PiwiRNA is the maximum class of non-coding small RNA molecules expressed in animal cells for interaction with RNA (pill). piRNA to form the RNA-protein complex by interaction with protein PIWI. Gene silencing of both post-transcriptional and epigenetic inheritance of the other elements of the germ cell line and retrotransposons, these complexes Pirna is associated with them in spermatogenesis more specifically. They size is different from the lack of complexity and more conservation of sequence, micro RNA (the miRNA). It is unclear how the piRNA may or may be generated, but the possible ways is different from the siRNA peace and the biosynthesis, but we are defined as sub-Pirna rasiRNAs proposal.
The piRNA, and have been identified in vertebrates, and operating mode biosynthesis and is slightly different between different species of invertebrates, but the number of features will be retained. piRNA you do not have a clear secondary structure motif, between 26-31 nucleotides, the length of the Pirna is, by definition, bias of the 5 ‘uridine, piRNA in both invertebrate and vertebrate is common. The piRNA nematode with a modification and a 3 ‘monophosphate 5’ acting on the oxygen so ‘or 3′ or 2 block in (Caenorhabditis elegans), that it is present in rat Drosophila melanogaster, zebra, and the mouse was confirmed was. The idea is this revision 3 “2’-O-methyl, the reason for this change is not clear, but as having hundreds of thousands of different types of pills found. Mammals that are supposed to increase the stability pill . To date, 000 unique sequence Pirna more than 50 were found in more than 13,000 in the Drosophila melanogaster and mouse.
The piRNA, it is found in the entire genome cluster, you can piRNA or 10 000 as including only to these groups, you may 1-100 kilobytes different sizes. Already, the discovery and annotation of the genome of Pirunakurasuta based on how the increasingly sophisticated in recent years. it will be saved piRNA Hano clustering across species well, but there is no sequence. On the other hand, the vertebrate piRNA and D. melanogaster, Caenorhabditis elegans, which is located areas lacking a protein encoding gene, is in the piRNA C. has been identified in protein-coding genes. It seems to be required for men only, but in mammals, it is located in both ovarian piRNA mother, and testis. In invertebrates, it has been found in the germline of both women and men piRNA mother. At the cellular level, it is possible pathway operates in two areas, suggesting that they may have multiple effects, pills, was found in the cytoplasm and nucleus piRNA.
Although not fully understood yet, but piRNA of biosynthesis, possible mechanisms have been proposed. That piRNA mothers, those indicating the direction of displacement rather, only be obtained from one strand of DNA, which may mean that they are the product of precursor long single-stranded molecule . It piRNA is the only path to be used in the manufacture of Pakiten processing time of the first have been proposed, as tends to result to channel 5 ‘uridine piRNA, in this mechanism, pills precursor is transferred that. In addition, it is the mechanism “ping-pong” The main piRNA that is proposed to recognize the complementary goal of them, causing the recruitment of protein PIWI. This results in the cleavage of the transcript in point 10 nucleotides from the 5 ‘end of the main production of Pirna Pirna average. Secondary piRNA these there is the position of the adenine tenth target sequence. Pirna to participate in the ping-pong cycle, direct the attack against the copy of the transposon, ping-pong cycle operates only at the level of transcription. Or both may be operated in various modes either of these mechanisms. For example, C. nematode, have the piRNA, but it does not seem to use the ping-pong mechanism at all. Adenine is included in the ten quite a few are identified piRNA in D. melanogaster and zebrafish, it is interpreted as a possible evidence of biosynthesis mechanisms between species conservative. Ping-pong signature, have been identified in primitive many animals, such as cnidarians and sponges that could indicate the presence of a ping-pong cycle already in the branch of early metazoan.