The proprietary terms and related names of RNAi technology-RNAi

1. RNAi: (RNA interference) RNA interference

Some small double stranded RNAs can efficiently and specifically block the expression of specific genes in the body, promote mRNA degradation, and induce cells to exhibit a phenotype of specific gene deletion, known as RNA interference (RNAi). It is also an important protective mechanism for the body to resist external infections.

2. siRNA: (small interfering RNAs) Small interfering RNAs

A short truncated double stranded RNA molecule that can degrade specific mRNAs by targeting homologous complementary sequences of mRNAs. This process is known as the RNA interference pathway.

3. shRNAs: (RNA Short hairpin RNAs) Short hairpin RNAs are non coding small RNA molecules designed to form hairpin structures, which can inhibit gene expression through RNA interference. Thomas Rosenquist's group and Greg Hannon's group jointly studied the mechanism by which the transfer of shRNAs in mammalian germ line cells leads to long-term stable gene silencing.

4. bp:(Base Pair) : A base pair is formed by hydrogen bonding between two bases (A and T, or C and G). The two strands of DNA are connected together by hydrogen bonds between base pairs, forming a double helix structure.

5. Base sequence: The arrangement order of bases in a DNA molecule.

6. Base Sequence Analysis: A method of analyzing the base sequence in DNA molecules using base sequence analysis (which can sometimes be fully automated)

cDNA： Refer to complementary DNA.

7. cDNA: Complementary DNA is synthesized using messenger RNA as a template, often using a strand of complementary DNA as a probe for drawing physical maps.

8. Complementary sequence: A complementary sequence formed by using a nucleotide chain as a template and following the rules of base complementarity is called the complementary sequence of the template.

9. Genomic Library: Cloning of randomly generated fragments of a chromosome with overlapping parts.

10. RISC: RNA induced silencing complex

In the RNAi effect stage, siRNA double stranded binds to a ribozyme complex to form the so-called RNA induced silencing complex. Activating RISC requires an ATP dependent process of untying siRNA double strands. Activated RISC locates homologous mRNA transcripts through base pairing and cleaves mRNA at a distance of 12 bases from the 3 'end of siRNA (3, 18, 27, 29). Although the precise mechanism of cleavage is still unknown, studies have shown that each RISC contains an siRNA and an RNAse different from Dicer.

A member of the RNaseIII family that specifically recognizes double stranded RNA, capable of progressively cleaving double stranded RNA introduced from external sources or through various means such as genetic modification or viral infection in an ATP dependent manner. The cleavage breaks down the RNA into 19-21 bp double stranded RNAs (siRNAs), with 2 base protrusions at the 3 'end of each fragment (27, 28).

12.PTGS：(Post-transcriptional Gene Silencing ,PTGS) The silencing of genes in plants occurs after transcription. It is relative to the gene silencing (TGS) that occurs during the transcription stage in some plants.

13. TGS: Transcriptional gene silencing;

14. Gene silence: Gene silencing;

The research results found that a large number of genetically modified plants cannot express normally, usually not due to the loss or mutation of the gene, but as a result of gene inactivation This phenomenon of inactivation is called gene silencing.

15. RNA transfection: RNA transfection.

16. Sense RNA: Justice Chain RNA;

17. Antisense RNA: Anti sense RNA;

18.19+2+2 nt siRNA：

Double stranded RNA is generally cleaved into 21-23 small fragments in cells, which can achieve better RNAi effects. Artificially synthesized siRNA is also based on this principle, and the synthesized RNA is a 

19 nt base sequence plus recognition sequences at both ends such as - GG, - TT, etc.

19. SECs (siRNA expression cassettes) :siRNA expression framework is an siRNA expression template obtained by PCR, which can be directly introduced into cells for expression without the need for pre cloning into a vector.

20. Homology: Homology refers to the similarity in chromosome or protein sequences between individuals of the same species but different individuals, or between individuals of different species

21. Homologous Chromosome: A pair of homologous chromosomes, derived from the paternal and maternal parents respectively, with the same linear gene sequence on each chromosome.

