Regulatory elements required for development of caenorhabditis elegans hermaphrodites are conserved in the tra-2 homologue of C. remanei, a male/female sister species.
The Caenorhabditis elegans hermaphrodite is essentially a female that produces sperm. In C. elegans, tra-2 promotes female fates and must be repressed to achieve hermaphrodite spermatogenesis. In an effort to learn how mating systems evolve, we have cloned tra-2 from C. remanei, the closest gonochoristic relative of C. elegans. We found its structure to be similar to that of Ce-tra-2 but its sequence to be divergent. RNA interference demonstrates that Cr-tra-2 promotes female fates. Two sites of tra-2 regulation are required for the onset of hermaphrodite spermatogenesis in C. elegans. One, the MX region of TRA-2, is as well conserved in C. remanei as it is in C. briggsae (another male/hermaphrodite species), suggesting that this control is not unique to hermaphrodites. Another, the DRE/TGE element of the tra-2 3' UTR, was not detected by sequence analysis. However, gel-shift assays demonstrate that a factor in C. remanei can bind specifically to the Cr-tra-2 3' UTR, suggesting that this translational control is also conserved. We propose that both controls are general and do not constitute a novel "switch" that enables sexual mosaicism in hermaphrodites. However, subtle quantitative or qualitative differences in their employment may underlie differences in mating system seen in Caenorhabditis.
Haag
E S
ES
Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
Kimble
J
J
D020413:3' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005260:Female; D017238:Genes, Helminth; D015801:Helminth Proteins / Q000235:genetics* / Q000502:physiology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology; D008969:Molecular Sequence Data; D018510:RNA, Helminth; D012333:RNA, Messenger; D012045:Regulatory Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D019849:Sex Determination Processes
D020413:3' Untranslated Regions; D029742:Caenorhabditis elegans Proteins; D015801:Helminth Proteins; D008565:Membrane Proteins; D018510:RNA, Helminth; D012333:RNA, Messenger; C076107:tra-2 protein, C elegans