Probing the initiation and effectors’ phases of the somatic piRNA pathway in Drosophila

Write a half a page discussion and criticism to the following essay:

 1

Probing the initiation and effectors’ phases of the somatic piRNA pathway in Drosophila

Introduction

To understand the combining RNAi in cultured cells and analysis, it is important to know the roles of known Piwi- interacting RNA(piRNA) pathway elements particularly in the initiation and the effecter phases of transposon silencing. Squash is one component that is physically with Piwi (Brennecke et al.,2007). The main components involved in the process are Squash, Zucchini or Armitage. These elements pose different effects on the transposon, and piRNAs. When squash expression is reduced, its effect is directly seen on the transposon. This is because when its expression is reduced, it leads to modest transposon depression but no results are seen on the piRNAs, consistent with an effecter role (Brower, 2007)

Zucchini, on the other hand, can reduce both piRNAs and Piwi protein when altered or is tampered with. Alteration in Zucchini leads to the formation of a stable Piwi RISC known as RNA- induced silencing complex (Brennecke, 2008)Continuance mutation or loss of Zucchini within its catalyst domain led to amassing of vulnerable herald transcripts from flamenco, steady with a role for this alleged nuclease in piRNA biogenesis.

There are a number of mechanisms that help regulate gene expression. The regulation is done Eukaryotic which are small RNAs, these RNAs perform the regulatory role at both the transcriptional and post-transcriptional levels. These small RNAs are divided into classes in accordance to their particular Argonaute protein partner and according to their mechanism of biogenesis. Piwi-interacting RNAs play a role of binding Piwi –clade Argonaute proteins and they do this in the gonadal tissues. Here, the piRNAs silence mobile genetic elements thereby guarding the integrity of the genome.

The piRNA pathway is divided into a number of phases namely: initiation phase, effectors phase and adaptation phase. There are different things happening in the three phases and this is why the activities were divided into the phases.

Initiation Phase

There are a number of things that happen in the initiation phase:•Production of small RNAs called piRNAs. The piRNAs are produced from their generative loci known as piRNA clusters.•The piRNA give rise to long, presumably single-stranded precursor transcripts which are produced as a result of unknown biogenesis mechanism into small RNAs that are larger than canonical microRNAs.•The piRNAs are stabilized when they are associated with Piwi proteins from Piwi RISCs.•The Piwi RISCs have additional proteins that help in the facilitation of target recognition and silencing(Lau et al., 2009).

Effectors Phase

There are many things that happen in the effectors phase:•Identification of target which is made by the Piwi RISCs via the complementary base-pairing (Lau et al, 2006)•Conservation of the Argonaute catalytic triad which is also made by the Piwi. (Klenov et al, 2007).

Adaptation Phase

This phase is restricted to germ cells and it constitutes the ping-pong cycle. In this period transposon microrna cleavage is directed by primary piRNAs to trigger the production of secondary piRNAs (Klattenhoff et al., 2009) Later on, the produced secondary RNA triggers the production of piRNA from the target, closing the loop that that makes it possible for the overall small RNA population to adjust to challenging by a particular transposon. It is also in this phase where the piRNA in germ cells can be transmitted to the next generation to prime piRNA responses in progeny.

However, when it comes to Drosophila follicle cells, initiation and effectors phase are the only relevant phases. In Drosophila follicle cells, the piRNA pathway relies on the coupling between a single Piwi protein and a principal piRNA cluster to silence gypsy family retrotrasnposons.

Results

From researches made, it was found that there are various ways by which Piwi proteins silence targets by interfering with their transcription. It was found out that piRNA are mostly absent from somatic tissues, results underlying these changes are presumed to have occurred during the development and to have been epigenetically maintained in the adult. Drosophila Piwi protein was found in the nucleus and it interacts with HP1. HP1 is a core part of heterochromatin. The results of the research showed that the effecter mechanism is what takes place in the Drosophila whereby Piwi-associated small RNAs direct heterochromatin formation and silencing of targets.

It was also found that the loss of Piwi poses some results on the transposon expression in the somatic cells (Ghildiyal, 2009). It was found out that the absence of Piwi proteins in the somatic cells during development is the major cause of genetic mutation.  In simple terms, it was found that the piRNA pathway is always required for transposon silencing.