22. Recombinant Clone: Recombination cloning synthesizes DNA fragments from different sources into a single DNA molecule, and the resulting molecule is called recombinant clone.

23. Ribonucleic acid: A chemical substance separated from the nucleus and cytoplasm of cells by ribonucleic acid RNA. It plays an important role in protein synthesis and other biochemical reactions. The structure of RNA is similar to that of DNA, both consisting of long chains of nucleotides arranged in a certain order. RNA can be divided into messenger RNA, transporter RNA, ribosomal RNA, and other types of RNA.

24. rRNA: RNA that exists in ribosomes.

25.Ribozyme: An organelle in the cytoplasm of ribosomes that contains rRNA and related proteins, serving as a site for protein synthesis.

26. Transformation: The process of integrating exogenous DNA into the genome of a cell.

27.Entrez：The online resource retriever provided by the National Center for Biotechnology Information in the United States. This resource links GenBank sequences with their original literature sources.

28. NCBI: National Center for Biotechnology Information

It is one of the departments under the National Library of Medicine (NLM) and the National Institutes of Health (NIH) in the United States, established in 1988. We mainly provide information services in the biomedical field, such as GenBank database, one of the world's three major nucleic acid databases, PubMed medical literature search database, etc.

29. GenBank: The gene sequence database of NIH is a collection of all publicly available DNA sequences (Nucleic Acid Research 1998 Jan 1; 26 (1): 1-7). As of December 1998, GenBank has collected approximately 2162000000 bases and 3044000 sequences.

30. Ribosomal RNA: (ribosomal RNA, abbreviated as rRNA) is a group of RNA molecules that exist in ribosomes.

31. UniGene: A public database provided by the National Center for Biotechnology Information in the United States, which concatenates all fragments belonging to the same gene in GenBank into a complete gene for inclusion.

32. BLAST: (Basic Local Alignment Search Tool) is a basic search tool based on local alignment, which is a technique for quickly finding sequences with consecutive identical fragments to a given sequence. It is a sequence alignment application. It can select databases on the server online for sequence comparison, including DNA/DNA RNA/DNA protein/protein sequence alignment. Sequence alignment has many functions, such as searching for homologous nucleic acid or protein sequences, analyzing primer or probe specificity, constructing species evolutionary trees, and so on. Currently, most websites and software provide free local or online BLAST retrieval. Famous providers of sequence alignment services include NCBI's BLAST retrieval. If you need to learn more about this program, you can go to http://www.ncbi.nlm.nih.gov/BLAST/ Please take a closer look at the help file, but to access NCBI, you need an international agent. For domestic friends, you can access the BLAST website through the Bioinformatics Center of Shanghai Academy of Biological Sciences http://bioinfo.biosino.org:8888/blast/ Good speed

33. RT-PCR: Reverse transcription PCR is the process of generating cDNA from RNA through reverse transcription reaction, followed by PCR amplification using cDNA as a template to obtain the target gene or detect gene expression.

34. DNA blot hybridization: There are two nucleic acid blot methods:

·Directly spot DNA or RNA solution onto nitrocellulose membrane or Ninon membrane (dot or narrow line imprint)

·The DNA or RNA of the fragment was transferred to the membrane by agarose gel electrophoresis (Southern and Northern blotting). DNA is digested with restriction endonucleases before electrophoresis.

35. RNA blot hybridization: (RNA blot hybridization)

RNA blot hybridization is a technique for detecting specific target sequences of total RNA or mRNA that have been fixed on a filter membrane.

36. RNAse control:In the early stage of the experiment, the construction and extraction of plasmids require the use of RNAse A. The presence of RNAse A can degrade the RNA that needs to be transcribed and produced in the later stage. If this enzyme is contaminated in the early stage, it will lead to the failure of the later experiment.

 In the later stage of transcription, other RNAses, such as RNA polymerase 3, need to be used. Therefore, strict control of RNAses is the key to RNA experiments. The specific approach is to achieve dedicated DNA and RNA pipettes, separate the use of items and equipment in DNA laboratories and RNA laboratories, and minimize the sources of task contamination in the laboratory.