Positive selection in Europeans and East-Asians at the ABCA12 gene

Natural selection acts on genetic variants by increasing the frequency of alleles responsible for a cellular function that is favorable in a certain environment. In a previous genome-wide scan for positive selection in contemporary humans, we identified a signal of positive selection in European and Asians at the genetic variant rs10180970. The variant is located in the second intron of the ABCA12 gene, which is implicated in the lipid barrier formation and down-regulated by UVB radiation. We studied the signal of selection in the genomic region surrounding rs10180970 in a larger dataset that includes DNA sequences from ancient samples. We also investigated the functional consequences of gene expression of the alleles of rs10180970 and another genetic variant in its proximity in healthy volunteers exposed to similar UV radiation. We confirmed the selection signal and refine its location that extends over 35 kb and includes the first intron, the first two exons and the transcription starting site of ABCA12. We found no obvious effect of rs10180970 alleles on ABCA12 gene expression. We reconstructed the trajectory of the T allele over the last 80,000 years to discover that it was specific to H. sapiens and present in non-Africans 45,000 years ago

Turismo y religión. El caso de los miembros de La Iglesia de Jesucristo de los Santos de los Últimos Días y sus desplazamientos por motivos religiosos

El presente trabajo se centra en el estudio de los desplazamientos por motivos religiosos y su relación con el turismo. Se realiza una revisión bibliográfica y conceptual centrada en las cuestiones de religión, peregrinación y la relación de éstas con la actividad turística. Se estudian las características de atractividad de algunos de los principales destinos religiosos a nivel mundial. Se selecciona como estudio de caso a la Iglesia de Jesucristo de los Santos de los Últimos Días, investigando los tipos de desplazamientos por motivos religiosos que realizan sus miembros y los sitios visitados por ellos con una motivación religiosa. Por último, se concluye el documento intentando generar una contribución teórica al tema de los desplazamientos humanos por motivos religiosos, a partir del análisis de diferentes fuentes secundarias y experiencias personales del autor.Fil: Valente Sticco, Ezequiel L. Universidad Nacional de Mar del Plata. Facultad de Ciencias Económicas y Sociales; Argentina

Purification and characterization of a viral chitinase active against plant pathogens and herbivores from transgenic tobacco.

The Autographa californica nucleopolyhedrovirus chitinase A (AcMNPV ChiA) is a chitinolytic enzyme with fungicidal and insecticidal properties. Its expression in transgenic plants enhances resistance against pests and fungal pathogens. We exploited tobacco for the production of a biologically active recombinant AcMNPV ChiA (rChiA), as such species is an alternative to traditional biological systems for large-scale enzyme production. The protein was purified from leaves using ammonium sulfate precipitation followed by anion exchange and gel-filtration chromatography. Transgenic plants produced an estimated 14mgkg−1 fresh leaf weight, which represents 0.2% of total soluble proteins. The yield of the purification was about 14% (2mgkg−1 fresh leaf weight). The comparison between the biochemical and kinetic properties of the rChiA with those of a commercial Serratia marcescens chitinase A indicated that the rChiA was thermostable and more resistant at basic pH, two positive features for agricultural and industrial applications. Finally, we showed that the purified rChiA enhanced the permeability of the peritrophic membrane of larvae of two Lepidoptera (Bombyx mori and Heliothis virescens) and inhibited spore germination and growth of the phytopatogenic fungus Alternaria alternata. The data indicated that tobacco represents a suitable platform for the production of rChiA, an enzyme with interesting features for future applications as “eco-friendly” control agent in agriculture

Purification and characterization of a viral chitinase active against plant pathogens and herbivores from transgenic tobacco

The Autographa californica nucleopolyhedrovirus chitinase A (AcMNPV ChiA) is a chitinolytic enzyme with fungicidal and insecticidal properties. Its expression in transgenic plants enhances resistance against pests and fungal pathogens. We exploited tobacco for the production of a biologically active recombinant AcMNPV ChiA (rChiA), as such species is an alternative to traditional biological systems for large-scale enzyme production. The protein was purified from leaves using ammonium sulfate precipitation followed by anion exchange and gel-filtration chromatography. Transgenic plants produced an estimated 14mgkg-1 fresh leaf weight, which represents 0.2% of total soluble proteins. The yield of the purification was about 14% (2mgkg-1 fresh leaf weight). The comparison between the biochemical and kinetic properties of the rChiA with those of a commercial Serratia marcescens chitinase A indicated that the rChiA was thermostable and more resistant at basic pH, two positive features for agricultural and industrial applications. Finally, we showed that the purified rChiA enhanced the permeability of the peritrophic membrane of larvae of two Lepidoptera (Bombyx mori and Heliothis virescens) and inhibited spore germination and growth of the phytopatogenic fungus Alternaria alternata. The data indicated that tobacco represents a suitable platform for the production of rChiA, an enzyme with interesting features for future applications as eco-friendly control agent in agriculture. © 2010

A non-invasive, improved RIA and overt observation in the study of singleton Apennines wolf (Canis lupus) reproductive behaviour

