Mitotic Recombination With Ichthyosis Biology Essay

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Many people young and old are faced with skin rashes and or some type of skin disorder. The specific skin disorder in particular would be Itchyosis. This will the patient with a spot like scaly appearance. There has been a lot of Dermatology research within this particular disorder, due to its ability to mitotically recombinate in pateints.Before any more discussion let's get familiar with the human skin and what encompasses a patient dealing with IWC. There are several different types of Icthyosis thruought the world they range from the more mild form to where the patient is perceived to have dry skin and mild redness and irritation, then there is the more severe form that causes the patient to appear like they are burning with red inflamed skin and scales that disfugire their bodies. All of these are all genetic types of Icthyhosis and they are as followed,Ichthyosis vulgaris,X-linked ichthyosis,Congenital ichthyosiform erythroderma,Epidermolytic hyperkeratosis, Harlequin type ichthyosis, Ichthyosis bullosa of Siemens,Ichthyosis hystrix, Ichthyosis lamellaris. The focus of this particular paper on Ichthyosis is the congenital reticular ichthyosiform erythroderma, or IWC for short.

The human skin encompasses several layers that keep our bodies protected and well insulated from our surrounding environment. The layers are the epidermis which is the outer layer of our skin and comes in various thicknesses ranging from your palm to your eyelids. Within the epidermis itself there are other layers. They include the cornified layer, that is considered to be various plate like envelopes that are filled with keratin, and dead skin. Next is a clear layer or stratus lucidum, here we have skin that can be associated with your palms and bottoms of your feet. The granular layer, stratum granuloso is an area comprised mainly of keratinocytes that recived a name change to distinguish it from the other layers.Lastly the basal layer is the most profound of the epidermis and contains cells that are identical and multiply, while in the process of superficially migrating toward the surface. The next available layer would be the dermis layer that can be found beneath the epidermis layer. The dermis consists of the papillary dermis, it houses an array of loosely arranged collagen fibers. Also within the dermis there is the reticular dermis, here we have the primary site for the elastic tissues. To conclude the skin layers there is the hypodermisor subcutaneous tissue, this is connective tissue and layers of fat that hold the larger blood vessels and nerves. The skin is a very obscure structure that can accomplish several things, for instance when there is a problem, your skin will let you know either by a weird sensation or a hideous rash. In patients with IWC it is the outer layer in which there is a genetic defect.

Keratin 10 or KRT10 a member of the type 1 cytokeratin family, which is considered a structural protein from which intermediate filaments are formed. Comprised with actin microfilaments and microtubules these come together to form the cytoskeleton of the epithelial cells. Keratin monomers or a small molecule that has the ability to bind chemically to other like monomers and form a polymer chain, assemble to form intermediate fillaments. These intermediate filaments are generally a family of related proteins that share like qualities. Intermediate filaments lie between the microfilaments or actin and microtubules. The diameter of the IF's are narrower then its counterparts actin and myosin. Not all but most types are of intermediate filaments are cytoplasmic. The microfilmants or actin as its called is the thinnest of of the cytoskeleton filaments. These actin filaments are versatile in a sense they can be used for locomotion of certain cells and the change within the cell shape. Microtubles on the other hand is one of the main componets of the cytoskeleton, they are involved in many cellular process such as cytokinesis and mitosis.

When I say Mitotic Recombination it is the dividing of the mother and father chromosomes that will exchange its DNA this is a common method that repairs the DNA.What initiates this process? Suggestions have been made that mostly all spontaneous recombination sites are initiated by a a break within the DNA double strand. When this breakeing of the strand occurs a new outline is required to fill the space, a homologous chromosome takes its place and presents an opportunity for recombination to occur. This mitotic recombination does not occur during mitosis but during interphase. It is speculated that some recombination sites are hotter than others. Basically what mitotic recombination entails is Mitotic recombination in complex cellular organisms is not a fetish that can be exploited for various experiments in model systems. This type of event also occurs naturally in humans. In some instances its rate will increase when it proves to be advantageous for the surrounding affected cells. Cancer research and studies have utilized this spectacle, when dealing with the rate of recombination to the speed loss of heterozygosity or LOH of tumor mutations to promote existence and evolution.

