Search

We aimed to estimate genetic parameters for the non-linear Gompertz growth curve parameters based on the two-step method and simulated data of a pig population. Data of true breeding values, growth curve parameters (a, b and k) and body weights at 1, 90, 210, 360 and 540 days of age were simulated for 1700 individuals. Afterwards, in the first stage of the two-step method, the Gompertz curves were fitted for each animal and the growth curve parameters were estimated. In the second step, considering the estimated parameters as phenotypes, animals’ breeding values were predicted by multitrait analyses. The simulation and two-step processes were replicated 10 times. For each replicate, the genetic parameters, accuracies and biases were calculated. Moderate to high average heritabilities for the curve parameters [0.62 (0.04), 0.56 (0.04) and 0.57 (0.04) for a, b and k, respectively] show the possibility of effective selection of animals based on these parameters. High and favorable average genetic correlations, especially between the most important growth curve parameters [a and k, 0.93 (0.01)], shows that selection for increased mature weight (a) will also increase maturation rate (k). High average accuracies [0.84 (0.02), 0.82 (0.02) and 0.83 (0.02)] and low average biases [0.06 (0.06), 0.06 (0.06) and 0.07 (0.07) for a, b, and k, respectively] indicate that the two-step approach is feasible for predicting breeding values for growth curve parameters and for dealing with longitudinal body weight measurements., Objetivamos estimar parâmetros genéticos para os parâmetros da curva de crescimento não-linear de Gompertz com base no método em duas etapas e em dados simulados de uma população de suínos. Dados de valores genéticos reais, dos parâmetros da curva de crescimento (a, b e k) e dos pesos corporais aos 1, 90, 210, 360 e 540 dias de idade foram simulados para 1700 indivíduos. Posteriormente, na primeira etapa do método em duas etapas, as curvas de Gompertz foram ajustadas para cada animal e os parâmetros da curva de crescimento foram estimados. Na segunda etapa, considerando os parâmetros estimados como fenótipos, os valores genéticos dos animais foram preditos por análises multicaracterísticas. Os processos de simulação e de duas etapas foram replicados 10 vezes. Para cada réplica, os parâmetros genéticos, acurácias e vieses foram calculados. Herdabilidades médias moderadas a altas para os parâmetros da curva [0,62 (0,04), 0,56 (0,04) e 0,57 (0,04) para a, b e k, respectivamente] mostram a possibilidade de seleção eficaz de animais com base nesses parâmetros. Correlações genéticas médias altas e favoráveis, especialmente entre os parâmetros mais importantes da curva de crescimento [a e k, 0,93 (0,01)], mostram que a seleção para o aumento do peso à maturidade (a) também aumentará a taxa de maturação (k). Acurácias médias altas [0,84 (0,02), 0,82 (0,02) e 0,83 (0,02)] e vieses médios baixos [0,06 (0,06), 0,06 (0,06) e 0,07 (0,07) para a, b e k, respectivamente] indicam que a abordagem em duas etapas é viável para predizer valores genéticos para os parâmetros da curva de crescimento e para trabalhar com medidas longitudinais de peso corporal.

The true myrtle, Myrtus communis, is a small perennial evergreen tree that occurs in Europe, Africa, and Asia with a circum-Mediterranean geographic distribution. Unfortunately, the Mediterranean Forests, where M. communis occurs, are critically endangered and are currently restricted to small fragmented areas in protected conservation units. In the present work, we performed, for the first time, a metabarcoding study on the spatial variation of fungal community structure in the foliar endophytome of this endemic plant of the Mediterranean biome, using bipartite network analysis as a model. The local bipartite network of Myrtus communis individuals and their foliar endophytic fungi is very low connected, with low nestedness, and moderately high specialization and modularity. Similar network patterns were also retrieved in both culture-dependent and amplicon metagenomics of foliar endophytes in distinct arboreal hosts in varied biomes. Furthermore, the majority of putative fungal endophytes species were basidiomycete woody saprotrophs of the orders Polyporales, Agaricales, and Hymenochaetales. Altogether, these findings suggest a possible adaptation of these wood-decaying fungi to cope with moisture limitation and spatial scarcity of their primary substrate (dead wood), which are totally consistent with the predictions of the viaphytism hypothesis that wood-decomposing fungi inhabit the internal leaf tissue of forest trees in order to enhance dispersal to substrates on the forest floor, by using leaves as vectors and as refugia, during periods of environmental stress.

A epigenética é definida como mudanças na expressão gênica que podem ser herdadas e que não alteram a sequência do DNA. Existem dois mecanismos epigenéticos principais, a metilação do DNA e a modificação de histonas. Também se destaca o imprinting genômico, o qual está relacionado com a regulação gênica quando apenas um alelo (herdado do pai ou da mãe) se expressa. A herança epigenética transgeracional consiste da herança de marcas epigenéticas através de células germinativas, que controla os padrões de expressão gênica e são passados de uma geração para a outra. Dentro do programa de melhoramento animal é importante avaliar a extensão com que a herança epigenética transgeracional também afeta a eficiência da seleção. Uma melhor compreensão dos mecanismos epigenéticos e seus efeitos transgeracionais no desempenho dos animais poderá permitir maiores ganhos sobre as características de importância econômica.

