Conserved regulation of the Caenorhabditis elegans labial/Hox1 gene ceh-13.
Caenorhabditis elegans contains a set of six cluster-type homeobox (Hox) genes that are required during larval development. Some of them, but unlike in flies not all of them, are also required during embryogenesis. It has been suggested that the control of the embryonic expression of the worm Hox genes might differ from that of other species by being regulated in a lineal rather than a regional mode. Here, we present a trans-species analysis of the cis-regulatory region of ceh-13, the worm ortholog of the Drosophila labial and the vertebrate Hox1 genes, and find that the molecular mechanisms that regulate its expression may be similar to what has been found in species that follow a regulative, non-cell-autonomous mode of development. We have identified two enhancer fragments that are involved in different aspects of the embryonic ceh-13 expression pattern. We show that important features of comma-stage expression depend on an autoregulatory input that requires ceh-13 and ceh-20 functions. Our data show that the molecular nature of Hox1 class gene autoregulation has been conserved between worms, flies, and vertebrates. The second regulatory sequence is sufficient to drive correct early embryonic expression of ceh-13. Interestingly, this enhancer fragment acts as a response element of the Wnt/WG signaling pathway in Drosophila embryos.
Streit
Adrian
A
Department of Biology, University of Fribourg, Pérolles, Fribourg, CH-1700, Switzerland.
Kohler
Reto
R
Marty
Thomas
T
Belfiore
Marco
M
Takacs-Vellai
Krisztina
K
Vigano
Maria-Alessandra
MA
Schnabel
Ralf
R
Affolter
Markus
M
Müller
Fritz
F
D000818:Animals; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000196:embryology / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics; D024202:Electrophoretic Mobility Shift Assay; D004742:Enhancer Elements, Genetic; D018507:Gene Expression Regulation, Developmental; D005801:Genes, Homeobox; D018398:Homeodomain Proteins / Q000235:genetics*
C118851:CEH-13 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D018398:Homeodomain Proteins