Instituto de Botanica Darwinion

Glucose transporter type 1 deficiency syndrome (Glut1DS) is a rare metabolic encephalopathy caused by pathogenic SLC2A1 variants. Ketogenic dietary therapy (KDT) is the mainstay of treatment. In Latin America, Glut1DS remains underdiagnosed due to limited awareness and restricted access to genetic testing. This study describes the clinical and genetic features, management, and response to KDT in an Argentine cohort. A retrospective multicenter study was conducted including patients with a clinical and/or genetic diagnosis of Glut1DS. Clinical data, seizure types, neurodevelopmental features, treatment response, and KDT characteristics were collected from medical records using a standardized form. Genetic confirmation was obtained by SLC2A1 sequencing. Descriptive and comparative analyses were performed. Thirty-nine patients with Glut1DS (64% males) were included. Mean age at evaluation was 13.7 years. Median ages at symptom onset and diagnosis were 6 and 55 months, respectively, with a median diagnostic delay of 49 months. Cognitive impairment was present in two-thirds of patients, and movement disorders in 79%. Epilepsy occurred in 74%. Of 39 patients, all but one received KDT, with MCT oil in 64%. Thirty patients remained on KDT, achieving seizure freedom in 86% and >50% reduction in four others. Improvements were reported in motor coordination (38%), cognition and attention (10%), energy (10%), and behavior (8%). No major adverse effects were reported. This first national report underscores the clinical diversity of Glut1DS in Argentina and a positive trend toward earlier KDT initiation. Strengthening early diagnosis, systematic follow-up, and equitable access to therapy remains essential.

Empowerment can be thought of as a gain of power and autonomy by an unfavored group, which creates a better situation. Women in Science (WIS) face multiple barriers that ultimately affect their performance. There is an urgent need to reverse the inequalities and disadvantages that WIS face. With this aim, in May 2023, 17 WIS gathered in person for four days in a workshop entitled Empowering Women in Science. As an outcome of the workshop, we cooperatively started to draw up a list of empowerment recommendations. We continued working together for more than a year to improve this list, which we now present as the Good Practice Guide for Empowering Women in Science (GPG). The GPG contains recommendations across the individual, collective and system levels that we believe help address inequalities for WIS. The aim of this debate is twofold: a) to present the GPG and b) to use the GPG to self-evaluate the number of actions we, the authors, undertook before and after participating in the workshop. Results show that one year after ending the workshop, we doubled the number of actions performed across all categories assessed: I) identify, confront and make visible systemic barriers; II) self-promotion; III) promote other women, and IV) foster diversity, equity and inclusion. This suggests that empowerment can be fostered through formal training programs and discussion spaces. We hope that the GPG will inspire WIS across disciplines and backgrounds to: A) act towards empowerment (at the individual, collective and system level); B) embrace the notion that each of us can be part of the change that we want to see happening towards higher equity for WIS, and C) recognize that any action is better than inaction. Finally, the GPG provides a framework that will continue to be improved and expanded with the feedback of readers and users.

