Variación morfológica y alometría de las vértebras precloacales en el ofidio daboia russelli (viperidae)

Understanding the variation of the ophidian vertebral morphology is an essential tool in snake paleobiology, but so far this field remains hardly investigated. A major problematic is the still scarce knowledge about the basis of homogeneity of intracolumnar shape variation along the vertebrae of the precloacal region in these animals. For instance, this variation can be overwhelmingly low in cases such as in vipers, for which it seems almost impossible to describe a concrete regionalization of the precloacal region without ambiguity. This study has applied geometric morphometrics to analyze if the shape variation of the vertebrae of the precloacal vertebrae of an adult specimen of Daboia russelli allows differentiating any sort of parcellation within the column of this organism. We have also explored if size is associated with the organization of vertebral shape along the axial skeleton. The multivariate analyses showed that the main pattern of vertebral shape variation in D. russelli concerns the neural spine and the hypapophysis, whereas the shape of the vertebral centrum appears to be nearly invariant along the series. Our analysis also showed that the precloacal region can be sudivided into two portions that merge in a transitional boundary of largest vertebrae in the middle of the column. From this middle region towards the distal ends of the column vertebrae become smaller changing their shapes in two antithetical waysFunds provided by the project CGL2009-11838 BTE and a FPU grant (AP2007-00904; MICINN) to I. Sarri

On the importance of examining the relationship between shape data and biologically meaningful variables. An example studying allometry with geometric morphometrics.

Geometric morphometrics (GM) is a tool for the statistical analysis of shape on Cartesian landmark coordinates. However, because GM studies commonly focus on the description of morphological trends within shape space (or morphospace), the predictive power of multivariate statistics to understand morphological change remains underutilized. Here we show the protocols to study allometry in 3D with these tools on a postnatal growth series of the domestic chicken. We contrast three approaches: a ?traditional? one in which size variables are compared statistically, a Principal Components Analysis on size and shape scores (Procrustes  form space), and a multivariate regression. In the latter  approach we further used three different independent factors  inherently related to ontogeny: skull centroid size, body weight, and age of the specimens. The results clearly stress the importance of studying shape change in relation to different causal factors (i.e., with regressions), demonstrating that, indeed, any independent variable or variables that make biological sense can be used to understand morphological change with GM.Fil: Marugán-Lobón, Jesús. Universidad Autónoma de Madrid. Facultad de Ciencias; España;Fil: Blanco-Miranda, David. Universidad Autónoma de Madrid. Facultad de Ciencias; España;Fil: Chamero Macho, Beatriz. Universidad Autónoma de Madrid. Facultad de Ciencias; España; Provincia del Chubut. Fundación Egidio Feruglio. Museo Paleontológico;Fil: Martín-Abad, Hugo. Universidad Autónoma de Madrid. Facultad de Ciencias; España

Patrones de modularidad en la evolución de arcosaurios: disparidad e integración morfológica en el post-cráneo de cocodrilos y aves

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología. Fecha de lectura: 13-01-201

Estimating the Ontogenetic Status of an Enantiornithine Bird from the Lower Barremian of El Montsec, Central Pyrenees, Spain.

An Enantiornithes specimen from El Montsec was initially described as an immature individual based upon qualitative traits such as its relatively large orbit and overall proportions of the skull and the postcranium. In this study we re-evaluate the precise determination of the ontogenetic stage of this individual, establishing a cross-talk among taphonomic, anatomic, and morphometric data. The exceptional preservation of the specimen has allowed pondering ontogenetic influence versus preservational bias in features like the external patterns of bone surfaces, instead of being aprioristically considered due to taphonomic alterations only. The rough texture of the periosteal bone associated with pores in the distal, proximal and mid-shaft areas of the humeral shaft, indicates a subadult stage when compared with long bones of modern birds. Forelimb proportions of embryo and juvenile Enanthiornithes are equivalent to those of adult individuals of other taxa within this clade, though this is not a reliable criterion for establishing a precise ontogenetic stage. The El Montsec specimen may be attributed a close adulthood, yet only if growth regimes in Enantiornithes are considered equivalent to those in Neornithes birds

