Three-dimensional modeling and diversity analysis reveals distinct AVR recognition sites and evolutionary pathways in wild and domesticated wheat Pm3 R genes.

The Pm3 gene confers resistance against wheat powdery mildew. Studies of Pm3 diversity have shown that Pm3 alleles isolated from southern populations of wild emmer wheat located in Lebanon, Jordan, Israel, and Syria are more diverse and more distant from bread wheat alleles than alleles from the northern wild wheat populations located in Turkey, Iran, and Iraq. Therefore, southern populations from Israel were studied extensively to reveal novel Pm3 alleles that are absent from the cultivated gene pool. Candidate Pm3 genes were isolated via a polymerase chain reaction cloning approach. Known and newly identified Pm3 genes were subjected to variation analysis and polymorphic amino acid residues were superimposed on a three-dimensional (3D) model of PM3. The region of highest interspecies diversity between Triticum aestivum and T. dicoccoides lies in leucine-rich repeats (LRR) 19 to 24, whereas most intraspecies diversity in T. aestivum is located in LRR 25 to 28. Interestingly, these two regions are separated by one large LRR whose propensity for flexibility facilitates the conformation of the PM3 LRR domain into two differently structured models. The combination of evolutionary and protein 3D structure analysis revealed that Pm3 genes in wild and domesticated wheat show different evolutionary histories which might have been triggered through different interactions with the powdery mildew pathogen.

First-degree atrioventricular block and restrictive physiology as cardiac manifestations of Fabry's disease.

Fabry's disease is an X-linked disorder of glycosphingolipid catabolism related to the defective activity of glycosphingolipid, mainly ceramide trihexoside, in the vascular smooth muscle, myocardium, cells of the sympathetic central nervous system, and epithelial cells of renal glomeruli. We describe a young man who had Fabry's disease and unusual electrocardiographic and echocardiographic patterns at admission for treatment of left leg cellulitis. Findings included a prolonged PR interval and a right bundle branch block pattern, no echocardiographic signs of septal or hypertrophic cardiomyopathy, and a restrictive physiologic pattern. This pattern of electrocardiographic and echocardiographic characteristics of Fabry's disease has not been reported previously and should be added to the other cardiac manifestations of Fabry's disease.