faces. In addition to these general features and size, we also considered the following traits: (a) cingulum; (b) presence of a commissural flange; (c) types of macro-ornamentation; (d) ornamentation in distal and proximal faces. In general, distal and proximal faces of Pteris spores are divided by a circumfluent cingulum, lacking ornamentation, infrequently not well defined, or interrupted. The laesura have a commissural flange in almost half of the studied species. The most common macro-ornamentation is muriform, less requently steliform or buliform. Ornamentation is usually different on both sides of the spore. In most of the studied species occasional to abundant globules are present on the spore surface. The combination of these traits allows us to recognise six spore types, which are described in detail. These spore types disagree with groups of species of Neotropical Pteris previously studied using other characteristics (mainly frond architecture and molecular data). Our results show that the use of spore characteristics can help clarify infrageneric taxonomy in Pteris.

The infrageneric classification of Asplenium, the most species-rich genus of ferns, is notoriously difficult as a result of extensive morphological homoplasy combined with exceptional morphological disparity. Besides a core Asplenium, 29 satellite genera have been described, but most of them have not been widely accepted. In recent years, molecular phylogenetic studies found most of these satellite genera to be nested in Asplenium, but several morphologically distinct taxa have not yet been included in such studies. One of these elements is the monospecific neotropical genus Schaffneria which is characterized by undivided suborbicular blades, lack of a costa, black stipes, netted veins and single or paired sori. Maximum likelihood and Bayesian phylogenetic inference based on the chloroplast DNA markers rbcL, rps4, rps4-trnS and trnL-trnF indicated a position of Schaffneria nigripes within Asplenium. We thus propose to treat Schaffneria as a synonym of Asplenium and adopt the name Asplenium nigripes. With the current sampling, Asplenium (Schaffneria) nigripes is placed sister to A. pumilum, the only species of Asplenium with whitish catenate hairs on its leaves. Despite considerable morphological differences, both species resemble each other in several features including filiform-lanceolate, mostly entire, brown-blackish rhizome scales with a dark-sclerotic center and some marginal projections, a striate, hairy epidermis, echinolophate spore ornamentation with slim microechinate folds forming small lacunae, and Aspidium-type gametophytes.

In this work, we contribute with the first essay devoted to relating the effect of brassinosteroids on the germination and development of fern spores of Pteridium aquilinum, Polystichum lonchitis and Pteris vittata. The effect of brassinosteroids (BRs) on the germination and development of fern spores is species-dependent. In the case of P. aquilinum, which is antheridiogen sensitive and in which rhizome reproduction predominates, BR treatment caused a negative effect over spore germination. For P. vittata, also antheridiogen sensitive and which forms large populations with sexual origin, BR treatment caused a slight negative effect on spore germination. Finally, for P. lonchitis, antheridiogen insensitive, the effect of BR treatment was positive. Thus, brassinosteroid application seems to regulate fern spore germination by modulating antheridiogen levels. Regarding further gametophyte development, the effects range from increasing the development velocity in P. lonchitis (which would aid the species in their reproductive role under adverse environmental conditions) to the independence in P. aquilinum and P. vittata (which, in general, live under less hard environmental conditions). Further research will be done in order to elucidate in detail the relationship between brassinosteroids, sexual organ expression and sporophyte production in the three species, considering at the time the use of antheridiogen system and the formation of apogamous plants. These results are providing valuable new information regarding the role of brassinosteroids on fern spore germination and growth as well as raising new questions for future studies.

Early life stress, in the form of MD (24 h at pnd 9), interferes with brain developmental trajectories modifying both behavioral and neurobiochemical parameters. MD has been reported to enhance neuroendocrine responses to stress, to affect emotional behavior and to impair cognitive function. More recently, changes in body weight gain, metabolic parameters and immunological responding have also been described. Present data give support to the fact that neuronal degeneration and/or astrocyte proliferation are present in specific brain regions, mainly hippocampus, prefrontal cortex and hypothalamus, which are particularly vulnerable to the effects of neonatal stress. The MD animal model arises as a valuable tool for the investigation of the brain processes occurring at the narrow time window comprised between pnd 9 and 10 that are critical for the establishment of brain circuitries critical for the regulation of behavior, metabolism and energy homeostasis. In the present review we will discuss three possible mechanisms that might be crucial for the effects of MD, namely, the rapid increase in glucocorticoids, the lack of the neonatal leptin surge, and the enhanced endocannabinoid signaling during the specific critical period of MD. A better understanding of the mechanisms underlying the detrimental consequences of MD is a concern for public health and may provide new insights into mental health prevention strategies and into novel therapeutic approaches in neuropsychiatry. Sin financiación 8.580 JCR (2015) Q1, 3/51 Behavioral Sciences, 16/256 Neurosciences UEM