That was just a fancy way of talking about, gene crossover or recombination of some somatic cells. Somatic cells contain chromosomes that are arranged in pairs. For humans our somatic cells contain a total of 46 chromosomes or 23 pairs that are inherited from each parent.What differentiates these cells from the rest is they make up several key componets of our bodies such as the skin,organs,bones and even blood, or in short the taking of any cell that forms the body of an organism Somatic reversion is associated with the natural form of gene therapy, these finding are encouraging to patients with IWC because it can be used as a therapeutic technique. It would include harvesting patches of healthy skin or revertant cells and expand them throughout the skin. The patients that are used in these studies are very valuable because they can advise corrections that need to be reserved in gene therapy, to acquire influential clinical effects.Somatic cells play a role in IWC because it has been linked to several gentic disorders that actually regenerate on the epidermis layer of the skin where IWC is present. The development of this process involves three significant steps, the correcting mutation in the already infected gene, the restoration of the revertant cells and finally the localization and enrichment of the revertant cells.

The migration process of the new arising cells to the inner surface of the stratum corneum will genrally take about 2-3 weeks. The actual migration through the corneum and appears to shed at the skin will take another 2 weeks. When the corneum layer is shed from the patients body, the new cells are being created in the basal layer of the epidermis, the skin will now display a steady state of normalcy. Some other cases have shown the entire process to be accelerated with the division of new basal cells reaching the corneum in less than one week. Other circumstances the maturation and regeneration are normal but the shedding of the skin will be delayed. One way to visualize this process is to think of a soda bottle, when u turn it upside down to release its contents you have a overflow of liquid trying to escape a very small opening. This creates a jam of the coreneoctyes that can occur for various reasons, such as the natural shedding has been delayed or inhibited or because the production of cells is to rapid or even both.

For the skin to shed efficiently, they must be released from the numerous connections that hold them to eachother. This is accomplished by the corneocytes move up and throught the corneum layer, as discussed above. This action is in correlation with proteases, these are turned on and off by the activators and or inhibitors. Patients with IWC the proteases is lacking due to there mis localization, others display a turned off activity because to much inhibitor. This is what we can visually see as the scaly thick skin of IWC patients, or a direct consequence of the jammed stratum corneum. Most scales in this particular situation will fall off in clumps.

To single out the genome that if affecting various patients with this disease, a sequencing of the infected hosts genes was the next step. Considered the most brilliant discovery of our time, the Human Genome Project which was declared completed in 2003, enabled us to accuraltely identify 20,00 -25,00 genes that complete our DNA. This project also privileged us with the knowledge to determine the sequences of 3 billion base pairs that actually make up the humans DNA. The purpose of sequencing someones DNA permit scientists to accurately pinpoint and localize the mutant or damaged genes. To cheapen the matters a common sequencing known as the Sanger sequencing gave scientists the ability to be site specific with chain terminiation, devolped by Frederick Sanger. This particular sequencing allows scientists to locate a specific termination of a DNA synthesis reaction by using modified nucleotide substrates. With knowledge accumulated through the human genome project and the Sanger sequencing, various studies were shown to display that the heterozygous mutation occurs on chromosome 17q. By mapping these common gentic recombination event within the reverted clones a frameshift mutation was found within the protein Keratin. . This gene is located with members on the chromosome 17.Chromosome 17 is noted for housing a gene cluster of encoding 28 type 1 Keratins and 24 keratin proteins. Keratinocytes are the the main type of cells that establishes our epidermis layer and these cells protect us from bacteria fungi and other harmful parasites

Since Keratinocytes make up 95% of our epidermis layer several infected samples have been taken and used for genome processing and then compared against other normal samples of surrounding skin. Sequencing has shown that in a diseased patient's skin the levels of KRT10 are reduced in numbers and not to mention their misplacement within the nucleus of the diseased patient's skin. This type of behavior is not shown in the normal patient's skin samples. The assumptions that can be made here is the keratin protein is mis-localized to the nucleus of other cells, which in turn allows the revertant cells to become stronger and allowing them to break through the surface of the inflamed skin causing spots.