It was also found out that Armitage is a part of the somatic piRNA pathway. Researchers found that there are as many as twelve proteins that have been linked to the fully elaborated piRNA pathway that operates in germ cells (Girard 2006). Many of them were found to show germ-cell specific expression patterns consistent with their selective biological effects (Brennecke 2007). In Armitage, mutilation occurs as a result of loss of both the functional nuclear accumulation of Piwi protein and decrease in Piwi-associated piRNAs. It was concluded that Armitage play a role in the somatic and germline compartments(Cook HA, 2004).

Another result showed that both Armitage and Zucchini work at the initial stage, or phase. Different experiments which were used to determine which phases do the two functions showed that both function at the initiation phase (Cox DN, 2000)

A proteomic analysis of Piwi RNPs was performed and it was found out that Armitage is a part of Piwi RISC. It was found that Piwi immunoprecipitates contained several peptides from Armitage. This was a clear indication that there is the presence of this protein in Piwi. A detection of an association of Squash with Piwi and Armitage was also made.

It was also discovered that Squash impacts the piRNA effectors phase. It was found out that a mutation in the squash showed little impact on the piRNA populations in mutant ovaries.

The discovery made was of high value in the field(Gunawardane 2007) This is because specialists in this field now know the different causes of genetic mutation and when the cause is known it is easy to apply appropriate solutions if a problem occurs (Grivna 2006).The results provide a road map to the specialists to know how to tackle genetic mutation.

Conclusion

From this article, it is clear that the three; Armitage, Piwi protein, and Squash in some point they associate with each other. This discovery is of great value in the field. People can now understand the whole thing of genetic mutilation.

 

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The original due dates will remain in effect and I will evaluate the last paper submitted

Papers: There are two papers for this course: an Abstract Paper, and a Research Paper that builds 

on the Abstract Paper. Papers are worth 100 points each and are to be submitted to the appropriate 

folder in the Dropbox area of the course on or before the due date. Papers are to be in either MS 

Word or Rich Text Format (RTF), follow current APA style guidelines, and have appropriate spelling 

and grammar. Papers are to have a minimum of three scholarly journal article references obtained 

from the library database, which excludes textbooks and websites. Paper format is graded according 

to the sample APA style paper available in the Content area of the course. 

This course will use Turnitin® to verify authenticity of your work and to assist you with handling 

quotes. Following submission of your paper to the Dropbox, both you and I will be able to view a 

report on the paper’s authenticity. I look at the individual items highlighted within the paper and 

those items with an individual percentage greater than 25% will be scrutinized. If you choose to 

modify the paper submitted to the Dropbox, you may do so by resubmitting your work to the 

Dropbox. The original due dates will remain in effect and I will evaluate the last paper submitted to 

your Dropbox. Papers submitted to previous courses will not be accepted. Previous papers cannot be 

submitted as original coursework. All work must be original. Plagiarized work will result in a zero 

score for the paper. Please check the course FAQ tab for APA website support. In addition, utilizing 

an online search engine you can search APA format with some excellent results. The papers are to be 

written using current APA formatting style. 

Abstract Paper (Week 4): The goal for this week’s paper is to introduce you to scientific 

writing using the APA style, the utilization of science/medical terminology in writing a 

paper, and conducting scientific research using the library databases rather than a website. 

In addition to submitting your abstract to the course Dropbox, you will post your paper to 

the appropriate Discussion for peer review by your classmates. The topic you use for this  

 Columbia College Online Campus P a g e | 6

Abstract Paper is the same as the Research Paper topic submitted to the Dropbox for 

approval during Week 2. For this paper, you are to utilize the library database to find 

articles, or you may contact the Stafford Library reference librarian to access books from the 

library. You may not utilize websites as references unless preapproved by the instructor. 

For the abstract/paper, a minimum of three articles must be obtained from the Stafford 

Library database. The Abstract Paper should be a minimum of three (3) pages (Title Page, 

Abstract Page, and Reference Page). 

