Small interfering RNA (siRNA) and microRNA silence genes at the transcriptional,
posttranscriptional, and/or translational level. Using human tissue culture cells, we show that
promoter-directed siRNA inhibits transcription of an integrated, proviral, elongation factor
1alpha (EF1A) promoter–green fluorescent protein reporter gene and of endogenous EF1A.
Silencing was associated with DNA methylation of the targeted sequence, and it required either
active transport of siRNA into the nucleus or permeabilization of the nuclear envelope by
lentiviral transduction. These results demonstrate that siRNA-directed transcriptional silencing is
conserved in mammals, providing a means to inhibit mammalian gene function.
The ‘nuclear side’ of RNA interference (RNAi) is increasingly recognized as an integral part of
RNA-mediated gene silencing networks. Current data are consistent with the idea that epigenetic
changes, such as DNA (cytosine-5) methylation and histone modifications, can be targeted to
identical DNA sequences by short RNAs derived via Dicer cleavage of double-stranded RNA
(dsRNA). To determine the relationships among RNA signals, DNA methylation and chromatin
structure, we are carrying out a genetic analysis of RNA-mediated transcriptional gene silencing
(TGS) in Arabidopsis. Results obtained so far indicate that in response to RNA signals, different
site-specific DNA methyltransferases (DMTases) cooperate with each other and eventually with
histone-modifying enzymes to establish and maintain a transcriptionally inactive state at a
homologous target promoter. Processing of dsRNA in Arabidopsis occurs in the nucleus and in
the cytoplasm, where distinct Dicer-like (DCL) activities are thought to generate functionally
distinct classes of short RNAs. RNA silencing pathways thus operate throughout the cell to
defend against invasive nucleic acids and to regulate genome structure and function.
Solution
Small interfering RNA (siRNA) and microRNA silence genes at the transcriptional,
posttranscriptional, and/or translational level. Using human tissue culture cells, we show that
promoter-directed siRNA inhibits transcription of an integrated, proviral, elongation factor
1alpha (EF1A) promoter–green fluorescent protein reporter gene and of endogenous EF1A.
Silencing was associated with DNA methylation of the targeted sequence, and it required either
active transport of siRNA into the nucleus or permeabilization of the nuclear envelope by
lentiviral transduction. These results demonstrate that siRNA-directed transcriptional silencing is
conserved in mammals, providing a means to inhibit mammalian gene function.
The ‘nuclear side’ of RNA interference (RNAi) is increasingly recognized as an integral part of
RNA-mediated gene silencing networks. Current data are consistent with the idea that epigenetic
changes, such as DNA (cytosine-5) methylation and histone modifications, can be targeted to
identical DNA sequences by short RNAs derived via Dicer cleavag.
RNA interference (RNAi) is a mechanism that inhibits gene expression at the stage of translation or by hindering the transcription of specific genes.
RNAi targets include RNA from viruses and transposons.
Yes, its true that most mutations are deleterious however there ar.pdfapexelectronices01
Yes, it\'s true that most mutations are deleterious however there are a few mutations that are
beneficial and provide for differential propagation of the variation which is the basis for
evolution
Solution
Yes, it\'s true that most mutations are deleterious however there are a few mutations that are
beneficial and provide for differential propagation of the variation which is the basis for
evolution.
RNA interference (RNAi) is a mechanism that inhibits gene expression at the stage of translation or by hindering the transcription of specific genes.
RNAi targets include RNA from viruses and transposons.
Yes, its true that most mutations are deleterious however there ar.pdfapexelectronices01
Yes, it\'s true that most mutations are deleterious however there are a few mutations that are
beneficial and provide for differential propagation of the variation which is the basis for
evolution
Solution
Yes, it\'s true that most mutations are deleterious however there are a few mutations that are
beneficial and provide for differential propagation of the variation which is the basis for
evolution.
The definitions of process just given could just as easily apply to .pdfapexelectronices01
The definitions of process just given could just as easily apply to activities wearing the labels
function, task, step, or operation. Indeed, if you accept the notion that a process is a set of related
activities, then any set of related activities, regardless of scope or scale, constitutes a process, and
any label for activity is also a legitimate synonym for process. In the end, words fail us. As a
result, the meaning of process eludes us. This lack of meaning creates much of the difficulty in
defining an organization’s business processes.
