Genomic signatures of drift and selection driven by predation and human pressure in an insular lizard

Genomic divergence was studied in 10 small insular populations of the endangered Balearic Islands lizard (Podarcis lilfordi) using double digest restriction-site associated DNA sequencing. The objectives were to establish levels of divergence among populations, investigate the impact of population size on genetic variability and to evaluate the role of different environmental factors on local adaptation. Analyses of 72,846 SNPs supported a highly differentiated genetic structure, being the populations with the lowest population size (Porros, Foradada and Esclatasang islets) the most divergent, indicative of greater genetic drift. Outlier tests identified ~ 2% of loci as candidates for selection. Genomic divergence-Enviroment Association analyses were performed using redundancy analyses based on SNPs putatively under selection, detecting predation and human pressure as the environmental variables with the greatest explanatory power. Geographical distributions of populations and environmental factors appear to be fundamental drivers of divergence. These results support the combined role of genetic drift and divergent selection in shaping the genetic structure of these endemic island lizard populations

Caracterización geoquímica preliminar de los metatasedimentos ordovicicos del sinforme de Alcanices (Zamora)

The geochemistry of the Ordovician metasediments and associated Fe sedimentary mineralizations of the South limb of the Alcañices Synform suggest a siliceous nature for the Cabeza de las Viñas (pre-Arenigian) and Pielgo Quartzite (Arenigian) Formations as compared with the essentially aluminic character of the Latedo (Llanvirnian-Llandeilian) Formation and a sediment essentially formed of Fe oxyhydroxides, quartz and clay minerals as precursors of the Fe mineralizations.La caracterización geoquímica de los metasedimentos ordovícicos y mineralizaciones sedimentarias de Fe asociadas del flanco S del Sinforme de Alcañices permite establecer que, las formaciones Cabeza de las Viñas (infra-Arenig) y Cuarcitas del Pielgo (Arenig) son de naturaleza silícea frente a la esencialmente alumínica de la Fm. Latedo (Llanvirn-Llandeilo) y, un sedimento constituido esencialmente por oxi-hidróxidos de Fe, cuarzo y minerales arcillosos como precursor de las mineralizaciones de Fe

Escape distance and escape latency following simulated rapid bird attacks in an Andean lizard, Phymaturus williamsi

Predatory birds represent the greatest risk for many lizard species. However, little is known about the functional relationship between the escape distance and escape latency of lizards during a rapid bird attack. We hypothesised that escape latency and distance in the Andean lizard species Phymaturus williamsi would increase proportionally, but vary according to the means of escape. Over a three-year period we observed seven types of antipredatory behaviour in 98% P. williamsi lizards on simulated predatory bird attacks. Escape distance and latency were positively correlated. 65% of lizards emerged from their refuge within 2 min of an attack. All of these behaviours were positively correlated with escape latency and distance, although we found the former to be more precise. This study contributes to a better understanding of the general antipredatory behaviour in this species of Andean lizard, and will assist in future decisions concerning its conservation.Fil: Fava, Gustavo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Acosta, Juan Carlos. Universidad Nacional de San Juan. Facultad de Ciencias Exactas, Físicas y Naturales; Argentin

The first transcriptome of Italian wall lizard, a new tool to infer about the Island Syndrome

Some insular lizards show a high degree of differentiation from their conspecific mainland populations, like Licosa island lizards, which are described as affected by Reversed Island Syndrome (RIS). In previous works, we demonstrated that some traits of RIS, as melanization, depend on a differential expression of gene encoding melanocortin receptors. To better understand the basis of syndrome, and providing raw data for future investigations, we generate the first de novo transcriptome of the Italian wall lizard. Comparing mainland and island transcriptomes, we link differences in life-traits to differential gene expression. Our results, taking together testis and brain sequences, generated 275,310 and 269,885 transcripts, 18,434 and 21,606 proteins in Gene Ontology annotation, for mainland and island respectively. Variant calling analysis identified about the same number of SNPs in island and mainland population. Instead, through a differential gene expression analysis we found some putative genes involved in syndrome more expressed in insular samples like Major Histocompatibility Complex class I, Immunoglobulins, Melanocortin 4 receptor, Neuropeptide Y and Proliferating Cell Nuclear Antigen

Search for new phenomena in monophoton final states in proton-proton collisions at root s=8 TeV

