Anti-PLAA (aa 639-738) polyclonal antibody

High levels of partial resistance are essential to manage northern corn leaf blight (NCLB) of maize, incited by the castual agent Exserobilum turcicum, in disease-prone environments. Maize inbred H99 displays high levels of partial resistance to E. turcicum and has been used as a donor line for the improvement of host resistance in susceptible temperate adapted germplasm. This study was undertaken to determine the potential of H99 as a prospective donor of partial resistance to E. turcicum in a disease-prone, mid-altitude tropical environment of List Africa. Estimates of the heritability of resistance in, and the number of genes for resistence to E. turcicum in H99 were determined using 120 F-2:3 families and their F-2.4 progenies derived from a cross between H99 and susceptible inbred A619. The lines were evaluated it replicated field experiments at Namulonge and Kamenyamiggo, Uganda, during 1993. Disease severity was assessed by counting lesion number, visually estimating percent leaf area affected (PLAA), and calculating the area under disease progress curves (AUDPC). Heritability estimates were computed from variance component analyses and parent-offspring regressions. Broad-sense heritability estimates of F-2:3 and F-2:4 lines were determined using plot-mean and family-mean bases across locations. Estimates of the number of genes controlling quantitative resistance to E. turcicum based on the Castle-Wright formula were oracle using the square of differences of phenotypic means of inbreds A619 and H99, and the square of the phenotypic range between the most susceptible and most resistant families in each generation. Heritability estimates for PLAA, and AUDPC based on PLAA, were Higher than those for lesion number and AUDPC based on lesion number, and ranged from 0.73 to 0.78. Narrow-sense heritability estimates calculated using parent-offspring regression also tended to be higher than those based on lesion number data. Gene number estimates were two to three for lesion number and four to five for PLAA based on the parental phenotypic means. Gene number estimates based on the phenotypic hinge of families were approxiinately eight for lesion number and five to seven for PLAA. Use of a modified Castle-Wright fomula raised all gene number estimates.

Leukoencephalopathies are a group of white matter disorders related to abnormal formation, maintenance, and turnover of myelin in the central nervous system. These disorders of the brain are categorized according to neuroradiological and pathophysiological criteria. Herein, we have identified a unique form of leukoencephalopathy in seven patients presenting at ages 2 to 4 months with progressive microcephaly, spastic quadriparesis, and global developmental delay. Clinical, metabolic, and imaging characterization of seven patients followed by homozygosity mapping and linkage analysis were performed. Next generation sequencing, bioinformatics, and segregation analyses followed, to determine a loss of function sequence variation in the phospholipase A(2)-activating protein encoding gene (PLAA). Expression and functional studies of the encoded protein were performed and included measurement of prostaglandin E-2 and cytosolic phospholipase A(2) activity in membrane fractions of fibroblasts derived from patients and healthy controls. Plaa-null mice were generated and prostaglandin E-2 levels were measured in different tissues. The novel phenotype of our patients segregated with a homozygous loss-of-function sequence variant, causing the substitution of leucine at position 752 to phenylalanine, in PLAA, which causes disruption of the protein's ability to induce prostaglandin E-2 and cytosolic phospholipase A(2) synthesis in patients' fibroblasts. Plaa-null mice were perinatal lethal with reduced brain levels of prostaglandin E-2. The non-functional phospholipase A(2)-activating protein and the associated neurological phenotype, reported herein for the first time, join other complex phospholipid defects that cause leukoencephalopathies in humans, emphasizing the importance of this axis in white matter development and maintenance.