Steereella lilliana se registra como una nueva cita para la flora briofítica de Argentina y Sudamérica. Además, se amplía la distribución de Frullania brasiliensis en Argentina, antes solo conocida para las provincias de Misiones y Salta, y ahora presente en las provincias de Tucumán y Córdoba. A su vez, Stephaniella paraphyllina , es una novedad para la provincia de San Luis, recolectada en la Sierra de Comechingones, representando éste su límite sur de distribución. Se aportan comentarios sobre la mor - fología, claves para las especies cercanas en Argentina y datos de hábitat.

Given the taxonomic complexity of the genus Pteris in the Neotropics, the present work aims to collect information about the anatomy of the petioles and the costae of native, adventitious, and introduced Mexican and Central American species of Pteris, and to analyse its taxonomic potential. We collected fresh and dried samples from 26 species, making histological sections by hand. With the naked eye or with a dissection microscope, the colour and size of the axes, and the characters of the awns were recorded. Other characters (indument, anatomy, specifically the stele) were observed in a compound microscope. The type of stele of the petiole, characterized by the shape of xylem, appeared to be an important taxonomic character because it presents a remarkable correlation with some of the groups formed by spore type. Some of these groups of Mesoamerican species of Pteris, formed by means of morphological criteria (petiole xylem + spore) fit very well certain clades established by means of molecular characters.

Se presenta una lista de 13 hepáticas talosas recolectadas en la Argentina. Ocho taxones son nuevas aportaciones a la brioflora provincial: Asterella chilensis para Misiones, Marchantia chenopoda y M. polymorpha en Jujuy, Plagiochasma rupestre var. rupestre y Targionia hypophylla var. fimbriata en San Luis, Lunularia cruciata subsp. thaxteri para Córdoba y Jujuy, Plagiochasma argentinicum para Jujuy y Tucumán y P. rupestre var. volkii para las provincias de Córdoba, La Pampa y San Luis. Además, como segunda cita provincial se mencionan: Dumortiera hirsuta en Jujuy y Salta, Lunularia cruciata subsp. thaxteri en Salta, Marchantia berteroana, para Tucumán y Tierra del Fuego, Plagiochasma argentinicum para Córdoba y P. rupestre var. volkii para la brioflora de Catamarca. Se incluyen comentarios sobre antecedentes bibliográficos, hábitat y corología de cada taxón. A list of 13 thalloid liverworts collected in the Argentina is presented. Eight taxa are new records for the provincial bryophyte flora: Asterella chilensis for Misiones, Marchantia chenopoda and M. polymorpha for Jujuy, Plagiochasma rupestre var. rupestre and Targionia hypophylla var. fimbriata for San Luis, Lunularia cruciata subsp. thaxteri for Córdoba and Jujuy, Plagiochasma argentinicum for Jujuy and Tucumán and P. rupestre var. volkii for Córdoba, La Pampa and San Luis provinces. Additionally second provincial records are reported: Lunularia cruciata susbp. thaxteri for Salta, Marchantia berteroana for Tucumán and Tierra del Fuego, Plagiochasma argentinicum for Córdoba and P. rupestre var. volkii for Catamarca. Comments on bibliographical precedents, ecology and chorology of each taxon are included.