Tecnologías y diseño de laboratorio: un proyecto para potenciar el posgrado y la investigación biomédica

La adecuada conducción de la ciencia, la innovación y la tecnología en salud favorece la generación de resultados científico-técnicos de impacto en la calidad universitaria y asistencial. En el laboratorio de investigaciones biomédicas de la universidad de ciencias médicas objeto de aplicación, existen tecnologías no aprovechadas y baja funcionalidad del espacio físico en que deben desarrollarse la docencia y la investigación, por lo que se propone como objetivo: rediseñar tecnológica y espacialmente esta instalación, a partir de un proyecto de mejora. Materiales y métodos: se emplearon técnicas y herramientas como marco lógico, cuestionarios, tormenta de ideas, revisión de documentos, observación directa, diagrama Gantt y método triangular. Resultados: el plan de medidas está asociado a la promoción de una oferta tecnológica para impulsar proyectos de investigación e innovación, la reorganización de equipos y espacios, la coordinación de acciones de mantenimiento y verificación de equipos y la superación del personal de trabajo. Conclusiones: una mejor gestión de la tecnología en el área junto a una infraestructura física orgánica, funcional y segura, constituyen un componente estratégico para la investigación y la formación posgraduada

Red and green aequorins for simultaneous monitoring of Ca2+ signals from two different organelles

International audienceSimultaneous control of different functions by calcium signals is possible because of subcellular compartmentalization. Targeted chemiluminescent Ca2+ probes, such as aequorins (AEQs) are optimal for detecting signals originating in different subcellular domains, but imaging is difficult because of low photon yield causing poor spatiotemporal resolution. To overcome this problem, we have co-expressed two spectrally distinct AEQs in different subcellular locations within the same cells. Seven chimeric proteins containing either green- or red-emitting AEQs, with different targeting sequences and Ca2+ affinities, have been designed and tested. We show here evidence for physical and functional independence of the different probes. Cytosolic Ca2+ signals were mirrored in the nucleus, but amplified inside mitochondria and endoplasmic reticulum, and had different time courses in the various locations. Our results demonstrate that these novel tools permit simultaneous and independent monitoring of [Ca2+] in different subcellular domains of the same cell

Estimating the Ontogenetic Status of an Enantiornithine Bird from the Lower Barremian of El Montsec, Central Pyrenees, Spain.

An Enantiornithes specimen from El Montsec was initially described as an immature individual based upon qualitative traits such as its relatively large orbit and overall proportions of the skull and the postcranium. In this study we re-evaluate the precise determination of the ontogenetic stage of this individual, establishing a cross-talk among taphonomic, anatomic, and morphometric data. The exceptional preservation of the specimen has allowed pondering ontogenetic influence versus preservational bias in features like the external patterns of bone surfaces, instead of being aprioristically considered due to taphonomic alterations only. The rough texture of the periosteal bone associated with pores in the distal, proximal and mid-shaft areas of the humeral shaft, indicates a subadult stage when compared with long bones of modern birds. Forelimb proportions of embryo and juvenile Enanthiornithes are equivalent to those of adult individuals of other taxa within this clade, though this is not a reliable criterion for establishing a precise ontogenetic stage. The El Montsec specimen may be attributed a close adulthood, yet only if growth regimes in Enantiornithes are considered equivalent to those in Neornithes birds

Taphonomy and palaeoecology in the upper Barremian of the SW Iberian chain (Spain): A model to compare taxonomy and diversity of biotas from different coeval basins

