Genome-wide analysis of sex-enriched gene expression during C. elegans larval development.
Sex determination in C. elegans is controlled by the TRA-1 zinc finger protein, a Ci/GLI homolog that promotes female cell fates throughout the body. The regulatory hierarchy that controls TRA-1 is well established, but the downstream effectors that establish sexual dimorphism during larval development remain largely unknown. Here, we describe the use of cDNA microarrays to identify sex-enriched transcripts expressed during three stages of C. elegans larval development. By excluding previously identified germline-enriched transcripts, we focused on somatic sexual development. This approach identified a large number of sex-enriched transcripts that are good candidates to encode regulators of somatic sexual development. We found little overlap between genes with sex-enriched expression in early versus late larval development, indicating that distinct sexual regulatory programs operate at these times. Genes with sex-enriched expression are found throughout the genome, with no strong bias between autosomes and X chromosomes. Reporter gene analysis revealed that these genes are expressed in highly specific patterns in a variety of sexually dimorphic cells. We searched for TRA-1 consensus DNA binding sites near genes with sex-enriched expression, and found that most strongly sex-enriched mRNAs are likely to be regulated indirectly by TRA-1. These results suggest that TRA-1 controls sexual dimorphism through a small number of intermediary regulators rather than by acting directly on the full constellation of genes involved in sex-specific differentiation.
Thoemke
Kara
K
Department of Genetics, Cell Biology, and Development, and Developmental Biology Center, University of Minnesota, Minneapolis, MN 55455, USA.
Yi
Woelsung
W
Ross
Jennifer M
JM
Kim
Shinseog
S
Reinke
Valerie
V
Zarkower
David
D
D000818:Animals; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002875:Chromosomes; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D012734:Disorders of Sex Development / Q000235:genetics; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D017930:Genes, Reporter; D016678:Genome; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D016366:Open Reading Frames; D020161:Physical Chromosome Mapping; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D012727:Sex Characteristics; D019849:Sex Determination Processes; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D019076:Transgenes
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C121025:tra-1 protein, C elegans; D049452:Green Fluorescent Proteins