5B). identified. Analysis by the KB-FuzzyART and subsequent molecular and genetic analyses previously showed that (repress the expression of some abaxial-determinant genes, such as ((and and were regulated by modifier genes, ((and by using KB-FuzzyART and molecular analyses. The results showed that expression of ((and functions, which suggests that the AS1CAS2CETT pathway plays a critical role in controlling the cell division cycle and the biosynthesis of cytokinin around SAM to stabilize leaf development in to make a new gene list (Gene-list-2). Using Gene-list-2, we applied KB-FuzzyART to two series of microarray data, to identify the genes downstream of ((gene (Takano et al. 2010, Betsuyaku et al. 2011, Uchida et al. 2013). As each leaf grows, its morphology becomes established along three axes, the proximalCdistal, adaxialCabaxial and medialClateral axes. AdaxialCabaxial patterning at the initial stage, occurring in regions adjacent to the SAM, is critical for the lateral expansion of the lamina along the medialClateral axis for formation of flat DHTR symmetric leaves (Waites and Hudson 1995, Byrne et al. 2000, Semiarti et al. 2001, Tsukaya 2006, Iwakawa et al. 2007, Bowman and Floyd 2008, Szakonyi et al. 2010, Moon and Hake 2011, Yamaguchi et al. 2012). In (((((((also has a role in the formation of flat leaves of (Prez-Prez et al. 2010). Nevertheless, information on gene networks that might control these regulators remains elusive. and are key regulators of the formation of flat symmetric leaves. and encode nuclear proteins and form a complex (referred to as AS1CAS2 in this report; Xu et al. 2003, Yang et al. 2008, Luo et al. 2012). Mutations in these genes are associated with pleiotropic abnormalities in leaves along the three developmental axes Palmitic acid (Rdei and Hirono 1964, Tsukaya and Uchimiya 1997, Byrne et al. 2000, Ori et al. 2000, Semiarti et al. 2001, Iwakawa et al. 2002, Iwakawa et al. 2007), suggesting that AS1CAS2 regulates multiple genes (Takahashi et al. 2008) that might be involved in leaf formation along these axes. The AS1CAS2 complex directly represses the transcription of and (Guo et al. 2008). Some of the pleiotropic abnormalities, including short leaves, of and plants have been attributed to ectopic expression of and (Ikezaki et al. 2010), suggesting a role for these genes in the proximalCdistal development of the leaf. Furthermore, transcripts levels of the and genes are repressed downstream of and in shoot apices (Iwakawa et al. 2007, Takahashi et al. 2008). AS1CAS2 directly represses expression of in and is responsible for defects in both development of the adaxial domain and expansion of the leaf lamina (Iwasaki et al. 2013). These results suggest the involvement of AS1CAS2 in both adaxial development and the expansion of leaves through, at least in part, the functions of and leaves are enhanced under certain growth conditions as well as in conjunction with mutations in members of certain groups of genes (see the Introduction of Horiguchi et al. 2011b, Kojima et al. 2011, Ishibashi et al. 2012, Nakagawa et al. 2012, Xu et al. 2012), which are designated as modifiers of adaxialCabaxial patterning (Szakonyi et al. 2010, Iwasaki et al. 2013). These modifier genes include several that mediate the biogenesis of tasiR-ARF [a (Kojima et al. 2011). The double mutant produces filamentous leaves with abaxialized epidermis. We have further reported a mutation, designated (or background (Ishibashi et al. 2012). encodes BOBBER1 (BOB1) (Jurkuta et Palmitic acid al. 2009, Perez et al. 2009), an Arabidopsis ortholog of eukaryotic NudC domain proteins. Transcript levels of and all four class 1 genes are markedly elevated in shoot apices of and mutants. While these observations do suggest genetic interactions between and and each of these modifier genes, our understanding of the regulation mechanism for the expression of polarity-related effectors by AS1CAS2 is still limited. Pathways of regulation by modifiers for the establishment of leaf polarity and cell proliferation to produce flat and symmetric leaves are largely unknown. In the present study, we have carried out clustering analysis by KB-FuzzyART with a new gene list, Gene-list-2, by which we here report that AS1CAS2 plays roles in the repression of the ((and is a common target of modifier genes, and background As mentioned in the Introduction, mutations of and act as modifiers of and to enhance both the adaxial defect to generate filamentous leaves with an abaxialized surface, and the expression levels of many genes including increased in and double mutants (Kojima et al. 2011, Ishibashi et al. 2012). In addition, introduction of the mutation into the double mutant partially suppressed its phenotype of filamentous leaves (Ishibashi et al. 2012), indicating that the increased level of transcripts is responsible for the adaxial defect. To confirm this indication further, we examined the effects of Palmitic acid the gene mutation, which is.