The T-box genes H15 and optomotor-blind in the spiders Cupiennius salei, Tegenaria atrica and Achaearanea tepidariorum and the dorsoventral axis of arthropod appendages.
Dorsoventral axis formation in the legs of the fly Drosophila melanogaster requires the T-box genes optomotor-blind (omb) and H15. Evolutionary conservation of the patterning functions of these genes is unclear, because data on H15 expression in the spider Cupiennius salei did not support a general role of H15 in ventral fate specification. However, H15 has a paralogous gene, midline (mid) in Drosophila and H15 duplicates are also present in Cupiennius and the millipede Glomeris marginata. H15 therefore seems to have been subject to gene duplication opening the possibility that the previous account on Cupiennius has overlooked one or several paralogs. We have studied omb- and H15-related genes in two additional spider species, Tegenaria atrica and Achearanea tepidariorum and show that in both species one of the H15 genes belongs to a third group of spider H15 genes that has an expression pattern very similar to the H15 pattern in Drosophila. The expression patterns of all omb-related genes are also very similar to the omb expression pattern in Drosophila. These data suggest that the dorsoventral patterning functions of omb and H15 are conserved in the arthropods and that the previous conclusions were based on an incomplete data set in Cupiennius. Our results emphasize the importance of a broad taxon sampling in comparative studies.
Janssen
Ralf
R
Institut für Genetik, Universität zu Köln, Abteilung für Evolutionsgenetik, Zülpicher Str. 47, 50674 Köln, Germany.
Feitosa
Natalia M
NM
Damen
Wim G M
WG
Prpic
Nikola-Michael
NM
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D019521:Body Patterning / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics; D005121:Extremities / Q000196:embryology; D005260:Female; D020440:Gene Duplication; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D017403:In Situ Hybridization; D008297:Male; D013045:Species Specificity; D013112:Spiders / Q000145:classification / Q000196:embryology* / Q000235:genetics*; D020825:T-Box Domain Proteins / Q000235:genetics*
D017931:DNA Primers; D020825:T-Box Domain Proteins