Research Paper (Week 8): The goals for Research Paper are to introduce you further to 

scientific writing, reinforcing the use of medical terminology in scientific writing using APA 

style, and to provide experience in conducting research using the library database and 

reference librarian. As with your Abstract Paper, the topic for your Research Paper is 

writing a descriptive paper over a medical or healthcare topic you chose for the abstract 

paper. For this paper, you are to utilize the library database to find articles or you may 

contact the reference librarian to access books from the library. You may not utilize websites 

as references unless preapproved by the instructor. For this paper, a minimum of five articles 

must be obtained from the Stafford Library Database. The Final Paper should be a minimum 

of ten (10) pages (Title Page, Abstract Page, Body (7-pages), and Reference Page)

 

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Cytology Lab

this assignment has to been used with the MUSE lab for this assignment. Only if you are fimiliar with this or done it then i don’t think you can do it but if you can then let me know. I need the template completly done so that I can submit it. So before you ask for a handshake please take the time to see if you can do it. I can not provide access to this MUSE lab because it is with my school AIU online.

Description:

Student Instructions

For each assignment, you will use the M.U.S.E. link to complete the lab.

In this lab, you will observe diagrams showing the structure of plant and animal cells. Using the textbook and virtual library resources, fill in the tables.

Cytology Lab

Using the M.U.S.E. link, review the background information and animation to complete your report. Use the Lab 2 worksheet to complete the tables.

This lab will familiarize you with the basic structures of animal and plant cells. You must thoroughly study the cell diagrams and memorize the major structures of cells as well as the function of each cellular part.

Your lab report will consist of the completed tables.

Click here for directions to M.U.S.E. lab.

Please submit your completed assignment.

 

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What theories about the causes of disease have persisted from the past until today?

HCS 330 Week 1 DQ’s (***** 3 Pages + APA Format + References *****)

HCS 330 Week 1 DQ 1

What theories about the causes of disease have persisted from the past until today?

HCS 330 Week 1 DQ 2

What were the major breakthroughs that contributed to a more scientific understanding of disease causation?

HCS330 HCS/330 HCS 330 Week 1 DQ

HCS 330 Week 1 Discussion Questions

 

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What theories about the causes of disease have persisted from the past until today?

HCS 330 Week 1 Discussion Questions (***** 3 Pages + APA Format + References *****)

HCS330 Week 1 DQ 1

What theories about the causes of disease have persisted from the past until today?

HCS330 Week 1 DQ 2

What were the major breakthroughs that contributed to a more scientific understanding of disease causation?

HCS330 HCS/330 HCS 330 Week 1 DQ

HCS 330 Week 1 Discussion Questions 1 and 2

 

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Create an educational or training tool for new nursing hires that describes the nurse’s role in the use of informatics and technology.

New Hire Education Tool

Week Two

Create an educational or training tool for new nursing hires that describes the nurse’s role in the use of informatics and technology.

Incorporate at least one theory (nursing theory, informatics theory, change theory, or other supporting theory) that relates to informatics in nursing.

Ensure that the educational tool addresses the following points:

·      Define nursing informatics.

·      Describe the nurse’s roles and responsibilities in quality data management.

·      Explain why comfort with technology and informatics is important in patient care and administration.

·      Identify ways the new nursing hire may become more comfortable with health care technology.

Include a minimum of three peer-reviewed resources, and develop an APA-formatted reference page.

Format the educational tool as a matrix, brochure, video, podcast, slide presentation, or another format approved by your facilitator.

 

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Food Web -Everglades Ecosystem

Food Web -Everglades Ecosystem

Assignment for week 5-Presentation 10-12 slides with speaker notes:

Food Web week 5-

Ilustrate the energy flow among organisms of a food chain in a

particular ecosystem. See Ch. 20 of the text for details and

examples.

.

Determine the interdependency of life in your ecosystem by

examining its organisms.

Include the following:

• List the organisms that can be found in your ecosystem.

• Identify the structure and function of the main organs in at least

two organisms, and indicate why they are suited for that

environment.

• Label major organisms that live in your selected ecosystem: P

for producers, C for consumers and D for decomposers.

• Name types of consumers in your ecosystem.

• List the food chains associated with your ecosystem. Address

the following items:

o Name of the plant or animal

o What it eats

o What eats it

o How it adapts to the ecosystem

• Describe the ecosystem’s population growth and regulation

through community interactions.