Abstract Barnadesioideae, consisting of 87 species distributed in mesic and xeric regions of South America, are the sister group of the remaining Asteraceae. Molecular phylogenetic hypotheses have revealed a consistent topology of relationships among the 10 currently recognized genera. Schlechtendalia is sister to two clades: (i) Dasyphyllum, Barnadesia, Huarpea, Archidasyphyllum, Arnaldoa, and Fulcaldea, and (ii) Chuquiraga, Doniophyton, and Duseniella. Chuquiraga consists of 22 species that are divided into two monophyletic sections, sect. Chuquiraga and sect. Acanthophylla. The former includes 13 species adapted to the Andean zone ranging from Chile and Argentina to Colombia. Sect. Acanthophylla encompasses nine species distributed primarily in arid zones in the southern Andes (Chile, SW Bolivia, and Argentina) and down into the Monte and Patagonia of Argentina. Doniophyton has two species with D. weddellii restricted to dry, higher elevations of the southern Andes between Chile and Argentina, and D. anomalum confined to the Monte and Patagonia, where the monospecific Duseniella (D. patagonica) is also located. Southern Andean and Patagonian taxa have morphological and anatomical adaptations for survival in arid environments. Chuquiraga sect. Acanthophylla has adapted by maintaining a shrubby habit with acicular leaves, whereas Doniophyton, although consisting of annual species, also has narrow, drought-resistant leaves. Duseniella patagonica is the most morphologically divergent species within the group, being annual and succulent, and the only succulent species within Barnadesioideae. Duseniella is distributed in arid and saline habitats in playas with seasonal rainfall. The leaves are succulent, amphistomatic, oriented vertically, with both surfaces sparsely pubescent or glabrous. The mesophyll is isobilateral with two or perhaps three palisade layers. Spongy mesophyll consists of large aquiferous cells that contain chloroplasts and have wavy contours. The vascular bundles are numerous from the base of the leaf, coalescing in a reticulate pattern at the apex. To meet the challenges of survival in environments of extreme water stress, it is proposed that, based on morphological and anatomical data, Duseniella may have a flexible C3/crassulacean acid metabolism (CAM) photosynthetic system, being C3 during its rapid growth during the spring rains followed by a transition to CAM in the extremely parched summer months.

Differential domains of activity of MIR394A and MIR394B gene promoters together with transcriptomic analysis of mutant plants, indicate that miR394 participates in the fine tuning of Arabidopsis flower development through regulation of transcription factors and chromatin remodeling factors. The initiation of flowering is a highly coordinated process that requires synchronization of endogenous plant developmental program with environmental signals through a complex interplay of genetic regulatory networks. We had previously demonstrated a role for miR394 in the regulation of flowering time, since mir394a mir394b plants harboring insertional mutations in the two MIR394 Arabidopsis genes exhibited an early flowering phenotype correlated with modified expression of flowering genes. In the present study we provide transcriptomic RNA-seq data and histologic staining of reporter lines to give further insight into the role of miR394 in the regulation of flowering in Arabidopsis thaliana and present an initial bioinformatic characterization of a newly identified lncRNA, which partially overlaps the MIR394B locus, and therefore we named MIR394B-ASSOCIATED TRANSCRIPT (MIRAST). We found that MIRAST expression is generally low and does not differ significantly between Col-0 and mir394a mir394b mutant plants, allowing for the transcriptomic analysis to focus specifically on the role of miR394 in Arabidopsis flowering. We identified 2405 differentially expressed genes, including 13 transcription factors involved in flower organ development and 7 chromatin remodeling factors. Histologic staining of reporter lines further demonstrated distinct domains of expression for MIR394A and MIR394B genes during flower development. Taken together, our results support a role for miR394 in the fine tuning of Arabidopsis flower development, likely through the regulation of key transcriptional and chromatin remodeling regulators.

Introducción: El uso de superficies rugosas para la fijación biológica en implantes es una alternativa que se está usando cada vez con más frecuencia. El objetivo del estudio fue determinar la rugosidad óptima de un implante endomedular que permita la osteointegración y la consecuente fijación biológica, mediante la proyección térmica por arco utilizando fémures de conejos como modelo biológico receptor. Materiales y Métodos: Se implantaron sistemas endomedulares cilíndricos con recubrimiento rugoso de titanio y distinto rango de rugosidad en fémures de seis conejos (unilaterales) para determinar dónde se produce una mayor osteointegración. El proceso de osteointegración se evaluó con radiografías mensuales y estudios de anatomía patológica del fémur del espécimen. Resultados: No se produjo migración o subsidencia en ninguno de los implantes. Todos los fémures mostraron signos de osteointegración radiográfica. Se demostró la presencia de neoformación ósea establecida alrededor de todos los implantes. Sin embargo, no se pudo realizar un testeo mecánico para evaluar la fuerza de adhesión al hueso. Conclusión: Las superficies con rugosidades >100 µm proporcionan una respuesta biológica favorable con una unión directa entre la superficie de los implantes y el hueso.

