MicroevolutionMicroevolution is nothing but the small change that occurs in plants or animals because of genetic inconsistency present in the gene pool of the inhabitants. Microevolution could be the main cause for the origin of a new species. The changes in allele (alternate terms of a gene) frequency, which could be a result of mutation, natural selection, genetic drifting and gene pool.
Microevolution could occur due to some destructive changes caused by environmental pollution or degeneration or due to changes in mutation and failure of proper genetic information, which could lead to the formation of a new species. Some of the examples of microevolution that could be discussed are, due to changes in the genes, and the separation of a small part of the gene pool, people might be born with certain handicaps like short stature of the body, an extra sixth finger, fingers that are very short and other blood diseases. Specific examples that can be mentioned are circular overlaps (gulls), exclusive Hawaii flies, the finches and tortoises in the islands of Galapagos, the sparrows in the United States, dog breeding through artificial means, Madeira rabbits and people with distinct skin color, mongoloid eyes, the stout Eskimos and the tall and thin Africans. All the above examples of microevolution were caused by natural selection.
This is evident in the case of the “circular overlaps”, the two types of the European gulls —the herring gull and the smaller black-backed gull, which breed with a chain of other subspecies that expand throughout the world, they do not interbreed with each other. In these circular overlaps a series of many forms of species, which interbreed with each other throughout the chain, broadens for a lengthy geological distance, other than where the main links in the series extend beyond; the final two species are different species, because they do not interbreed with one another. The Finches can also be taken as an example of such variation change. Other examples that could be described are birds and other insects like the fruit-flies.
Sexual selection, the evolution that is entirely based on greater reproduction and an example of this is the male peacock’s feathers. Sickle-cell anemia is an example of balancing selection. Descriptive and hand waving, could be used as an example of kin selection, because similar genes are inherited from the ancestors to their immediate relatives, any gene which controls a person to assist its relations can consequently develop the endurance of the other replica of the same gene which is carried by the relatives.Certain bacteria’s developing resistance to certain antibiotics and viruses that manage to transform their formation so that they can avoid resistance are all examples of microevolution through mutation.
An incredible amount of difference and alteration can happen due to the genetic diversity. Most of the genetic diversity like different alleles and amalgamation of genes are caused by mutation. Microevolution by means of genetic variation is a practical fact. There is no evidence of the formation of fresh genes with exclusively new groups of gene arrangement and function.
References;MICROEVOLUTION, Evolution in Action?, Retrieved 24 September 2007, http://mywebpages.comcast.net/mkent595/Microevolution.htmlR.
Totten, Evolution is partly true, World View Test Site, Retrieved 24 September 2007, http://www.geocities.com/worldview_3/parttrueevol.html;
Microeconomics On Hilton Hotels
Microeconomics on Hilton HotelsIntroductionHilton Hotel Corporation- one of the most successful companies in the international market and currently operating around 3000 hotels in less than 100 countries (Schein 1). Just recently, Hilton Hotel made an announcement of merging with Blackstone Group, one of the chief private equity firms in the world, and the said merging costs $26 billion. Furthermore, Hilton Hotel Corporation does not only operate hotels but also casino and tourism.
With this wide range service line of Hilton Hotel, it is not surprisingly the said company was able to dominate the hospitality industry.CostAs expected, the volume of expenditure by Hilton Hotel justifies the size of its operation and service coverage. One component of Hilton Hotel Corporation total costs would be their plant, property and equipment expenses. This includes all the tangible assets that they purchase in order to improve the services of Hilton Hotel to its customers, see Appendix 1.
With their high quality standards, Hilton Hotel spends around 7 million USD just to buy new equipments and improve their facilities. Since 2002, they budget allotted to this said costs component will not be less than $5 million. Some of the equipments that Hilton Hotel is being purchased every year are kitchen and utility equipment as well as other maintenance equipment of the company. The management of Hilton Hotel also purchases state of the art furniture and appliance to suit the style of living of their customers.
They see to it that their furniture and appliance are with accordance to the “mainstream” of their target customers.Moreover, another factor of cost component of Hilton Hotel’s operation would be the selling, general and administrative expenses. This includes all the costs acquired by the company in providing services such as salaries of the employees, office supplies, telephone expenses, electrical and water expenses. In other words, this cost component encompasses all the intangible current expenses of Hilton Hotel.