• Evaluate potential hazards caused by humans that might affect

your ecosystem’s stability, such as environmental pollution.

Utilize labels and associated details in the diagram.

Format consistent with APA guidelines.

Chapter 20 diagram-see below of copy and pasted diagram.-example of food chain

 

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Food Web -Everglades Ecosystem

Food Web -Everglades Ecosystem

Assignment for week 5-Presentation 10-12 slides with speaker notes:

Food Web week 5-

Ilustrate the energy flow among organisms of a food chain in a

particular ecosystem. See Ch. 20 of the text for details and

examples.

.

Determine the interdependency of life in your ecosystem by

examining its organisms.

Include the following:

• List the organisms that can be found in your ecosystem.

• Identify the structure and function of the main organs in at least

two organisms, and indicate why they are suited for that

environment.

• Label major organisms that live in your selected ecosystem: P

for producers, C for consumers and D for decomposers.

• Name types of consumers in your ecosystem.

• List the food chains associated with your ecosystem. Address

the following items:

o Name of the plant or animal

o What it eats

o What eats it

o How it adapts to the ecosystem

• Describe the ecosystem’s population growth and regulation

through community interactions.

• Evaluate potential hazards caused by humans that might affect

your ecosystem’s stability, such as environmental pollution.

Utilize labels and associated details in the diagram.

Format consistent with APA guidelines.

Chapter 20 diagram-see below of copy and pasted diagram.-example of food chain

 

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The muscular layer of the heart is called the myocardium

The Circulatory System

1: Which of the following is not true?
[removed] The muscular layer of the heart is called the myocardium
[removed] The pulmonary circuit of the cardiovascular system transports blood from the heart to the lungs
[removed] Blood is transported to the body via the vena cavae
[removed] The left ventricle pumps blood that is distributed to the head and the rest of the body
2: The _________ valves are one-way valves that prevent blood from draining from the aorta back into the left ventricle.
[removed] semilunar
[removed] bicuspid
[removed] tricuspid
[removed] atrioventricular
3: Heart sounds heard through a stethoscope are
[removed] produced by the flow of blood through the heart
[removed] produced by the closing of the valves
[removed] produced only by the closing of the semilunar valves
[removed] produced only by the closing of the atrioventricular valves
4: The pacemaker of the heart is
[removed] the atrioventricular node
[removed] located in the wall of the left atrium
[removed] known as the Purkinje fiber
[removed] the sinoatrial node
5: Defibrillation
[removed] occurs during some heart attacks and is characterized by abnormal electrical activity in the heart muscle cells
[removed] can be achieved by cardiopulmonary resuscitation
[removed] is a procedure used to measure electrical activity in the heart
[removed] is a procedure in which the electrical activity of the heart muscle cells is restored
6: A myocardial infarction
[removed] is a type of heart attack that occurs when blood flowing through the cardiac arteries is blocked, causing muscle cells to die
[removed] occurs when heart muscle cells die as a result of abnormal electrical activity
[removed] is a procedure used to measure stroke volume and cardiac output
[removed] is common in people who eat low fat diets and get plenty of exercise
7: Which of the following is not a risk factor for heart attack?
[removed] a fatty diet
[removed] a sedentary lifestyle
[removed] smoking
[removed] stress management capabilities
8: A heart murmur is caused by
[removed] weak heart muscle
[removed] a defective heart valve
[removed] a defect in the aorta
[removed] a defect in the vena cave
9: Which of the following is not true?
[removed] Arteries transport blood away from the heart
[removed] Nutrients and waste are transported across veins into body tissues
[removed] Capillaries are found in branching networks in the tissues of the body
[removed] The transport of blood through veins is aided by valves
10: The aorta and its large branches
[removed] contain numerous elastic fibers that help propel blood throughout the body
[removed] are large veins with irregular walls
[removed] are supplied with blood from the right atrium of the heart
[removed] have the lowest blood pressure in the circulatory system
11: An aneurysm is a ballooning that occurs in
[removed] arteries
[removed] veins
[removed] the wall of the heart
[removed] None of the above
12: The lymph is pumped through the body by
[removed] the heart
[removed] the lungs
[removed] the kidneys
[removed] skeletal muscle movement
[removed] the spleen
 

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