title: Patterns and symmetries in leaf development.
abstract: The leaf is a coordinated mosaic of developmental domains, which are evident from leaf inception on the flanks of the apical meristem. The subdivision of the meristem into molecularly defined domains is regulated by the interactions of a number of gene products and by receptor kinase-mediated signals. The acquisition of symmetry axes in the emerging leaf is a process coordinated by hormones (such as auxin and cytokinins) and the expression of classes of genes (such as the knox and the ARP, as1/rs2/phan, genes). As with simple leaves, the architecture of compound leaves is defined by spatial/temporal gradients of regulatory gene functions: complexity results from the interplay between leaf differentiation processes and genes maintaining a partial level of indeterminacy in the developing primordium. Boundaries between regions with different molecular 'addresses' are considered, in plants as in Drosophila, as organizing centres for lateral organ development.
authors.affiliation: Centro Ricerche e Studi Agroalimentari (CERSA-FPTP), c/o DiProVe Via Celoria 2, 20133, Milano, Italy. carlo.pozzi@unimi.it
authors.forename: C
authors.initials: C
authors.lastname: Pozzi
authors.forename: L
authors.initials: L
authors.lastname: Rossini
authors.forename: F
authors.initials: F
authors.lastname: Agosti
mesh_terms: D019521:Body Patterning / Q000235:genetics / Q000502:physiology; D005801:Genes, Homeobox / Q000235:genetics / Q000502:physiology; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D001467:Hordeum / Q000235:genetics / Q000502:physiology; D018551:Solanum lycopersicum / Q000235:genetics / Q000502:physiology; D018519:Meristem / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D008954:Models, Biological; D018532:Pisum sativum / Q000235:genetics / Q000502:physiology; D018515:Plant Leaves / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology; D010940:Plant Proteins; D011494:Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D018398:Homeodomain Proteins; C405985:Knox1 protein, plant; D010940:Plant Proteins; D011494:Protein Kinases