Avaliação de famílias e progênies de arroz de terras altas, em Vilhena, RO, em 2012/13.

O objetivo desse trabalho foi avaliar e selecionar famílias e progênies de arroz de terras altas

Avaliação de famílias e progênies de arroz de terras altas, em Vilhena, RO, em 2011/12.

O objetivo desse trabalho foi avaliar famílias e progênies de arroz de terras altas, em Rondônia

Avaliação de genótipos de girassol para Vilhena, RO, na safrinha 2013.

O girassol (Helianthus annus) apresenta-se como cultura promissora para a diversificação da agricultura em todas as regiões do país, sobretudo como alternativa em sistemas de rotação ou em sucessão às culturas de soja e milho. Rondônia, apesar de todas as condições favoráveis não apresenta plantio de girassol em escala comercial. O ensaio foi realizado no campo experimental da Embrapa Rondônia em Vilhena, com o objetivo de avaliar diferentes genótipos de girassol e selecionar os mais adequados para o cultivo no cerrado de Rondônia. A semeadura foi realizada nos dias 6 e 7 de março de 2013, em delineamento de blocos casualizados, com três repetições; a parcela foi composta por 4 linhas de 5 m de comprimento, espaçadas em 0,90 m e parcela útil constituída por 2 linhas centrais de 4 m. As variáveis avaliadas foram dias para floração inicial, altura de planta, número de dias para maturação fisiológica, tamanho do capítulo e produtividade média de grãos (corrigida para 13% de umidade). O ensaio foi composto por oito genótipos: 12P3H1, 12P3H2, 12P3H3, 12P3H4, 12P3H5, 12P3H6 e as testemunhas: M734(T) e SYN039A(T). Os resultados foram analisados com software GENES, por meio de análise de variância e aplicação de teste Tuckey (P<0,01). Todas as variáveis apresentaram diferença significativa pelo teste F, exceto tamanho de capítulo. A média para início de florescimento foi de 57 dias após a semeadura. A altura média de plantas foi de 168 cm (variando entre 156 cm a 194 cm). A maturação fisiológica foi atingida, em média, aos 83 dias após a semeadura. A produtividade média foi de 1.682 kg.ha-1 , sendo o genótipo 12P3H3 o mais produtivo com 2.261 kg.ha-1 . Os resultados obtidos serão utilizados em análise com resultados de outros anos e localidades para indicar os melhores genótipos para cultivo na região

Myosin VI in PC12 cells plays important roles in cell migration and proliferation but not in catecholamine secretion

Myosin VI (MVI) is the only known myosin walking towards minus end of actin filaments and is believed to play distinct role(s) than other myosins. We addressed a role of this unique motor in secretory PC12 cells, derived from rat adrenal medulla pheochromocytoma using cell lines with reduced MVI synthesis (produced by means of siRNA). Decrease of MVI expression caused severe changes in cell size and morphology, and profound defects in actin cytoskeleton organization and Golgi structure. Also, significant inhibition of cell migration as well as cell proliferation was observed. Flow cytometric analysis revealed that MVI-deficient cells were arrested in G0/G1 phase of the cell cycle but did not undergo increased senescence as compared with control cells. Also, neither polyploidy nor aneuploidy were detected. Surprisingly, no significant effect on noradrenaline secretion was observed. These data indicate that in PC12 cells MVI is involved in cell migration and proliferation but is not crucial for stimulation-dependent catecholamine release

The Role for HNF-1β-Targeted Collectrin in Maintenance of Primary Cilia and Cell Polarity in Collecting Duct Cells

