Tag: DNA

DNA and rDNA Explained

DNA and rDNA Explained

Brian FBioScience

DNA AND rDNA Explained

Every living organism has its method of reproducing or replicating itself. These methods vary among different species. Some organisms reproduce at the cellular level, others reproduce in a more complex way.

DNA and rDNA are related scientifically and are both referred to in terms of genetic codes and information needed for reproduction and cell division. However, they vary in some ways. We’ll take a look at what both terms entail and how they function.

What Is DNA?

Deoxyribonucleic acid(DNA) is a complex organic molecular structure that contains genetic codes and information contained in a cell and is necessary for the reproduction, development, and function of an organism. They are present in eukaryotic cells( cells with a defined nucleus), prokaryotic cells( cells without a defined nucleus), and viruses as well.

Discovery Of DNA

The DNA molecule was first discovered by a Swiss researcher, Johann Friedrich Meischer while trying to study white blood cells in the year 1869. However, credit is also given to James D. Watson and Francis H.C. Crick, notable for discovering the double helix structure of the DNA in 1953.

Function

DNA is a molecule that is two-stranded and contains codes or instructions responsible for the transmission of traits from parents to offspring. However, these instructions are being synthesized into proteins, that in turn determine the traits that are being passed to offspring during reproduction. Threadlike structures made up protein and DNA are known as Chromosomes.

DNA Composition, Structure, And Storage

A DNA strand is composed of long chain molecules known as nucleotides. Each monomer molecule however consists of 3 components: a phosphate group, a nitrogenous base, and a five carbon, deoxyribose sugar.

The structure of a DNA can also be denoted as a “twisted ladder”. It is however known to have the double helix structure. The building blocks or information stored as a code in the DNA are composed of 4 chemical bases: adenine (A), thymine (T), guanine (G), and cytosine (C)

These nitrogenous bases form pairs that constitute the double helix structure of DNA. The pattern of a pairing of these bases is as follows: A to T and C to G. Moreover, one important part of the structure of the DNA is the deoxyribose sugar, which is also known as the backbone of the structure of a DNA molecule.

What Is rDNA?

The term rDNA can be used in two different sense:

  • Recombinant DNA
  • Ribosomal DNA

Recombinant DNA

Recombinant DNA refers to the genetic combination of two different fragments of DNA, from different species, to form a new strand of DNA. This is also known as Chimera. They are also composed of 3 different methods: transformation, non-bacterial transformation, and phage introduction.

How It Works And Its Function

Recombinant DNA works when there’s a visible amount of protein expression from the host cell. However, this visible amount of protein expression must be from the host or rDNA will not be synthesized. The proteins obtained from the expression of rDNA in a living cell are known as recombinant proteins. Also, to obtain the expression of foreign proteins, specialized expression vectors.

The function and application of recombinant DNA have proven to be very useful in various sectors like healthcare, agriculture, biotechnology, and research, among others. Some specific areas of application include:

  • For producing clotting factors for cases like hemophilia
  • For the production of vaccines in cases of Hepatitis B
  • Production of insect and heat resistance crops
  • Production of human growth hormones and insulin.
  • For pharmaceuticals
  • For the prevention and production of cures for sickle cell diseases.

Ribosomal DNA

Ribosomal DNA (rDNA) is a type of DNA that is found in the ribosomes of cells. Ribosomes are responsible for protein synthesis, and rDNA plays an important role in this process. The sequence of rDNA is used to create proteins that are essential for cell function. In addition, rDNA is involved in the regulation of gene expression. Because of its important role in cell function, rDNA is a target for studies that aim to understand how genes are expressed. Additionally, rDNA has been used as a tool for identifying and classifying different species of organisms. Therefore, ribosomal DNA is a vital component of cells that plays an essential role in both protein synthesis and gene expression.

rDNA Technology

In the past, rDNA technology was thought to be just an imaginary conception that could be deployed to modify certain traits and characteristics in living bodies by controlling the expression of target genes. Thankfully, in recent times, as a result of the input by researchers, rDNA technology has demonstrated significant advancement in human life and science at large.

Recombinant DNA technology is defined as a process of merging two different molecules of DNA and inserting them into a new organism.

Another aspect of recombinant DNA technology is “DNA Cloning”-which refers to a technique used in creating copies of DNA molecules, genes or organisms and induce their reduplication in host organisms. The single partners of a clone are similar genetically because cell replication generates similar daughter cells every time.

The usage of cloning has been broadened to recombinant DNA (rDNA) technology, which has given scientists the means to produce several copies of a single fragment of DNA. The importance of recombinant DNA cannot be over-emphasized, as it has been proven to be responsible for the increase in the genetic diversity of eukaryotes. Another useful importance of recombinant DNA technology is visible in the production of insulin. Insulin is obtained from the human insulin gene that is introduced into a plasmid and then to a bacterial cell where the protein insulin is further produced.

Conclusion

For every form of life, there’s a means of replication and reproduction to ensure the continuity of such species in question. The stages of development and reproduction could take place at the cellular level and that is where the concept of DNA and rDNA comes in.

