Four quantitative trait loci associated with low Nosema ceranae (Microsporidia) spore load in the honeybee Apis mellifera

Nosema ceranae has been recently introduced into the honeybee Apis mellifera as a novel microsporidian gut parasite. To locate the genetic region involved in N. ceranae infection tolerance, we fed N. ceranae spores to haploid drones of a F1 hybrid queen produced from a cross between a queen of a Nosemaresistant bred strain and drones of susceptible colonies. The spore loads of the infected F1 drones were used as the phenotype to identify quantitative trait loci (QTLs) associated with N. ceranae spore load. One hundred forty-eight infected drones were individually genotyped with microsatellite markers at an average marker distance of 20 cM along the genome. Four QTLs were significantly associated with low spore load, explaining 20.4 % of total spore load variance. Moreover, a candidate gene Aubergine (Aub) within the major QTL region was significantly overexpressed in drones with low spore loads than in those with high spore loads. Our results confirm the genetic basis of Nosema tolerance in the selected strain and show that both additive effects and epistatic interactions among the QTLs interfere with the tested phenotype.European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement BEE DOC FP7-KBBE-2009-3 244956CPFP, the Deutsche Forschungsgemeinschaft Project DFG SPP 1399(MO 373/26-1) and the China Scholarship Council.http://link.springer.com/journal/13592hb201

Factors affecting late survival after surgical remodeling of left ventricular aneurysms

Surgical remodeling of the left ventricle has involved various techniques of volume reduction. This study evaluates factors that influence long-term survival results with 3 operative methods. From 1979 to 2000, 157 patients (134 men, mean age 61 years) underwent operations for class III or IV congestive heart failure, angina, ventricular tachyarrhythmia, and sudden death after anteroseptal myocardial infarction. The preoperative ejection fraction was 28% ± 0.9% (mean ± standard error), and the pulmonary artery occlusive pressure was 15 ± 0.07 mm Hg. Cardiogenic shock was present in 26 patients (16%), and an intra-aortic balloon pump was used in 48 patients (30%). The type of procedure depended on the extent of endocardial disease and was aimed at maintaining the ellipsoid shape of the left ventricle cavity. In group I patients (n = 65), radical aneurysm resection and linear closure were performed. In group II patients (n = 70), septal dyskinesis was reinforced with a patch (septoplasty). In group III patients (n = 22), ventriculotomy closure was performed with an intracavitary oval patch. Hospital mortality was 16% (25/157) and was similar among the groups. Actuarial survival up to 18 years was better with a preoperative ejection fraction of 26% or greater ( P = .004) and a pulmonary artery occlusive pressure of 17 mm Hg or less ( P = .05). Survival was worse in patients who had intra-aortic balloon pump support ( P = .03). Five-year survival for all patients in group III was higher than for patients in group II (67% vs 47%, P = .04). Factors that improved long-term survival after left ventricular surgical remodeling were intraventricular patch repair, preoperative ejection fraction of 26% or greater, and pulmonary artery occlusive pressure of 17 mm Hg or less without the need for balloon pump assist