Collectrin, a homologue of angiotensin converting enzyme 2 (ACE2), is a type I transmembrane protein, and we originally reported its localization to the cytoplasm and apical membrane of collecting duct cells. Recently, two independent studies of targeted disruption of collectrin in mice resulted in severe and general defects in renal amino acid uptake. Collectrin has been reported to be under the transcriptional regulation by HNF-1α, which is exclusively expressed in proximal tubules and localized at the luminal side of brush border membranes. The deficiency of collectrin was associated with reduction of multiple amino acid transporters on luminal membranes. In the current study, we describe that collectrin is a target of HNF-1β and heavily expressed in the primary cilium of renal collecting duct cells. Collectrin is also localized in the vesicles near the peri-basal body region and binds to γ-actin-myosin II-A, SNARE, and polycystin-2-polaris complexes, and all of these are involved in intracellular and ciliary movement of vesicles and membrane proteins. Treatment of mIMCD3 cells with collectrin siRNA resulted in defective cilium formation, increased cell proliferation and apoptosis, and disappearance of polycystin-2 in the primary cilium. Suppression of collectrin mRNA in metanephric culture resulted in the formation of multiple longitudinal cysts in ureteric bud branches. Taken together, the cystic change and formation of defective cilium with the interference in the collectrin functions would suggest that it is necessary for recycling of the primary cilia-specific membrane proteins, the maintenance of the primary cilia and cell polarity of collecting duct cells. The transcriptional hierarchy between HNF-1β and PKD (polycystic kidney disease) genes expressed in the primary cilia of collecting duct cells has been suggested, and collectrin is one of such HNF-1β regulated genes

Lipid Metabolites Enhance Secretion Acting on SNARE Microdomains and Altering the Extent and Kinetics of Single Release Events in Bovine Adrenal Chromaffin Cells

Lipid molecules such as arachidonic acid (AA) and sphingolipid metabolites have been implicated in modulation of neuronal and endocrine secretion. Here we compare the effects of these lipids on secretion from cultured bovine chromaffin cells. First, we demonstrate that exogenous sphingosine and AA interact with the secretory apparatus as confirmed by FRET experiments. Examination of plasma membrane SNARE microdomains and chromaffin granule dynamics using total internal reflection fluorescent microscopy (TIRFM) suggests that sphingosine production promotes granule tethering while arachidonic acid promotes full docking. Our analysis of single granule release kinetics by amperometry demonstrated that both sphingomyelinase and AA treatments enhanced drastically the amount of catecholamines released per individual event by either altering the onset phase of or by prolonging the off phase of single granule catecholamine release kinetics. Together these results demonstrate that the kinetics and extent of the exocytotic fusion pore formation can be modulated by specific signalling lipids through related functional mechanisms

RyRCa2+ Leak Limits Cardiac Ca2+ Window Current Overcoming the Tonic Effect of Calmodulin in Mice

Ca2+ mediates the functional coupling between L-type Ca2+ channel (LTCC) and sarcoplasmic reticulum (SR) Ca2+ release channel (ryanodine receptor, RyR), participating in key pathophysiological processes. This crosstalk manifests as the orthograde Ca2+-induced Ca2+-release (CICR) mechanism triggered by Ca2+ influx, but also as the retrograde Ca2+-dependent inactivation (CDI) of LTCC, which depends on both Ca2+ permeating through the LTCC itself and on SR Ca2+ release through the RyR. This latter effect has been suggested to rely on local rather than global Ca2+ signaling, which might parallel the nanodomain control of CDI carried out through calmodulin (CaM). Analyzing the CICR in catecholaminergic polymorphic ventricular tachycardia (CPVT) mice as a model of RyR-generated Ca2+ leak, we evidence here that increased occurrence of the discrete local SR Ca2+ releases through the RyRs (Ca2+ sparks) causea depolarizing shift in activation and a hyperpolarizing shift inisochronic inactivation of cardiac LTCC current resulting in the reduction of window current. Both increasing fast [Ca2+]i buffer capacity or depleting SR Ca2+ store blunted these changes, which could be reproduced in WT cells by RyRCa2+ leak induced with Ryanodol and CaM inhibition.Our results unveiled a new paradigm for CaM-dependent effect on LTCC gating and further the nanodomain Ca2+ control of LTCC, emphasizing the importance of spatio-temporal relationships between Ca2+ signals and CaM function

Arroz de terras altas: ensaio de valor de cultivo e uso em Vilhena, RO, em 2012/13.

O objetivo deste trabalho foi conduzir Ensaio de Valor de Cultivo e Uso de Arroz de terras altas, para lançamento de novas cultivares ou extensão de recomendação.201