In the electricity alone, Hilton Hotel spends around 5 million USD every year since they consume more than 4 billion kWh of electricity. They also consume five million “therms” of natural gas and around 7 billion gallons of water every year not to mention the 100,000 employees that need to be paid twice a month and the office supplies like paper; pen etc. to be purchased for administrative purposes. In 2006 the selling, general and administrative expenses of Hilton Hotel accounts to around 900 million USD from 400 USD in 2003.
The said figures are justifiable given the fact that Hilton Hotel is continuously expanding every year.Another cost component of Hilton Hotel would be interest expense or the interest paid by the company from the loans and mortgages that they have from various financial institutions. Those long term loans incurred by Hilton Hotel are being used for the expansion of the company’s operation. One example of loans that were acquired by Hilton Hotel for its expansion would be the 5 million USD loan allotted for Park Place Entertainment last 2001.
From 2003 to 2006, the spending of Hilton Hotel to interest rate continuously increased from 300 million USD to 500 million USD respectively. Most of the reason why Hilton Hotel acquires millions of dollars of loans to financial institutions is their acquisition of other businesses in the industry to increase their operation. With limited cash on hand, borrowing money is the easiest way of Hilton Hotel to generate money to buy those companies in the market.Aside from the already given cost component of Hilton Hotel, taxes is also one of the primary source of capital outflow of Hilton Hotel.
From 2003 to 2006 the total amount of taxes that is being paid by Hilton Hotel would be from 81 million USD to 260 million USD respectively. The gross profit of Hilton Hotel from 2003 to 2006 was doubled from 1,300 USD to 2,600 USD respectively. As what have already said a while ago, Hilton Hotel has been aggressively expanding its operation which enormously increases the taxable income of the said company. Therefore, the increase in the tax expenses of Hilton Hotel is already justified.
The said above tax payment made by Hilton Hotel is the net of the tax rate of various countries where Hilton Hotel operates. Meaning, tax expenditure of Hilton Hotel varies depending on which country, where Hilton Hotel operates, is being considered.The last but not the least costs component of Hilton Hotel would be the dividend costs of it stocks. Just last July of this year, Hilton Hotel announced the dividend rate per share of stocks in the company.
The company declared a $0.4 dividend per share and paid last September of this year. Since 2005 up to the present, the dividend rate of Hilton Hotel increased from $0.2 to $0.
4 although the divided per share of the company seems to became stagnant from 1999 to 2005. This said dividends paid by Hilton Hotel deplete the net income of the company since it is also considered as financial obligation on the side of the company.RevenueBased from the 2006 financial issue of Hilton Hotel Corporation, the net income of the said company reached around 600 million USD as compared to the 500 million net incomes in 2005. As for its operating income, around 1.
2 billion USD was generated by Hilton Hotel in 2006 as compared to 800 million operating income in 2005. Moreover, the revenue generated by the said company reached up to 8 billion USD in 2006 in contrast to 4.4 billion USD in 2005 (“Hilton Hotels Corporation 2006 Annual Report: Growing Brands Globally” 1).The total revenue that is being received by Hilton Hotel from its owned chain of hotels around the world is around 2.
5 billion in 2006. If the revenue generated from the chain of hotels of Hilton Hotel Corporation is to be monitored, one could clearly see that it increases every year due to the establishment of new hotels in Asia and Europe in the previous years. In 2005 around 2 billion USD was the revenue generated by Hilton Hotel Corporation from the hotels that they originally owned. As for those acquired hotels of Hilton Hotel, it was stated in the financial report of the company that their comparable owned hotels worldwide was up by 8% in 2005 and reached 9% growth in 2006.
The “time share business” of Hilton Hotel, “Hilton Grand Vacations Company”, contributed revenue of around 650 million USD in 2006 as compared to 550 million USD in 2005. In other words, the revenue of HGCV has increased by 19% from 2005 to 2006 to the increase in the unit sales and the marginal increase in the average unit sales in 2006.Another income generating activity of the Hilton Hotel is the selling of properties. In 2006, around 1.
