581 research outputs found
Stearoyl CoA desaturase gene polymorphism in Italian cattle breeds
AbstractStearoyl COA desaturase (SCD) is a rate-limiting enzyme in the biosynthesis of monounsaturated fatty acids. In cattle, a number of studies support the hypothesis that SCD gene regulation and polymorphism may affect fatty acid composition and fat quality in meat and milk. In ruminant-derived food products, SCD activity has been correlated to the content of conjugated linoleic acid (CLA), a mixture of geometrical and positional isomers of linoleic acid C18:2 having several positive effects on human health (i.e. anticarginogenic, antiatherogenic and immunomodulating effects).Aim of this study was to assess the polymorphism of 3 previously reported Single Nucleotide Polymorphisms (SNPs) in exon 5 of SCD gene in 12 cattle breeds raised in Italy, to evaluate the genetic variability and the genetic differences due to breed and/or selection purpose. Breeds sampled cover the whole geographic area of Italian peninsula and represent different selective purposes: 6 meat-purpose or meat-prevalence breeds (Pied..
Enhancer SINEs Link Pol III to Pol II Transcription in Neurons
Spatiotemporal regulation of gene expression depends on the cooperation of multiple mechanisms, including the functional interaction of promoters with distally located enhancers. Here, we show that, in cortical neurons, a subset of short interspersed nuclear elements (SINEs) located in the proximity of activity-regulated genes bears features of enhancers. Enhancer SINEs (eSINEs) recruit the Pol III cofactor complex TFIIIC in a stimulus-dependent manner and are transcribed by Pol III in response to neuronal depolarization. Characterization of an eSINE located in proximity to the Fos gene (FosRSINE1) indicated that the FosRSINE1-encoded transcript interacts with Pol II at the Fos promoter and mediates Fos relocation to Pol II factories, providing an unprecedented molecular link between Pol III and Pol II transcription. Strikingly, knockdown of the FosRSINE1 transcript induces defects of both cortical radial migration in vivo and activity-dependent dendritogenesis in vitro, demonstrating that FosRSINE1 acts as a strong enhancer of Fos expression in diverse physiological contexts
Predictive value of hematological and phenotypical parameters on postchemotherapy leukocyte recovery
Background: Grade IV chemotherapy toxicity is defined as absolute neutrophil count <500/μL. The nadir is considered as the lowest neutrophil number following chemotherapy, and generally is not expected before the 7th day from the start of chemotherapy. The usual prophylactic dose of rHu-G-CSF (Filgrastim) is 300 μg/day, starting 24-48 h after chemotherapy until hematological recovery. However, individual patient response is largely variable, so that rHu-G-CSF doses can be different. The aim of this study was to verify if peripheral blood automated flow cytochemistry and flow cytometry analysis may be helpful in predicting the individual response and saving rHu-G-CSF. Methods: During Grade IV neutropenia, blood counts from 30 cancer patients were analyzed daily by ADVIA 120 automated flow cytochemistry analyzer and by Facscalibur flow cytometer till the nadir. "Large unstained cells" (LUCs), myeloperoxidase index (MPXI), blasts, and various cell subpopulations in the peripheral blood were studied. At nadir rHu-G-CSF was started and 81 chemotherapy cycles were analyzed. Cycles were stratified according to their number and to two dose-levels of rHuG-CSF needed to recovery (300-600 vs. 900-1200 μg) and analyzed in relation to mean values of MPXI and mean absolute number of LUCs in the nadir phase. The linear regressions of LUCs % over time in relation to two dose-levels of rHu-G-CSF and uni-multivariate analysis of lymphocyte subpopulations, CD34+ cells, MPXI, and blasts were also performed. Results: In the nadir phase, the increase of MPXI above the upper limit of normality (>10; median 27.7), characterized a slow hematological recovery. MPXI levels were directly related to the cycle number and inversely related to the absolute number of LUCs and CD34 +/CD45+ cells. A faster hematological recovery was associated with a higher LUC increase per day (0.56% vs. 0.25%), higher blast (median 36.7/μL vs. 19.5/μL) and CD34+/CD45+ cell (median 2.2/μL vs. 0.82/μL) counts. Conclusions: Our study showed that some biological indicators such as MPXI, LUCs, blasts, and CD34 +/CD45+ cells may be of clinical relevance in predicting individual hematological response to rHu-G-CSF. Special attention should be paid when nadir MPXI exceeds the upper limit of normality because the hematological recovery may be delayed. © 2009 Clinical Cytometry Society
Electronic Instability in a Zero-Gap Semiconductor: The Charge-DensityWave in (TaSe4)(2)I
We report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T-CDW = 263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T-CDW.open114sciescopu
Identification of polymorphism in the SCL24A5 gene of cattle
