Chronic Progressive External Ophthalmoplegia Is Associated with a Novel Mutation in the Mitochondrial tRNA(Asn) Gene

Chronic progressive external ophthalmoplegia (CPEO) is caused by a decreased oxidative phosphorylation (OXPHOS) activity due to large-scale deletions of the mitochondrial genome in 50 % of the patients. The deletions encompass structural OXPHOS genes as well as tRNA genes, required for their expression so that the pathogenesis could be due to the deleted OXPHOS subunits or to an impaired mitochondrial translation. We have analyzed the mitochondrial genome of a patient presenting with CPEO for single base substitutions and discovered a novel heteroplasmic mutation in the tRNAAsn gene at position 5692 that converts a highly conserved adenine into a guanine. This mutation is unique because it is located at the transition of the anticodon loop to the anticodon stem and it leads to an additional base pair, thus reducing the number of loop-forming nucleotides from seven to five. Our findings suggest that CPEO can be caused by a single base substition in a mitochondrial tRNA gene so that the mitochondrial protein synthesis becomes the rate limiting step in OXPHOS fidelity

The role of pheromone receptors for communication and mating in Hypocrea jecorina (Trichoderma reesei)

AbstractDiscovery of sexual development in the ascomycete Trichoderma reesei (Hypocrea jecorina) as well as detection of a novel class of peptide pheromone precursors in this fungus indicates promising insights into its physiology and lifestyle. Here we investigated the role of the two pheromone receptors HPR1 and HPR2 in the H. jecorina pheromone-system.We found that these pheromone receptors show an unexpectedly high genetic variability among H. jecorina strains. HPR1 and HPR2 confer female fertility in their cognate mating types (MAT1-1 or MAT1-2, respectively) and mediate induction of fruiting body development. One compatible pheromone precursor–pheromone receptor pair (hpr1–hpp1 or hpr2–ppg1) in mating partners was sufficient for sexual development. Additionally, pheromone receptors were essential for ascospore development, hence indicating their involvement in post-fertilisation events.Neither pheromone precursor genes nor pheromone receptor genes of H. jecorina were transcribed in a strictly mating type dependent manner, but showed enhanced expression levels in the cognate mating type. In the presence of a mating partner under conditions favoring sexual development, transcript levels of pheromone precursors were significantly increased, while those of pheromone receptor genes do not show this trend. In the female sterile T. reesei strain QM6a, transcriptional responses of pheromone precursor and pheromone receptor genes to a mating partner were clearly altered compared to the female fertile wild-type strain CBS999.97. Consequently, a delayed and inappropriate response to the mating partner may be one aspect causing female sterility in QM6a

Caracterização sensorial e rendimento de extrato hidrossolúvel em cultivares de soja especiais para a alimentação humana.

Estudos realizados a partir dos anos 90, evidenciando a funcionalidade da soja, vêm despertando o interesse aumentar o consumo, tanto do grão in natura como de seus derivados. O extrato hidrossolúvel de soja (EHS) ou leite de soja é um dos derivados da soja mais conhecidos pelos brasileiros. O presente trabalho teve por objetivo diferenciar sensorialmente os EHS das cultivares de sojas especiais para a alimentação humana: Embrapa 48, BRS 213, BRS 216, BRS 257, BRS 258, BRS 267 e BRS 282; e da cultivar convencional BRS 232, todas desenvolvidas pela Embrapa Soja e cultivadas na safra 2009/10, comparando seus rendimentos durante o processamento. Com os extratos padronizados a 3,4% de proteína, os maiores rendimentos foram obtidos pelas cultivares BRS 232, BRS 257 e BRS 282, diferenciando-se das demais cultivares testadas em relação ao potencial para a produção de extrato de soja. Todos os EHS foram muito semelhantes em relação à análise sensorial, entretanto a BRS 213 se destacou por apresentar o menor gosto residual. Amostras com características sensoriais mais próximas às características habituais de consumo (extrato com adição de açúcar e de aromatizante), possivelmente teriam resultado em maior discriminação sensorial entre as cultivares

Progression of myopathology in Kearns-Sayre syndrome

We report on the progression of myopathology by comparing two biopsies from a patient with a Kearns-Sayre-Syndrome. The first biopsy was taken in 1979 and showed 10% ragged-red fibers. Myopathic changes were slight including internal nuclei and fiber splitting in 10% of the fibers. Electron microscopy revealed typical mitochondrial abnormalities with regard to number and shape. In 1989 a second biopsy was performed for an extended analysis of mitochondrial DNA. This time less than 5% of all fibers were ragged-red. Severe myopathic changes could be detected which so far has rarely been reported in mitochondrial cytopathy

