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Showing posts from 2020

Why is genetics important?

I suppose a brief explanation would be genetics is what allows life to continue. DNA replication allows for one cell to turn into two, and therefore allow multicellular organisms such as ourselves to exist. To most people genetics is very interesting, and has greatly influenced the world in good and bad ways. Trait inheritance  - A physical molecule (DNA) which can be passed on to offspring, encodes a physical property of a human. E.g. Eye colour. Eugenics  - The aim to improve the genetic quality of a human population, historically by excluding people (as believed by Hitler). Genetic diseases  - Once understood interventions can be developed to increase the quality of life for the human race. Epigenetics  - Heritable biological traits that do not involve changes in DNA. Part of the ' nature ' vs ' nurture ' debate. What causes you to look the way you do? Is it 100% your DNA or partially your environment too? Genetic Counselor  - A new job has stemmed from genetics whic

Is stem cell treatment an effective cure for nerve damage from peripheral neuropathy?

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Mesenchymal stem cell therapy is a promising and scientifically proven cell therapy. This article  explains in detail the types of Mesenchymal stem cell therapies to treat peripheral neuropathy. Peripheral nerves have a limited regenerative potential, meaning if peripheral nerves are damaged it is difficult for healing to occur. ( E.g. As opposed to the liver, a highly regenerative organ - "51% of the original liver mass can regenerate back to its full size" .) Therefore peripheral nerves are harder to repair when compared to other tissue. Upon peripheral nerve injury, molecular disease events occur whereby multiple cell types assist each other in order to restore nerve function. The Image below shows the cell types involved and the stages of nerve injury. For this explanation we need to focus on stage 4. Schwanncell alignment; axon regeneration. Schwann cells change their function when the nerve is injured. Originally their role was to support the nerve function & insula

Viroid

Viroids have 'no protein coating' as opposed to 'protein coating'. A protein coating would make it a virus, however we are talking about a Viroid and therefore it is single stranded RNA with no protein coating. As far as we know, DNA Viroids do not exist. But this is an advancing field of research and it depends on what you mean by DNA. The general different types of genetic material include - but are not limited to: Single-stranded DNA (ssDNA), Double-stranded DNA (dsDNA), Single-stranded RNA (ssRNA), and double-stranded RNA (dsRNA). There is more information on Classes I and II DNA viruses here:  https://www.ncbi.nlm.nih.gov/books/NBK21523/ If there were no DNA viruses without a protein coating - what is the reason? Viroids only infect plant cells. It may be that Viroids route of entry via microscopic junctions between plant cells (Plasmodesmata) are only large enough to fit single stranded genetic material.

Does the damage from sun exposure outweigh the benefit of getting vitamin D?

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The sun emits ultraviolet light radiation which is the component of sunlight that is able to damage skin. Ultraviolet (UV) is a form of electromagnetic radiation with wavelengths between 10 to 400 nanometers, shorter than that of visible light but longer than X-rays. To put nanometers into perspective - A human hair is around 75,000 nanometers in diameter. There are sub-types of UV which define the wavelength size: Ultraviolet A - UVA - 400–315 nanometers Ultraviolet B - UVB - 315–280 nanometers Ultraviolet C - UVC - 280–100 nanometers Interestingly UVB is essential to synthesize Vitamin D. UV light is able to damage DNA. This results with humans cells (typically skin cells) to attempt to repair themselves. As a result sometimes genetic mutations arise - some of which give the cell the ability to divide more frequently (cancer). The process of UV damage is shown in the image below. Although advertises I'm sure would love you to believe that Vitamin D should always be gained from th

Mitochondrial Membrane Potential

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The mitochondrial membrane is important for ATP synthesis ( oxidative phosphorylation ) to occur.  Electron transport chains  are situated on the inner mitochondrial membrane where electrons traverse the chain across proteins - causing protons to traverse into the mitochondrial matrix. Creating an electrochemical proton gradient. This is a very interesting topic and is best understood with an explanation of the JC-1 Dye. Explanation Mitochondrial membrane potential changes - depending on cellular events. The dye ' JC-1 ' is able to  indicate mitochondrial membrane potential  in different cells. If there is a negative charge inside mitochondria then the monomers express green fluorescence. If there is a positive charge inside mitochondria then the monomers form J-aggregates and now express red fluorescence. The ratio between red & green florescence shows the mitochondrial membrane potential. A low or negative mitochondrial membrane potential will show more green florescence.

Knock-out, knock-down and knock-sideways

In genetics and molecular biology there are differences between the terms knock-out, knock-down and (the lesser known term) knock-sideways. Knock-sideways : Inactivates proteins. Could be done using small molecule inhibitors. Knock-out : Gene removal, no gene expression. Could be done using CRISPR. Knock-down : Gene expression is reduced. Could be done using  interference RNA . (Another reference for Knock-sideways: "Importantly, the rapidity of the “knock-sideways” system allowed the researchers to observe a phenotype distinct from siRNA-mediated knockdown of the same protein..." )

RNA World Hypothesis

How do you derive a human? It is a big question, but a fundamental principal of biology can assist us in finding a potential answer to how biology has advanced to far - that we exist.  To continue to the existence of a species, passing of genetic information from parent to offspring must occur. This process is known as meiosis and requires genetic replication to take place. Replication must take place.  Interestingly prydamine (nucleotides incorporate prydamine  in their structure) and nucleotides adenine, guanine and thymine have been found on meteorites and supports the hypothesis of panspermia . RNA has been shown to have the ability to self-replicate. More information can be found here .

How do organisms develop and organised themselves?

