xol-1 acts as an early switch in the C. elegans male/hermaphrodite decision.
xol-1 is the earliest-acting gene in the known hierarchy that controls C. elegans sex determination and dosage compensation. We show that the primary sex-determining signal (the X/A ratio) directs the choice of sexual fate by regulating xol-1 transcript levels: high xol-1 expression during gastrulation triggers male development, whereas low expression at that time permits hermaphrodite development. Inappropriately high xol-1 expression causes hermaphrodites to activate the male program of development and die from a disruption in dosage compensation. These results demonstrate that xol-1 functions as an early developmental switch to set the choice of sexual fate and suggest that assessment of the X/A ratio occurs only early in embryogenesis to determine sex. Moreover, sdc-2, a gene that must be repressed by xol-1 to ensure male development, may be a direct target of negative regulation by xol-1.
Rhind
N R
NR
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Miller
L M
LM
Kopczynski
J B
JB
Meyer
B J
BJ
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D003001:Cloning, Molecular; D012734:Disorders of Sex Development / Q000235:genetics; D004303:Dosage Compensation, Genetic; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005775:Gastrula / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000737:chemistry / Q000235:genetics* / Q000502:physiology; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D018510:RNA, Helminth / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D012732:Sex Determination Analysis
D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D018510:RNA, Helminth; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C091429:XOL-1 protein, C elegans