RT Journal Article
SR Electronic
T1 A re-inducible genetic cascade patterns the anterior-posterior axis of insects in a threshold-free fashion
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 321786
DO 10.1101/321786
A1 Alena Boos
A1 Jutta Distler
A1 Heike Rudolf
A1 Martin Klingler
A1 Ezzat El-Sherif
YR 2018
UL http://biorxiv.org/content/early/2018/05/15/321786.abstract
AB Gap genes mediate the division of the anterior-posterior axis of insects into different fates through regulating downstream hox genes. Decades of tinkering the segmentation gene network of the long-germ fruit fly Drosophila melanogaster led to the conclusion that gap genes are regulated (at least initially) through a threshold-based French Flag model, guided by both anteriorly- and posteriorly-localized morphogen gradients (bicoid and caudal, respectively). In this paper, we show that the expression patterns of gap genes in the intermediate-germ beetle Tribolium castaneum are mediated by a self-regulatory and threshold-free ‘Speed Regulation’ mechanism, guided by a posterior gradient of the transcription factor caudal. We show this by re-inducing the gap gene cascade at arbitrary points in time by simply re-inducing the leading gene in the gap gene cascade (namely, hunchback). This demonstrates that the gap gene network is self-regulatory and is primarily under the control of a posterior morphogen in short- and intermediate-germ insects.