mi RNA Reading http www ambion comtechlibhottopicsrnai Lecture

mi. RNA Reading: http: //www. ambion. com/techlib/hottopics/rnai/ Lecture notes

Components of the RNAi machinery are used for other processes.

The first mi. RNA was discovered in C. elegans. lin-14(lf) mutations caused precocious development. lin-14(gf) and lin-4 mutations caused retarded development. wild type: embryo preccious: embryo retarded: embryo L 1 L 2 L 3 L 1 L 3 L 4 L 2 L 4 adult L 3…. .

lin-14(lf); lin-4(lf) mutants are precocious.

lin-14 gene (simplified) loss-of-function gain-of function mutations in coding sequences mutations in 3’UTR lin-4 encodes no protein. Only an RNA. LIN-14 RNA always present, but protein decreases through larval development. lin-4 required for LIN-14 decrease. lin-4 RNA increases though larval development. lin-4 RNA potentially could base pair with lin-14 3’ UTR.

LIN-14 protein lin-4 lin-14 lin-4 RNA Developmental time LIN-14 protein in lin-14(gf) or lin-4(lf) LIN-14 protein in wild type

Model

Used lac-z: : lin-14 3’ UTR reporter transgene to test model lac. Z lin-14 3’UTR Lac. Z decreases through larval development. lin-4 required for Lac. Z decrease. Reduction of Dicer and Risc components results in lin-4 phenotype; also required for Lac. Z decrease.

mi. RNA complex contains Risc proteins

Two Drosophila mi. RNAs regulate cell proliferation, apoptosis and fat storage.

~300 estimated mi. RNAs in C. elegans ~530 estimated mi. RNAs in humans