Se llevó a cabo un detallado estudio citológico de las células madres de las esporas de ejemplares de B. occidentale procedentes del noroeste de la Argentina. Los resultados de esta contribución permiten dar a conocer un nuevo poliploide, en este caso un hexaploide, cuyo número básico se analiza y discute, estimándose como más probable en x=31. Los datos obtenidos sugieren un origen aloploiploide, es decir, este citótipo nuevo sería producto de hibridación interespecífica y posterior duplicación cromosómica. En el curso del estudio se observó también una notable estabilidad en los rasgos esporangiales, que se consideran diagnósticos en el nivel específico e independiente de la ploidía. A detailed cytological study of the spore mother cells of specimens of B. occidentale collected in locations from the northwest of the Argentina was carried out here. The results of this contribution allowed to report a new polyploid, in this case a hexaploid, whose most probably basic number was considered x = 31, and which origin is analyzed and discussed. The study suggests an allopolyploid origin of this new cytotype which would be a product of interspecific hybridization and later chromosomal duplication. In the course of the study a notable stability was observed in the sporangial characters that are considered to be diagnostic at the specific level, and independent from the ploidy. Fil: González, Graciela Esther. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Prada, Cármen. Universidad Complutense de Madrid. Facultad de Biología; España Fil: Rolleri, Cristina Hilda. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Modern molecular phylogenetic studies of the Pteridaceae have recognized a well supported cheilanthoid clade that includes four major subclades: myriopteroids, pellaeoids, hemionitidoids and notholaenoids. Many of the morphological characters used in delimitation of the cheilanthoid lineages and genera appear to be the result of convergent evolution, a result of adaptation to xeric environments. Faced with the apparent lack of sporophytic synapomorphies for the cheilanthoid subclades, farina production by gametophytes has been proposed as a character of possible phylogenetic utility. All the notholaenoid species observed to date produce farina in their gametophytes, but species of the other cheilanthoid clades (pellaeoids, hemionitidoids, and myriopteroids) do not. In this work we provide the first account of farina production in the gametophyte of a non-notholaenoid: two accessions of Argyrochosma nivea from different geographical localities were found to have farina on their gametophytes, sugge...

Morphological, cytological and taxonomical analyses of Asplenium delitescens and A. laetum in Cuba resulted in the recognition of both species belonging to the genus Hymenasplenium Hayata. The combinations of the Neotropical species to this genus are presented. Some remarks on gametophyte morphology of H. delitescens are included.

Los caracteres morfológicos estomáticos, tales como tamaño, forma y frecuencia, han sido objeto de abundante investigación, incluyendo su relación con los factores ambientales. Sin embargo, poco esfuerzo se ha realizado en esta materia en helechos y menos todavía en el género Blechnum. En este trabajo se midieron la longitud, anchura y frecuencia (como índice estomático) de estomas de pin-nas adultas de un número de individuos en catorce especies de Blechnum neotropicales. El objetivo fue encontrar rela-ciones biométricas entre los caracteres estomáticos, y entre los caracteres estomáticos y el hábito, hábitat y ecosistema de las plantas. Se realizaron análisis estadísticos como Análisis Exploratorios de Datos y Métodos Estadísticos Multivariantes. La longitud y la anchura de los estomas mostraron una muy fuerte correlación, sugiriendo un control genético endógeno que otorga a estos caracteres un considerable valor diagnóstico. Con respecto a las relaciones entre los caracteres estomáticos y el ambiente, encontramos una relación estadísticamente significativa entre la altitud y el índice estomático. También se incluyen interpretaciones de la significación ecológico-selectiva de un conjunto de caracteres estomáticos en diferentes conjun-tos de hábitos, hábitats y ecosistemas. Morphological stomatal traits, such as size, form and frequency, have been subject of much literature, including their relationships with environmental factors. However, little effort have focused on ferns, and very few in the genus Blechnum. Stomatal length, width and frequency (as stomatal index) of a number of specimens of fourteen Neotropical species of Blechnum were measured in adult pinnae. The aim of the work was to find biometrical relationships between stomatal traits and between stomatal traits and habit, habitat and ecosystem of the plants. Statistical analyses of data were conducted using Exploratory Data Analysis and Multivariate Statistical Methods. Stomatal length and width showed a very high correlation, suggesting an endogenous, genetic control, thus giving these traits a considerable diagnostic utility. With respect to the relationships between stomatal traits and environment, we found significant statistical relationships between altitude and stomatal index. We also addressed the interpretation of the ecological-selective significance of various assemblages of stomatal traits in a diverse conjunction of habits, habitats and ecosystems. Fil: Gabriel y Galán, José María. Universidad Complutense de Madrid. Facultad de Biología; España Fil: Prada, Carmen. Universidad Complutense de Madrid. Facultad de Biología; España Fil: Rolleri, Cristina Hilda. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina Fil: Lahoz Beltrá, Rafael. Universidad Complutense de Madrid. Facultad de Biología; España Fil: Martinez Calvo, Evangelina Cristina. Universidad Complutense de Madrid. Facultad de Biología; España