5 billion USD worth of properties were able to sell by Hilton Hotels Corporation. This said activity of Hilton Hotel started in 2004 to cater their “company strategy” of further increasing their profits from managing and franchising their assets in the market.Aside from hotel chains of Hilton Hotel Corporation, their spa services also generate considerable amount of income for the company. The Hilton Glasgow Hotel is one of the hotels of Hilton Hotel Corporation that offers spa services and other fitness related activities like sauna, 15 meter pool and fitness center.
Another company under Hilton Hotel Corporation that also offers spa and health related services is the Hilton Sandestin Beach Golf Resort and Spa.Moreover, Hilton Hotel Corporation also handles gaming companies in Las Vegas. The Las Vegas Hilton is one of the subsidiaries of Hilton Hotel Corporation concentrating on gaming and casino business.CompetitionFor the past years, Hilton Hotels seems to concentrate more on developing businesses that is les related to hotel line of business.
Like for instance the “casino hotel” and “spa-hotel” of the Hilton Hotel Corporation is really unique and attracts more customers. On the other hand, their competitors like Marriott and Hyatt Hotels gives more attention in the “luxury-hotels” line of business.Marriott International Inc., just like Hilton Hotel, is also one of the successful hospitality companies in the world.
Marriott International Inc. also operates chains of hotels and casinos to various countries around the world. Currently, Marriott handles around 3,000 lodging properties on 70 countries (“Corporate Information” 1). Most of the services being offered by Marriott belong under full-service lodging.
Its initial capital is only equal to 200 million USD after it split to its mother company. The revenue of Marriott International reached around 15.1 billion USD in 2004 and employs around 150,000 workers in 2006. Marriott, despite of limited available capital, still manages to acquire hotels and other related business firms to revitalize their product lines and gain market influence to compete with par to larger hotel chains like Hilton Hotel.
Given the size and coverage of operation, Marriott imposes a small threat to Hilton Hotel, but it would be better to keep on eye in this company since for the past years, it was able to experience impressive growth and acquisitions in the market. Hilton Hotel must monitor every actions of Marriott in order not to give chance this company to further gain market influence.On the other hand, the Global Hyatt Corporation is being comprised by hotel brands and other related business line. It currently specializes in luxury hotel line of brand and one of the top companies which offers full service of luxury hotels, resorts and spa.
The target customers of Hyatt are travelers and vacationers from around the world. Moreover, like Hilton Hotel, Hyatt also offers resorts and spa services to their customers, thus, adding up to the brand of the company, like the Grand Hyatt Kauai Resorts and Spa located in Hawaii and the Hyatt Regency Huntington Beach Resort and Spa located in California. In 2006, Global Hyatt Corporation made 3,500 million USD worth of revenue and they received a negative growth rate of around 45%. Given the limited target customers of Hyatt, it is not surprisingly that their revenue is not that high enough to justify the wide operation of the said company.
Maybe, they are just spending much from developing their hotels into a luxury one and later on, in the long run, be able to experience the benefits from their investments today. Another possible reason why this company has low revenue is due to the fact that this company just started in the market in 2004 from separating into its mother company. Due to this, like the Marriott International Inc., Hilton Hotel Corporation must monitor the company status of Global Hyatt Corporation to prevent any possible great threat from Hyatt Corporation.
Aside from Hyatt and Marriott there are still other companies in the hospitality industry that serves to be the competitors of Hilton Hotel like the InterContinental Hotels and Choice Hotel. The former concentrates on hotel chains and has a revenue equivalent to 960 million pounds in 2006 and was founded in 2003. Slowly but surely, InterContinental Hotels Group is penetrating to the luxury-hotel market just like Marriott and Hyatt Hotel. In terms of size and operation coverage, still, Hilton Hotel is larger as compared to InterContinental Hotels Group.
With this, there is only little threat on the welfare of Hilton Hotel the existence of InterContinental Hotels Group in the industry.On the other hand, Choice Hotels International franchises around 5,000 hotels in over 40 countries around the globe (“About Choice Hotels” 1. For the past years, Choice Hotel was able to manage to maintain a continuous growth level for the entire company. In terms of market coverage, Hilton Hotel still larger as compared to Choice Hotel.
