TENDÊNCIA DOS EFEITOS GENÉTICOS DIRETOS E MATERNOS DO PESO A DESMAMA DE BOVINOS DA RAÇA NELORE MOCHA NA REGIÃO PECUÁRIA CAMPO GRANDE E DOURADOS MATO GROSSO DO SUL

Dados relativos a 2891 observações de pesos de animais da raça Nelore Mocha, nascidos e criados na região pecuária Campo Grande - Dourados, no Estado de Mato Grosso do Sul, no período de 1975 a 1996, foram analisados com o objetivo de avaliar as mudanças genéticas aditivas diretas e maternas, dos pesos à desmama, padronizados para os 205 (P205) dias de idade. A tendência genética foi estimada pela regressão ponderada das médias anuais dos valores genéticos (aditivo e materno) sobre o ano de nascimento do animal. As estimativas dos componentes de (co) variância utilizadas para o cálculo dos valores genéticos, foram obtidas pelo método de máxima verossimilhança restrita livre de derivadas (REML), usando o aplicativo MTDFREML (sob modelo acima). No modelo foram incluídos os efeitos aleatórios aditivo direto e materno, além dos efeitos fixos de grupo de contemporâneos (fazenda, sexo, estação e ano de nascimento do animal) e a covariável idade da vaca ao parto (efeitos linear e quadrático). As tendências genéticas estimadas dos efeitos diretos e maternos foram 0,78 kg/ano e 0,35 kg/ano, respectivamente. A evolução do ganho genético oriundo do efeito aditivo direto foi de -0,51 a 2,14 kg/ano, resultando em uma amplitude de 0,1262 kg/ano, e a mesma medida da dispersão da tendência genética do efeito materno foi de -0,0611 kg/ano, conseqüente de uma de variação de 0,27 a -1,02 kg/ano no período estudado. Considerando a variabilidade genética existente nos rebanhos da região, os resultados observados estão bem aquém das mudanças possíveis. Tendency of the direct and maternal genetic effects on the weight at the weaning of Nelore bovines at the cattle raising region of Campo Grande and Dourados Abstract Data related to 2891 observations of weights of Nelore Polled breed, borned and servants in the region of Campo Grande - Dourados, in the state of South Mato Grosso, in the period from 1975 to 1996, were analyzed with the objective of evaluating the direct and maternal addictive genetic trends. The weights were standardized for the 205 (P205) days of age. The genetic trends were dear for the pondered regression of the annual averages of the genetic values (addictive and maternal) on the year of birth of the animal. The estimates of the components of (co) variance used for the calculation of the genetic values, were obtained by the method of maximum restricted verisimilitude free from having derived (REML), using the application MTDFREML (animal models) contends direct and maternal addictive aleatory effects, besides the fixed effects of contemporaries group (farm, sex, season and weight of the animal) and the co-variable age of the cow to the childbirth (lineal and quadratic). The esteemed genetic trends of the direct and maternal effects were 0,78 kg/ year and - 0,35 kg/year, respectively. The evolution of the genetic gain originating from of the direct addictive effect was from -0,51 to 2,14 kg/year, resulting in a width of 0,1262 kg/year, and the same measure of the dispersion of the genetic trends of the maternal effect was of -0,0611 kg/year, as a consequence from a variation of 0,27 to -1,02 kg/year in the period. Considering the existent genetic variability in the region, the observed results are bellow possible changes

AT1 and AT2 receptor knockout changed osteonectin and bone density in mice in periodontal inflammation experimental model

BACKGROUND: The aim of this study was to evaluate the role of AT1 and AT2 receptors in a periodontal inflammation experimental model. METHODS: Periodontal inflammation was induced by LPS/Porphyromonas gingivalis. Maxillae, femur, and vertebra were scanned using Micro-CT. Maxillae were analyzed histopathologically, immunohistochemically, and by RT-PCR. RESULTS: The vertebra showed decreased BMD in AT1 H compared with WT H (p < 0.05). The femur showed increased Tb.Sp for AT1 H and AT2 H, p < 0.01 and p < 0.05, respectively. The Tb.N was decreased in the vertebra (WT H-AT1 H: p < 0.05; WT H-AT2 H: p < 0.05) and in the femur (WT H-AT1 H: p < 0.01; WT H-AT2 H: p < 0.05). AT1 PD increased linear bone loss (p < 0.05) and decreased osteoblast cells (p < 0.05). RANKL immunostaining was intense for AT1 PD and WT PD (p < 0.001). OPG was intense in the WT H, WT PD, and AT2 PD when compared to AT1 PD (p < 0.001). AT1 PD showed weak immunostaining for osteocalcin compared with WT H, WT PD, and AT2 PD (p < 0.001). AT1 H showed significantly stronger immunostaining for osteonectin in fibroblasts compared to AT2 H (p < 0.01). CONCLUSION: AT1 receptor knockout changed bone density, the quality and number of bone trabeculae, decreased the number of osteoblast cells, and increased osteonectin in fibroblasts

Global gene flow releases invasive plants from environmental constraints on genetic diversity

When plants establish outside their native range, their ability to adapt to the new environment is influenced by both demography and dispersal. However, the relative importance of these two factors is poorly understood. To quantify the influence of demography and dispersal on patterns of genetic diversity underlying adaptation, we used data from a globally distributed demographic research network comprising 35 native and 18 nonnative populations of Plantago lanceolata. Species-specific simulation experiments showed that dispersal would dilute demographic influences on genetic diversity at local scales. Populations in the native European range had strong spatial genetic structure associated with geographic distance and precipitation seasonality. In contrast, nonnative populations had weaker spatial genetic structure that was not associated with environmental gradients but with higher within-population genetic diversity. Our findings show that dispersal caused by repeated, long-distance, human-mediated introductions has allowed invasive plant populations to overcome environmental constraints on genetic diversity, even without strong demographic changes. The impact of invasive plants may, therefore, increase with repeated introductions, highlighting the need to constrain future introductions of species even if they already exist in an area

Plant-plant competition influences temporal dynamism of soil microbial enzyme activity.

Root-derived compounds can change rates of soil organic matter decomposition (rhizosphere priming effects) through microbial production of extracellular enzymes. Such soil priming can be affected by plant identity and soil nutrient status. However, the effect of plant-plant competition on the temporal dynamics of soil organic matter turnover processes is not well understood. This study used zymography to detect the spatial and temporal pattern of cellulase and leucine aminopeptidase activity, two enzyme classes involved in soil organic matter turnover. The effect of plant-plant competition on enzyme activity was examined using barley (Hordeum vulgare) plants grown in i) isolation, ii) intra- and iii) inter-cultivar competition. The enzyme activities of leucine aminopeptidase and cellulase were measured from portions of the root system at 18, 25 and 33 days after planting, both along the root axis and in the root associated area with detectable enzyme activity. The activities of cellulase and leucine aminopeptidase were both strongly associated with plant roots, and increased over time. An increase in the area of cellulase activity around roots was delayed when plants were in competition compared to in isolation. A similar response was found for leucine aminopeptidase activity, but only when in intra-cultivar competition, and not when in inter-cultivar competition. Therefore, plant-plant competition had a differential effect on enzyme classes, which was potentially mediated through root exudate composition. This study demonstrates the influence of plant-plant competition on soil microbial activity and provides a potential mechanism by which temporal dynamism in plant resource capture can be mediated