High impact information on lin-42

• Per mRNA levels oscillate with an approximately 24-hour periodicity. lin-42 mRNA levels also oscillate, but with a faster rhythm; the oscillation occurs relative to the approximately 6-hour molting cycles of postembryonic development [1].
• The time of LIN-29 appearance in the hypodermis is controlled by the heterochronic gene pathway: LIN-29 accumulates in the hypodermis abnormally early, during the third larval stage, in loss-of-function lin-14, lin-28 and lin-42 mutants, and fails to accumulate in hypodermis of lin-4 mutants [2].
• We demonstrate that lin-42 acts broadly, timing developmental events in the gonad, vulva, and sex myoblasts, in addition to its well-established role in timing terminal differentiation of the hypodermis [3].
• In contrast, lin-42 function in timing gonad morphogenesis is unique among the known heterochronic genes: inactivation of lin-42 causes the elongating gonad arms to reflex too early, a phenotype which implicates lin-42 in temporal regulation of cell migration [3].
• The heterochronic gene lin-42 is the C. elegans homolog of Drosophila and mammalian period, key regulators of circadian rhythms, which specify changes in behavior and physiology over a 24 hr day/night cycle [4].

Biological context of lin-42

• In the vulva, sex myoblasts, and hypodermis, lin-42 activity prevents stage-specific cell division patterns from occurring too early [3].

References