Therefore, just like the first three companies, Choice Hotel only imposes a small amount of threats to the operation of Hilton Hotel.ConclusionWith the aggressive market expansion of Hilton Hotels Corporations, they were able to establish great margin with its competitors in terms of market coverage, capitalization, profitability and target customers. Although its competitors has the advantage over Hilton Corporation in terms of luxury-hotel brand line, but the point is that with the sufficient amount of assets on Hilton Hotels, it is not possible for them to cope up with their competitors and be able to penetrate the luxury-hotel brand line.With regards to the profitability of Hilton Hotel, one of the reasons why they were able to attain the said status is due to the fact that they were able to cater to a larger group of people and finds way on how to minimize their operational costs and give value to their investors and customers.
One of their ways on minimizing their operational costs is the purchase of cheaper yet quality products. They also start to use electricity wisely and purchased “ENERGY STAR” labeled products in the market as well as swapping older and inefficient boilers of the company. With this, Hilton Corporation was able to save around 2.5 million USD within a year (“ENERGY STAR Success Story: Hilton Hotels Corporation”1).
Good working relationship is also being established in the floors of Hilton Hotels Corporation and it helped the company to get along with the changes in the market behavior as well as on their employees. Moreover, since Hilton Hotel Corporation has been in the hospitality industry for many decades, they already establish brand loyalty with their target customers. With this, there is nothing to worry about the competitors for the mean time. But Hilton Hotel must monitor its competitors to prepare their management from any strategies of the latter that aims to run over Hilton Hotel Corporation.
Appendix 1Hilton Hotels CorporationAnnual Income StatementPeriod Ended12/31/200612/31/200512/31/200412/31/200312/31/2002Net Sales8,162.004,437.004,146.003,819.
002,895.00Cost of Goods Sold5,597.002,770.002,722.
002,566.001,563.00Gross Profit2,565.001,667.
001,424.001,253.001,332.00R & D Expendituren/an/an/an/an/aSelling, General & Admin Expenses907607485404381Depreciation & Amort.
441299330334348Non-Operating Income11913638310Interest Expense498259274295328Income Before Taxes838638373223285Prov. For Inc. Taxes2591661275381Minority Interest712866Realized Investment (Gain/Loss)n/an/an/an/an/aOther Incomen/an/an/an/an/aNet Income Before Extra Items572460238164198Extra Items & Disc. Ops.
n/an/an/an/an/aNet Income572460238164198in millions of USD Works citedSchein, Amy. “Hilton Hotels Corporation,” 2007. Hoovers.com.
23 November 2007 <http://www.hoovers.com/hilton/–ID__10733–/free-co-factsheet.xhtml>.
“About Choice Hotels,” 2007. Choicehotels.com. 23 November 2007 <http://www.
choicehotels.com/ires/en-US/html/AboutChoiceHotels?sid=2TIIi.6XG7dg3HZ.8>.
“Corporate Information,” 2007. Marriott.com. 23 November 2007 <http://www.
marriott.com/corporateinfo/default.mi>.“ENERGY STAR Success Story: Hilton Hotels Corporation,” 2001.
Energystar.gov. 23, November 2007 <http://www.energystar.
gov/index.cfm?c=hospitality.bus_hospitality_hilton>.“Hilton Hotels Corporation 2006 Annual Report: Growing Brands Globally,” 2006.
Corporate.net. 23 November 2007 <http://library.corporate-ir.net/library/88/885/88577/items/239651/Hilton_AR_2006.pdf>.
Micro RNA – An Introduction
In the beginning when the first Micro RNA lin – 4 was discovered, it was thought that it was the only Micro RNA. This Micro RNA was acknowledged by genetics in the nematode Caenorhabditis elegans.
This Micro RNA is related to the development of the creature with time. Quite interesting to know about this gene is that, it is not responsible for encoding a protein itself, but generates two dissimilar codes for two tiny RNA molecules. These two RNA molecules are approximately 61 and 21 nucleotides in length.The first RNA molecule is the ancestor of the second RNA molecule which is of 21 nucleotides in length.
