A Case of Prosopometamorphopsia Restricted to the Nose and Mouth with Right Medial Temporooccipital Lobe Infarction that Included the Fusiform Face Area.

BACKGROUND: Metamorphopsia includes a broad spectrum of visual perceptual distortions, such as alteration of perceived object size or, rarely, altered perception of faces, termed prosopometamorphopsia. CASE REPORT: This report describes a patient who complained of metamorphopsia restricted to the center of the face, particularly the lower part of the face (nose and mouth), following infarction of the right medial temporooccipital lobe that included the fusiform face area. CONCLUSIONS: The fusiform face area is commonly believed to be a face-selective cortical region dedicated to the visual analysis of face stimuli. We speculate that any injury to this brain area could bring about prosopometamorphopsia involving whole or unilateral face perception, or very rarely, as in our case, distortion restricted to the central area of the face. Furthermore, there could be topographical correspondences between facial structures and the fusiform face area.

Brassinosteroids control AtEXPA5 gene expression in Arabidopsis thaliana.

To elucidate the spatial and temporal roles of EXPANSIN A5 (AtEXPA5) in growth and development of Arabidopsis thaliana, phenotypic alterations in loss-of-function mutants were observed. Seedlings of the null mutant, expA5-1, had shorter roots and hypocotyls than those of wild-type plants under both light and dark conditions. Compared to wild-type plants, the mutants had smaller rosette leaves. AtEXPA5 was dominantly expressed in aerial parts of A. thaliana, especially in the inflorescence stems and flowers. Expression of AtEXPA5 was enhanced by exogenously applied brassinosteroids. AtEXPA5 expression was reduced in a brassinosteroid-deficient mutant (det2) and a signaling mutant (bri1-301), while it was increased in bzr1-1D, a dominant mutant of a brassinosteroid transcription factor. A double mutant, bzr1-1DXexpA5-1, showed reduced growth compared to the bzr1-1D mutant. In addition, the brassinazole resistance of bzr1-1D was impaired in the double mutant. These findings indicate that AtEXPA5 is a growth-regulating gene whose expression is controlled by brassinosteroid signaling downstream of BZR1 in A. thaliana.

Arabidopsis CYP85A2, a cytochrome P450, mediates the Baeyer-Villiger oxidation of castasterone to brassinolide in brassinosteroid biosynthesis.

The conversion of castasterone (CS) to brassinolide (BL), a Baeyer-Villiger oxidation, represents the final and rate-limiting step in the biosynthesis of BL in plants. Heterologously expressed Arabidopsis thaliana CYP85A2 in yeast mediated the conversion of CS to BL as well as the C-6 oxidation of brassinosteroids (BRs). This indicated that CYP85A2 is a bifunctional enzyme that possesses BR C-6 oxidase and BL synthase activity. CYP85A2 is thus a cytochrome P450 that mediates Baeyer-Villiger oxidation in plants. Biochemical, physiological, and molecular genetic analyses of Arabidopsis CYP85A2 loss-of-function and overexpression lines demonstrated that CS has to be a bioactive BR that controls the overall growth and development of Arabidopsis plants. Mutant studies also revealed that BL may not always be necessary for normal growth and development but that Arabidopsis plants acquire great benefit in terms of growth and development in the presence of BL.