An organization’s transformational processes (the conversion of inputs to outputs) and its
transactional processes (the exchange of outputs for inputs) define the organization from the
process perspective. The transformational-transactional view of organizations shown in Figure 1
suggests that all organizations have only a few basic processes. Some basic processes clearly
implied by Figure 1 are listed below.
Process 1
Converting products, and services coming in to products and services going out.
Process 2
Getting products and services from the producer to the customer or the marketplace.
Process 3
Influencing customers’ decisions to buy and to pay, that is, obtaining orders and payments.
Process 4
Managing the money coming in, the money going out, and any surplus.
Process 5
Obtaining from suppliers the inputs necessary to sustain the functioning of the organization. [
Although Figure 1 emphasizes products and services as the major inputs, capital in the form of
loans from lenders and investments from investors is another major input, as is information.]
These basic processes are themselves parts of larger loops of activity, some of which are
transformational and some of which are transactional in nature. An organization’s processes, that
is, the flow of inputs and outputs through its transformational and transactional loops, are
typically divided up into some commonly accepted business functions.
With additional thought, other functions can be added to those above:
The precise form these functions take, the labels they wear, and their distribution among a firm’s
functional structures vary with the industry, the technology, and the history of the firm in
question. That aside, the basic lesson is plain to see: There are only about a dozen or so basic
business functions in any organization, and even fewer business processes.
Examples at ETS
Consider the case at my company, Educational Testing Service (ETS), home to a host of tests
recognizable by their initials: for example, SAT, GRE, and GMAT. Ask almost anyone at ETS to
generate a list of ETS’s key processes and, chances are, the list will include the following:
Press for a longer list and you’ll probably see some of the following—plus others:
Pose any of the items above as examples of processes, however, and they will be immediately
disputed. The primary reason for this contentiousness is that most analyses of processes are
\"floating,\" adrift in a sea.
SolutionThe string which has two different syntax trees is -id-id.pdfapexelectronices01
Solution
:
The string which has two different syntax trees is -id-id.
The leftmost derivation for each of the trees is same and it is given below:
A-> -A
A -> -A-id
A-> -id-id.
RhizopusRhizopus is a genus of common saprophytic fungi on plants .pdfapexelectronices01
Rhizopus
Rhizopus is a genus of common saprophytic fungi on plants and specialized parasites on animals.
They are found on a wide variety of organic substrates, including \"mature fruits and vegetables.
jellies, syrups, leather, bread, peanuts, and tobacco. Some Rhizopusspecies are opportunistic
agents of human zygomycosis (fungal infection) and can be fatal. Rhizopus infections may also
be a complication of diabetic ketoacidosis. This widespread genus includes at least eight species.
Rhizopus species grow as filamentous, branching hyphae that generally lack cross-walls (i.e.,
they are coenocytic). They reproduce by forming asexual and sexual spores. In asexual
reproduction, sporangiospores are produced inside a spherical structure, the sporangium.
Sporangia are supported by a large apophysate columella atop a long stalk, the sporangiophore.
Sporangiophores arise among distinctive, root-like rhizoids. In sexual reproduction, a dark
zygospore is produced at the point where two compatible myceliafuse. Upon germination, a
zygospore produces colonies that are genetically different from either parent.
· R. microsporus var. oligosporus is used to make tempeh, a fermented food derived from
soybeans.
· R. oryzae is used in the production of alcoholic beverages in parts of Asia and Africa.
· Rhizopus stolonifer (black bread mold) causes fruit rot on strawberry, tomato, and sweet
potato and used in commercial production of fumaric acid and cortisone.
Various species, including R. stolonifer, may cause soft rot in sweet potatoes and Narcissus.
Penicillium chrysogenum
Penicillium chrysogenum or Notatum (formerly)
is a species of fungus in the family Trichocomaceae. It is common in
temperate and subtropical regions and can be found on salted food products,[1] but it is mostly
found in indoor environments, especially in damp or water-damaged buildings.[2] It was
previously known as Penicillium notatum. It has rarely been reported as a cause of human
disease.[. It is the source of several -lactam antibiotics, most significantly penicillin. Other
secondary metabolites of P. chrysogenum include roquefortine C, meleagrin, chrysogine,
xanthocillins, secalonic acids, sorrentanone, sorbicillin, and PR-toxin.
