Skip to main content
. 2019 Jul 26;8(3):55. doi: 10.3390/biology8030055

Figure 2.

Figure 2

Two sides of the same coin? (A) Cytokinesis signaling molecules localize to the plus-ends of astral MTs (referred to as cytokinesis signaling (CS)-TIPs; shown in red) within minutes of anaphase onset and activate RhoA (shown in blue) upon cortical contact. In this model, a putative polar gradient (shown in orange gradient) inhibits the localization of CS-TIP components to MT plus-ends. During the “Pre-Patterning” phase in early-mid anaphase, the polar gradient does not reach astral MT plus-ends and; therefore, astral MT plus-ends in both the polar and equatorial regions are capable of triggering transient RhoA activation. (B) The unexplained phenomenon of CS-TIP patterning involves the retention of CS-TIPs on equatorial astral MTs and the loss of CS-TIPs from polar astral MTs during late anaphase and telophase (referred to as ‘Post-Patterning’). In this model, polar CS-TIPs are lost as the spindle poles approach the polar cortex and the inhibitory polar gradient envelops polar astral MT plus-ends. Since the inhibitory polar gradient still does not reach the equatorial MT plus-ends, CS-TIPs in this area are retained and sustained RhoA activation supports cleavage furrow assembly and ingression in the equatorial region.