Feedback control of sex determination by dosage compensation revealed through Caenorhabditis elegans sdc-3 mutations.
In Caenorhabditis elegans, sex determination and dosage compensation are coordinately controlled through a group of genes that respond to the primary sex determination signal. Here we describe a new gene, sdc-3, that also controls these processes. In contrast to previously described genes, the sex determination and dosage compensation activities of sdc-3 are separately mutable, indicating that they function independently. Paradoxically, the sdc-3 null phenotype fails to reveal the role of sdc-3 in sex determination: sdc-3 null mutations that lack both activities disrupt dosage compensation but cause no overt sexual transformation. We demonstrate that the dosage compensation defect of sdc-3 null alleles suppresses their sex determination defect. This self-suppression phenomenon provides a striking example of how a disruption in dosage compensation can affect sexual fate. We propose that the suppression occurs via a feedback mechanism that acts at an early regulatory step in the sex determination pathway to promote proper sexual identity.
DeLong
L
L
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Plenefisch
J D
JD
Klein
R D
RD
Meyer
B J
BJ
D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D004303:Dosage Compensation, Genetic; D005246:Feedback; D005260:Female; D005809:Genes, Regulator; D015801:Helminth Proteins / Q000235:genetics*; D008297:Male; D009154:Mutation; D010641:Phenotype; D012333:RNA, Messenger / Q000235:genetics; D012732:Sex Determination Analysis; D014960:X Chromosome
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; D012333:RNA, Messenger; C079666:Sdc-3 protein, C elegans; C079744:her-1 protein, C elegans