La posición taxonómica de varias especies anuales de la sección Alpinae, afines a O. laxa, ha sido controvertida en recientes publicaciones sobre el género Oxalis. Es así que diversos taxones han sido considerados en la sinonimia de O. laxa o bien eventualmente tratados como válidos o al nivel varietal. En esta contribución se considera correcto incluir a O. micrantha, y otros taxones bajo el concepto de O. laxa, mientras que se concluye que O. campanensis, O. cumingii y O. rigida son especies claramente diferentes de la primera; a la vez se incluyen bajo el concepto de O. laxa a dos variedades de la especie. Los cuatro taxones reconocidos se reconocen e ilustran y se proponen lectotipos para los siguientes nombres: O. dichotomiflora, O. laxa var. minor, O. platycaulis, O. puberula y O. torcana.

Pycnophyllum macropetalum Matff. es una especie originalmente descrita para los Andes de Chile, que además se la ha coleccionado en Bolivia y ha sido citada para la Argentina sobre la base de un único ejemplar estéril coleccionado en 1945. Debido a esto, y al ser morfológicamente afín a P. molle, la especie fue excluida de la flora argentina; sin embargo, recientemente se ha localizado una población de P. macropetalum en la provincia de Jujuy (Argentina). Por este motivo, el objetivo de este trabajo es describir e ilustrar a dicha especie, proporcionar notas ambientales acerca del hábitat en donde se la encontró y proveer un mapa de distribución geográfica de la especie para la Argentina, Bolivia y Chile. Además, sobre la base de análisis moleculares del ejemplar coleccionado se corrobora la identificación morfológica y se confirma la monofilia del género. Por último, se proporciona una clave dicotómica para diferenciar las cuatro especies de Pycnophyllum registradas hasta el momento para la Argentina.

Premise of research. The southern conifer family Podocarpaceae inhabits wet environments and is highly diverse in its vegetative and megasporangiate structures. The Podocarpaceae are today divided into a tropical clade and a prumnopityoid clade. We study the morphology and anatomy of leaves and megasporangiate cones at postpollination and the maturity of two native Patagonian Podocarpaceae, Saxegothaea conspicua (tropical clade) and Lepidothamnus fonkii (prumnopityoid clade). We aim to add to the knowledge of the South American Podocarpaceae and to interpret their unique morphologies to aid in our understanding of the deep and cryptic fossil record of the family and its relationships with other conifer families.Methodology. Specimens of S. conspicua and L. fonkii were collected in natural and cultivated populations of southern Chile and imaged using different macro- and microscopic techniques, including epifluorescence, bright-field, and scanning electron microscopy.Pivotal results. Leaf and megasporangiate cone anatomy and morphology are described in detail for both species. For S. conspicua, we observed a helical to slightly planate leaf arrangement with leaf reorientation, expanded leaves without accessory transfusion tissue, an apparent lack of vascularization of the epimatium (which is bikeeled and does not surround the ovule completely), and nonsaccate pollen germinating on the bract toward the protruding nucellus. For L. fonkii, we observed the absence of leaf hypodermis and resin canals, the presence of a micropylar hook in the ovule and seed integument, bisaccate pollen germinating within the ovule, cone bracts reduced in number and size, and a basal receptacle-like structure.Conclusions. Leaf arrangement in Saxegothaea shows an intermediate condition between the primary helical phyllotaxis common in the family and the secondary planate arrangement seen in most podocarps with expanded leaves. Lepidothamnus fonkii was determined to have a false receptacle (i.e., a receptacle-like structure originated from vegetative basal bracts rather than by sterile ovuliferous complexes). The presence of a false receptacle in L. fonkii is a morphological novelty in Podocarpaceae.