This incipient model for the translational control of lin-14
proposes a temporal gradient of regulation by lin-4
is progressively repressed from stages L1 to L3, driving the transition from one stage to the next. The proponent of this model, Dr. Gary Ruvkun
argues that the fact that there are seven consensus sequences in lin-14
3'-UTR that can form hybrids with lin-4
small RNAs can be construed as the mechanism by which the temporal regulation is effected. I.e., the time that takes the small RNAs to occupy seven position. Notwithstanding, this model seems to remain a point of controversy in the field. Kimble and a close colleague and collaborator Marvin Wikens
are quick to point out that the hybrid molecules proposed in this molecule have not been detected by any direct methods at this point. A possible point of contention may be the method used by Ruvkun to test his "temporal gradient" hypothesis, which consisted of a reporter gene bearing 3 of the 7 consensus elements and which showed partial temporal gradient activity. A more exhaustive analysis of the literature would be required to discern this issue in its full scope.