The larger one is capable of structuring another stem loop molecule which is stored in the nematodes.The smaller of the two RNA molecules controls the first Micro RNA lin – 4 by the formation of base paring. This is done to imperfect the opposite sites in the 30 un-translated areas or the UTR of the first Micro RNA lin – 4. In the start, the scientists regarded this phenomenon of gene silencing by a small RNA as a rare sight.
This was especially regarded to be rare in the case of nematodes.However, after the scientists discovered the second first Micro RNA, let-7, this view changed. This Micro RNA Let-7 is another type of small RNA that works for the developmental timing in small RNA that is also involved in developmental timing in Caenorhabditis elegans and also controls the first Micro RNA lin – 4.Both the first and the second Micro RNA’s, lin – 4 and let – 7 are known as small temporal RNA’s and are basically known for their part in developmental timing.
Out of these two RNA’s, let – 7 is more conserved in many multi cellular organisms than lin – 4. Even more, the second Micro RNA, let-7 is differentially articulated during development of bilateral animals.These findings clearly showed that the control and regulation of gene expression by these small RNAs was not limited to nematodes and was certainly a more general phenomenon that was expressed by various other multi cellular organisms. Until now, more than a hundred Micro RNA’s have already been discovered by the scientists in Caenorhabditis elegans and man.
The newly found Micro RNA’s are not listed according to the previous way – that is in a temporal specific method, like lin -4 and let – 7 were classified, but the new ones are expressed in tissue arrangement. These Micro RNA’s have been discovered in many other multi cell organisms and it is expected that the vertebrate organisms might have up to one thousand dissimilar Micro RNA’s.Further, it is also expected that these Micro RNA’s found in vertebrate organisms control almost 30% of the genes. This paper studies about the function of Micro RNA’s in animal development.
Micro RNA AND ITS MECHANISMThe Micro RNA biological genesis is divided amongst many various steps. At first the micro RNA genes are directly copied as RNA polymerase II which are in the form of a longer structured micro RNA. These RNA polymerase II are also called as Pri – Micro RNA’s. The development of the primary Micro RNA’s undergoes a step to step phase of growth and they are compartmentalized.
The Pri – Micro RNA’s are developed into a 80-75 -nucleotide in length Micro RNA’s with the help of an enzyme known as RNase III enzyme Drosha. The role of this RNase III enzyme Drosha, is to form a protein complex which has a double stranded RNA. This protein is called as DGCR8 (Pasha in flies). The Pri – Micro RNA’s are shifted from the nucleus by Exportin-5 in the existence of Ran-GTP as cofactor.
Within the cytoplasm, these Pri – Micro RNA’s are developed into 22 nucleotide in length, duplex Micro RNA’s with the help of another enzyme – RNase III enzyme Dicer. This enzyme – RNase III enzyme Dicer was first known for its function in RNA interference. In this interference, the RNase III enzyme Dicer, changes the doubly stranded RNA into small interfering RNA’a that also play a role in RNA interference.RNase III enzyme Dicer works together with the doubly stranded RNA to bind up the protein TRBP in Caenorhabditis elegans and Loquacious in Drosophila.
This process effectively brings closer the initiator and effectors steps of Micro RNA action. Next, the Micro RNA duplex are loosened and unwinded, and this process in initiated at the lowest possible lowest thermodynamic stability of the duplex end. The Micro RNA that is developed at this stage is the future Micro RNA and is also known as the GUIDE RNA. These mature Micro RNA’s areincluded into a ribo-nucleoprotein complex, which is known as miRNP, and is comparable to the to the RNA-induced silencing complex or RISC, which is the effector of the RNA interference.
However, ribo-nucleoprotein complex, miRNP and the RNA-induced silencing complex are not identical in nature. In RNA-induced silencing complex, the Micro RNA’s can intervene in the lower regulation of the target gene activity in two different methods or modes:Translational inhibitionTarget mRNA cleavage.However, the selection of the method / mode is made according to the level of complementarities, amongst the Micro RNA and the target gene in amalgamation with an Argonaut family protein. If there are high results of complementarities between Micro RNA and the target gene, then the second mode is selected – Target mRNA cleavage.
