Chicago team shows moth-fly odd-paired gene sets head-tail axis like bicoid

University of Chicago researchers report in PLOS Biology that the moth fly Clogmia albipunctata uses the zic-family gene odd-paired as an anterior determinant, establishing the head-to-tail body axis through a mechanism different from Drosophila's bicoid gene. In fruit flies, bicoid controls anterior patterning but exists only in some fly species. In 2019, Urs Schmidt-Ott and colleagues identified other conserved genes that took on the same job in other flies, an example of developmental system drift in which gene networks diverge while the head-tail outcome remains. The new work, with Ezra Amiri and co-workers, finds that Clogmia odd-paired initiates anterior patterning by opening chromatin and activating transcription at the homeobrain and sloppy-paired loci. Schmidt-Ott's lab is using new genetic tools across fly species to test how such substitutions rewire embryonic gene networks downstream. DOI: 10.1371/journal.pbio.3003896.