Prolamin storage proteins and alloploidy in wild populations of the small grass Brachypodium distachyon (L.) P. Beauv.

This paper reports the glutenin diversity of a collection of 23 wild populations of the grass Brachypodium distachyon collected in the Mediterranean and southern areas of the Iberian Peninsula. The plant material studied included the three different cytotypes of this species: 2n?=?10, 2n?=?20 and 2n?=?30. A specific method of extraction was used to isolate the glutenin subunits from the caryopsis. Separation by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed them to correspond to wheat low-molecular-weight glutenin subunits (LMW-GS). Twenty-two LMW-GS?Clike were identified that showed great diversity within and between populations. All the populations investigated were polymorphic for the endosperm proteins studied. The 2n?=?30 forms had the largest number of subunits; these were also more diverse than those of the 2n?=?10 or 2n?=?20 forms. The 2n?=?10 forms, the most common in the higher, interior areas of the Iberian Peninsula, showed the smallest subunit variation. In fact, negative correlations were found between subunit diversity and altitude and longitude. In contrast, a positive correlation was detected with the annual average temperature and the indices of thermicity and Mediterraneity. The similarity between the populations was estimated using the Sorensen?CDice coefficient, calculated on the basis of the presence/absence of the 22 LMW-GS proteins. The similarity indices were used to produce a dendrogram using the unweighted pair-group method with arithmetic means (UPGMA). This method produced three main groups corresponding to the three cytotypes. An analysis was made of the possible correlation between eco-geographic and climatic factors and the gene diversity and polymorphism shown in the populations. The diversity correlated positively with the number of chromosomes (2n), annual mean temperature, index of thermicity and index of Mediterraneity. In contrast, diversity correlated negatively with altitude, longitude and index of precipitation during the summer. The number of chromosomes correlated negatively with altitude, longitude and precipitation during summer and positively with all the other climatic indices. These results are coherent with the fact that diploid forms were more common in areas of the interior and at higher altitude, where the climate is more extreme.     

SciDBMaker: new software for computer-aided design of specialized biological databases

Background  

The exponential growth of research in molecular biology has brought concomitant proliferation of databases for stocking its findings. A variety of protein sequence databases exist. While all of these strive for completeness, the range of user interests is often beyond their scope. Large databases covering a broad range of domains tend to offer less detailed information than smaller, more specialized resources, often creating a need to combine data from many sources in order to obtain a complete picture. Scientific researchers are continually developing new specific databases to enhance their understanding of biological processes.     

Place des explorations isotopiques dans les otites externes nécrosantes

BackgroundThe necrotizing otitis externa (NOE) is potentially lethal which mainly occurs on the most among the elderly and diabetic. The aim of our study was to evaluate the contribution of isotopic explorations in diagnosis, staging and monitoring of the NOE.MethodsOur retrospective study was about 50 patients with a strong suspicion of NOE who benefited a bone and/or gallium scintigraphy.ResultsOur population was composed of 38 men and 12 women with mean age of 68 years. All patients were diabetic. The most common complaint was otalgia (98% of cases). The sensitivity of computed tomography (CT) which was performed in 84% of cases was 66.6% of cases. Bone scintigraphy (BS) was performed in all patients showing increased uptake in the temporal region in 90% of cases. An extension to surrounding structures was objectified in 26% of cases. Follow-up Ga 67 SPECT was performed in 56% of cases, demonstrated increased uptake at the temporal region in 43% of cases. The statistical study showed that only the presence of an extended tympanic lysis on CT was statistically significant to the positivity of BS (P = 0.036). No statistically significant correlation was found between all other CT abnormalities, clinical and biological signs and the positivity of bone scintigraphy.ConclusionIsotopic explorations were a great contribution in the management of the NOE. At the initial phase, the BS allowed to confirm very early an existence of osteomyelitis of the skull base. During the follow-up, the gallium-67 scan allowed the following of the evolution of infectious process.