Cypress surrogate mother produces haploid progeny from alien pollen

International audienceAlthough most living organisms reproduce sexually, some have developed a uniparental reproduction where the embryo usually derives from the female parent. A unique case of paternal apomixis in plants has been recently reported in Cupressus dupreziana, an endangered Mediterranean conifer. This species produces unreduced pollen that develop into all-paternal embryos within the seed tissues. We analyzed seedlings produced by open-pollinated C. dupreziana seed trees using morphological descriptors, ploidy levels assessed through flow cytometry, and AFLP genetic diversity. In situ C. dupreziana seed trees (from Algeria) produced only diploid C. dupreziana progeny. In contrast, only one-third of the progeny produced by ex situ C. dupreziana seed trees planted in French collections were similar to C. dupreziana seedlings; the other progeny were haploid or diploid C. sempervirens seedlings. These results demonstrate that C. dupreziana ovules allow for the development of all-paternal embryos from pollen produced by another species, C. sempervirens. Thus, the in planta androgenesis is achieved through the combination of the embryogenic behavior of pollen grains and the ability of seed tree ovules to act as a surrogate mother. This phenomenon offers a unique opportunity to produce, by natural means, highly valuable material for genetic studies and selection of sterile cultivar

Facilitating coronary artery evaluation in MDCT using a 3D automatic vessel segmentation tool

The purpose of this study was to investigate a 3D coronary artery segmentation algorithm using 16-row MDCT data sets. Fifty patients underwent cardiac CT (Sensation 16, Siemens) and coronary angiography. Automatic and manual detection of coronary artery stenosis was performed. A 3D coronary artery segmentation algorithm (Fraunhofer Institute for Computer Graphics, Darmstadt) was used for automatic evaluation. All significant stenoses (>50%) in vessels >1.5 mm in diameter were protocoled. Each detection tool was used by one reader who was blinded to the results of the other detection method and the results of coronary angiography. Sensitivity and specificity were determined for automatic and manual detection as well as was the time for both CT-based evaluation methods. The overall sensitivity and specificity of the automatic and manual approach were 93.1 vs. 95.83% and 86.1 vs. 81.9%. The time required for automatic evaluation was significantly shorter than with the manual approach, i.e., 246.04±43.17 s for the automatic approach and 526.88±45.71 s for the manual approach (P<0.0001). In 94% of the coronary artery branches, automatic detection required less time than the manual approach. Automatic coronary vessel evaluation is feasible. It reduces the time required for cardiac CT evaluation with similar sensitivity and specificity as well as facilitates the evaluation of MDCT coronary angiography in a standardized fashion

Growth of Bauhinia forficata Link, Curcuma zedoaria Roscoe and Phaseolus vulgaris L. cell suspension cultures with carbon sources Crescimento de cultura de células em suspensão de Bauhinia forficata Link, Curcuma zedoaria Roscoe e Phaseolus vulgaris L. em fontes de carbono

Cell suspension cultures of Bauhinia forficata Link, Curcuma zedoaria Roscoe and Phaseolus vulgaris L. were used to test plant ability to utilize an alternative to sucrose as carbon source and energy for growth. Glycerol, sorbitol and galactose were the alternative carbon sources tested. Cell suspension cultures established on liquid medium containing sucrose were transferred to culture medium supplemented with sucrose or glycerol, or sorbitol, or galactose as the sole carbon source. Fresh and dry weight increasing and protein content showed marked differences among the different carbon sources used. Sucrose was the best carbon source for all the three plant species tested. Galactose and glycerol promoted slow or no growth of the three studied species. Sucrose in liquid medium promoted initiation of meristemoid formation. Sorbitol, which was ineffective on promoting significant growth, was the only alternative carbon source tested that also promoted this effect.<br>Culturas de células em suspensão de Bauhinia forficata Link, Curcuma zedoaria Roscoe e Phaseolus vulgaris L. foram usadas para avaliar a eficiência de fontes alternativas de carbono e energia. Glicerol, sorbitol e galactose foram as fontes alternativas estudadas. As culturas de células estabelecidas em meio líquido contendo sacarose foram transferidas para meios de cultura suplementados com sacarose ou glicerol ou sorbitol ou galactose. A fonte de carbono afetou distintamente os ganhos de matéria fresca, matéria seca e o acúmulo de proteína. A sacarose foi a melhor fonte de carbono para as três espécies estudadas. Galactose e glicerol promoveram pequeno crescimento das três espécies estudadas. A sacarose utilizada como fonte de carbono no meio líquido, promoveu o início de organização celular conhecido como a formação de meristemóides. Sorbitol, que não promoveu crescimento significativo, foi a única fonte alternativa de carbono testada que também promoveu este efeito