There are several different types of Icthyosis

Now that the particulars are out of the way, Ichthyosis with confetti (IWC) can be characterized by an intense failure in the structure of a certain patients skin cells at the epidermis layer of skin. This problem will leave its patients with a scaly and inflamed skin, hence its Greek translation of meaning fish. It emergence is seen around the first year of childhood and continues to follow them throughout their lifetime, although it will get better intime the patient will always have this condition. The most common places for this type of rash to appear are around the face and head region of the subject. In some other instances a patient will become engulfed with a number of healthy patches of skin that will appear to grow though the inflamed areas of skin causing confetti like appearance. Patients will often exhibit psychological issues ranging from and very low self-esteem to even total isolation from the outside world due to the shedding of their skin. This type of skin disorder is a genetic mutation that usually is passed on through one of the parents that is also infected with this skin disorder or in some cases both parents will be a carrier of the disorder and then pass it on to their newborn, and in very rare cases the patient will accumulate IWC spontaneously. IWC has been theorized to be a Mitotic recombination and natural selection that will occur within the skin, while the infected are of the skin is found to be the dominant genetic mutation the confetti or healthy patches display reversion or cells that have lost the mutation. The healthy white spots will basically trick the infected area of tissue back into normal health, which creates the white splotches in patients. This is all originated by loss of a heterozygous this LOH is explained by a loss of normal function of one allele in a certain gene. LOH will occur when the remaining functional allele in a convinced somatic cell of the offspring will become inactivated by mutations. A mutation that occurs within C17 this interval contains about 20 known genes that have been expresses within the skin.This will cause a display of thousands of healthy normal spots as time passes these spots will grow in size and numbers

. To take a more in depth look a mapping of the genome in which the recombination in revertant clones were taking place yielded a discovery of a frameshift mutation within KRT10, has been found to be a possible explanation for the inflamed skin and confetti spots. A frameshift mutation is an insertion or deletion of a small number of nucleotides that will ultimately change how the genome is being read and executed. This type of affect can be detrimental to the patient that the frameshift mutation is occurring in. The exact mutation in KRT10 will vary from patient to patient, generally all of these mutations will exhibit a frameshift that alters the reading frame of KRT10. When this frameshift is being decoded it produces an arginine -rich peptide that mislocalizes to the nucleous, which ultimately affects the keratin filament network of skin cells. Arginine-rich cell-penetrating peptides are short cationic peptides capable of traversing the plasma membranes of cells. Some reversion to wild type can occur at a higher frequency, concluding a general increase in the mitotic recombination within patients diagnosed with IWC.

These findings may not be able to cure the condition as of now but with advancments in technology this feat will soon be tackled. This research is not only beneficial to patients with IWC , It gives us the power to harness the process in which the elimination of the mutations that cause other diseases. The most crucial would be various blood disorders, only because the recombination of blood stem cells are easily detectable in cancer mutations before they would be introduced into the patients

With all this knowledge and research that is being done on this skin disorder, unfortunately the cure for IWC is still underdetermined. This life long form can only merely be handled or controlled. Patients that display a less milder form of IWC will treat themselves with an array of moisturizers, creames, blams, lotions and bath oils. These patiennts that display milder symptons should mix and match until they find a remedy that works betst for their skin. Doctors in some cases will recommend a hydroxyacid lotion that not only moisturizes your skin it will also melt away the scaly appearance. What makes this skin condition like a see saw, if a patient tends to scratch the skin and infection sets in a regiment of antibiotics will be administered regularly. The main focus to correcting theses conditons lie with the revising of the mutations. There is a possibility that induced and or natural selection of mitotic recombination can be exploited to reverse the detrimental effects caused by rare skin disorders.


What makes IWC so resilient is its ability to have a high frequency of spontaneous reversion