کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2043279 | 1073339 | 2009 | 5 صفحه PDF | دانلود رایگان |
SummaryPosterior expression of Caudal is required for early embryonic development in nematodes, arthropods, and vertebrates 1, 2, 3, 4, 5, 6, 7, 8 and 9. In Drosophila, ectopic Caudal in anterior cells can induce head defects, and in Caenorhabditis the absence of Caudal in anterior embryonic cells is required for proper development 6 and 10. Anterior Caudal repression in these species is achieved through unrelated translational repressors, the homeodomain protein Bicoid [11] and the KH domain factor Mex-3 6 and 12, respectively. Here we report that the Mex-3 ortholog in the flour beetle Tribolium plays a crucial role in head formation and that Caudal in this species is repressed by the combined activities of Mex-3 and Zen-2, a protein sharing common ancestry with the dipteran morphogen Bicoid. We propose that Mex-3 represents an ancient “anterior” promoting factor common to all Ecdysozoa (and maybe all Bilateria), whose role has been usurped in higher dipterans by Bicoid.
Journal: - Volume 19, Issue 21, 17 November 2009, Pages 1811–1815