The insertion/deletion in the DNA-binding region allows the discrimination and subsequent identification of the glucocorticoid receptor 1 (gr1) and gr2 nucleotide sequences in gilthead sea bream (Sparus aurata): Standardizing the gr nomenclature for a better understanding of the stress response in teleost fish species

Cortisol carries out its physiological mechanism of action through the recognition by the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR) 1 (GR1) and GR2. Previous studies reported that the main difference between gr1 and gr2 nucleotide sequences resides in a 27-nucleotide insertion/deletion in the DNA-binding region, respectively. However, in gilthead sea bream (Sparus aurata) the annotation for gr1 and gr2 seems contradictory. The gr2 sequence possesses the characteristic 27-nucleotide insertion that, in fact, is associated with the gr1 nucleotide sequence. Thus, this study aimed to elucidate the nucleotide sequences for the gr1 and gr2 in gilthead sea bream. The Clustal Omega alignment for different fish species corroborated the presence of such 27-nucleotide insertion/deletion in the DNA-binding region for gr1 and gr2, respectively. Then, we design specific primers set for the amplification of the gilthead sea bream gr1 by polymerase chain reaction (PCR). Importantly, the gr1 nucleotide partial sequence has a high similarity with other gr1 sequences already published for other fish species, being present in all of them the 27-nucleotide insertion in the DNA-binding region. We also detected that in European sea bass the gr1 and gr2 sequences had not been named according to the 27-nucleotide insertion/deletion criteria in the DNA-binding region. Thus, our study makes an urgent call to the scientific community to discuss the establishment of an updated agreement that allows homogenizing the criteria for the nomenclature defining the gr1 and gr2 nucleotide sequences for a better understanding of the stress response in teleost fish species.This study thanks to the AGL2016-76069-C2-2- R, PID2020-117557RB-C21, PID2020-117557RB-C22 grants (AEI-MINECO; Spain). EV-V thanks the support of Fondecyt iniciacion grant (project number 11221308; Agencia Nacional de Investigacion y Desarrollo de Chile, Government of Chile). AK was the recipient of a Ministry of Science, Research, and Technology (Iran) fellowship. MT thanks for the support of the post-doctoral fellowship "Ramon y Cajal" (ref. RYC2019-026841-I) (Ministerio de Ciencia e Innovacion, Spanish Government). FER-L thanks the support of Fondecyt regular grant (project number: 1211841; Agencia Nacional de Investigacion y Desarrollo de Chile, Government of Chile)

The gene expression profile of the glucocorticoid receptor 1 (gr1) but not gr2 is modulated in mucosal tissues of gilthead sea bream (Sparus aurata) exposed to acute air-exposure stress

The perception of an acute stressor (short-duration; high-intensity) induces a physiological response that activates the hypothalamic-pituitary-interrenal (HPI) axis and the subsequent release of cortisol. Cortisol carries out its effect at the molecular level through its recognition by the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). Recently, we unveiled the nucleotide sequence of the glucocorticoid receptor 1 (gr1) and gr2 in gilthead sea bream (Sparus aurata). Importantly, GR1 and GR2 respond to different levels of cortisol concentration in fish and, consequently, play a differential role in the stress response. To date, and despite their relevance, no data describes the modulation of these receptors in response to an acute stressor in gilthead sea bream (S. aurata). In this study, we evaluated the kinetics of modulation of cortisol receptors expression (gr1, gr2, mr), and its similarity with the expression pattern of selected genes associated with stress (hsp70; enolase) and immune response (lysozyme; c3; il-1 beta; tnf-alpha; il-10; tgf-beta 1) in gilthead sea bream mucosal tissues (skin; gills; anterior gut). To do it, fish were acutely stressed by three-minute air exposure, and the expression profile was evaluated at zero, 1 h, 6 h, and 24 h post-stress (hps). The cortisol level in plasma and skin mucus peaked at 1 hps. All the mucosal tissues showed a time-dependent and tissue-specific upregulation of gr1 and mr. The immune-related genes showed the upregulation of il-1 beta at 6 hps (gills; anterior gut), and tnf-alpha and c3 at 24 hps (anterior gut). Taking together, our study concludes that fish subjected to three-minute air exposure modulated the expression of gr1 but not gr2 in mucosal tissues (skin; gills; anterior gut). Furthermore, our data reinforce the idea of a stimulatory effect induced in genes associated with the innate immune response after acute stress but focused at the mucosal level and in a time- and tissue-dependent manner

