High-density microarrays for gene expression analysis.
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Biomedical subjects
Publications and source records attributed to M K Deyholos.
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We analyzed the 4-kb intragenic control region of the AGAMOUS (AG) gene to gain insight into the mechanisms controlling its expression during early flower development. We identified three major expression patterns conferred by 19 AG::reporter gene constructs: the normal AG pattern, a stamen-specific pattern, and a predominantly carpel pattern. To determine whether these three expression patterns were under negative control by APETALA2 (AP2) or LEUNIG (LUG), we analyzed beta-glucuronidase staining patterns in Arabidopsis plants homozygous for strong ap2 and lug mutations. Our results indicated that the stamen-specific pattern was independent of AP2 but dependent on LUG; conversely, the carpel-specific pattern was independent of LUG but dependent on AP2. These results lead to a model of control of AG expression such that expression in each of the two inner whorls is under independent positive and negative control.
Mechanisms controlling vein patterning are poorly understood. We describe a recessive Arabidopsis mutant, scarface (sfc), which maps to chromosome 5. sfc mutants have vein pattern defects in cotyledons, leaves, sepals and petals. In contrast to the wild type, in which these organs all have linear veins that are continuous with at least one other vein, in sfc mutants these organs' secondary and tertiary veins are largely replaced by small segments of discontinuous veins, which we call vascular islands. Patterning defects are manifest in cotyledon provascular tissue, suggesting that the patterning defect occurs early in organogenesis. sfc mutants have exaggerated responses to exogenous auxin. Analysis of monopteros (mp(T370)) sfc-1 double mutants suggested that SFC has partially overlapping functions with MP in patterning of both primary and secondary veins.