βFTZ-F1 and Broad-Complex positively regulate the transcription of the wing cuticle protein gene, BMWCP5, in wing discs of Bombyx mori

Key roles of the Broad-Complex gene in insect embryogenesis

“…Indeed, specific functions for particular isoforms have been elucidated through functional studies in D. melanogaster, for example in flight muscles (Sandstrom et al, 1997) and in other tissues and processes (see Spokony and Restifo (2007), and references therein), as well as in M. sexta Riddiford, 2001, 2002) and in B. mori (Uhlirova et al, 2003;Wang et al, 2009). There are even cases where the expression pattern suggests that different isoforms are functionally redundant but detailed studies have shown that they are actually acting at different times and in different cell types Restifo, 2007, 2009).…”

Ecdysone directly and indirectly regulates a cuticle protein gene, BMWCP10, in the wing disc of Bombyx mori

“…We also reported the binding sequences of bFTZ-F1 (Nita et al, 2009;Wang et al, 2009b), BR-Z2 (Wang et al, 2009a), and BR-C Z4 (BR-Z4; Wang et al, 2009b) upstream of cuticle protein genes, and they are also conserved in Diptera and Lepidoptera. The transcription factors and the sequences of the binding site of the target genes have co-evolved, and most of the transcription factors appeared before the appearance of the holometabolous insect (Bonneton et al, 2008); therefore, these ecdysone-responsive transcription factors and their binding sequences are conserved, as demonstrated in our present and previous studies.…”

“…7, three different types of cuticle protein genes are expressed in the wing discs during the fifth larval instar. BMWCP5 is expressed during pupation and the mid-pupal stage, when the ecdysteroid titer is declining and bFTZ-F1 is being expressed (Wang et al, 2009b). The promoter activity of BMWCP5 that required bFTZ-F1 was enhanced by BR-Z4, which is correlated with the in vivo expression of BR-Z4 and bFTZ-F1.…”

“…Identification of ecdysone receptor and BR-Z2 as the regulators of the BMWCP10 promoter is a novel finding for cuticle protein gene regulation. The promoter activity of BMWCP5 was regulated by bFTZ-F1 and enhanced by BR-C (Wang et al, 2009b). Thus, it was suggested that BR-C functioned with other factors as an enhancement of promoter activity.…”

“…7. Schematic representation of the hemolymph ecdysteroid titer (Kiguchi et al, 1985;Kawasaki et al, 1986) and the expression pattern of BmbFTZ-F1 (Nita et al, 2009), BmBR-Z2 (Wang et al, 2009a), BMWCP5 (Wang et al, 2009b), BMWCP10 (Wang et al, 2009a), and BMWCP11 (Futahashi et al, 2008) in wing discs of fifth larval instar and wing tissues of the pupal stage.…”