Small RNA survey of mouse genome

ABSTRACT: Using criteria based on known examples, we identified approximately 1.7 million and 2.4 million sequences encoding putative miRNA precursor (stem-loop) structures in the mouse and human genomes, respectively, as well as large numbers of such structures in the genomes of fish, fruitfly and nematode worm. These predictions were then tested using high density custom microarrays containing modified oligonucleotides interrogated with purified small RNAs from different tissues. We found that 19% of 4,006 randomly chosen mouse predictions and 40% of 1,859 randomly chosen human predictions gave positive signals with small RNA isolated from whole 10-12 day embryos and a mixture of brain and testis, respectively, 84% of which hybridized to only one strand of the predicted stem-loop structure, whereas only 2% and 12% of equivalent random mouse and human predictions were positive. There was no difference in the validation rates between sequences exhibiting conservation and those that did not. High validation rates were also observed with predictions from fish, fly and worm genomes. Northern blot analysis of the array-positive mouse predictions confirmed that the vast majority of these sequences were detectable as small RNAs whose sizes ranged from 20-110 nucleotides. Taking into account false negative rates of the prediction and detection of known miRNAs, and assuming that this holds for other small RNAs, we estimate that there are 1 million small RNAs expressed in mouse and 3 million small RNAs in human. Keywords: genomic survey of small RNAs

ORGANISM(S): Mus musculus

PROVIDER: GSE7217 | GEO | 2009/12/07

SECONDARY ACCESSION(S): PRJNA98285

REPOSITORIES: GEO