The retina of nonmammalian vertebrates has a loose myelin that enwraps the large axons of the ganglion cells in all areas, whereas that of mammals lacks myelin, with some exceptions, such as the rabbit retina, which shows compact myelin restricted to the myelinated streak. Electron microscopy studies in chicken retina showed processes of Muller cells (MCs) and oligodendrocytes enwrapping ganglion cell axons. How each of these cells contributes to chicken retina myelination and whether the MC of other myelinated retinas is involved in myelination remain unknown. By immunohistochemistry, with a monoclonal antibody against myelin oligodendrocyte-specific protein (MOSP), we show that MOSP is intensely expressed in the MC and the optic-fiber layer (OFL) in myelinated but not in unmyelinated retinas. By immunocytochemistry with isolated MCs from the chick and rabbit retinas, we show that MOSP is concentrated in the innermost domain of the vitread processes. By immunoblotting, we show that protein extracts from myelinated retinas, but not those from unmyelinated retinas, presented a single band labelled with anti-MOSP of molecular weight similar to that of brain MOSP. In addition, we show that the MC of the embryonic chicken retina starts to express MOSP just before myelination starts. Our results agree with those of electron microscopy studies showing myelin in chick retina formed by MC processes and with those of immunohistochemistry studies in rabbit and human retinas showing expression of other myelin molecules in the MC. Altogether, our results suggest that the MC in myelinated retinas might contribute MOSP to myelin. © 2011 Wiley-Liss, Inc.

Ce travail identifie les communautes vegetales, en particulier leur contenu en Isoetes, et analyse leurs caracteristiques spatiales dans un systeme de mares temporaires mediterraneennes situe au centre de l'Espagne. La zonation de la vegetation comprend trois bandes de communautes vegetales et trois ecotones, dans un gradient allant de la marge vers l'interieur, avec l'augmentation de la duree de la periode d'inondation. Les communautes vegetales disposees dans la zone intermediaire incluent les elements phytogeographiques les plus interessants, Ranunculus longipes et Isoetes setacea. Ce travail met en evidence le role important que les Isoetes ephemeres des mares temporaires de la Mediterranee peuvent jouer dans la caracterisation des types de communautes vegetales. Les trois especes etudiees (I, velata, I. setacea et I. histrix) montrent une distribution en bandes superposees liees a la periode d'inondation.

A study of the spores of 64 neotropical and palaeotropical taxa of the genus Blechnum was performed using scanning electron microscopy (SEM). Two basic types of perispores were recognised: perispore smooth or only slightly ornamented (laevigate, with micro-granules or micro-lamellae, venulose and rugulate), and perispore ornamented (rugate, low reticulate, cristatereticulate, orbiculate, and colliculate). SEM observations allow for distinguishing differences in the structure of perispores, but the character does not correlate with the ornamentation. The smooth exospore predominates among the studied species. Results suggest that perispore characters have important diagnostic value, since different combinations of ornamentation/ structure were found among the studied species. Moreover, when spore characters are considered together with other morphological traits of the sporophytes and the habit of plants, ornamentation of spores becomes a useful complementary feature at the specific level. The results are discussed in light of the recent systematic studies and emphasise that any eventual subdivision of the genus Blechnum must include characters of the sporophyte as well as spore features to ensure a more robust classification than the previously proposed. The spores also show a significant affinity between Blechnum and other genera of Blechnaceae, which was also suggested by recent phylogenetic studies., Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemática

Asplenium auritum Sw. is a sexual fern that produces 64 spores per sporangium, while A. monodon Liebm. is an apogamous species that produces 32 spores. The hybrid between them, A. × lellingerianum Sanchez & Regalado, also shows an apogamous life cycle, with mainly abortive spores. The scope of this work was to study the sexual and apogamous behavior in these taxa. We studied spore germination and gametophyte development of the three species, a process that followed the Adiantum type. Afterward, we observed morphological apogamous characters in A. monodon and A. × lellingerianum. Apogamous sporophytes arose from apical and basal regions of gametophytes, lacking feet and roots in the first instance, but developing other normal sporophytic structures, such as tracheids, stomata, glandular hairs, and scales. Finally, we studied the gametangia production in all three taxa, finding that the scarce production of antheridia in A. monodon is indicative of the Braithwaite apogamous life cycle scheme, and this scheme has probably been inherited by A. × lellingerianum.

