Hot answers tagged

47 votes
Accepted

How could a species be engineered to go extinct?

Short answer The article in particular that you reference is discussing the possibility of using a mechanism called gene drive. The concept of gene drive breaks the normal "rules" of inheritance and ...
user avatar
  • 34.8k
26 votes

What does it mean to "write an image and GIF into the DNA of bacteria"?

The image was not in the DNA as such, only as an abstract representation that could be converted into an image from knowledge of the code. Briefly, they encoded the image into DNA, using a couple of ...
user avatar
  • 14.1k
17 votes
Accepted

What does it mean to "write an image and GIF into the DNA of bacteria"?

Just to add what might have been missing in the beautiful answer by @iayork. I just want to give a more simple picture of the encoding done in the E. coli DNA. First for the rigid strategy in which 4 ...
user avatar
6 votes

What does it mean to "write an image and GIF into the DNA of bacteria"?

Since a few people asked why the AAG triplet is avoided in the code, I thought I'd add this in addition to the other answers. The interesting part of this research ...
user avatar
  • 17.5k
6 votes
Accepted

Splice in with CRISPR/Cas

A paper was published about a week ago in Nature Biotechnology and adresses your question, Maruyama T et al., 2015. I must say I found the authors' strategy extremely clever. It is not about ...
user avatar
  • 2,863
5 votes
Accepted

what's the difference between traditional genetic engineering and and CRISPR?

Bacteria and archaea evolved CRISPR as part of their adaptive immune system to protect themselves from invading viruses and foreign plasmids. The defence system relies on small, non-coding RNA ...
user avatar
4 votes

How specific are CRISPR-cas9 cuts?

The problem of off-targets in CRISPR/Cas is often discussed. It was shown that the system allows mismatches up to five basepairs. For your question, if it is helpful to elongate the gRNA: it was shown ...
user avatar
  • 404
4 votes
Accepted

How does one insert cas9 into animal cells?

If you are talking about the nuclease functionality of Cas9, then you aren't adding the Cas9 gene into the genome, you are transfecting it on a plasmid. Usually there is either some form of ...
user avatar
  • 4,970
4 votes

Can CRISPR also remove DNA viruses?

Yes, this should in principle work, and a number of groups have shows that it works in cultured cells: We found that CRISPR/Cas9 introduced InDel mutations into exon 2 of the ICP0 gene profoundly ...
user avatar
  • 14.1k
4 votes
Accepted

What is meant by "heads" and "tails" in the context of gene orientation?

The heads and tails, in this paper, refer to the orientation of sgRNA binding sites. If there are two tandem sites in the same orientation then they are referred to as head-to-tail (end of the first ...
user avatar
  • 35k
3 votes
Accepted

Does gene editing have any technical cross-species limits?

So, I'll assume that you are talking about gene editing in a laboratory (e.g. using a technique like CRISPR). Theoretically, there are almost no limits to what you can do - or at least try. ...
user avatar
  • 4,296
3 votes

Can a gene be inactivated using CRISPR if it is not in the interspace of short palindromic repeats?

When people talk about genome editing with CRISPR, they are really talking about using CRISPR associated nucleases like Cas9 and Cpf1. These nucleases are useful since their sequence specificity is ...
user avatar
  • 17.5k
3 votes

What does metal-dependent mean?

It means that these enzymes need a metal ion as a co-factor for their function. This metal ion is typically bound somewhere near or in the active center and helps stabilizing transition states. ...
user avatar
  • 49.1k
3 votes

In CRISPR bacteria, how does viral genomes get integrated into the spacers of CRISPR? Also, in its use, where does Cas9 cut the DNA?

This paper should clear up a lot more than anyone on here truly can about the CRISPR system. CRISPR/Cas9 is very unique, even compared to other proteins purified from bacteria like Taq Poly. The ...
user avatar
  • 509
3 votes
Accepted

Mutations/deletions with CRISPR

You can do with a single gRNA. All that CRISPR-Cas, ZFN or TALEN systems do is to introduce a double strand break at a specific site. The DNA gets repaired via two mechanisms — non-homologous end ...
user avatar
  • 35k
3 votes
Accepted

Is Cas9 unique in it's ability to act in response to a specific DNA sequence?