The SLC24A5 (Solute Carrier family 24, member 5) gene is implicated in skin pigmentation in zebrafish and humans as it regulates the morphogenesis of melanosomes, specialized lysosomes involved in melanin deposit. In humans, the ancestral allele predominates in African and East Asian populations, while the allelic variant is nearly fixed in European populations and correlates with lighter pigmentation. Considering the role of melanin in the protecting of DNA from ultraviolet radiation, the lack of information in cattle and the importance of polymorphisms associated with pigmentation phenotypes, we investigated the SLC24A5 gene in cattle with light and dark skin pigmentation. To identify SNPs (Single Nucleotide Polymorphisms) in this gene and their association to dark skin pigmentation in cattle, each of the nine SLC24A5 exons, three introns (1, 3 and 8) and a portion of intron 5, were sequenced in a set of sixteen animals belonging to four Italian cattle breeds, two African zebu breeds and two African sanga breeds. The region spanning exons 3 and 4 was sequenced in fifteen animals belonging to seven additional breeds. A total of sixteen SNPs were identified: eleven positioned in introns (six in intron 1, one in intron 5 and four in intron 8) and five in exons (one in exon 1, two in exon 6 and two in exon 7). Three SNPs (located in exons 1, 6 and 7) were non synonymous, determining Pro19Leu, Ala238Val, and Met341Ile amino acid changes, respectively. All the SNPs identified were polymorphic between Bos taurus, Bos indicus and Sanga, while none of them resulted associated with the studied phenotype and discriminated the three breeds (Chianina, Mucubal and Goudali) characterized by dark pigmented skin from the others
Giant ambipolar Rashba effect in a semiconductor: BiTeI
We observe a giant spin-orbit splitting in bulk and surface states of the
non-centrosymmetric semiconductor BiTeI. We show that the Fermi level can be
placed in the valence or in the conduction band by controlling the surface
termination. In both cases it intersects spin-polarized bands, in the
corresponding surface depletion and accumulation layers. The momentum splitting
of these bands is not affected by adsorbate-induced changes in the surface
potential. These findings demonstrate that two properties crucial for enabling
semiconductor-based spin electronics -- a large, robust spin splitting and
ambipolar conduction -- are present in this material.Comment: 4 pages, 3 figure
Molecular characterization of the Montecristo feral goats in the Mediterranean context
The Montecristo wild goat is an endangered feral population occurring on the homonymous island in the Tuscan Archipelago since a long time. The origins of Montecristo goats are still debated, with authors dating their introduction either back to Neolithic times or between the 6th and 13th century of the Common Era. To investigate the evolutionary history and relationships of this population we assembled a 50K SNP dataset including 55 Mediterranean breeds and two nuclei of Montecristo goats sampled on the island and from an ex situ conservation project on the Italian mainland, respectively. Diversity levels, gene flow, population structure and relationships were assessed through multiple approaches. The insular population scored the lowest values of both observed and expected heterozygosity, highlighting reduced genetic variation, while the ex situ nucleus highlighted a less severe reduction. Multivariate statistics, Neighbour-network and population structure analyses clearly separated the insular nucleus from all other breeds, but also the two Montecristo populations from each other. Treemix software analysis pinpointed possible genetic inputs received by the two Montecristo goat nuclei from different sources, while Runs Of Homozygosity (ROHs) indicated an ancient bottleneck/founder effect in the insular population and recent inbreeding in the ex situ one. Overall, our results suggest that Montecristo goats experienced several demographic fluctuations combined with admixture events over time, and highlighted a noticeable differentiation between the two nuclei. This evidence can serve as a starting point to implement marker-assisted conservation plans for the endangered Montecristo feral goat
The momentum and photon energy dependence of the circular dichroic photoemission in the bulk Rashba semiconductors BiTeX (X = I, Br, Cl)
Bulk Rashba systems BiTeX (X = I, Br, Cl) are emerging as important
candidates for developing spintronics devices, because of the coexistence of
spin-split bulk and surface states, along with the ambipolar character of the
surface charge carriers. The need of studying the spin texture of strongly
spin-orbit coupled materials has recently promoted circular dichroic Angular
Resolved Photoelectron Spectroscopy (cd-ARPES) as an indirect tool to measure
the spin and the angular degrees of freedom. Here we report a detailed photon
energy dependent study of the cd-ARPES spectra in BiTeX (X = I, Br and Cl). Our
work reveals a large variation of the magnitude and sign of the dichroism.