Müller cells in the chick retina are generally thought to be a homogeneous population. We show that the transcription factor Pax2 is expressed by Müller cells in the central chick retina and its expression was first observed at stage 32 (embryonic day [E] 7.5). Birth-dating indicated that the majority of Pax2-positive Müller cells are generated between stage 29 and 33 (E5.5-E8). At stage 42 (E16), several Müller cell markers, such as Sox2 and 2M6, had reached the peripheral retina, while the Pax2 labeling extended approximately half-way. A similar pattern was maintained in the 6-month-old chicken. Neither the Pax2-positive nor the Pax2-negative Müller cells could be specifically associated to proliferative responses in the retina induced by growth factors or N-methyl-D-aspartate. Pax2 was not detected in Müller cells in mouse, rat, guinea-pig, rabbit, or pig retinas; but the zebrafish retina displayed a similar pattern of central Pax2-expressing Müller cells.

The gametophytic generation of Polystichum pycnolepis (Dryopteridaceae), including spore germination, morphological development of the gametophytes, major vegetative features and sexual expression, was studied. Spore germination was of the Vittaria model and the developmental pattern was of the Aspidium model. Adult gametophytes were cordate and hairy, with unicellular hairs located in the margins and the surface of the prothalli. In addition, hairs of P. pycnolepis were papillate, secretory and the marginal ones septate. Gametangia were of the normal type described for leptosporangiate ferns. The gametophytes produced at first instance a high proportion of female gametophytes. Polystichum pycnolepis formed few bisexual gametophytes with scarce antheridia. No male gametophytes for this species were detected. Thus, the species seemed to be promoting intragametophytic selfing and, to a lesser extend, intergametophytic unions between bisexuals and females.

The gametophytic generation of Cheilanthes pilosa (Pteridaceae), including spore germination, morphological development of the gametophytes, major vegetative features and sexual expression, was studied. In C. pilosa spore germination was of the Vittaria model and the developmental pattern was intermediate between Adiantum and Ceratopteris models. Adult gametophytes were cordate and hairy, with unicellular hairs located in the margins and both the ventral and dorsal surfaces of the prothalli. Gametangia were of the normal type described for leptosporangiate ferns. In C. pilosa populations the gametophytes produced at first instance a high proportion of female gametophytes, few male gametophytes developed and most of the female gametophytes became bisexual with time. Thus, although outbreeding is possible, this species seemed to be promoting intragametophytic selfing as the major reproductive strategy.

En este trabajo se estudia la germinación de la espora, el desarrollo morfológico de los gametófitos y la expresión sexual de dos pteridófitos sudamericanos rupícolas: Pleurosorus papaverifolius (Kunze) Fée. y Cheilanthes glauca (Cav.) Mett. Las esporas mostraron una germinación vigorosa, y se alcanzaron porcentajes relativamente altos de germinación (>70%) en menos de tres semanas. Pleurosorus papaverifolius desarrolló una fase filamentosa de lento crecimiento, con células gruesas e hinchadas que daban al gametófito un aspecto algo redondeado; por el contrario, en Cheilanthes glauca esta etapa fue efímera y rápidamente se dio paso a la fase laminar. Las formas presexuales fueron cordadas en ambas especies, pero en Pleurosorus papaverifolius se desarrollaron, además, abundantes protalos alargados de mayor tamaño. Mientras que los protalos de Cheilanthes glaucafueron desnudos, los de Pleurosorus papaverifoliuspresentaron numerosos tricomas unicelulares tanto marginales como superficiales. Ambos pteridófitos difirieron también en su expresión sexual, que comenzó con el desarrollo de anteridios en Pleurosorus papaverifolius y de arquegonios en Cheilanthes glauca. En Pleurosorus papaverifolius nunca se observaron gametófitos femeninos, pero sí abundantes bisexuales. Cheilanthes glauca mantuvo durante largo tiempo un número similar de gametófitos femeninos y masculinos, produciendo solamente un reducido número de protalos bisexuales.