Light-dependent roles of the G-protein α subunit GNA1 of Hypocrea jecorina (anamorph Trichoderma reesei)

<p>Abstract</p> <p>Background</p> <p>The filamentous ascomycete <it>Hypocrea jecorina </it>(anamorph <it>Trichoderma reesei</it>) is primarily known for its efficient enzymatic machinery that it utilizes to decompose cellulosic substrates. Nevertheless, the nature and transmission of the signals initiating and modulating this machinery are largely unknown. Heterotrimeric G-protein signaling represents one of the best studied signal transduction pathways in fungi.</p> <p>Results</p> <p>Analysis of the regulatory targets of the G-protein α subunit GNA1 in <it>H. jecorina </it>revealed a carbon source and light-dependent role in signal transduction. Deletion of <it>gna1 </it>led to significantly decreased biomass formation in darkness in submersed culture but had only minor effects on morphology and hyphal apical extension rates on solid medium. Cellulase gene transcription was abolished in Δ<it>gna1 </it>on cellulose in light and enhanced in darkness. However, analysis of strains expressing a constitutively activated GNA1 revealed that GNA1 does not transmit the essential inducing signal. Instead, it relates a modulating signal with light-dependent significance, since induction still required the presence of an inducer. We show that regulation of transcription and activity of GNA1 involves a carbon source-dependent feedback cycle. Additionally we found a function of GNA1 in hydrophobin regulation as well as effects on conidiation and tolerance of osmotic and oxidative stress.</p> <p>Conclusion</p> <p>We conclude that GNA1 transmits a signal the physiological relevance of which is dependent on both the carbon source as well as the light status. The widespread consequences of mutations in GNA1 indicate a broad function of this Gα subunit in appropriation of intracellular resources to environmental (especially nutritional) conditions.</p

Tempeh flour as a substitute for soybean flour in coconut cookies.

The objective of this study was to prepare roasted and lyophilized tempeh flour with soybean cultivar BRS 267 to apply them in the formulation of coconut biscuits. The cookies produced with whole soy flour and mixed flour of soybean and tempeh were evaluated for proximate composition, fatty acid profile, and isoflavone aglycones in order to verify the effects of inoculation with the fungus Rhizopus oligosporus and those of the drying processes of roasting and lyophilization on the chemical characteristics of the final product. Sensory acceptance and purchase intention of the formulated products were also evaluated. The results indicate the maintenance of linolenic acid, which is important in the prevention of coronary diseases, and an increase in the aglycones levels when the tempeh flour was used. Lipids and proteins showed differences, and the sensory analyses demonstrated similarity between the cookies with satisfactory scores for aroma, flavor, texture, and overall acceptability for both samples. when compared to the control. Purchase intent was also positive for the lyophilized and toasted tempeh flours, thus enabling the use of the roasting process as a simple drying method, for processing tempeh and obtaining a flour rich in proteins and aglycones that can be used as a partial substitute for soy flour in cookies and other bakery products

Composição centesimal, teores de isoflavonas e inibidor de tripsina em cultivares de soja especiais para a alimentação humana.

A soja é considerada uma das principais culturas mundiais por apresentar ampla variabilidade genética e morfológica, que resulta em plantas distintas em relação à composição dos grãos, a à produtividade, à resistência a doenças e pragas e ao cultivo em diferentes regiões. A fim de salientar as características nutricionais desse grão, o presente trabalho teve como objetivo a caracterização físico-química e a quantificação dos teores de isoflavonas e inibidores de tripsina das cultivares de soja especiais para a alimentação humana: Embrapa 48, BRS 213, BRS 216, BRS 257, BRS 258, BRS 267 e BRS 282; e da cultivar convencional BRS 232, todas desenvolvidas pela Embrapa Soja e cultivadas na safra 2009/10. Foram realizadas as seguintes análises: composição centesimal (umidade, proteínas, lipídios, cinzas, carboidratos), teores de isoflavonas totais e de inibidor de tripsina. A cultivar BRS 258 se destacou pelo alto teor de proteína, Embrapa 48 pelo alto teor de lipídios; BRS 213 pelo alto teor de isoflavona e a cultivar BRS 232, pelo baixo teor de inibidor de tripsina. Assim sendo, é possível a indicação de uma cultivar para fins industriais específicos, resultando em maior viabilidade econômica e qualidade dos produtos obtidos