Like the many other species of the genus Penicillium, P. chrysogenum usually reproduces by
forming dry chains of spores (or conidia) from brush-shaped conidiophores. The conidia are
typically carried by air currents to new colonisation sites. In P. chrysogenum the conidia are blue
to blue-green, and the mold sometimes exudes a yellow pigment. However, P. chrysogenum
cannot be identified based on colour alone. Observations of morphology and microscopic
features are needed to confirm its identity and DNA sequencing is essential to distinguish it from
closely related species such as Penicillium rubens. The sexual stage of P. chrysogenum was
discovered in 2013 by mating cultures in the dark on oatmeal agar supplemented with biotin,
after the mating types (MAT1-1 .
Questions has 4 parts.1st part Program to implement sorting algor.pdfapexelectronices01
Questions has 4 parts.
1st part: Program to implement sorting algorithms:
#include
#include
#include
using namespace std;
void swap(std::vector & data, int i, int j)
{
int tmp = data[i];
data[i] = data[j];
data[j] = tmp;
}
void print(std::vector const & data)
{
std::vector::const_iterator iter = data.begin();
for (; iter != data.end(); ++iter)
{
cout << *iter << \" \";
}
if (data.size() > 0)
{
cout << endl;
}
}
int generateRandom(int low, int high);
void Shuffle(std::vector & data)
{
int length = data.size();
for (int i = 0; i < length-1; ++i)
{
swap(data, i, generateRandom(i+1, length-1));
}
print(data);
}
int generateRandom(int low, int high)
{
srand(low);
int gen = 0;
gen = rand() % (high - low + 1) + low;
return gen;
}
//useful for small lists, and for large lists where data is
//already sorted
void BubbleSort(std::vector & data)
{
int length = data.size();
for (int i = 0; i < length; ++i)
{
bool swapped = false;
for (int j = 0; j < length - (i+1); ++j)
{
if (data[j] > data[j+1])
{
swap(data, j, j+1);
swapped = true;
}
}
if (!swapped) break;
}
}
//useful for small lists and where swapping is expensive
// does at most n swaps
void SelectionSort(std::vector & data)
{
int length = data.size();
for (int i = 0; i < length; ++i)
{
int min = i;
for (int j = i+1; j < length; ++j)
{
if (data[j] < data[min])
{
min = j;
}
}
if (min != i)
{
swap(data, i, min);
}
}
}
//useful for small and mostly sorted lists
//expensive to move array elements
void InsertionSort(std::vector & data)
{
int length = data.size();
for (int i = 1; i < length; ++i)
{
bool inplace = true;
int j = 0;
for (; j < i; ++j)
{
if (data[i] < data[j])
{
inplace = false;
break;
}
}
if (!inplace)
{
int save = data[i];
for (int k = i; k > j; --k)
{
data[k] = data[k-1];
}
data[j] = save;
}
}
}
void Merge(std::vector & data, int lowl, int highl, int lowr, int highr);
void MergeSort(std::vector & data, int low, int high)
{
if (low >= high)
{
return;
}
int mid = low + (high-low)/2;
MergeSort(data, low, mid);
MergeSort(data, mid+1, high);
Merge(data, low, mid, mid+1, high);
}
void Merge(std::vector & data, int lowl, int highl, int lowr, int highr)
{
int tmp_low = lowl;
std::vector tmp;
while (lowl <= highl && lowr <= highr)
{
if (data[lowl] < data[lowr])
{
tmp.push_back(data[lowl++]);
}
else if (data[lowr] < data[lowl])
{
tmp.push_back(data[lowr++]);
}
else
{
tmp.push_back(data[lowl++]);
tmp.push_back(data[lowr++]);
}
}
while (lowl <= highl)
{
tmp.push_back(data[lowl++]);
}
while (lowr <= highr)
{
tmp.push_back(data[lowr++]);
}
std::vector::const_iterator iter = tmp.begin();
for(; iter != tmp.end(); ++iter)
{
data[tmp_low++] = *iter;
}
}
int Partition(std::vector & data, int low, int high);
void QuickSort(std::vector & data, int low, int high)
{
if (low >= high) return;
int p = Partition(data, low, high);
QuickSort(data, low, p-1);
QuickSort(data, p+1, high);
}
int Partition(std::vector & data, int low, int high)
{
int p = low;
for (int i = p+1; i <= high; ++i)
{
if (data[i] < data[p])
{
swap.