The chick retina has four morphological cone types that differ not only in shape, but also in the visual pigment in the outer segment, in the colour of the oil droplet in the inner segment and in synaptic connectivity. Neither the type of droplet nor the visual pigment has been definitively established for the four cone types. The main aim of the present work has been the isolation of entire live photoreceptors in order to study the oil droplet colour in each cone type and to quantify each type. We have improved an earlier retinal cell isolation method and obtained large numbers of entire cones. Principal cones (27% of the cones) possess a yellow or colourless droplet. Accessory cones (27% of the cones) all contain a small pale green droplet. Straight cones (44% of the cones) have a red, orange, yellow, or colourless droplet. Oblique cones (1.66% of the cones) all have a colourless droplet. We have found that straight cones with a red, orange, or yellow droplet differ in terms of the position of the nucleus and their percentage and conclude that they are distributed in three rows in the outer nuclear layer (ONL) of the central retina. Our study of 4,6-diamidino-2-phenylindole-stained retinal sections has revealed three rows of nuclei instead of the two currently thought to form the ONL. Together, our results show a larger cone diversity than previously known, suggest a larger functional diversity and provide an efficient method for isolating entire chick photoreceptors.

The gametophytic phase of several species of Pteris has been well studied, but for others, due perhaps to their more restricted distribution, little is known. Agar and soil cultures of different spore samples of P. incompleta were established in order to analyze developmental features of its gametophytes. Gametophyte development followed the Ceratopteris pattern, but resulted in a slightly different morphology from that of other more common species of the genus. Sex expression was variable among gametophyte populations, and was affected by culture medium. An antheridiogen system was present and promoted both male precocity and dark germination. Antheridiogen response was variable among gametophyte populations. Positive antheridiogen response in interspecific gametophyte pairings suggests a common antheridiogen system in Pteris vittata and P. incompleta.

Foliar characters were studied in 25 European, North African, North American, and South American terrestrial, amphibious, and aquatic taxa of the genus Isoetes L. (Pteridophyta, Isoetaceae). The foliar characters investigated have a variable diagnostic value. The presence and types of cuticular ornamentations, types of margins, epidermal patterns and cell ratios of the epidermis, types of IPP (intercellular pectic protuberances) in the cells of the leaf diaphragms, epidermal patterns and cell ratios of velum, epidermal patterns, and nature of walls in the adaxial epidermis of sporangia may be good diagnostic specific characters that should be included in taxonomic descriptions. Transverse sections of the microphylls, the types and distribution of collenchyma (fascicular, lacunar, or partially laminar collenchyma, with the latter two types described here for the first time), the cell types of leaf diaphragms, the presence of IPP in these cells, the partial or complete endodermis in the air chamber...

The present study aimed to better understand the role of the neonatal leptin surge, which peaks on postnatal day (PND)9–10, on the development of the hippocampal formation. Accordingly, male and female rats were administered with a pegylated leptin antagonist on PND9 and the expression of neurones, glial cells and diverse markers of synaptic plasticity was then analysed by immunohistochemistry in the hippocampal formation. Antagonism of the actions of leptin at this specific postnatal stage altered the number of glial fibrillary acidic protein positive cells, and also affected type 1 cannabinoid receptors, synaptophysin and brain-derived neurotrophic factor (BDNF), with the latter effect being sexually dimorphic. The results indicate that the physiological leptin surge occurring around PND 9–10 is critical for hippocampal formation development and that the dynamics of leptin activity might be different in males and females. The data obtained also suggest that some but not all the previously reported effects of maternal deprivation on hippocampal formation development (which markedly reduces leptin levels at PND 9–10) might be mediated by leptin deficiency in these animals.

