A concerted action of a paired-type homeobox gene, aristaless, and a homolog of Hox11/tlx homeobox gene, clawless, is essential for the distal tip development of the Drosophila leg.
The subdivision of the developing field by region-specific expression of genes encoding transcription factors is an essential step during appendage development in arthropod and vertebrates. In Drosophila leg development, the distal-most region (pretarsus) is specified by the expression of homeobox genes, aristaless and Lim1, and its immediate neighbor (distal tarsus) is specified by the expression of a pair of Bar homeobox genes. Here, we show that one additional gene, clawless, which is a homolog of vertebrate Hox11/tlx homeobox gene family and formerly known as C15, is specifically expressed in the pretarsus and cooperatively acts with aristaless to repress Bar and possibly to activate Lim1. Similar to aristaless, the maximal expression of clawless requires Lim1 and its co-factor, Chip. Bar attenuates aristaless and clawless expression through Lim1 repression. Aristaless and Clawless proteins form a complex capable of binding to specific DNA targets, which cannot be well recognized solely by Aristaless or Clawless.
Kojima
Tetsuya
T
Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan. skojima@mail.ecc.u-tokyo.ac.jp
Tsuji
Takuya
T
Saigo
Kaoru
K
D000818:Animals; D001483:Base Sequence; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D004628:Embryonic Structures / Q000033:anatomy & histology / Q000502:physiology; D005121:Extremities / Q000033:anatomy & histology / Q000196:embryology / Q000254:growth & development; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D060850:LIM-Homeodomain Proteins; D009024:Morphogenesis / Q000502:physiology; D046912:Multiprotein Complexes; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D014157:Transcription Factors; D060589:Zyxin
C499642:C15 protein, Drosophila; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; C085473:LHX1 protein, human; D060850:LIM-Homeodomain Proteins; D046912:Multiprotein Complexes; D012097:Repressor Proteins; D014157:Transcription Factors; C499520:Zyx protein, Drosophila; D060589:Zyxin; C079410:al protein, Drosophila