Mir-48

mir-48 microRNA is a microRNA which is found in nematodes, in which it controls developmental timing. It acts in the heterochronic pathyway, where it controls the timing of cell fate decisions in the vulva and hypodermis during larval development.^[1]

Gene structure and location

Along with mir-241, mir-48 is found in the lin-58 allele between the genes hum-5 and unc-76.^[2] It is related to (at least) three other miRNAs (let-7,mir-84 and mir-241), with which it shares eight identical bases at the 5' end of the mature miRNA.^[3]

Function

mir-48, along with let-7, mir-84 and mir-241, controls developmental timing events in C. elegans proliferative seam cells and hypodermal syncytial cells. Double mutations in mir-48 and mir-214 result in worms displaying a retarded cell lineage phenotype; extra seam cells are observed in the L3 and L4 developmental stages when compared to wild-type worms. It is thought that the extra cells arise due to mutant miRNAs being unable to repress the gene hbl-1, which also plays a role in developmental timing.^[4]

1. ^ Li, M.; Jones-Rhoades, M. W.; Lau, N. C.; Bartel, D. P.; Rougvie, A. E. (2005). "Regulatory Mutations of mir-48, a C. Elegans let-7 Family MicroRNA, Cause Developmental Timing Defects". Developmental Cell 9 (3): 415–422. doi:10.1016/j.devcel.2005.08.002. PMID 16139229.  edit
2. ^ Lau, N. C.; Lim, L. P.; Weinstein, E. G.; Bartel, D. P. (2001). "An Abundant Class of Tiny RNAs with Probable Regulatory Roles in Caenorhabditis elegans". Science 294 (5543): 858–862. doi:10.1126/science.1065062. PMID 11679671.  edit
3. ^ Abbott, A. L.; Alvarez-Saavedra, E.; Miska, E. A.; Lau, N. C.; Bartel, D. P.; Horvitz, H. R.; Ambros, V. (2005). "The let-7 MicroRNA Family Members mir-48, mir-84, and mir-241 Function Together to Regulate Developmental Timing in Caenorhabditis elegans". Developmental Cell 9 (3): 403–414. doi:10.1016/j.devcel.2005.07.009. PMID 16139228.  edit
4. ^ Abbott, A. L.; Alvarez-Saavedra, E.; Miska, E. A.; Lau, N. C.; Bartel, D. P.; Horvitz, H. R.; Ambros, V. (2005). "The let-7 MicroRNA Family Members mir-48, mir-84, and mir-241 Function Together to Regulate Developmental Timing in Caenorhabditis elegans". Developmental Cell 9 (3): 403–414. doi:10.1016/j.devcel.2005.07.009. PMID 16139228.  edit