This is followed by common RNA degradation of the gene target. If in case the results of complementarities between Micro RNA and the target gene are low, or there is partial complementarity, then it results in the selection of translational inhibition. The scientists are still not aware of the function of the translational inhibition mode. It is only suggested at the time being that the Micro RNA’s target the genes and these genes could be seized on polysomes.
Another suggested function of the translational inhibition mode is that the genes be employed by the P-bodies where they are used up of the translation machinery and are in the process worn out and degraded. In disparity to the plant kingdom, Micro RNA’s brought about the Target mRNA cleavage in animals, for example the Target mRNA cleavage of HOXB8 mRNA by miR-196 in mouse embryos. However, this is much less common in Translational inhibition. Argonaut proteins are significantly in attendance in the RNA-induced silencing complex or RISC and all the Argonaut proteins that are present in mammals, actually do the binding up between the Micro RNAs.
On the other hand, in both mammals and Drosophila, Argonaut 2 proteins is the only main catalytic locomotive of RNA-induced silencing complex or RISC that act as a go-between the targeted RNA cleavage. Furthermore, Drosophila Argonaute1 and the two Argonaute1 homologs alg-1 and alg-2 in C. elegans are required for miRNA production, stability and function. BIOLOGICAL FUNCTIONS OF Micro RNA’s IN ANIMALSThe Micro RNA’s perform multiple biological processes.
Several experiments have shown the various functions that are performed by the Micro RNA’s. Developmental timing in worms – the first two Micro RNA’s lin – 4 and let – 7, were studied and it was found that they have a role to play in the hetero-chronic pathway, which controls the developmental timing in C. elegans. Let – 7 was found to be a suppressor of lin-14 mutants.
This clearly showed that the Let -7 acts in some way. If there occurs a loss of function mutation in let 7 and lin 4, then both of them experience retardation but at different developmental stages. The null mutants of Lin 4, repeat detailed upshots of the primary larval phase at following later on stages, let-7 null mutants repeat larval cell upshots at the mature phase. On the other hand, over expression of let-7 provides intelligent growth, the contradictory heteroc-hronic phenotype.
The timing of the phenotypes keep up a correspondence with the onset of lin-4 and let-7 expression, which is early and late in improvement, in that order. Thus, lin-4 is an early developmental timer and let-7 a late developmental timer.Neuronal asymmetry in worms – “A surge of genes, concerning two micro RNAs, settle on the issue of Neuronal left/right asymmetric expression of chemosensory receptorgenes in the left (ASEL) and right (ASER) chemosensory neurons of C. elegans.
The lsy-6 miRNA is expressed in the ASEL neuron and inhibits the expression of its target, the Nkx-type homeobox gene cog-1. This ultimately leads to the expression of the GCY-7 chemosensory receptor in ASEL. In the ASER neuron, miR-273 inhibits the translation of die-1 mRNA. DIE-1 is a zinc-finger transcription factor needed for the transcription of lsy-“.
Therefore, the expression of miR-273 leads to the down regulation of lsy-6 and subsequently to the expression of the GCY-5 chemosensory receptor in ASER [112]. Thus, inverse and sequential expression of two micro RNAs leads to asymmetric expression of chemosensory receptors in neurons of C. elegans. (Lau, N.
C., Lim, L.P., Weinstein, E.
G. and Bartel, D.P. (2001), abundant class of tiny RNAs with probable regulatory roles, 294, 858–862.
) Vertebrate development – more than a few observations demonstrate that micro RNAs are necessary for the standard growth of mammals. initially, mouse and human cells state a particular set of micro RNAs that are down regulated over differentiation into embryo bodies. Secondly, the cells that are lacking in dicer are workable, other than do not shape up in mature micro RNAs and they do not succeed to set apart in vitro and in vivo.First, most of the Micro RNA’s were discovered by the loss / gain processes of the genetic screens in Caenorhabditis elegans and Drosophila.
