Evolution Of Rna And Sirnas

siRNA are a form of molecular RNA, they are formed from a long double stranded piece of RNA. The dsRNA is cleaved into siRNA segments by the endonuclease DICER, these segments range from 21-25 nucleotides in length. The siRNA becomes part of the RISC complex, one strand is removed, and the remaining strand binds to its exact compliment in the mRNA. At this point exonucleases will enter and degraded the cleaved mRNA.

The last difference between RNA and DNA is that DNA has Thymine as one of its four bases while RNA replaces Thymine with Uracil. All the other three bases are the

Both of them are used to store and regulate the use of genetic information in a living organism. They are both constructed using nearly the same molecular structure, having phosphate groups and sugars linked together to form a phosphate backbone with variable nitrogenous bases utilized to encode the genetic information, the bases are only differ by an uracil base instead of a thymine base. DNA, unlike RNA, is not able to catalyse its own replication so they cannot be the primitive molecules. Also, observing the chemical composition of RNA and DNA, the difference between the uracil and thymine is the 5th position of the ring structure. Genetic mutation occurred so a CH3 group was added onto the 5th position of uracil to form thymine. Not only RNA has catalytic activity as pointed above, it also has the ability to control gene regulation, which is known as riboswitch. The ribosome is one of the most ancient molecules in our cells. In addition, ribosome is composed of RNA and a protein called Ribonucleoprotein. If the majority of protein content is eliminated, protein synthesis could be maintained. Therefore, RNA is the most crucial part of the macromolecule and this observation is in agreement with the knowledge of ribozymes, RNA with an autocatalytic capacity. Taken together, it strongly suggests that RNA has a

The mechanism for RNAi follows one of two major pathways: one originating with foreign injected double-stranded RNA (dsRNA) and the other originating with micro-RNA

The development of 19 to 22-nucleotide siRNAs specifically recognizing particular mRNA sequences provides new powerful reagents to selectively down-regulate gene expression and holds great potential not only for the analysis of

Silencers are regions that actively repress transcription of particular genes to produce mRNA. These are capable of binding with transcription regulation factors, which prevents RNA polymerase enzyme from binding to the promoter region thereby blocking the transcription of DNA to mRNA. In the absence of silencers there will be promiscuous or non-restricted expression of the gene.

The RNA sequence in the anticodon region, as well as other parts of the transfer RNA molecule, are important

Small Interfering RNA (SiRNA) was discovered by Andrew Fire and Craig Mello, receiving the Nobel Prize in 2006 for their work. (Kaur et al, 2012) Typically SiRNA are between 21 and 23 RNA nucleotides in length. SiRNA has the ability to cause the inactivity of a genes’ expression in somatic mammalian cells; has proven to be an exceptional tool for researchers for the control of disease-causing genes and theoretical treatments of inherited diseases in the future. However siRNA can only be used once the target mRNA sequence is known. (Sioud, 2004) However due to the Human Genome Project, a large portion of the target genes have been sequenced allowing SiRNA to become more practical.

Since the discovery of the small RNA lin-4 in 1993 (Lee et al., 1993; Wightman et al., 1993), it has become evident that the miRNA machinery regulates many proteins and almost all cellular pathways (Pasquinelli et al., 2005; Stark et al., 2007; Filipowicz et al., 2008; Friedman et al., 2009). miRNAs are 20-23 nucleotide (nt) long RNA sequences encoded by genomic DNA (Bartel, 2004). After transcription, the RNA sequence destined to become a miRNA folds into a hairpin structure called the pri-miRNA. Pri-miRNAs are cleaved by the Drosha-Pasha complex in the nucleus and become ~70-nucleotide pre-miRNAs (He & Hannon, 2004), which are transported to the cytoplasm by Exportin 5. There, it is cleaved a second time by Dicer-TRBP complex to yield a 20 base pair (bp) double stranded sequence. The two strands are then separated, and one is degraded while the other is assembled into the miRNA-induced silencing complex (miRISC) (Filipowicz et al., 2008). Other components of miRISC are Argonaute proteins and other regulatory proteins such as fragile X-mental retardation protein (FMRP) (Jin et al., 2004a; Filipowicz et al., 2008). Mature miRNAs bind to seed regions in the 3 ' UTR of target mRNAs to either suppress their translation or mark them for degradation (Pasquinelli et al., 2005; Behm-Ansmant et al., 2006; Filipowicz et al., 2008).

I think the RNA world theory, combined with other process, including clay chemistry and deep sea vents activities, is an extremely possible theory for origin of life. With addition of icy chemistry, the RNA world theory may also help us to find life outside Earth. “The RNA world theory is widely accepted by origin-of-life theorist” (Ricardo and Szostak 2009)

In Elbashir, Lendeckel, and Tuschl’s article, they explore how 21- and 22-nucleotides RNAs mediate RNA interference by using an in vitro Drosophila system; this article is still referenced today as an authoritative source for RNAi research They show that the

A long ncRNA called Xist is believed to recruit proteins associated with epigenetic marks, a type of X chromosome inactivation (Heard and Disteche, 2006). Another long ncRNA produced by the HOXC locus can influence gene expression at the HOXD locus on a different chromosome (Rinn et al., 2007). A circular RNA acts as an intracellular sponge for miRNAs, which shows that one ncRNA can be regulated by another (Memczak et al., 2013). In mice, long ncRNAs have been discovered through chromatin signature assessment (Guttman et al., 2009). Given the thousands of long ncRNAs, it is likely there are many functions yet to be identified.

The central dogma of molecular biology is widely known as the transcription of DNA to RNA, and then the translation of RNA to protein. In these past few experiments, the students looked at mRNA, treated them with PMA and DMSO. The students then performed reverse transcriptase on their mRNAs in order to convert them into cDNA, which is more stable. After that, the students then performed PCR on their cDNA to zero in on the gene of choice. Those genes were then run through gel electrophoresis. The reasons behind these particular processes were to try to isolate the genes MMP-9 and beta-actin in both the DMSO and PMA groups.

Gene is a small unit of molecule which is a living organism. It has commonly known as DNA (deoxyribonucleic Acid) and Ribonucleic Acid (RNA). There is a long chain which works for its functioning. We see that all the living creatures have DNA which separates the identity of two individuals. There are better to examine all the information and maintain the cells and traits of a creature. These genes are related with the regions which are regulatory along with transcribed. They provide with better functionalities as well. Every cell contained in the human body is mainly featured or inherited from the parents and genes helps in differentiating the both. Considering and observing the chromosomes closely, we see that there is a big

Ribonuclease P is a type of ribonuclease which cleaves RNA. Its function is to cleave off an extra, or precursor, sequence of RNA on tRNA molecules (Stark et al., 1978). It is an essential ubiquitous enzyme, present in all cells and cellular compartments that synthesize tRNA (Gopalan et al., 2002). RNase P is a ribonucleoprotein complex and is responsible for the 5’ maturation of tRNAs (Frank and Pace, 1998). RNase P has been proposed as a novel RNA-based gene interference strategy for down regulating gene expression.