A epigenética é definida como mudanças na expressão gênica que podem ser herdadas e que não alteram a sequência do DNA. Existem dois mecanismos epigenéticos principais, a metilação do DNA e a modificação de histonas. Também se destaca o imprinting genômico, o qual está relacionado com a regulação gênica quando apenas um alelo (herdado do pai ou da mãe) se expressa. A herança epigenética transgeracional consiste da herança de marcas epigenéticas através de células germinativas, que controla os padrões de expressão gênica e são passados de uma geração para a outra. Dentro do programa de melhoramento animal é importante avaliar a extensão com que a herança epigenética transgeracional também afeta a eficiência da seleção. Uma melhor compreensão dos mecanismos epigenéticos e seus efeitos transgeracionais no desempenho dos animais poderá permitir maiores ganhos sobre as características de importância econômica.

We report on experimental total electron scattering cross-section (TCS) from pyridine (CHN) for incident electron energies between 10 and 1000 eV, with experimental uncertainties within 5–10%, as measured with a double electrostatic analyser apparatus. The experimental results are compared with our theoretical calculations performed within the independent atom model complemented with a screening corrected additivity rule (IAM-SCAR) procedure which has been updated by including interference effects. A good level of agreement is found between both data sources within the experimental uncertainties. The present TCS results for electron impact energy under study contribute, together with other scattering data available in the literature, to achieve a consistent set of cross section data for modelling purposes.

We report on novel total electron scattering cross section (TCS) measurements for electrons scattering from sevoflurane, at incident electron impact energies in the range 1–300 eV. The experimental results, obtained from a newly implemented magnetic beam apparatus based in Madrid, are compared with theoretical results from the independent atom model with screening corrected additivity rule including interference effects and rotational excitation (IAM-SCAR+I+R). A very good level of agreement has been found between the present experimental and theoretical data at above about 20 eV electron impact and to within the experimental uncertainties.

We report integral cross sections for electron interactions with tungsten and beryllium atoms in the incident electron energy range from 0.1 up to 5000 eV. The calculated cross sections are obtained for electron-atom scattering processes represented by a complex potential. For tungsten, ionization cross sections are discussed in the electron energy region from threshold up to 5000 eV against the available data from the Deutsch-Mark formalism and a semi-empirical complex scattering potential. Although a reasonable agreement for the ionization cross sections has been found in the overlapping energy region, inconsistencies on the integral inelastic cross sections from the previous semi-empirical approach based on a complex scattering potential ionization contribution, are now amended and comprehensively explained. For beryllium atoms an excellent agreement with previous 'state-of-the-art' scattering theory calculations has been found for the integral elastic cross sections. However, the partial contribution of the excitation and ionization channels to the inelastic part shows serious discrepancies which deserve further investigations. Calculated elastic differential cross sections for tungsten are also reported from 0.1 to 5000 eV for scattering angles from 0° to 180°. The present set of cross sectional data may be of relevance for the plasma fusion community.

High-resolution vacuum ultraviolet photoabsorption measurements in the wavelength range of 115-320 nm (10.8-3.9 eV) have been performed together with comprehensive relativistic time-dependent density functional calculations (TDDFT) on the low-lying excited sates of tungsten hexacarbonyl, W(CO). The higher resolution obtained reveals previously unresolved spectral features of W(CO). The spectrum shows two higher-energy bands (in the energy ranges of 7.22-8.12 eV and 8.15-9.05 eV), one of them with clear vibrational structure, and a few lower-energy shoulders in addition to a couple of lower-energy metal-to-ligand charge-transfer (MLCT) bands reported in the literature before. Absolute photoabsorption cross sections are reported and, where possible, compared to previously published results. On the basis of this combined experimental/theoretical study the absorption spectrum of the complex has been totally re-assigned between 3.9 and 10.8 eV under the light of spin-orbit coupling (SOC) effects. The present comprehensive knowledge of the nature of the electronically excited states may be of relevance to estimate neutral dissociation cross sections of W(CO), a precursor molecule in focused electron beam induced deposition (FEBID) processes, from electron scattering measurements.

Background: Reproductive traits such as number of stillborn piglets (SB) and number of teats (NT) have been evaluated in many genome-wide association studies (GWAS). Most of these GWAS were performed under the assumption that these traits were normally distributed. However, both SB and NT are discrete (e.g. count) variables. Therefore, it is necessary to test for better fit of other appropriate statistical models based on discrete distributions. In addition, although many GWAS have been performed, the biological meaning of the identified candidate genes, as well as their functional relationships still need to be better understood. Here, we performed and tested a Bayesian treatment of a GWAS model assuming a Poisson distribution for SB and NT in a commercial pig line. To explore the biological role of the genes that underlie SB and NT and identify the most likely candidate genes, we used the most significant single nucleotide polymorphisms (SNPs), to collect related genes and generated gene-transcription factor (TF) networks. Results: Comparisons of the Poisson and Gaussian distributions showed that the Poisson model was appropriate for SB, while the Gaussian was appropriate for NT. The fitted GWAS models indicated 18 and 65 significant SNPs with one and nine quantitative trait locus (QTL) regions within which 18 and 57 related genes were identified for SB and NT, respectively. Based on the related TF, we selected the most representative TF for each trait and constructed a gene-TF network of gene-gene interactions and identified new candidate genes. Conclusions: Our comparative analyses showed that the Poisson model presented the best fit for SB. Thus, to increase the accuracy of GWAS, counting models should be considered for this kind of trait. We identified multiple candidate genes (e.g. PTP4A2, NPHP1, and CYP24A1 for SB and YLPM1, SYNDIG1L, TGFB3, and VRTN for NT) and TF (e.g. NF-κB and KLF4 for SB and SOX9 and ELF5 for NT), which were consistent with known new