Independent domains of the Sdc-3 protein control sex determination and dosage compensation in C. elegans

Cell. 1993 Feb 12;72(3):349-64. doi: 10.1016/0092-8674(93)90113-5.


sdc-3 is an early-acting regulatory gene that controls both sex determination and X chromosome dosage compensation in C. elegans. It is unique among sdc genes in that its sex determination and dosage compensation functions act independently. The molecular analysis reported here demonstrates that separate domains of the Sdc-3 protein control these two developmental processes. Sequence analysis of 16 sdc-3 alleles reveals that the dosage compensation mutations specifically eliminate a pair of zinc finger motifs at the carboxyl terminus of Sdc-3, while the sex determination mutations after a region with limited homology to the ATP-binding domain of myosin. Null mutations, which disrupt both processes, abort translation of Sdc-3 prior to both domains. Analysis of site-directed changes confirms the functional significance of the two separate regions in sex determination and dosage compensation and reveals that an additional region, undetected by genetic analysis, is also required for proper dosage compensation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins*
  • Cloning, Molecular
  • DNA-Binding Proteins*
  • Dosage Compensation, Genetic
  • Gene Expression Regulation
  • Genes, Helminth*
  • Genes, Regulator*
  • Helminth Proteins / chemistry
  • Helminth Proteins / genetics*
  • Helminth Proteins / metabolism
  • Molecular Sequence Data
  • Myosins / chemistry
  • Oligodeoxyribonucleotides / chemistry
  • RNA, Messenger / genetics
  • Restriction Mapping
  • Sequence Deletion
  • Sex Determination Analysis
  • Structure-Activity Relationship
  • Transcription, Genetic
  • Zinc Fingers


  • Caenorhabditis elegans Proteins
  • DNA-Binding Proteins
  • Helminth Proteins
  • Oligodeoxyribonucleotides
  • RNA, Messenger
  • Sdc-3 protein, C elegans
  • Adenosine Triphosphate
  • Myosins

Associated data

  • GENBANK/M72713