Localized Bicaudal-C RNA encodes a protein containing a KH domain, the RNA binding motif of FMR1

EMBO J. 1995 May 1;14(9):2043-55.


The Bicaudal-C (Bic-C) gene of Drosophila melanogaster is required for correct targeting of the migrating anterior follicle cells and for specifying anterior position. Females lacking any wild type copies of Bic-C produce only eggshells open at the anterior end, because of the failure of the columnar follicle cells to migrate in the correct position at the nurse cell--oocyte boundary. Embryos which develop from eggs produced in females with only one wild type copy of Bic-C show defects in anterior patterning and an abnormal persistence of oskar RNA in anterior regions. We cloned Bic-C and found that, in ovaries, Bic-C RNA is expressed only in germline cells. Bic-C RNA is localized to the oocyte in early oogenesis, and later concentrates at its anterior cortex. The Bic-C protein includes five KH domains similar to those found in the human fragile-X protein FMR1. Alteration of a highly conserved KH domain codon by mutation abrogates in vivo Bic-C function. These results suggest roles for the Bic-C protein in localizing RNAs and in intercellular signaling.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA / genetics
  • Drosophila Proteins*
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics
  • Drosophila melanogaster / metabolism
  • Female
  • Fragile X Mental Retardation Protein
  • Genes, Insect
  • Humans
  • Insect Hormones / genetics*
  • Male
  • Molecular Sequence Data
  • Nerve Tissue Proteins / metabolism*
  • Oocytes / metabolism
  • Phenotype
  • RNA / genetics*
  • RNA / metabolism
  • RNA Splicing
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism*
  • Receptor Protein-Tyrosine Kinases / genetics
  • Signal Transduction


  • BicD protein, Drosophila
  • Drosophila Proteins
  • FMR1 protein, human
  • Insect Hormones
  • Nerve Tissue Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • Fragile X Mental Retardation Protein
  • RNA
  • DNA
  • Receptor Protein-Tyrosine Kinases

Associated data

  • GENBANK/U15928