Small RNAs have been identified within the C. elegans

Caenorhabditis elegans

Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...

genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

 and comparative genomics

Genomics

Genomics is a discipline in genetics concerning the study of the genomes of organisms. The field includes intensive efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping efforts. The field also includes studies of intragenomic phenomena such as heterosis,...

 has shown that they are conserved across several nematode

Nematode

The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...

 species. These sRNAs contain a characteristic 2,2,7-trimethylguanosine (TMG) cap structure that identifies them as non-coding RNA

Non-coding RNA

A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...

s that have a functional role within the cell but at present the exact function of these sRNAs is unknown. Immunoprecipitation

Immunoprecipitation

Immunoprecipitation is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many thousands of different proteins...

 using antibodies against TMG and RNA microarrays were used to identify these sRNA.

See also

• Mycobacterium tuberculosis sRNA
  Mycobacterium tuberculosis sRNA
  Mycobactierum tuberculosis contains at least nine small RNA families in its genome. The small RNA families were identified through RNomics - the direct analysis of RNA molecules isolated from cultures of Mycobacterium tuberculosis. The sRNAs were characterised through RACE mapping and Northern...
  
  
• Bacillus subtilis BSR sRNAs
  Bacillus subtilis BSR sRNAs
  In a screen of the Bacillus subtilis genome for genes encoding ncRNAs, Saito et al. focused on 123 intergenic regions over 500 bp in length, the authors analyzed expression from these regions. Seven IGRs termed bsrC, bsrD, bsrE, bsrF, bsrG, bsrH and bsrI expressed RNAs smaller than 380 nt...
  
  
• Escherichia coli sRNA
  Escherichia coli sRNA
  Escherichia coli contains a number of small RNAs located in intergenic regions of its genome. The presence of at least 55 of these has been verfied experimentally. 275 potential sRNA-encoding loci were identified computationally using the QRNA program. These loci will include false positives, so...