Se presenta una lista de 32 especies de musgos pertenecientes a 15 familias: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae y Trachypodaceae, recolectados en los bosques montanos de las Yungas del NO de la Argentina (Jujuy, Salta, Catamarca y Tucumán) y en las selvas del NE del país (Misiones). Ocho especies: Atrichum polycarpum, Chryso-hypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus y Thamnobryum fasciculatum son nuevas aportaciones para la flora briológica argentina. Braunia imberbis y Squamidium brasiliense son nuevas citas para la brioflora de la provincia de Catamarca; Porotrichodendron superbum es novedad para Salta mientras que Forsstroemia coronata es primera cita para las provincias de Catamarca y Jujuy. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei y Meteoridium remotifolium son cinco nuevas citas para la brioflora de la provincia de Jujuy y Schoenobryum concavifolium es nueva para la flora briofítica de Misiones. La mayoría de las especies estudiadas son más frecuentes en las Yungas (NO argentino); otras tienen una distribución disyunta en las Yungas y en la selva Paranaense, y otras están restringidas a la selva Paranaense del NE de la Argentina. Se actualiza la taxonomía de especies y se incluyen comentarios sobre antecedentes bibliográficos, ecología y corología de cada taxón., The authors present here a list of 32 mosses belonging to 15 families: Brachytheciaceae, Cryphaeaceae, Entodontaceae, Hedwigiaceae, Hypnaceae, Leptodontaceae, Meteoriaceae, Neckeraceae, Pilotrichaceae, Polytrichaceae, Pterobryaceae, Racopilaceae, Rigodiaceae, Stereophyllaceae, and Trachypodaceae, all collected in the mountainous forests of the Yungas of the NW of the Argentina (Jujuy, Salta, Catamarca and Tucumán provinces), and also in the rainforests from the NE of the country (Misiones province). Eight species: Atrichum polycarpum, Chrysohypnum elegantulum, Pilosium chlorophyllum, Pilotrichella flexilis, Porotrichodendron lindigii, Pseudotrachypus martinicensis, Steerecleus scariosus, and Thamnobryum fasciculatum are new records for the bryologic flora from Argentina. Braunia imberbis and Squamidium brasiliense are two new records for the bryophytic flora of the Catamarca province; Porotrichodendron superbum is new for the Salta province, while Forsstroemia coronata is the first record for the Catamarca and Jujuy provinces. Aerolindigia capillacea, Braunia reflexifolia, Chryso-hypnum diminutivum, Meteorium deppei and Meteoridium remotifolium are five new citations for the Jujuy province, and Schoenobryum concavifolium is new for the bryophytic flora of the Misiones province. Many studied species occur more frequently in the Yungas than in the NE rainforests; others show separated distribution but live in both areas, the Yungas and Paranaense area, and others are more or less restricted to the Paranaense rainforest of the NE of Argentina. The taxonomy of species is updated, and comments are included on bibliographical precedents, ecology and chorology of each taxon., Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemática

Revisión de los grupos de especies del género Blechnum (Blechnaceae-Pteridophyta): el grupo B. penna-marina. Blechnum asperum, B. penna-marina, B. spicant y B. stoloniferum (grupo B. penna-marina) se estudian aquí conjuntamente con‘B. blechnoides, B. corralense, B. fernandezianum, B. lehmannii, B. microphyllum, B. mochaenum subsp. mochaenum, B. mochaenum subsp. achalense y B. mochaenum subsp. squamipes. Los esporófitos de estos taxones son pequeños a medianos, con rizomas postrados a erectos y frondas dimórficas. Los caracteres analizados fueron: tipo de rizoma, indumento de ejes y lámina, arquitectura de las frondas, todas con segmentos adnatos y estípites con tres haces vasculares, venación, morfología interna de los segmentos, tales como estructura marginal, modelos epidérmicos de la lámina, estomas, hidatodos, secciones transversales de los estípites, modelos epidérmicos de los indusios y esporas. Esos caracteres resultan‘diagnósticos para distinguir los taxones. Se encontraron protuberancias intercelulares pécticas (PIP) en forma de verrugas y filamentos cortos en el mesofilo y tejidos parenquimáticos del estípite y raquis de algunas especies. En el parénquima de los estípites se acumula a menudo almidón de granos simples, elipsoidales. Las esporas son monoletes, aclorofílicas, con esporodermo formado por un exosporio psilado y un perisporio cuya ornamentación varía en los niveles específico e infraspecífico. Tres especímenes de B. penna-marina y tres de B. mochaenum subsps. mochaenum presentaron esporas, células epidérmicas y estomas más grandes que el resto, lo que sugiere diferencias de ploidía, aunque esos ejemplares no muestran variaciones morfológicas externas o internas. Se ha cambiado el estatus de las variedades de B. mochaenum como sigue: B. mochaenum var. fernandezianum es reconocido con el rango de especie, mientras que B. mochaenum var. squamipes y B. mochaenum var. achalense son elevadas al rango de subespecie. Blechnum microphyllum se trata aquí como una especie bien caracterizada y no una subespecie de B. penna-marina. Las plantas de B. penna-marina de Argentina, Brasil y Chile varían algo en el tamaño, pero los rasgos de la morfología interna son muy constantes y no se han reconocido subespecies en el área. Se presenta una descripción completa de los taxones, se actualizan aspectos nomenclaturales, sinonimia, tipos, distribución geográfica, ecología, se da una clave para su determinación y se discute la importancia de los caracteres analizados para redefinir el grupo., Laboratorio de Estudios de Anatomía Vegetal Evolutiva y Sistemática