Peer reviewe

Diet of the Insular Lizard, Podarcis lilfordi (Günther, 1874): Complementary Morphological and Molecular Approaches

[EN] The diets of insular lizards are extremely varied, depending on the different environmental characteristics of each island population. This is particularly evident in the case of the populations of small coastal islets of the Balearic Islands, where the Balearic lizard, Podarcis lilfordi, is found. The study of trophic ecology carried out by means of traditional tools, such as morphological analysis of feces, has made it possible to detect numerous prey and nutritional elements. However, these methods are clearly insufficient, as some rare groups are not detected. It is also difficult to identify remains of marine subsidies or of foods contributed to these small islands by other predators, such as seabirds. The current study demonstrates the advantages of combining morphological diet analysis with the molecular study of individual feces samples obtained from the same populations. We obtained a greater diversity of prey groups using the combined methodologies, with each method identifying prey items that were not detected using the other method. Particularly, the study of diets at the molecular level identified plant species consumed by lizards that were, occasionally, not identified in morphological analyses. Conversely, the traditional morphological study of an equivalent number of fecal samples allowed for the identification of several prey groups that had not been detected in the molecular study. From this viewpoint, the advantages and disadvantages of each methodology are discussed.Ministerio de Economía y Competitividad; Conselleria d'Educació, Cultura i Universitats (Govern de les Illes Balears); Fondo Europeo de Desarrollo Regional (FEDER

Faecal Microbiota Divergence in Allopatric Populations of Podarcis lilfordi and P. pityusensis, Two Lizard Species Endemic to the Balearic Islands

[EN] Gut microbial communities provide essential functions to their hosts and are known to influence both their ecology and evolution. However, our knowledge of these complex associations is still very limited in reptiles. Here we report the 16S rRNA gene faecal microbiota profiles of two lizard species endemic to the Balearic archipelago (Podarcis lilfordi and P. pityusensis), encompassing their allopatric range of distribution through a noninvasive sampling, as an alternative to previous studies that implied killing specimens of these IUCN endangered and near-threatened species, respectively. Both lizard species showed a faecal microbiome composition consistent with their omnivorous trophic ecology, with a high representation of cellulolytic bacteria taxa. We also identified species-specific core microbiota signatures and retrieved lizard species, islet ascription, and seasonality as the main factors in explaining bacterial community composition. The different Balearic Podarcis populations are characterised by harbouring a high proportion of unique bacterial taxa, thus reinforcing their view as unique and divergent evolutionary entities.Ministerio de Economía y Competitividad; FEDER; Conselleria d'Educació, Cultura i Universitat

Mineralogical study of the silurían variscites and turquoises of Punta Corveiro (Pontevedra, Spain)

In this paper we resume the geological and essential mineralogical characteristics of the phosphated mineralization found in the Silurian of W sector in the Pontevedra province, in "Punta Corveiro", south of La Lanzada beach. The mineralization appears in centimetric fractures in a level of black quartzites, shales and lidites, and consists of variscile, turquoise and occasionally crandallite and quartz. The mineralogical and chemical characteristics of these minerals have been determined by polarized microscope, X-ray diffraction (XRD) and electron microprobe (EDAX

Diet of the Insular Lizard, Podarcis lilfordi (Günther, 1874): Complementary Morphological and Molecular Approaches

The diets of insular lizards are extremely varied, depending on the different environmental characteristics of each island population. This is particularly evident in the case of the populations of small coastal islets of the Balearic Islands, where the Balearic lizard, Podarcis lilfordi, is found. The study of trophic ecology carried out by means of traditional tools, such as morphological analysis of feces, has made it possible to detect numerous prey and nutritional elements. However, these methods are clearly insufficient, as some rare groups are not detected. It is also difficult to identify remains of marine subsidies or of foods contributed to these small islands by other predators, such as seabirds. The current study demonstrates the advantages of combining morphological diet analysis with the molecular study of individual feces samples obtained from the same populations. We obtained a greater diversity of prey groups using the combined methodologies, with each method identifying prey items that were not detected using the other method. Particularly, the study of diets at the molecular level identified plant species consumed by lizards that were, occasionally, not identified in morphological analyses. Conversely, the traditional morphological study of an equivalent number of fecal samples allowed for the identification of several prey groups that had not been detected in the molecular study. From this viewpoint, the advantages and disadvantages of each methodology are discussed