Ques-1 How would agriculture be impacted in this country if the soi.pdfapexelectronices01
Ques-1: How would agriculture be impacted in this country if the soils were lacking in
microbes? Can you imagine a time in the future when we will have eliminated all of the fatal
diseases caused by microbes? If you could cure just one microbial disease which one would it be
and why? Which disease would be the easiest and cheapest to prevent and why?
Answer:
Microbes are natural scavangers and they are essential to convert disposing waste sludge into
final product as an organic fertilizer through the anaerobic digestion, pasteurization and compost
preparation. In order to minimize the error and to enable efficient growth of plant, it is better to
supply plant with equal ratios at which plant can survive followed by supplying soil worms to
enable proper nitrate and phosphorous fixation. These soil worms also should be in a proper
ratio. In order to get better yield, fertilizers, which have the properties of not inhibiting the
growth of soil microbes, are crucial. Providing plants with sufficient mineral supply is also
important.
The above methods of waste sludge treatment produces ----> organic manure or organic natural
fertilizer for plant growth. Therefore, absence of microbes is leading to lack of leaf, shoot and
root systems for plants result in no adequate mineral supplement to plants. This is leading to
imbalance of ecosystem equilibrium.
Plant growth was observed only in plants with soil and soil with worms. The major reason
behind this is aerobic decomposition of soil microbes and worms supplying sufficient amount of
nutrient such as nitrogen, phosphorous in the form of nitrates, phosphates. Soil worms efficiently
performing nitrate fixation and phosphate fixation followed by carbon fixation. Soil worms are
major symbiotic parasites, which can fix these complex phosphates, nitrates to supply to the
plant efficiently as plant cannot fix nitrate and phosphates straightaway. Soil worms are natural
scavengers.
But in the treatments \"fertilizers with no worms and also fertilizers with worms, plant growth
did not observed considerably as in which organophosphorous nitrate and phosphate fertilizers
may have properties to act on soil microbes to inhibit their growth and reproduction. Thereby
excess fertilizers may lead to excessive concentration inside the plant root cells (endoderm)
followed by hyperosmotic cell death finally result in plant roots inability to supply minerals and
water to the plant. Growth is going to be inhibited by excessive amount of fertilizers or even in
the absence of soil worms.
No, it is not possible to eliminate all the communicable diseases caused by microbes in future
because microbes do exist antibiotic resistant and they have a property of transferring genes
(transformation, conjugation and transduction) to other microbe of same genus result in
acquiring resistance to host defense system. Sometimes some viral species have ability to
undergo phage variation through mutated genome in the host cells. Curing a micro.
import java.util.Scanner;public class Digits { public static v.pdfapexelectronices01
import java.util.Scanner;
public class Digits
{
public static void main(String[] args)
{
int oddCount = 0, evenCount = 0, zeroCount = 0; //digit counters
int value, digit; //stores input value and digit respectively
int copy; //stores copy of entry
Scanner scan = new Scanner(System.in);
//Get value from user
System.out.println(\"enter number :\");
int value=scan.nextInt();
copy=value;
//Make the value positive
value=Math.abs(value);
//What if the value is actually zero?
if(value==0)
zeroCount++;
while(value>0)
{
digit=value10;
if(digit==0)
zerocount++;
if(digit%2==0)
evenCount++;
else
oddCount++;
value=value/10;
}
System.out.println(\"original value:\"+copy);
System.out.println(\"zero digits :\"+zeroCount);
System.out.println(\"odd digits :\"+oddCount);
System.out.println(\"even digits :\"+evenCount)
}
}
Solution
import java.util.Scanner;
public class Digits
{
public static void main(String[] args)
{
int oddCount = 0, evenCount = 0, zeroCount = 0; //digit counters
int value, digit; //stores input value and digit respectively
int copy; //stores copy of entry
Scanner scan = new Scanner(System.in);
//Get value from user
System.out.println(\"enter number :\");
int value=scan.nextInt();
copy=value;
//Make the value positive
value=Math.abs(value);
//What if the value is actually zero?
if(value==0)
zeroCount++;
while(value>0)
{
digit=value10;
if(digit==0)
zerocount++;
if(digit%2==0)
evenCount++;
else
oddCount++;
value=value/10;
}
System.out.println(\"original value:\"+copy);
System.out.println(\"zero digits :\"+zeroCount);
System.out.println(\"odd digits :\"+oddCount);
System.out.println(\"even digits :\"+evenCount)
}
}.
