title: bloated tubules (blot) encodes a Drosophila member of the neurotransmitter transporter family required for organisation of the apical cytocortex.
abstract: We have identified a novel member of the vertebrate sodium- and chloride-dependent neurotransmitter symporter family from Drosophila melanogaster. This gene, named bloated tubules (blot), shows significant sequence similarity to a subgroup of vertebrate orphan transporters. blot transcripts are maternally supplied and during embryogenesis exhibit a complex and dynamic pattern in a subset of ectodermally derived epithelia, notably in the Malpighian tubules, and in the nervous system. Animals mutant for this gene are larval lethals, in which the Malpighian tubule cells are distended with an enlarged and disorganised apical surface. Embryos lacking the maternal component of blot expression die during early stages of development. They show an inability to form actin filaments in the apical cortex, resulting in impaired syncytial nuclear divisions, severe defects in the organisation of the cortical cytoskeleton, and a failure to cellularise. For the first time, a neurotransmitter transporter-like protein has been implicated in a function outside the nervous system. The isolation of blot thus provides the basis for an analysis of the relationship between the function of this putative transporter and epithelial morphogenesis.
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Johnson
authors.forename: E
authors.initials: E
authors.lastname: Knust
authors.forename: H
authors.initials: H
authors.lastname: Skaer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001756:Blastoderm; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003599:Cytoskeleton; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D005260:Female; D017344:Genes, Insect; D005838:Genotype; D008317:Malpighian Tubules / Q000196:embryology*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000302:isolation & purification*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D010641:Phenotype; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D012333:RNA, Messenger / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D027981:Symporters; D014018:Tissue Distribution
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D050480:Plasma Membrane Neurotransmitter Transport Proteins; D012333:RNA, Messenger; D027981:Symporters; C120970:blot protein, Drosophila