More so, research and technology are committed to ensuring that the application of recombinant DNA technology proves to be useful in sectors like healthcare, agriculture, and biotechnology, among others.

CRISPR Explained

CRISPR Explained

Brian FBioScience

CRISPR Explained

In the last four decades, scientists have carried out a lot of experiments into understanding genes, their functions, and how they could be edited. While reasonable progress has been made in understanding genetics, especially human genetics, editing the genes still requires expertise, money, and the usage of expensive technology.

However, the development of CRISPR, a new gene editing tool in 2012 changed the course of gene editing. This tool is regarded as being precise and effective in tweaking the genomes of humans, plants, and animals. What exactly is this tool? How is it used and what are the potential concerns? Keep reading for more information.

What is CRISPR?

Firstly, it is the short form of Clustered Regularly Interspaced Short Palindromic Repeats. It is a powerful tool that could be used to tweak genes. This simply means that the tool easily allows researchers or scientists to change the sequence of DNA and also modify the functions of genes. Nevertheless, it has other potential applications. With ongoing research, CRISPR has the potential to transform human health and medication. It could be used to treat and prevent some diseases, regulate immunity, enhance the growth of crops, etc.

The natural defense mechanism of bacteria was used in the development of CRISPR. Bacteria use RNA, a genetic messenger that is also close to DNA to repel attacks from viruses. While repelling this attack, these organisms will retain some bits of the virus’s DNA and store them in theirs. This stored DNA serves as a memory that will enable the organisms to quickly recognize and prevent future attacks from such viruses and other similar invaders.

How it works

Genomes contain various messages and information that are related to their DNA sequence. When editing genomes, these DNA sequences are changed and this also means a change to the information they contained. Through CRISPR, the editing could be done with the introduction of a cut that works like a pair of scissors in the DNA which will then trigger self-repair and the targeted changes will be introduced.

To direct CRISPR to the intended region of DNA, whether in humans, animals, or crops, scientists will only alter the sequence of the crRNA that binds to that of the target DNA. To simplify the process, crRNA and tracrRNA were fused to form RNA. To make it work, the researcher will first design up to 20 bases of the pairs sequence, which must all match with the gene of either the human, animal or plant you want to edit. However, the similarity of the pairs must be with the targeted gene alone and must not match with any other gene in the genome.

Once introduced, CRISPR will then cut the DNA at the intended gene and not ideally anywhere else in the genome. The process of self-repair will begin immediately. In the process of joining together the pieces of the cut DNA, the intended tweaking or editing will be carried out.

Risks and concerns about it

Despite its potential benefits, CRISPR is not yet a perfect tool because it is relatively new and this has raised some concerns. One of the major concerns of using CRISPR on humans is that it might not go to the targeted gene. For instance, it might locate and also cut any gene similar to the target. When this happens, it could lead to mutations in the other genes. There might not be any side effects, but it could also cause cancer.

The use of CRISPR on humans has been limited to cells that are not transferable to the next generation but this tool can also be used to edit the genes of the embryo. There has not been consensus about this editing which is also known as germline editing due to risk, lack of regulation, and ethical concerns. However, this doesn’t stop some researchers in the US, UK, and China from editing human embryos. This has raised concern about whether we will not have designer babies with enhanced genes that will increase their intelligence, muscle strength, and a lot more.

Another ethical concern about gene editing is that it could lead to an unintended ecological impact. For instance, an introduced trait in the gene of a target population could spread beyond such population through cross-breeding. Moreover, it could reduce the genetic uniqueness of a population, thereby putting concern for the survival of such a population.

This is not to say that efforts have not been made to regulate the usage of CRISPR. For instance, the U.S congress has banned any clinical trial that could lead to modified babies. Meanwhile, some organizations have also come up with guidelines on how to edit human embryos. With the guideline, gene editing will only be allowed for convincing reasons such as fixing faulty genes with no known medical alternatives. This will, however, be done under strict supervision.

Recent advances

With these concerns, research is ongoing on how to refine CRISPR. It has been revealed by the pioneer researchers that another enzyme could be used to edit genes in the future. The new enzymes will be smaller, more precise, and have more chances of success than the current one, Cas9 which could cut an unintended gene.

Moreover, CRISPR has also been used to develop cells that are invisible to the immune system in the body. This is because the body’s immune system will attack any foreign invader, including stem cells. When these stem cells are invisible, they will develop into adult cells that could be used to repair damaged organs in the body.

A red blood cell disease, known as beta-thalassemia disease has been cured by some CRISPR researchers. This happened when some CRISPR team took stem cells from a patient and edited them with CRISPR outside the body. This was done to increase the production of hemoglobin before the stem cell was transfused back into the body. With the announcement that CISPR-developed drug has been used to treat beta-thalassemia disease, researchers also believe that a similar approach could be used in the future to treat other blood-related diseases such as sickle cell anemia.

Conclusion

Research on CRISPR is advancing every day and some scientists believe that it could be used to change the course of human living for life.