Detection of gastrointestinal nematode populations resistant to albendazole and ivermectin in sheep

Gastrointestinal parasite infections represent a major welfare problem in small ruminants reared in extensive systems, which may be exacerbated by anthelmintic resistance. Therefore, we aimed to study the efficacy of albendazole and ivermectin in sheep. Eighty-six animals were selected from commercial farms in the temperate area of the State of Mexico at the age of seven months. These animals were randomly distributed into three groups: Group A, treated with albendazole, Group I, treated with ivermectin and Group C, left untreated. Faecal samples were collected before the anthelmintic was administered and 15 days post-treatment. Both Group A and Group I displayed a significant decrease of faecal egg counts when pre-and post-treatment values were compared (p = 0.003 and p = 0.049, respectively), and a significantly lower faecal egg count when compared with Group C after the treatment (p < 0.05). However, the faecal egg count reduction test showed that gastrointestinal nematodes (GIN) developed anthelmintic resistance to both albendazole and ivermectin. The results of the polymerase chain reaction (PCR) allowed the identification of Cooperia spp., and Trichostrongylus colubriformis. The allele-specific PCR results confirmed that T. colubriformis was resistant to albendazole. In conclusion, this study showed the presence of resistant GIN to albendazole and ivermectin in sheep reared in Mexican temperate zones. Therefore, nematode infections should be systematically monitored in order to implement integrated management strategies to prevent the spread of anthelmintic resistance

Observation of Pulsed Gamma-rays Above 25 GeV from the Crab Pulsar with MAGIC

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 GeV. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 GeV, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.Comment: Slight modification of the analysis: Fitting a more general function to the combined data set of COMPTEL, EGRET and MAGIC. Final result and conclusion is unchange

Constraints on the steady and pulsed very high energy gamma-ray emission from observations of PSR B1951+32/CTB 80 with the MAGIC Telescope

We report on very high energy gamma-observations with the MAGIC Telescope of the pulsar PSR B1951+32 and its associated nebula, CTB 80. Our data constrain the cutoff energy of the pulsar to be less than 32 GeV, assuming the pulsed gamma-ray emission to be exponentially cut off. The upper limit on the flux of pulsed gamma-ray emission above 75 GeV is 4.3*10^-11 photons cm^-2 sec^-1, and the upper limit on the flux of steady emission above 140 GeV is 1.5*10^-11 photons cm^-2 sec^-1. We discuss our results in the framework of recent model predictions and other studies.Comment: 7 pages, 7 figures, replaced with published versio

Discovery of VHE Gamma Radiation from IC443 with the MAGIC Telescope

We report the detection of a new source of very high energy (VHE, E_gamma >= 100GeV) gamma-ray emission located close to the Galactic Plane, MAGIC J0616+225, which is spatially coincident with SNR IC443. The observations were carried out with the MAGIC telescope in the periods December 2005 - January 2006 and December 2006 - January 2007. Here we present results from this source, leading to a VHE gamma-ray signal with a statistical significance of 5.7 sigma in the 2006/7 data and a measured differential gamma-ray flux consistent with a power law, described as dN_gamma/(dA dt dE) = (1.0 +/- 0.2)*10^(-11)(E/0.4 TeV)^(-3.1 +/- 0.3) cm^(-2)s^(-1)TeV^(-1). We briefly discuss the observational technique used and the procedure implemented for the data analysis. The results are put in the perspective of the multiwavelength emission and the molecular environment found in the region of IC443.Comment: Accepted by ApJ Letter

A High Statistics Measurement of the Lambdac+ Lifetime

A high statistics measurement of the Lambdac+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat.) +/- 2.5 (syst.) fs from 8034 +/- 122 Lambdac -> pKpi decays represents a significant improvement over the present world average.Comment: Submitted to Physical Review Letter