Tissue-specific regulation of the LIM homeobox gene lin-11 during development of the Caenorhabditis elegans egg-laying system.
The egg-laying system of Caenorhabditis elegans hermaphrodites requires development of the vulva and its precise connection with the uterus. This process is regulated by LET-23-mediated epidermal growth factor signaling and LIN-12-mediated lateral signaling pathways. Among the nuclear factors that act downstream of these pathways, the LIM homeobox gene lin-11 plays a major role. lin-11 mutant animals are egg-laying defective because of the abnormalities in vulval lineage and uterine seam-cell formation. However, the mechanisms providing specificity to lin-11 function are not understood. Here, we examine the regulation of lin-11 during development of the egg-laying system. Our results demonstrate that the tissue-specific expression of lin-11 is controlled by two distinct regulatory elements that function as independent modules and together specify a wild-type egg-laying system. A uterine pi lineage module depends on the LIN-12/Notch signaling, while a vulval module depends on the LIN-17-mediated Wnt signaling. These results provide a unique example of the tissue-specific regulation of a LIM homeobox gene by two evolutionarily conserved signaling pathways. Finally, we provide evidence that the regulation of lin-11 by LIN-12/Notch signaling is directly mediated by the Su(H)/CBF1 family member LAG-1.
Gupta
Bhagwati P
BP
HHMI and Division of Biology, California Institute of Technology, Pasadena 91125, USA.
Sternberg
Paul W
PW
D000818:Animals; D017173:Caenorhabditis elegans / Q000033:anatomy & histology / Q000196:embryology* / Q000502:physiology; D029742:Caenorhabditis elegans Proteins; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000502:physiology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000502:physiology*; D009154:Mutation; D009928:Organ Specificity; D010058:Oviposition
D029742:Caenorhabditis elegans Proteins; D018398:Homeodomain Proteins; C111267:Lin-11 protein, C elegans