Consuming both E.coli and Salmonella are risky. But Salmonella is mu.pdfapexelectronices01
Consuming both E.coli and Salmonella are risky. But Salmonella is much more pathogenic and
cause deliterious effects on human beings than E.coli.
E.coli causes diarrhea, in most cases the diarrhea subsides without any medical intervention.
Some strains of E.coli are not pathogenic and do not cause any pathogenic effect. But some
strains can damage intestinal epithelium and cause ulcers in the intestine. Enteropathogenic
E.coli, Enterohaemmorhagic E.coli are dangerous.
Whereas in case of Salmonella, all the strains are pathogenic and can cause Typhoid,
gastroenteritis based on the species. Typhoid or enteric fever and salmonella gastroenteritis are
complicated without medical intervention. The person who consumed may also become carrier.
The number of Salmonella bacteria required to cause infection is less than the number of E.coli
required to cause infection. In other terms, the infectivity of Salmonella is higher than E.coli.
Solution
Consuming both E.coli and Salmonella are risky. But Salmonella is much more pathogenic and
cause deliterious effects on human beings than E.coli.
E.coli causes diarrhea, in most cases the diarrhea subsides without any medical intervention.
Some strains of E.coli are not pathogenic and do not cause any pathogenic effect. But some
strains can damage intestinal epithelium and cause ulcers in the intestine. Enteropathogenic
E.coli, Enterohaemmorhagic E.coli are dangerous.
Whereas in case of Salmonella, all the strains are pathogenic and can cause Typhoid,
gastroenteritis based on the species. Typhoid or enteric fever and salmonella gastroenteritis are
complicated without medical intervention. The person who consumed may also become carrier.
The number of Salmonella bacteria required to cause infection is less than the number of E.coli
required to cause infection. In other terms, the infectivity of Salmonella is higher than E.coli..
Debt-equity ratio=DebtequityHence debt=0.65equityLet equity be .pdfapexelectronices01
Debt-equity ratio=Debt/equity
Hence debt=0.65equity
Let equity be $x
Hence debt=$0.65x
Total=debt+equity
=(x+0.65x)=$1.65x
After tax cost of debt=9(1-0.4)=5.4%
WACC=Respective costs*Respective investment weights
=(5.4*0.65x/1.65x)+(x/1.65x*13)
which is equal to
=10.01%(Approx).
Solution
Debt-equity ratio=Debt/equity
Hence debt=0.65equity
Let equity be $x
Hence debt=$0.65x
Total=debt+equity
=(x+0.65x)=$1.65x
After tax cost of debt=9(1-0.4)=5.4%
WACC=Respective costs*Respective investment weights
=(5.4*0.65x/1.65x)+(x/1.65x*13)
which is equal to
=10.01%(Approx)..
As we move from left to right in a period the E.N valuesincreases & .pdfapexelectronices01
As we move from left to right in a period the E.N valuesincreases & as we move from top to
bottom in a group the E.Nvalue decreases .
Part (A)
P having more E.N value
Part (B)
K has more E.N value
Part (c)
C is having more E.N value
Part (d)
I having more E.N value a
Solution
As we move from left to right in a period the E.N valuesincreases & as we move from top to
bottom in a group the E.Nvalue decreases .
Part (A)
P having more E.N value
Part (B)
K has more E.N value
Part (c)
C is having more E.N value
Part (d)
I having more E.N value a.
Answernondiversifiable riskmeaningRisk of an investment asset .pdfapexelectronices01
Answer
nondiversifiable risk
meaning
Risk of an investment asset that cannot be reduced or eliminated by adding that asset to a
diversified investment portfolio. Market or systemic risks are non-diversifiable risks
The amount of investment might decrease over a period of time only due to economic changes or
other events which affect high varities of the market. However, investment diversification and
asset allocation can provide protection against non-diversifiable risk as different sections of the
market have a tendency to underperform at different times.
Solution
Answer
nondiversifiable risk
meaning
Risk of an investment asset that cannot be reduced or eliminated by adding that asset to a
diversified investment portfolio. Market or systemic risks are non-diversifiable risks
The amount of investment might decrease over a period of time only due to economic changes or
other events which affect high varities of the market. However, investment diversification and
asset allocation can provide protection against non-diversifiable risk as different sections of the
market have a tendency to underperform at different times..