Abstract. The analysis of fecal hormones allows a close but non-invasive monitoring of animals avoiding the stress of restraint/capture, which in turn can upset animals’ hormonal profile. Steroid hormone progesterone was analysed in three singleton, female grey wolves of different age, belonging to the endangered species of the Apennines’ Canis lupus. The analysis was carried out during the breeding season by using an improved radioimmunoassay on samples collected on the field. To reduce the stress to animals and danger to people, the overt observations were carried out by operators who were already familiar with the animals, saving the money of a camera-monitoring-system. Concurrently, a male and a female gray wolves housed together were monitored as a control. The results indicated the importance of dehydration of fecal samples before the extraction with petroleum ether, which was shown to be more efficient than diethyl ether, and that pre-treatment with methanol greatly enhances extraction (p<0.01). Females of Apennines’ grey wolf showed the first sign of oestrus by a vaginal blood loss, that was easily detected on the ground; the analysis carried out on fecal samples revealed a rapidly declining luteal phase, with P4 metabolites reaching the basal values of a non-cyclic female. In the matter of welfare, behavioural observations on Apennines’ grey wolf showed that unpaired animals, although familiar with the operators, failed to display a sexual social behavior during the reproductive season, that is the behavioural signs were hidden in overt observational situation. [...

Functional architecture of pancreatic islets identifies a population of first responder cells that drive the first-phase calcium response

Insulin-secreting β-cells are functionally heterogeneous. Whether there exist cells driving the first-phase calcium response in individual islets, has not been examined. We examine “first responder” cells, defined by the earliest [Ca2+] response during first-phase [Ca2+] elevation, distinct from previously identified “hub” and “leader” cells. We used islets isolated from Mip-CreER; Rosa-Stop-Lox-Stop-GCamP6s mice (β-GCamP6s) that show β-cell-specific GCamP6s expression following tamoxifen-induced CreER-mediated recombination. First responder cells showed characteristics of high membrane excitability and lower electrical coupling to their neighbors. The first-phase response time of β-cells in the islet was spatially organized, dependent on the cell’s distance to the first responder cell, and consistent over time up to approximately 24 h. When first responder cells were laser ablated, the first-phase [Ca2+] was slowed down, diminished, and discoordinated compared to random cell ablation. Cells that were next earliest to respond often took over the role of the first responder upon ablation. In summary, we discover and characterize a distinct first responder β-cell state, critical for the islet first-phase response to glucose

Functional architecture of pancreatic islets identifies a population of first responder cells that drive the first-phase calcium response

Insulin-secreting β-cells are functionally heterogeneous. Whether there exist cells driving the first-phase calcium response in individual islets, has not been examined. We examine “first responder” cells, defined by the earliest [Ca2+] response during first-phase [Ca2+] elevation, distinct from previously identified “hub” and “leader” cells. We used islets isolated from Mip-CreER; Rosa-Stop-Lox-Stop-GCamP6s mice (β-GCamP6s) that show β-cell-specific GCamP6s expression following tamoxifen-induced CreER-mediated recombination. First responder cells showed characteristics of high membrane excitability and lower electrical coupling to their neighbors. The first-phase response time of β-cells in the islet was spatially organized, dependent on the cell’s distance to the first responder cell, and consistent over time up to approximately 24 h. When first responder cells were laser ablated, the first-phase [Ca2+] was slowed down, diminished, and discoordinated compared to random cell ablation. Cells that were next earliest to respond often took over the role of the first responder upon ablation. In summary, we discover and characterize a distinct first responder β-cell state, critical for the islet first-phase response to glucose

C1QL3 promotes cell‐cell adhesion by mediating complex formation between ADGRB3/BAI3 and neuronal pentraxins

Synapses are the fundamental structural unit by which neurons communicate. An orchestra of proteins regulates diverse synaptic functions, including synapse formation, maintenance, and elimination-synapse homeostasis. Some proteins of the larger C1q super-family are synaptic organizers involved in crucial neuronal processes in various brain regions. C1Q-like (C1QL) proteins bind to the adhesion G protein-coupled receptor B3 (ADGRB3) and act at synapses in a subset of circuits. To investigate the hypothesis that the secreted C1QL proteins mediate tripartite trans-synaptic adhesion complexes, we conducted an in vivo interactome study and identified new binding candidates. We demonstrate that C1QL3 mediates a novel cell-cell adhesion complex involving ADGRB3 and two neuronal pentraxins, NPTX1 and NPTXR. Analysis of single-cell RNA-Seq data from the cerebral cortex shows that C1ql3, Nptx1, and Nptxr are highly co-expressed in the same excitatory neurons. Thus, our results suggest the possibility that in vivo the three co-expressed proteins are presynaptically secreted and form a complex capable of binding to postsynaptically localized ADGRB3, thereby creating a novel trans-synaptic adhesion complex. Identifying new binding partners for C1QL proteins and deciphering their underlying molecular principles will accelerate our understanding of their role in synapse organization