A detailed study of the floral and faunal diversity of an upper Barremian lentic ecosystem was performed by examining 50,000 microfossils. The study provides an assemblage of 41 species of charophytes, spermatophytes, ostracods, molluscs, and vertebrates (including eggshells). The main goal of this study is to reconstruct the palaeoecology of a fluvio-lacustrine and associated carbonate depositional system, by integrating the sedimentology, taphonomy, and diversity from twelve horizons cropping out in the Buenache de la Sierra and the Las Hoyas basins. The studied area corresponds to the lowermost succession of the Tragacete Formation (Serrania de Cuenca, Iberian chain). Four facies associations (polymictic alluvial; carbonate palustrine and lacustrine; eutrophic lacustrine; and calcarenitic drainage facies) were correlated to the composition of the fossil assemblages, which have yielded a set of taphofacies confirmed by the non-metric multidimensional scaling ordination test of all the horizons. The taphofacies are: (alpha) dominated by bones and plant leaves, (beta) by charophytes-ostracods-bivalves and eggshells, and (gamma) by coal-leaves and bones. The Tragacete depositional system consists of demic and mostly autochthonous (non-catastrophic) fossil associations. A mixture of aquatic and terrestrial plants, freshwater molluscs and ostracods coupled with aquatic and terrestrial vertebrate species fosters a biodiversity typical of depositional environments that are congruent with modern floodplain wetland systems. These floodplain wetlands are characterised by a combination of periodically inundated ponds, small lakes, and floodplain areas with terrestrial habitats. As such, they provide suitable environments for the diversification and colonisation of charophytes, ostracods, gastropods, fish, and an ample herpetofauna. The abundance and diversity of eggshells also suggest the development of nesting areas, whereas the occurrence of charred cheirolepidiacean conifer would indicate intermittent wild fires linked to drought events. The taxonomic breadth of this ecosystem is characterised by the taxonomic distinctness index, which, in turn, becomes a referential model to which other Lower Cretaceous microfossil sites may be compared

Pectoral girdle and forelimb variation in extant Crocodylia: the coracoid–humerus pair as an evolutionary module

To date, all statements about evolutionary morphological transformation in Crocodylia have essentially been based on qualitative observations. In the present study, we assessed the morphological variation and covariation (integration) between the scapula, coracoid, humerus, radius, and ulna of 15 species of Crocodylidae, Alligatoridae, and Gavialis + Tomistoma using three-dimensional geometric morphometrics. The results obtained reveal that the variation of elements within species (intraspecific) is large. However, despite this variability, variation across species (interspecific) is mainly concentrated in two dimensions where the disparity is constrained: ‘robusticity’ and ‘twist’ (forelimbs) and ‘robusticity’ and ‘flexion’ (pectoral girdle). Robusticity (first dimension of variation) embodies a set of correlated geometrical features such as the broadening of the girdle heads and blades, or the enlargement of proximal and distal bone ends. The twist is related to the proximal and/or distal epiphyses in the forelimb elements, and flexion of the scapula and coracoid blades comprises the second dimension of variation. In all crocodylians, forelimb integration is characterized by the strong correlations of a humerus–ulna–radius triad and by a radius–ulna pair, thus forming a tight forelimb module. Unexpectedly, we found that the humerus and coracoid form the most integrated pair, whereas the scapula is a more variable and relatively independent element. The integration pattern of the humerus–coracoid pair distinguishes a relatively robust configuration in alligatorids from that of the remainder groups. The patterns of variation and integration shared by all the analyzed species have been interpreted as an inherited factor, suggesting that developmental and functional requirements would have interacted in the acquisition of a semi-aquatic and versatile locomotion at the Crocodylia node at least 65 Mya. Our findings highlight the need to incorporate the humerus–coracoid pair in biodynamic and biomechanical studies.Fil: Chamero Macho, Beatriz. Universidad Autónoma de Madrid. Facultad de Ciencias; España. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marugán Lobón, Jesús. Universidad Autónoma de Madrid. Facultad de Ciencias; EspañaFil: Buscalioni, Ángela D.. Universidad Autónoma de Madrid. Facultad de Ciencias; Españ