Given that, most of these micro RNA’s have been identified by their functions, it is likely to be accurate that they are involved in tissue differentiation. The other functions that have been identified of the Micro RNA’s seem to originate form the reverse genetic approaches. These approaches include likes of Micro RNA’s knockout or knockdown and micro RNA’s over expression studies. In addition, the micro RNA’s appearance outline, are mainly determined by, the various experiments like for example, the microarray- and in situ analysis experiments have shown that there are some special Micro RNA’s with specific expression designs which give hints to the functions of some special micro RNA’s.
According to the scientists there are only seven micro RNA target genes have been discovered by reverse and forward genetic screens. Many of the target genes are discovered by computational predictions. Recent study and research shows that for every Drosophila Micro RNA, there are an average of 100 various / dissimilar target genes. Most of these target genes are regulated within the seed site interactions.
GENERAL FUNCTION OF Micro RNA’s IN ANIMALS Until so far, these micro RNA’s have only been discovered in multi-cellular organisms and are not found to exist in single cell organisms. This fact confirms that the presence of Micro RNA’s is required for tissue differentiation. Many tests and experiments have proved that this Micro RNA’s are indeed the regulators behind the cell / tissue differentiation. Firstly, since poorly formed or poorly differentiated cells do not need Micro RNA’s in order to exist and this is quite obvious from the detailed information that mouse cells that do not have Micro RNA’s are feasible but be unsuccessful to differentiate and the zebra fish germ cells do not need micro RNA’s for their survival and contribution to the germ line.
Secondly, a number of Micro RNA’s are not present in the early samples of zebra fish, when the cells of the zebra fish were not differentiated. Although the cells of Zebra fish have tissue specific categories developed at a later stage. Third, since the absence of the Micro RNA’s are also not necessary for tissue fate foundation, for the duration of early zebra fish growth, but are necessary for later on improvement steps and tissue development / functioning. Fourth, numerous kinds of human cancer cells have condensed the Micro RNA’s appearance as compared to their complete distinguished tissue at the time of origin.
Fifth, the animals possessing the vertebrae, program hundreds dissimilar micro RNAs that are anticipated to control up to 30% of the genes. Sixth, the micro RNAs posses a larger number of molecular abundance in each cell. In Caenorhabditis elegans there are some micro RNA’s that are predicted to ne present in as much as 55000 copies in each cell. This estimate is at least 500 times higher than the level estimated in a characteristic worm.
The autonomous formation of micro RNAs is identified by the elevated level of assortment that is linking the numerous micro RNA families of the plant and animal micro RNAs. In addition, a small number of DNA base-pair alterations that have been discovered, corresponding to the seed sequences of micro RNAs and are expected to change the collection of target genes. In corresponding, the target genes can without difficulty be included underneath the power of micro RNAs in the course of changes of only a few base-pairs in the DNA. Single micro RNAs possess the ability to regulate over a hundred target genes and the mixed action of micro RNAs is anticipated to control the face of thousands of micro RNAs.
The controlling of such a high number of genes is actually important for the purpose of tissue differentiation. Moreover, the post-transcriptional ruling of the gene expression can also control the variations that are recorded in gene expression. These results of controlling the target genes leads to the creation of stable protein levels, which might also be required to keep cells differentiated. CONCLUSIONSEver since the first of the Micro RNA lin – 4 and let – 7 were discovered by the scientist it has also been proved that these Micro RNA’s form a significant part and a major category of post transcriptional gene controllers.
These micro RNA’s are present widely in all multi cellular organisms, from plants, animals to humans. A majority of animals’ posses about hundred of Micro RNA’s of which most of them are unknown or their functions are unknown to the scientists. However, the limited number of Micro RNA’s that are known to the fraternity, already show signs that these Micro RNA’s possess ultimate abilities to perform in various biological processes. Moreover, in animals like mouse and zebra fish, which do not possess the Micro RNA’s or their production, reveal that Micro RNA’s are required for the development of vertebrae and are responsible for the division and control of tissue and cells.
The current existing sets of Micro RNA’s that are known to the medical science are known to regulate the millions of target Micro RNA’s up to 30%. This figure may still move up because a large number of Micro RNA’s and their functions are still unknown to the scientists. The confirmation of the continuation of these micro RNA’s and their interface with target genes will be the solution to discover the role of all individual micro RNAs during expansion, disease and other cellular processes. REFERENCES[1] Lee, R.
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