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Biology is a world of great symmetry. Pleasing to the eye and of spectacular beauty. Some examples include butterflies, others that are less beautiful may include crayfish and ones that are of great curiosity include yourself. The exceptional symmetry of a butterfly But, biology is also approximate and so there are slight unintended modifications - mistakes. I must stress, these mistakes (often genetic mutations) are not always bad. Some mutations may cause cancer , some may be of benefit and and some may do nothing at all. But how do you understand organisation when it has small random inaccuracies? Scientists are studying the incredible developmental coordination and organisation phenomena that our cells, tissues and organs undergo. Fate Mapping is a method used to study the organisation of cells - typically the embryonic stages of life. 42 years ago an enzyme from the roots of horseradishes was isolated and proved to be an effective marker to study cell progeny. It was ab

Why is finding "patient zero" in an pandemic so important?

Where did it come from? Where did it go? It came from patient zero. And reasons to know why include: How did they obtain the virus? Who have they been in contact with? As of the 21st of June there is no reason to know who patient zero has been in contact with. But for point number 1, it seems abundantly clear that 'fake news' and conspiracy theories have taken the reins amid the Corona Virus pandemic.  What is the origin of the Corona Virus? Before we answer that question, it is best to reflect on history. " Those who cannot remember the past are condemned to repeat it. " - George Santayana. The source of the disease Ebola was unclear for many years. Patient Zero allowed for the identification of the location of patient 0 and subsequently the animals they were in contact with. If animals were suspected as the source of the virus they could be genetically tested and evaluated. If identified as the source, then available it can be public information for

What is the 'Good Genes Hypothesis' and is it true?

The famous philanthropist Oprah has advised thousands of women across the globe on how to find ' the one '. But Oprah never mentioned the good genes hypothesis. The good genes hypothesis was originally proposed in the 1980s and propagates the idea that observed mates are selected by their ability to pass on genes that increase reproductive success. How might it work? An organisms phenotype is determined by its genotype. Meaning your body observable properties (organs, tissues and cells) are determined by their genes. Therefore if your face is asymmetrical then more mutations have arisen, making you a sub-optional candidate compared to a more symmetrical competitor, who is less prone to mutations. Many psychology studies have shown that greater symmetry has a relationship with attractiveness. Is the good genes theory well supported or true? Whilst it is an appealing hypothesis, a recent study with almost 5000 participants with varying degrees of facial symmetry fou

NKX2-5 Gene Overview

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NKX2-5 Gene Overview In mammalian cells the gene NKX2-5 is found on chromosome 5, more specifically on the long (q) arm of chromosome 5 at position 35.1. (Cytogenetic Location: 5q35.1) Cytogenetic Location: 5q35.1 Transcription of the homeobox NKX2-5 gene into RNA and consequential translation, synthesizes a homeodomain protein. Homeodomain proteins regulate gene expression and cell differentiation during early embryonic development, thus mutations in homeobox genes can cause developmental disorders. The NKX2-5 protein is known as: " Homeobox protein NKX2-5 " and is essential for cardiac development. In the fetal development of mice, disruption of NKX2-5 has proven to be lethal. NKX2-5 is ~3,213 nucleotide bases long and is involved in biological processes that give an organism its shape. Disruption of NKX2-5 has proven to cause abnormal heart shape. Cardiac expression of NKX2-5 continues throughout development and into adult life. References: Myogenic and

Forcing cancer into submission

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Have you ever assisted a goal when scoring in a game? Or set a trap in the hopes to capture an animal? In the recent Nature article:  Springing an evolutionary trap on cancer,  Charles Y. Lin describes how - in an alley-oop like fashion - cancers evade the first drug allowing the second drug to  defeat cancer. Cancer is a complex topic and requires explanation, there are over 100 types (E.g. Breast cancer, Liver cancer or Lung cancer) of cancer so it can be hard to generalize.  A single cell can form a tumor, cells can spread to form tumors at other sites A tumor is a bundle of 'cancer cells' that have uncontrollably divided. Typically this starts as one cell that has 'gone rogue'. In some cases 'metastasis' occurs where cells spread from the original tumor location to other locations around the body, forming multiple tumors. This type of cancer is defined as metastatic cancer - with the other type being benign tumors that cannot spread. Cancer ce

The public health war you’re forgetting

Amid the coronavirus crisis we have forgotten our old friend. Antimicrobial resistance is one of the greatest threats to global health – killing an estimated 700,000 people every year. A World Health Organization report outlined that in a post-antibiotic age where common infections can kill. Generating a time of crisis for developing countries. What do the statistics say? By 2030 antimicrobial resistance severity has been predicted to double. It is forecasted to double again by 2050, with approximately 10,000,000 deaths every year. Are there any solutions on the horizon? Fortunately, artificial intelligence approaches have been advancing the front of the antimicrobial resistance war across different aspects. Machine-learning has allowed identification of novel compounds and genetic signatures involved in antimicrobial resistance.   Identifying antibiotics such as carbapenem resistance with a 88–99% accuracy and other antibiotics (isoniazid, kanamycin, ofloxaci

Discrepancies between men and women

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There are obvious physiological brain differences and therefore psychological differences in gender – but what subtleties can be explained? It is best to start with the question, what is a gender? Scientifically is it male and female as defined by our chromosome arrangement of X/X female and X/Y male. However, there are exceptions to this rule – like XX male syndrome – which is where a gene or mutation (depending on severity) can cause the development of a male from a female chromosome arrangement. 90% of the time this occurs from the introduction of a single gene ( SRY ) from the Y chromosome that is swapped to one of the X chromosomes in the farther. So maybe we aren’t that different after all? What are the differences between males and females? Anatomically there are obvious contrasting features between males and females, in terms of height, reproductive organs and location of muscle mass. The psychological differences are more complicated. There are ma