A screen for modifiers of decapentaplegic mutant phenotypes identifies lilliputian, the only member of the Fragile-X/Burkitt's Lymphoma family of transcription factors in Drosophila melanogaster.
The decapentaplegic (dpp) gene directs numerous developmental events in Drosophila melanogaster. dpp encodes a member of the Transforming Growth Factor-beta family of secreted signaling molecules. At this time, mechanisms of dpp signaling have not yet been fully described. Therefore we conducted a genetic screen for new dpp signaling pathway components. The screen exploited a transvection-dependent dpp phenotype: heldout wings. The screen generated 30 mutations that appear to disrupt transvection at dpp. One of the mutations is a translocation with a recessive lethal breakpoint in cytological region 23C1-2. Genetic analyses identified a number of mutations allelic to this breakpoint. The 23C1-2 complementation group includes several mutations in the newly discovered gene lilliputian (lilli). lilli mutations that disrupt the transvection-dependent dpp phenotype are also dominant maternal enhancers of recessive embryonic lethal alleles of dpp and screw. lilli zygotic mutant embryos exhibit a partially ventralized phenotype similar to dpp embryonic lethal mutations. Phylogenetic analyses revealed that lilli encodes the only Drosophila member of a family of transcription factors that includes the human genes causing Fragile-X mental retardation (FMR2) and Burkitt's Lymphoma (LAF4). Taken together, the genetic and phylogenetic data suggest that lilli may be an activator of dpp expression in embryonic dorsal-ventral patterning and wing development.
Su
M A
MA
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
Wisotzkey
R G
RG
Newfeld
S J
SJ
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D002051:Burkitt Lymphoma / Q000235:genetics*; D002874:Chromosome Mapping; D003433:Crosses, Genetic; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D051860:Fragile X Messenger Ribonucleoprotein 1; D018507:Gene Expression Regulation, Developmental; D005799:Genes, Dominant; D005808:Genes, Recessive; D019476:Insect Proteins / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics*; D010641:Phenotype; D010802:Phylogeny; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
D029721:Drosophila Proteins; D051860:Fragile X Messenger Ribonucleoprotein 1; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D014157:Transcription Factors; C064196:dpp protein, Drosophila; C423386:lilli protein, Drosophila