From Mendel’s discovery on pea to today’s plant genetics and breeding

In 2015, we celebrated the 150th anniversary of the presentation of the seminal work of Gregor Johann Mendel. While Darwin’s theory of evolution was based on differential survival and differential reproductive success, Mendel’s theory of heredity relies on equality and stability throughout all stages of the life cycle. Darwin’s concepts were continuous variation and “soft” heredity; Mendel espoused discontinuous variation and “hard” heredity. Thus, the combination of Mendelian genetics with Darwin’s theory of natural selection was the process that resulted in the modern synthesis of evolutionary biology. Although biology, genetics, and genomics have been revolutionized in recent years, modern genetics will forever rely on simple principles founded on pea breeding using seven single gene characters. Purposeful use of mutants to study gene function is one of the essential tools of modern genetics. Today, over 100 plant species genomes have been sequenced. Mapping populations and their use in segregation of molecular markers and marker–trait association to map and isolate genes, were developed on the basis of Mendel's work. Genome-wide or genomic selection is a recent approach for the development of improved breeding lines. The analysis of complex traits has been enhanced by high-throughput phenotyping and developments in statistical and modeling methods for the analysis of phenotypic data. Introgression of novel alleles from landraces and wild relatives widens genetic diversity and improves traits; transgenic methodologies allow for the introduction of novel genes from diverse sources, and gene editing approaches offer possibilities to manipulate gene in a precise manner

Spectral and High Order Methods for Partial Differential Equations - ICOSAHOM 2012Selected papers from the ICOSAHOM conference, June 25-29, 2012, Gammarth, Tunisia /

IX, 425 p. 145 illus., 71 illus. in color.online

DESIGN POWER SUPPLY CONSIDERATIONS TO COMPENSATE BOOSTER POWER SUPPLIES EFFECTS ON THE SOLEIL STORAGE RING

Abstract The booster power supplies influence the storage ring beam position in synchrotron SOLEIL.To compensate these disturbances, a dedicated wire loop fed by an inhouse developed power supply (PS) was installed in the booster cable tray. The power supply output current is driven by direct measurement of the 3Hz booster power supplies. This paper discusses the PS requirements according to beam position measurements and the original design. Finally the orbit stability improvements when this power supply is switched on are presented

Somatotypes et débit cardiaque chez les handballeurs d'élite

L'étude montre que la masse maigre pourrait être considérée comme un facteur déterminant de la variation du débit cardiaque entre les joueurs de handball endomorphes et mésomorphes, au repos et à 70 % de VO2ma

Genetic characterization of Staphylococcus aureus isolated from nasal samples of healthy ewes in Tunisia. High prevalence of CC130 and CC522 lineages

Staphylococcus aureus is a versatile bacterium, which can infect or colonize a variety of host species. The objective of this study was to characterize S. aureus isolates recovered from nasal swabs of 167 healthy ewes sampled from 12 farms in different areas of Tunisia during the period of 20142015. Genetic lineages, virulence factors and antibiotic resistance mechanisms were determined for recovered isolates. S. aureus was detected in 45 out of 167 tested samples (26.9%). All isolates were methicillin-susceptible (MSSA) and the majority of them were susceptible to tested antibiotics with few exceptions (% of resistance): penicillin (8.8), ciprofloxacin (4.4), and tobramycin or tetracycline (2.2, each). Twelve different spa types were detected (t15098, t15099, t1773, t3576, t1534, t5428, t3750, t5970 t254, t2883, t127 and t933), two of them were new (t15098 and t15099). S. aureus isolates were ascribed to agrI (n = 23), agrII (n = 1) and agrIII (n = 20), and one was non-typeable. According to the sequence-type (ST) determined and/or the spa-type detected, the 45 S. aureus isolates were assigned to six clonal complexes, with CC522 (44.4%) and CC130 (37.7%) being the most common lineages. Twenty-one (46.6%) and two (4.2%) isolates harbored the tst and eta genes encoding TSST-1 and ETA, respectively. In conclusion, nares of healthy ewes could be a reservoir of MSSA CC522 and CC130, lineages associated with TSST-1 and ETA that might represent a risk to human health. © 2017 Elsevier Lt

Decrease of spermatozoa with an unbalanced chromosome content after cell sorting in men carrying a structural chromosomal abnormality

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