Name ____________________________________________________________
Date ____________
Introducing Arabidopsis thaliana
Warm Up
1. When do plants normally flower?
2. What are some factors that you think plants use to decide that it is time to flower?
Yesterday we watched some time-lapse footage of plants growing. But what exactly was that plant?
In this video, we will learn more about the plant that you saw: Arabidopsis thaliana.
Video
Notes
What are two reasons scientists use Arabidopsis in
their research?
1.
2.
How big is the Arabidopsis genome compared to
other plants?
What is the difference between a mutant and a
wildtype plant?
Recall our plants from yesterday:
Label the wildtype
plant and the
mutant plant in the
image to the left.
What is the mutation for that caused
the differences between these two
plants?
Name ____________________________________________________________
Date ____________
Now that we know the mutation in the gene, how can we find out more about it?
Hint: What might you normally do when you want to learn more about something?
is like
for Arabidopsis!
Compare Google and Araport in their uses, number, and types of hits.
Google
Used for…
Araport
# of hits for “flower”
Example category and
the type of results it
gives
Now let’s use Araport to look up constans, the gene that was mutated in the time-lapse
video.
1. Go to www.araport.org and enter constans
in the search bar.
2.
When we enter constans into Araport, we get
results of many categories. All we want is the
gene, so click on the gene category to get only
gene results.
3. Click on the top result, which
you’ll notice has the gene name
constans.
4. Take a deep breath…
There is a lot of information on the page that comes up! Let’s focus on three main pieces of
information on the gene page. Find the following items on the menu at the top of the page:
Name ____________________________________________________________
Date ____________
Genomics
Function
Expression
Question
Analogy
Genomics: Where is
this
gen
e
“wri
tten” in the genome?
When you look in the Genomics section, you will find a window that shows a small portion of the
Arabidopsis genome.
If you click on the gene,
another window will pop up
that shows you the actual DNA
sequence for the gene.
Can you figure out which
chromosome constans is on
from the window that pops
up?
You can also scroll left and
right within this part of the
genome in the Genomics
section. Can you find the names of any nearby genes?
Gene Function: What does this gene do?
Name ____________________________________________________________
Date ____________
If you scroll down to the gene function section of
the gene page, you will find a list called Gene
Ontology. The items in the list are Gene
Ontology Terms, or GO Terms for short, and
they describe things about a protein’s job in the
cell, where it does that job, and what affect that
job has on the whole organism.
Some of these terms may look familiar, while
others may not. Can you find any GO terms in
the list that match with the affect that
changing this gene has on the plant?
Where can you find this gene doing its job?
Gene Expression: Where and when is
this gene doing its job?
What does it mean to “express yourself?”
Gene expression describes when, where, and how much a gene is used in an organism. To
illustrate why this is important, think about a marching band. What would the band’s playing sound
like if each player decided to “express” him or herself musically without listening to each other or
playing together?
Furthermore, what would the band’s formations look like if some of the players forgot where they
were supposed to march or stand?
Just like each player in a marching band, each gene has a specific time and place
to “play” in order to help a plant or a person grow and develop properly. If a
gene is expressed at the wrong time and place, it can have drastic effects. Take,
for instance, this fly that has legs growing out of its head instead of antennae.
When you scroll to the Expression part of the gene page, you will see a map of
Name ____________________________________________________________
Date ____________
an Arabidopsis plant. Some structures may be familiar, while others may look new.
What are some plant structures
that you recognize?
What do the colors on the chart
mean?
What are three areas with high
expression of constans?
One of the areas with highest
expression is the shoot apex. Here
are our plants from the video again
with arrows pointing to the shoot apex on each plant:
The shoot apex is where the plant is most actively
growing, and it transitions from growing just leaves
(vegetative growth) to growing a long stem with
flowers, or an inflorescence.
What do you think that the constans gene is doing in the
shoot apex, and why?
Shoot apex