There are two classes of proteins that I can think of off the bat that are DNA sequence-specific. First are restriction enzymes, which recognize a specific (usually short) sequence of DNA and cleave ...
user avatar
  • 14.7k
3 votes
Accepted

Why doesn't CAS9 cleave the original CRISPR sequence in the bacterial genome?

It is not the methylation status. The crRNA is not only complementary to the spacer sequence within the CRISPR array but also to the repeat sequence flanking that spacer. The additional base pairing ...
user avatar
3 votes
Accepted

Crispr complex in human cells?

No analogues of the CRISPR-Cas system have been found in any eukaryotic species, including humans. So far, it appears to have evolved only in prokaryotes and archaea. Reference: Evolution of RNA- and ...
user avatar
3 votes

DIYbio - CRISPR injection sites for targeting the ABCC11 gene

Creating changes in the genome in order to get your favorable results is not always as easy as it looks. Expression of a particular gene is not necessarily bound to its existence. There are other ...
user avatar
3 votes

How do DNA viruses keep themselves in the nucleus without inserting themselves into genome?

Herpesviruses maintain themselves during the latent state as "episomes", circular DNA elements, with no capsid, that are in the nucleus but that are not integrated into the host genome. Host enzymes ...
user avatar
  • 14.1k
3 votes

Does using CRISPR/Cas9 knockout need to add donor DNA in the process?

Short Answer: No, for CRISPR/Cas9 knockout you do not need to add donor DNA. Little bit more detail: CRISPR/Cas9 allows you to cut at a given position (defined by the gRNA). This will lead to double ...
user avatar
  • 666
3 votes

Gene knockdown vs gene knockout vs knocksideways?

Hello and welcome Adil Amchi. In genetics and molecular biology there are differences between the terms knock-out, knock-down and (the lesser known term) knock-sideways. Knock-sideways: Inactivates ...
user avatar
  • 695
3 votes

Do bacteria duplicate the copied virus DNA to put into a Cas9 protein when fighting the virus off again?

So does the bacteria then copy that portion of bacteria that it had copied in the past to put into the Cas9 protein? The DNA is not copied, but rather transcribed. The captured piece of viral DNA (...
user avatar
  • 7,129
2 votes
Accepted

Could we eradicate mosquitoes?

Could we use this technology to completely eradicate from the world all species of mosquito that prey on humans? Yes, implemented correctly, a gene drive has this capability. Also, could we ...
user avatar
  • 351
2 votes

Functions of tracrRNA and crRNA in the CRISPR/Cas9 system

I have also been wondering the same thing for a while now and I think that the best answer that I could find after reading several review papers on CRISPR/Cas9 and online information, points to ...
user avatar
2 votes

What is the role of tracrRNA in CRISPR-cas9?

Your two questions are related and you are correct in your supposition that the Cas9 protein associates to a specific RNA sequence. That of the tracrRNA processed with the crRNA into a gRNA. This is ...
user avatar
  • 251
2 votes
Accepted

CRISPR guide RNA design and primer synthesis

A quick check with BLAST returned the following result: ...
user avatar
  • 3,008
2 votes
Accepted

Where does tracrRNA comes from?

Usually the tracrRNA is a part of the CRISPR locus and is encoded in the the vicinity of the CRISPR array (e.g. upstream or downstream of the cas genes or the array). http://www.genome-engineering....
user avatar
2 votes

Mutated cell proliferation

There are some diseases in which a minority population of normal cells can rescue the organism, even in the presence of a majority of mutant cells. Sort of like a group vacation to Kazakhstan with ...
user avatar
  • 2,848
2 votes
Accepted

Is it possible to use virus for genetic modification of embryos during the fetus stage

Zika doesn't alter the host genome at all. Since Zika can alter the genome of a baby to cause deformities Zika virus is incapable of altering the host genome. The exact mechanism by which Zika ...
user avatar
  • 3,338

Only top scored, non community-wiki answers of a minimum length are eligible