Id |
Subject |
Object |
Predicate |
Lexical cue |
T1 |
89-148 |
DRI_Background |
denotes |
Tissue morphogenesis is orchestrated by cell shape changes. |
T2 |
149-285 |
DRI_Background |
denotes |
Forces required to power these changes are generated by non-muscle myosin II (MyoII) motor proteins pulling filamentous actin (F-actin). |
T3 |
286-465 |
DRI_Approach |
denotes |
Actomyosin networks undergo cycles of assembly and disassembly (pulses) to cause cell deformations alternating with steps of stabilization to result in irreversible shape changes. |
T4 |
466-579 |
DRI_Background |
denotes |
Although this ratchet-like behaviour operates in a variety of contexts, the underlying mechanisms remain unclear. |
T5 |
580-718 |
DRI_Approach |
denotes |
Here we investigate the role of MyoII regulation through the conserved Rho1-Rok pathway during Drosophila melanogaster germband extension. |
T6 |
719-932 |
DRI_Approach |
denotes |
This morphogenetic process is powered by cell intercalation, which involves the shrinkage of junctions in the dorsal-ventral axis (vertical junctions) followed by junction extension in the anterior-posterior axis. |
T7 |
933-957 |
DRI_Approach |
denotes |
While polarized flows of |
T8 |
978-1082 |
DRI_Approach |
denotes |
pulses deform vertical junctions, MyoII enrichment on these junctions (planar polarity) stabilizes them. |
T9 |
1083-1353 |
DRI_Approach |
denotes |
We identify two critical properties of MyoII dynamics that underlie stability and pulsatility: exchange kinetics governed by phosphorylation-dephosphorylation cycles of the MyoII regulatory light chain; and advection due to contraction of the motors on F-actin networks. |
T10 |
1354-1501 |
DRI_Background |
denotes |
Spatial control over MyoII exchange kinetics establishes two stable regimes of high and low dissociation rates, resulting in MyoII planar polarity. |
T11 |
1502-1661 |
DRI_Background |
denotes |
Pulsatility emerges at intermediate dissociation rates, enabling convergent advection of MyoII and its upstream regulators Rho1 GTP, Rok and MyoII phosphatase. |
T12 |
1662-1731 |
DRI_Approach |
denotes |
Notably, pulsatility is not an outcome of an upstream Rho1 pacemaker. |
T13 |
1732-1876 |
DRI_Background |
denotes |
Rather, it is a self-organized system that involves positive and negative biomechanical feedback between MyoII advection and dissociation rates. |