Interestingly, we find that the dichroic signal modulates differently for the
three compounds and for the different spin-split states. These findings show a
momentum and photon energy dependence for the cd-ARPES signals in the bulk
Rashba semiconductor BiTeX (X = I, Br, Cl). Finally, the outcome of our
experiment indicates the important relation between the modulation of the
dichroism and the phase differences between the wave-functions involved in the
photoemission process. This phase difference can be due to initial or final
state effects. In the former case the phase difference results in possible
interference effects among the photo-electrons emitted from different atomic
layers and characterized by entangled spin-orbital polarized bands. In the
latter case the phase difference results from the relative phases of the
expansion of the final state in different outgoing partial waves.Comment: 6 pages, 4 figure
Electronic Instability in a Zero-Gap Semiconductor: The Charge-DensityWave in (TaSe4)(2)I
International audienceWe report a comprehensive study of the paradigmatic quasi-1D compound (TaSe4)(2)I performed by means of angle-resolved photoemission spectroscopy (ARPES) and first-principles electronic structure calculations. We find it to be a zero-gap semiconductor in the nondistorted structure, with non-negligible interchain coupling. Theory and experiment support a Peierls-like scenario for the charge-density wave formation below T-CDW = 263 K, where the incommensurability is a direct consequence of the finite interchain coupling. The formation of small polarons, strongly suggested by the ARPES data, explains the puzzling semiconductor-to-semiconductor transition observed in transport at T-CDW
Ancient DNA from domestic animal species remains : preliminary approaches
DNA analysis from ancient and old remains offers new tools to answer archaeozoological questions and investigate the origin of the genetic variability in domestic animal species. Molecular genetics techniques contribute to identify the species supporting classical osteological studies and to establish the relationship to modern species and breeds. Mitochondrial DNA (mtDNA) sequences are useful to reconstruct the history of maternal lineages comparing haplotype variations of present and old DNA samples. Mitochondrial data from modern cattle populations show a high diversity in Anatolia and in the Middle East supporting a near-Eastern matrilineal centre of origin. On the contrary in Europe a single family of mitochondrial haplotypes strongly dominates. A number of recent studies reported the successful recovery of ancient and old nuclear DNA (nuDNA) sequences. Such studies represent an important breakthrough, as nuDNA can be used for the characterisation of genetic loci directly involved in phenotypic traits, answering challenging questions. A bright example is offered by the study on the single nuclear exon of melanocortin type 1 receptor gene from a ca. 43,000 years old mammoth bone from Siberia, showing that mammoth populations were polymorphic with regard to hair colour, harbouring both dark and light haired animals. In contrast, these studies on ancient and old DNA sequences need great caution, due to the analytical problems caused by post-mortem damage of DNA, contamination from exogenous sources of mt- and nuDNA, and the consequent reliability of observed polymorphisms. The present research describes the preliminary analytical approach to DNA study of faunal remains (103 animal bones of different domestic species: Bos taurus 51; Ovis aries/Capra hircus 39; Sus scrofa/Sus domesticus 10; Gallus gallus 1; Equus caballus/Equus sp. 2), collected in seven archaeological sites located within the province of Trento, in the Alpine region of Trentino Alto-Adige (N-E Italy). The chosen sites, dating from the Bronze Age to the late Middle Ages, display different settlement typology and include Iron Age retic houses, votive Bronze Age contexts, a 4th century roman villa and several 13th century medieval buildings. Archaeozoological data will be collected on species, skeletal parts, age of slaughter, method of butchery, evidence of bone working and presence of paleopathologies. We describe the analytical procedure used in preparing and collecting samples and in extracting and analysing DNA from a subset of the bones previously described
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