Let v be the number of vertices. Then Eulers formula tells,.pdfapexelectronices01
Let v be the number of vertices.
Then Euler\'s formula tells, v + 16 - 28 = 2
Hence, v = 14 vertices
Solution
Let v be the number of vertices.
Then Euler\'s formula tells, v + 16 - 28 = 2
Hence, v = 14 vertices.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Introduction to AI for Nonprofits with Tapp NetworkTechSoup
Dive into the world of AI! Experts Jon Hill and Tareq Monaur will guide you through AI's role in enhancing nonprofit websites and basic marketing strategies, making it easy to understand and apply.
Introduction to AI for Nonprofits with Tapp Network
Small interfering RNA (siRNA) and microRNA silence genes at the tran.pdf
1. Small interfering RNA (siRNA) and microRNA silence genes at the transcriptional,
posttranscriptional, and/or translational level. Using human tissue culture cells, we show that
promoter-directed siRNA inhibits transcription of an integrated, proviral, elongation factor
1alpha (EF1A) promoter–green fluorescent protein reporter gene and of endogenous EF1A.
Silencing was associated with DNA methylation of the targeted sequence, and it required either
active transport of siRNA into the nucleus or permeabilization of the nuclear envelope by
lentiviral transduction. These results demonstrate that siRNA-directed transcriptional silencing is
conserved in mammals, providing a means to inhibit mammalian gene function.
The ‘nuclear side’ of RNA interference (RNAi) is increasingly recognized as an integral part of
RNA-mediated gene silencing networks. Current data are consistent with the idea that epigenetic
changes, such as DNA (cytosine-5) methylation and histone modifications, can be targeted to
identical DNA sequences by short RNAs derived via Dicer cleavage of double-stranded RNA
(dsRNA). To determine the relationships among RNA signals, DNA methylation and chromatin
structure, we are carrying out a genetic analysis of RNA-mediated transcriptional gene silencing
(TGS) in Arabidopsis. Results obtained so far indicate that in response to RNA signals, different
site-specific DNA methyltransferases (DMTases) cooperate with each other and eventually with
histone-modifying enzymes to establish and maintain a transcriptionally inactive state at a
homologous target promoter. Processing of dsRNA in Arabidopsis occurs in the nucleus and in
the cytoplasm, where distinct Dicer-like (DCL) activities are thought to generate functionally
distinct classes of short RNAs. RNA silencing pathways thus operate throughout the cell to
defend against invasive nucleic acids and to regulate genome structure and function.
Solution
Small interfering RNA (siRNA) and microRNA silence genes at the transcriptional,
posttranscriptional, and/or translational level. Using human tissue culture cells, we show that
promoter-directed siRNA inhibits transcription of an integrated, proviral, elongation factor
1alpha (EF1A) promoter–green fluorescent protein reporter gene and of endogenous EF1A.
Silencing was associated with DNA methylation of the targeted sequence, and it required either
active transport of siRNA into the nucleus or permeabilization of the nuclear envelope by
lentiviral transduction. These results demonstrate that siRNA-directed transcriptional silencing is
conserved in mammals, providing a means to inhibit mammalian gene function.
The ‘nuclear side’ of RNA interference (RNAi) is increasingly recognized as an integral part of
RNA-mediated gene silencing networks. Current data are consistent with the idea that epigenetic
changes, such as DNA (cytosine-5) methylation and histone modifications, can be targeted to
2. identical DNA sequences by short RNAs derived via Dicer cleavage of double-stranded RNA
(dsRNA). To determine the relationships among RNA signals, DNA methylation and chromatin
structure, we are carrying out a genetic analysis of RNA-mediated transcriptional gene silencing
(TGS) in Arabidopsis. Results obtained so far indicate that in response to RNA signals, different
site-specific DNA methyltransferases (DMTases) cooperate with each other and eventually with
histone-modifying enzymes to establish and maintain a transcriptionally inactive state at a
homologous target promoter. Processing of dsRNA in Arabidopsis occurs in the nucleus and in
the cytoplasm, where distinct Dicer-like (DCL) activities are thought to generate functionally
distinct classes of short RNAs. RNA silencing pathways thus operate throughout the cell to
defend against invasive nucleic acids and to regulate genome structure and function.