Isoetes anatolica sp. nov. is described from a population growing in seasonal ponds of a mountain near the southern coast of the Black Sea in Bolu, Turkey. It is a robust, amphibious quillwort, characterized by semiterete, carnose microphylls, semicircular foliar section, smooth cuticle, prominent cuticular pegs, stomata, several collenchymatous strands, abundant pectic filaments and connections in the cells of the translacunar diaphragms, incurved alae, well developed ligula, small carnose labium, no velum, well-formed bulliform megaspores and obscurely muriform microspores. Plants were investigated anatomically and a description with additional diagnostic characters is included. Morphological affinities with other species of the genus are discussed. Intercellular pectic protuberances (IPP) were studied in the cells of the translacunar diaphragms of the microphylls of several species of Isoetes including I. anatolica. The IPP were examined to determine if they could provide diagnostic characters. They were detected with TBO and analysed using light and scanning electron microscopy. Types of IPP and species bearing them were as follows: warts in I. adspersa, I. andina, I. boliviensis, I. duriei, I. engelmannii, I. lechleri, I. longissima, I. melanopoda, I. storkii, I. velata. ssp. velata, and I. velata ssp. asturicense; warts and filaments in I. brochonii, I. lacustris, and I. setacea, and connections in I. anatolica and I. malinverniana. IPP are lacking in I. boryana, I. echinospora, I. histrix and I. novogranadensis. Combination of type, density, and distribution of IPP promises to be a useful vegetative character in a genus in which diagnostic characters are scarce. © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society, 2005, 147, 213–228.

Avian cone photoreceptors have an oil droplet in the outer portion of their inner segment that acts as a long-pass cut-off filter between incident light and visual pigment. Chick cone droplets are mainly red, orange, yellow, green, and colorless, and the colors are due to three carotenoid pigments with characteristic absorption spectra. Little is known of the differentiation of this organelle, the natural marker of cones, and the little that is known is largely controversial. We used flat whole-mounts of fresh retinas to study the time and place of the appearance of droplets, their growth rates, the sequence of droplet color differentiation, and the spatial distribution of these colors. We show that droplet differentiation starts on embryonic Day 10 (E10) in a relatively small area above the optic nerve head. The differentiation spreads to the rest of the retina in a manner similar to that of photoreceptor neurogenesis, with three decreasing gradients of droplet size and color between E13-E20: from central to peripheral, dorsal to ventral, and temporal to nasal. The rate of growth of the droplets was not constant, but showed a maximum between E17 and postnatal Day 1 (P1) in most of the retinal zones. Color differentiation started at E16-E17, 5-6 days after their appearance, when the droplets were already of considerable size. Initially, all droplets were colorless, and then turned pale green or yellow to acquire progressively the mature colors. Differentiation ended in the whole retina by P15, with ventral droplets of larger diameter than dorsal ones, the peripheral ones generally larger than the central ones, and with the color distribution varying with the retinal area. Our results show that growth and color differentiation of the droplets is regulated temporally and spatially, and the cones complete differentiation at P15 rather than at prenatal stages, as is thought generally.

Gametophytes of Asplenium foreziense and related taxa have been studied by culture of spores on mineral agar and soil. Those of A. obovatum ssp. obovatum var. protobillotii and var. deltoideum, ssp. numidicum, and of A. macedonicum are described for the first time. Gametophyte development follows the Adiantum type in the A. obovatum group, and the Aspidium type in A. fontanum. Both types of development have been found in A. foreziense, depending on the sporophytic sample. The taxa with hairy gametophytes show significant differences in hair density. As in most of the homosporous ferns, antheridia are formed first and in a high proportion of gametophytes in the A. obovatum group and in A. fontanum, except for one sample; most of these male gametophytes become bisexual. In A. foreziense and A. macedonicum archegonia are formed first or at the same time as antheridia, but the proportion of female gametophytes is higher than in the other taxa; some of the gametophytes become bisexual, most of them differentiated from the female ones. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society, 2002, 139, 87‐98.