Archive for genes

Do-it-yourself genetic engineering

Posted in science with tags , , , , , on December 25, 2008 by airtightnoodle

There’s an interesting article in the news today about amateurs attempting their own genetic engineering at home.  A quick excerpt from the article:

In her San Francisco dining room lab, for example, 31-year-old computer programmer Meredith L. Patterson is trying to develop genetically altered yogurt bacteria that will glow green to signal the presence of melamine, the chemical that turned Chinese-made baby formula and pet food deadly…

…But critics of the movement worry that these amateurs could one day unleash an environmental or medical disaster. Defenders say the future Bill Gates of biotech could be developing a cure for cancer in the garage.

You can read the rest of the article here.

Merry Christmas!

The Night Before Christmas–cell style!

Posted in science with tags , , , , , , , , on December 20, 2008 by airtightnoodle

The Night before Christmas in a Cell

(found at the AP Bio list-serv)

Twas the night before Christmas and all through the cell,

Not a creature was stirring, not even an organelle.

The chromosomes were hung in nucleus with care,

In hopes that mitosis would soon take place there.

The genes were all nestled and snug in their beds,

While cells in their pj’s and vacuoles of sap,

Had just settled down for their Interphase nap.

Then in the nucleus there arose such a clatter,

The chromosomes sprang from their beds to see what was the matter.

They flew from the nucleoplasm in less than a flash,

Hit the nucleolus and made quite a crash.

 

The light on the center of the newly formed cell

Gave the excitement of metaphase to the objects beheld.

Then what to the scientist’s eye should appear,

But a division – how odd!- with a haploid now here.

With a nod, he said, “This is strange for mitosis.”

Then he knew in a moment it must be meiosis.

More rapid than eagles his excitement came,

And he whistled and shouted and called them by name:

Now eggs! Now sperms! Now X’s and Y’s!

On, diploids! On, haploids! On, Gametes and XY’s!

To the top of the cell! To the top of the ball!

Now dashaway! dashaway! dashaway all.

 

Now into the middle the chromosomes flew,

With a sleigh full of Genes and DNA too.

And then in a twinkling they precisely did start,

The duplicating and changing of each little part.

As the scientist moved his head and was turning around,

Suddenly meiosis came with a bound.

They were all double up from their head to their feet

And spread through the cell in one great sheet.

And their outside were all mingled with bluish and green;

A bundle of colors was all that was seen.

The strands how they twinkled, Their movements how merry!

The reds were like roses and red as a cherry!

The small bits of black were like that of a crow,

And the white on the ends was as white as the snow.

 

The strands, still held by the centromere,

Were through crossing-over, but still very near;

Each part looked to him like a little round belly,

That would shake, if it could, like a bowl full of jelly.

They were chubby and plump, a right set of each,

And he sighed when he saw them, for none he could reach.

A quick divide and untwist of a strand

Soon let him know he’d seen nothing so grand.

 

They stopped once again, but went straight to work,

And filled all the new cells, then turned with a jerk,

And laying the membrane ‘round the nuclear glob,

And giving a nod, they finished their job.

They sprang to their sides, their teams gave a whistle,

And away they all flew like the down of a thistle.

But he heard them exclaim as they went out of sight,

“Happy Christmas to all, and to all a good night!”

Ultraconserved regions of DNA–we still have a lot to learn

Posted in Evolution, science with tags , , , , , , , on October 11, 2008 by airtightnoodle

In the news two days ago on Yahoo I read the following article: Mysterious DNA Found to Survive Eons of Evolution.  Basically, scientists have discovered segments of DNA that have survived long periods of evolution though they seem to have no apparent purpose.  The sequences in question are not non-coding or “junk” DNA. 

Since these segments haven’t been lost as a result of natural selection, one would assume they give some important advantage.  However, mice were bred to lack these sections of DNA, and they appeared to be healthy.

The article goes on to discuss potential answers to the puzzle, such as the possibility that these strands code for multiple layers of information or that they might protect against diseases that only rarely strike. 

What leaves me in awe is the fact that despite learning so much over the past few hundred years–and especially the past 60 or so–we still have so much yet to learn!  This article goes to show that science is certainly not stagnant.  Science doesn’t have all the answers about how the natural world works…though it’s still working on it!  🙂

Evolution of pregnancy in mammals

Posted in Evolution with tags , , , , , , on September 21, 2008 by airtightnoodle

Summary: Research suggesting that a change in transcription factors may play an active role in the evolution of structures like the uterus (specifically, the HoxA-11 transcription factor, which is present in all placental mammals but not marsupials).

Interesting stuff. Go here to read more.

Gene mutations and mad cow disease

Posted in science with tags , , , , , , , , , , on September 12, 2008 by airtightnoodle

I’ve always been interested in prions, so an article about mad cow disease in the news today caught my eye.

According to the article, a rare genetic mutation may underlie some cases of mad cow disease in cattle.  Apparently this mutation is identical to one that causes Creutzfeldt-Jakob disease (a related brain-wasting disease in humans), suggesting BSE may sometimes arise spontaneously in cattle.  Of course, this suggests that cattle can develop BSE without ever eating contaminated feed.

Click here to read the rest of the article.